Research ArticleActivatedCarbon forDyesRemovalModeling andUnderstandingthe Adsorption Process

Y El maguana N Elhadiri M Benchanaa and R Chikri

Research Laboratory on Materials Reactivity and Process Optimization laquoREMATOPraquo Department of ChemistryFaculty of Science Semlalia Cadi Ayyad University BP 2390 Marrakech Morocco

Correspondence should be addressed to Y El maguana youssefelmaguanagmailcom

Received 7 June 2020 Revised 16 August 2020 Accepted 1 September 2020 Published 14 September 2020

Academic Editor Jose M G Martinho

Copyright copy 2020 Y El maguana et al)is is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

Batch adsorption experiments have been conducted to investigate the removal of methyl orange from aqueous solution by anactivated carbon prepared from prickly pear seed cake by phosphoric acid activation )e adsorption process has been described byusing kinetic and isotherm models )e kinetic of adsorption was examined by pseudo-first-order pseudo-second-order andintraparticle diffusion models Adsorption isotherm was modeled using Langmuir Freundlich Temkin and DubininndashRadushkevichisotherms)e adsorption process of methyl orange was well explained by the pseudo-second-order model and Freundlich isothermAlso pseudo-n-order model has been applied to estimate the order of adsorption kinetic and it was found equal to 2 which confirmthe good accuracy of the pseudo-second order Moreover DubininndashRadushkevich isotherm reveals that the adsorption of methylorange onto activated carbon was a physisorption process in nature )e adsorption capacity of activated carbon was found to be33612mgg at temperature 20degC and pH sim 7)ese results demonstrated that the prickly pear seed cake is a suitable precursor for thepreparation of appropriate activated carbon for dyes removal from aqueous solution

1 Introduction

Industrial liquid effluents contain a wide variety of chemicalswhich affect if discharged without any treatment riversseas lakes and groundwater and therefore cause environ-mental pollution and harmful effects on human and animalhealth even in low concentrations [1ndash4] Among thesechemicals the dyes used in several sectors such as textilescosmetics plastics pigments units leather and paper in-dustries have been considered as the primary pollutant dueto their stability and low biodegradability [3] Indeed sig-nificant quantities of dyes are released into the environmentby colored textile wastewater Approximately it is estimatedthat 10 to 15 is lost in the effluent during the dyeingprocess [5] Consequently the scientific community hasfocused their research on the development effective dyesremoval techniques In recent years Considerable interesthas been focused on the adsorption technique for dyes re-moval from solutions using various adsorbent such as ac-tivated carbon [6ndash8] clays [9 10] siliceous material [11 12]

zeolites [13 14] alumina [15] and hybrid materials [16 17])e adsorption is highly effective technique for dyes removalfrom wastewater )e major advantages of adsorptionprocess are its relative simplicity low cost and possibleregeneration of the adsorbent [3]

Activated carbon is well known as an adsorbent char-acterized by its large specific surface its porous structureand its thermostability which is extensively used in a varietyof applications such as removal of pollutants and odor fromliquid and gaseous phases medical uses catalysis gasstorage electrode materials in electrochemical devices andremoval of organic pollutants from drinking water and inthe waste water treatment [7 18ndash24] Adsorption on acti-vated carbon has been found to be a very efficient techniquefor removal of dyes from wastewater in terms of capabilityfor efficiently adsorbing a broad range of pollutants fastadsorption kinetics simplicity of design and low cost[25ndash27] In recent years there has been increasing interest inthe research of the production of activated carbons from theagricultural byproducts and industrial wastes for dyes

HindawiJournal of ChemistryVolume 2020 Article ID 2096834 9 pageshttpsdoiorg10115520202096834

removal [8 28ndash32] )e utilization of those biomass wasteshas a positive impact in environment protection by reducingsolid wastes and also the production of low-cost activatedcarbons with high added value which can reduce contam-inants in wastewater at a reasonable cost

In industrial scale the adsorbent and liquid effluent arein contact with each other for a given time thereforepredicating the equilibrium time and the rate of adsorptionis of paramount importance For that the kinetic andequilibrium properties of the adsorbateadsorbent systemhave been investigated to understand the characteristic ofthe adsorption behavior )e modeling of adsorption pro-cesses is usually carried out using well-established adsorp-tion kinetic and isotherm models Adsorption kineticsmodels provide invaluable information on the controllingmechanisms of adsorption process )e overall adsorptionprocess may be controlled by either external or film diffu-sion pore diffusion and adsorption on the pore surface or acombination of more than one step )e adsorption iso-therm describes the interaction between the adsorbatemolecules and the adsorbent when the system reaches theequilibrium It provides the qualitative information on thenature of adsorbate-adsorbent surface interactions andcould be used to evaluate the adsorption capacity

)e aim of this work is to investigate both kinetic andequilibrium adsorption of methyl orange (MO) onto anactivated carbon prepared from prickly pear seed cake byphosphoric acid activation Methyl orange was chosen as anadsorbate to evaluate the adsorption characteristics of ac-tivated carbon and also serves as a model compound foradsorption of organic contaminants from aqueous solution

2 Materials and Methods

21 Materials Activated carbon prepared by El maguanaet al [33] was sieved to obtain particles size less than 100 μmMethyl orange used as adsorbate in the present study andwithout further purification was supplied by Merck A stocksolution was prepared by dissolving the weighted quantity ofmethyl orange in distilled water )en solutions of desiredconcentrations were prepared by diluting stock solutionwith distilled water

)e structure of methyl orange is given by

H3C

H3C

N

NN

SO3 Nandash +

22 Adsorption Experiments Batch adsorption experimentshave been conducted to evaluate the efficiency of activatedcarbon to remove methyl orange dye from aqueous solution)e experiments were performed in flasks containing adefined amount of activated carbon and 100 cm3 of desiredconcentration of methyl orange solution )e suspensionswere mixed on a shaker at 180 rpm at 20degC during a giventime and separated with centrifuge After adsorption the

residual concentration of methyl orange was determined byspectrophotometric method (UV-3100PC Spectrophotom-eter) at 462 nm )e amount of adsorption at equilibrium(qe) was defined as the amount of adsorbate per Gram ofadsorbent (in mgg) and was calculated using the followingequation

qe C0 minus Ce

mtimes V (1)

)e percentage removal (R) of the methyl orange atequilibrium was calculated using the following relationship

R C0 minus Ce

C0x 100 (2)

where C0 and Ce (in mgL) are the initial and equilibriumconcentrations in aqueous solution respectively V(L) is thevolume of the solution and m(g) is the mass of theadsorbent

3 Results and Discussion

Activated carbon used in this study was prepared fromprickly pear seed cake by phosphoric acid activation [33])e authors reported that the obtained activated carbon iseffective for removing cationic dyes such as methylene bluefrom aqueous solution FTIR analysis indicated the presenceof various functional groups (oxygen functions and phos-phorus compounds) on the surface of the obtained activatedcarbon which gave the adsorbent an acidic surface(pHPZC 38) Moreover the adsorption process was welldescribed by the pseudo-second-order model and Freund-lich isotherm )e adsorption capacity of the prepared ac-tivated carbon for methylene blue at temperature 20degC andpH sim 7 was found to be 260mgg [33] To test the perfor-mance of the prepared activated carbon in the removal ofanionic dyes from aqueous solution methyl orange waschosen as a model adsorbate )e adsorption performancewas evaluated by kinetic and isotherm studies

31 Adsorption Kinetic To investigate the adsorption ki-netic the amount of methyl orange adsorbed by the acti-vated carbon is studied at pH sim 7 for an adsorbent dose of02 gL and an initial methyl orange concentration of100mgL at 20degC Figure 1 shows the effect of contact timeon the adsorption capacity of the activated carbon preparedfrom prickly pear seed cake for methyl orange at roomtemperature It reveals that the adsorbed amount increasedwith contact time at the initial stage of adsorption andreached equilibrium in 120min )e adsorption process ofmethyl orange was rapid at the beginning of the process dueto the availability of active sites on the exterior surfaces andafter the saturation of those active sites the methyl orangeentered to the pores of the adsorbent with a slower rate toreach the equilibrium time [33] )e amount of methylorange removed by adsorption onto the activated carbon atthe equilibrium time was 194mgg

Adsorption kinetics models provide invaluable infor-mation on the controlling mechanisms of adsorption

2 Journal of Chemistry

process [34] )e overall adsorption process may be con-trolled by either external or film diffusion pore diffusion andadsorption on the pore surface or a combination of morethan one step [34] In order to predict the mechanism of theadsorption process of methyl orange onto the activatedcarbon the experimental data were fitted with differentkinetic models In a first step the experimental kinetic datawere fitted by pseudo-first-order and pseudo-second-orderkinetic models We employed pseudo-first-order andpseudo-second-order models in their nonlinear forms todetermine the kinetic parameters because in this way thekinetic parameters are predicted better than in the linearizedforms of these models [33 35]

)e nonlinear form of pseudo-first-order model [36] isgiven by the following equation

qt qe 1 minus eminus k1t

1113872 1113873 (3)

)e nonlinear form of pseudo-second-order model [37]is given as follows

qt k2q

2et

1 + k2qet (4)

where qe (mgg) is the adsorption amount at equilibriumqt (mgg) is the adsorption amount at time t (min) and k1(1min) and k2 (gmg min) are the adsorption rate con-stants of pseudo-first-order and pseudo-second-ordermodels respectively Kinetic parameters qe k1 and k2can be calculated from the plots of qe versus t

)e validity of these models was evaluated by the co-efficient of regression R2 and by the normalized standarddeviation ∆q () which is defined as follows

Δq () 100

1113936 qexp minus qcal1113872 1113873qexp1113960 11139612

N minus 1

1113971

(5)

where qexp and qcal are the experimental and calculatedequilibrium adsorption capacity value respectively and N isthe number of data points

Figure 2 shows the plots for pseudo-first-order andpseudo-second-ordermodels)e calculated values of k1 k2 qe

correlation coefficient (R2) and normalized standard deviation∆q are presented in Table 1 It can be seen that both pseudo-first-order and pseudo-second-order models have a good fit tothe experimental data (R2 greater than 099 and ∆q lower than5) Moreover the equilibrium adsorption capacities (qecal)calculated by the pseudo-first order and pseudo-second orderare closer to the experimental value (qeexp 19408mgg)According to these results we can say that both pseudo-first-order and pseudo-second-order models could be used to de-scribe the adsorption process of methyl orange onto activatedcarbon However ∆q for pseudo-second order was lower thanthat for pseudo-first order thus suggesting an order kineticgreater than 1 Taking into account that the kinetic order cantake a decimal value the kinetic data were fitted with a pseudo-n order kinetic model [38] expressed as follows

qt qe 1 minus 1 +(n minus 1)knt1113858 111385911minus n

1113960 1113961 (6)

where qe (mgg) is the adsorption amount at equilibriumqt (mgg) is the adsorption amount at time t (min) and kn(1min) is the adsorption rate constant of pseudo-n-ordermodel

)e plot corresponding to the nonlinear fit of pseudo-n-order kinetic model for methyl orange adsorption ontoactivated carbon is presented in Figure 3 )e kineticparameters obtained from the pseudo-n-order kinetic modelare listed in Table 2 )e results show that the values of R2

and ∆q obtained by pseudo-n-order kinetic model are equalto those for pseudo-second order Moreover the equilib-rium adsorption capacities (qecal) calculated by pseudo-n-order and pseudo-second-order kinetic models are similarand the value of n is almost equal to 2 (n 197) )ereforethe adsorption process of methyl orange on the activatedcarbon can be well described by pseudo-second-ordermodel suggesting that the boundary layer resistance was notthe rate-limiting step [33] So if the pseudo-first-orderkinetic parameters are closer to those for pseudo-secondorder then we cannot deduce the kinetic model which can

0

50

100

150

200

MO

adso

rptio

n (m

gg)

150 2000 50 100t (min)

Figure 1 Effect of contact time on the MO adsorption onto ac-tivated carbon (C0 100mgL adsorbent dose 02 gL pH sim 7T 20degC)

Experimental dataPseudo-first orderPseudo-second order

0

50

100

150

200

q t (m

gg)

150 2000 50 100t (min)

Figure 2 Nonlinear fits of pseudo-first-order and pseudo-second-order kinetics for MO adsorption onto activated car-bon (C0 100 mgL adsorbent dose 02 gL pH sim 7 T 20degC)

Journal of Chemistry 3

be used to predict the mechanism of the adsorption processHence it appears that the use of a general kinetic model(pseudo-n order) with no preset reaction order is advisablewhenR2 and∆q of pseudo-first-order and pseudo-second-ordermodels are comparable

)e possibility of intraparticle diffusion resistance wasexplored by using the intraparticle diffusion model proposedby Weber and Morris [39] expressed as follows

qt kidt12

+ c (7)

where qt (mgg) is the adsorption amount at time t (min) kid(mggmin12) is the adsorption rate constant of intraparticlediffusion model and c is a constant related to the thicknessof the boundary layer

If the plot of qt versus t12 is linear and passes through theorigin then intraparticle diffusion is the sole rate-limitingstep of the adsorption process Figure 4 shows the plot of theintraparticle diffusion model which is not linear and did notpass through the origin indicating that intraparticle diffu-sion was not the only rate-limiting step of the adsorptionprocess of methyl orange onto the activated carbon but alsoother mechanisms may control the rate of the adsorption allof which may be operating simultaneously [8 34 40] )e

first portion of the plot is attributed to the transport of solutefrom bulk solution through liquid film to the adsorbentexterior surface)ereafter the second part is ascribed to theintraparticle diffusion as slower process In fact the slope ofthe linear portion indicates the rate of the adsorptionprocess the lower slope corresponds to a slower adsorptionprocess [34 41] )us the rate of the diffusion of methylorange molecules through boundary layer film in the initialstage of the adsorption process was faster than the rate of theintraparticle diffusion because the slope of the first linearportion was higher than of the second linear portion Ini-tially the methyl orange molecules are quickly adsorbedonto the surface of the activated carbon and when satu-ration is reached the methyl orange molecules are diffusedinto the interior of adsorbent particles [34] Finally the lastportion is attributed to the final equilibrium stage for whichthe intraparticle diffusion slows down due to the low con-centration dye in the aqueous solution [42]

32 Equilibrium Adsorption Adsorption equilibrium isestablished between the adsorbed molecules and the ad-sorbent surface when an adsorbate is in contact with theadsorbent )e equilibrium relationship between theadsorbed amount of adsorbate (qe) and the residual ad-sorbate concentration (Ce) at constant temperature is de-scribed by the adsorption isotherm )is last is very usefulfor understanding the adsorption mechanism In generaladsorption isotherms provide information on the affinityand the binding energy between the adsorbate and theadsorbent on the adsorption capacity and on the surfacephase which may be considered as a monolayer or multi-layer All this information can be extracted from equilibrium

Table 1 Pseudo-first-order and pseudo-second-order kinetic parameters (C0 100mgL adsorbent dose 02 gL pH sim 7 T 20degC)

qeexp (mgg)Pseudo-first order Pseudo-second order

qecal (mgg) k1 (1min) R2 Δq () qecal (mgg) k2 (gmgmin) R2 Δq ()19408 18842 795 10minus2 0990 383 20034 715 10minus4 0998 160

Experimental dataPseudo-n order

0

50

100

150

200

q t (m

gg)

50 100 150 2000t (min)

Figure 3 Nonlinear fit of pseudo-n-order kinetic model for MOadsorption onto activated carbon (C0 100mgL adsorbentdose 02 gL pH sim 7 T 20degC)

Table 2 Pseudo-n-order kinetic parameters (C0 100mgLadsorbent dose 02 gL pH sim 7 T 20degC)

qeexp (mgg)Pseudo-n order

qecal (mgg) kn (1min) n R2 Δq ()19408 19978 1407 10minus2 197 0998 159

Experimental data

0

50

100

150

200

q t (m

gg)

25 50 75 100 125 15000t12 (min12)

Figure 4 Plot of the intraparticle diffusion model for MO ad-sorption onto sugar scum (C0 100mgL adsorbent dose 02 gLpH sim 7 T 20degC)

4 Journal of Chemistry

isotherm models describing the adsorption process Severalisotherm models are presented in the literature whichpermit a better understanding of the adsorption phenom-enon of chemical species on the adsorbent )e modeling ofthe adsorption isotherms consists in describing the exper-imental data using theoretical or empirical mathematicalequations and allowing determination of isotherm param-eters to compare the efficiency of different adsorbents

To investigate the adsorption isotherm the adsorptioncapacity of the activated carbon prepared from pricklypear seed cake for methyl orange is studied at temperature20degC and pH sim 7 for an adsorbent dose of 1 gL Figure 5shows the adsorption isotherm of methyl orange onto theactivated carbon which indicates a significant adsorptionat low concentrations According to Giles classification[43] this isotherm displayed an H curve pattern indi-cating that the methyl orange and activated carbon have ahigh affinity

In the first step the experimental data of adsorptionisotherm were fitted to the Langmuir and Freundlich modelsto find which one can be used to describe the adsorptionprocess of methyl orange onto the surface of the activatedcarbon Langmuir equation assumes the monolayer ad-sorption on a homogenous surface without interactionbetween adsorbates [44] while the Freundlich isotherm wasbased on the assumption of the multilayer adsorption onheterogeneous surface [45]

)e Langmuir isotherm equation is expressed as follows

qe qmKLCe

1 + KLCe (8)

)e Freundlich isotherm equation is given as follows

qe KFC1ne (9)

where Ce (mgL) is the equilibrium concentration of ad-sorbate qe (mgg) is the amount of adsorption at theequilibrium qm (mgg) is the monolayer adsorption ca-pacity n is the Freundlich intensity constant and KL and KFare the Langmuir and Freundlich constants respectively

Figure 6 shows the Freundlich and Langmuir curvesgenerated using (8) and (9) It can be seen from this figurethat the adsorption isotherm of methyl orange onto theactivated carbon was well described by the Freundlichequation Calculated parameters of Langmuir and Freund-lich isotherms along with R2 values obtained by the non-linear fitting method are listed in Table 3 Via comparison ofthe R2 values Freundlich equation represents a better fit ofequilibrium experimental data than Langmuir )ereforethe adsorption process of methyl orange onto the activatedcarbon can be described more appropriately by theFreundlich isotherm indicating the multilayer adsorptionon the heterogeneous surface with a different energy dis-tribution Freundlich constant n is a measure of adsorptionintensity As seen from Table 3 a value of 1n was foundbetween 0 and 1 indicating the favorable adsorption ofmethyl orange on the activated carbon [33]

)e experimental data of the adsorption isotherm werealso fitted to Temkin isotherm equation to approach

energetic aspects Temkin isotherm is based on the as-sumption that the heat of adsorption of all the molecules inthe layer decreased linearly with coverage and adsorption ischaracterized by a uniform distribution of binding energies[46]

)e Temkin isotherm equation is expressed as

qe RTb

ln KTCe( 1113857 (10)

0

100

200

300

q e (m

gg)

150 2502000 50 100Ce (mgL)

Experimental data

Figure 5 Adsorption isotherm of MO onto activated carbon(tcontact 2 h adsorbent dose 1 gL pH sim 7 T 20degC)

0

100

200

300q e

(mg

g)

150 2502000 50 100Ce (mgL)

Experimental dataLangmuirFreundlich

Figure 6 Nonlinear fits of the Langmuir and Freundlich isothermsfor MO adsorption onto activated carbon (tcontact 2 h adsorbentdose 1 gL pH sim 7 T 20degC)

Table 3 Langmuir and Freundlich isotherm parameters(tcontact 2 h adsorbent dose 1 gL pH sim 7 T 20degC)

Langmuir Freundlichqm (mgg) KL (Lmg) R2 1n KF ((mgg) (Lmg)1n) R2

31906 00748 093 029 6982 099

Journal of Chemistry 5

where qe (mgg) is the amount of adsorption at the equi-librium Ce (mgL) is the equilibrium concentration ofadsorbate T (K) is the temperature R is the universal gasconstant and KT is the equilibrium binding constant cor-responding to the maximum binding energy )e constant b(Jmol) is related to the heat of adsorption )e Temkinisotherm parameters were obtained by plotting qe versus Ceshown in Figure 7 and summarized in Table 4 According tothe R2 value the Temkin isothermmodel did not fit well withthe experimental data indicating the energetic heterogeneityof the adsorption sites

Besides the Langmuir Freundlich and Temkin modelsthe DubininndashRadushkevich isotherm model was alsoemployed for the estimation of the adsorption energy (E)and further finding the nature of the adsorption [41 47] Itsequation is given as follows

qe qm exp minusKDR RT ln 1 +1

Ce1113888 11138891113890 1113891

2⎡⎣ ⎤⎦ (11)

where qe (mgg) is the amount of adsorption at the equi-librium Ce (mgL) is the equilibrium concentration ofadsorbate qm is the monolayer adsorption capacity KDR isthe D-R constant which gives the adsorption energy (E)T (K) is the temperature and R is the universal gas constant)e adsorption energy can be computed using the followingrelationship

E 12B

radic (12)

)e adsorption energy (E) value gives information aboutadsorption mechanism and more specifically its physical orchemical nature When E is lower than 8 kJmol the type ofadsorption can be explained by physisorption and it can becontrolled by ion-exchange or chemical adsorption when Eis higher than 8 kJmol [48]

Figure 8 shows the fitting curve of DubininndashRadushkevichisotherm and the obtained parameters are listed in Table 4)ecalculated adsorption energy (E 057 kJmol) reveals that thetype of adsorption of methyl orange onto activated carbon canbe explained by physisorption indicating that the adsorption isillustrated by the formation of week physical attraction forcessuch as hydrogen-bonding and van der Waals forces betweenadsorbate molecules and solid surface and thus adsorption isreversible )is result indicates that the adsorption of methylorange onto the surface of the prepared activated carbon is amultilayer adsorption which confirms that this process followsthe Freundlich isotherm

)e results of the previous [33] and present studyshowed that the activated carbon prepared from prickly pearseed cake by phosphoric acid activation is effective for re-moving cationic and anionic dyes such as methylene blueand methyl orange from aqueous solution )is can beexplained by the presence of a variety of functional groupson the adsorbent surface which have enhanced the ad-sorption capacity [33] )e activated carbon simultaneously

presents acidic and basic sites able to fix cationic and anionicdyes by electrostatic interactions )e adsorption mecha-nism can also be explained by the interactions betweendelocalized π-electrons of the activated carbon surface andthe free electrons of the dye molecules present in the aro-matic rings and multiple bonds [49 50] )e adsorptioncapacities of MO onto various materials are given in Table 5

Table 4 Temkin and DubininndashRadushkevich isotherm parameters(tcontact 2 h adsorbent dose 1 gL pH sim 7 T 20degC)

Temkin DubininndashRadushkevichb KT R2 qm KDR E R2(Jmol) (Lmg) mgg mol2kJ kJmol5966 609 095 19380 153 057 084

0

100

200

300

q e (m

gg)

150 2502000 50 100Ce (mgL)

Experimental data

Figure 7 Nonlinear fit of the Temkin isotherm for MO adsorptiononto activated carbon (tcontact 2 h adsorbent dose 1 gL pH sim 7T 20degC)

600 20 40Ce (mgL)

Experimental data

q e (m

gg)

0

100

200

300

Figure 8 Nonlinear fit of the DubininndashRadushkevich isotherm forMO adsorption onto activated carbon (tcontact 2 h adsorbentdose 1 gL pH sim 7 T 20degC)

6 Journal of Chemistry

in order to evaluate the performance of the activated carbonprepared from prickly pear seed cake

4 Conclusion

In this study the use of the activated carbon preparedfrom prickly pear seed cake by thermo chemical processusing phosphoric acid for the removal of methyl orangefrom aqueous solution has been studied )e kineticof adsorbate-adsorbent interactions can be represented bythe pseudo-second-order model )e equilibriumadsorption data are best fitted by the Freundlich model ascompared to Langmuir and Temkin models )e ad-sorption capacity for methyl orange was found to be33612mgg at temperature 20degC and pH sim 7 indicatingthat the activated carbon may be an efficient adsorbentwith great adsorptive capacity DubininndashRadushkevichisotherm reveals that the adsorption of methyl orangeonto the activated carbon was a physisorption process innature )e results demonstrated that the prickly pear seedcake is a suitable precursor for the preparation of anadequate activated carbon for dyes removal from indus-trial effluents

Data Availability

All the data used to support the findings of this study areincluded within the article

Conflicts of Interest

)e authors declare that they have no conflicts of interest

Acknowledgments

)e authors are grateful to the Center of Analyses andCharacterization (CAC) of University Caddy Ayyad Mo-rocco Also the authors also extend their appreciation toprofessors of REMATOP LCOA and REMINEX ManagemLaboratories in Marrakech Morocco

References

[1] S Kumar C Patra S Narayanasamy and P V RajaramanldquoPerformance of acid-activated water caltrop (Trapa natans)

shell in fixed bed column for hexavalent chromium removalfrom simulated wastewaterrdquo Environmental Science andPollution Research vol 27 no 22 pp 28042ndash28052 2020

[2] T Shahnaz V Sharma S Subbiah and S NarayanasamyldquoMultivariate optimisation of Cr (VI) Co (III) and Cu (II)adsorption onto nanobentonite incorporated nanocellulosechitosan aerogel using response surface methodologyrdquoJournal of Water Process Engineering vol 36 p 101283 2020

[3] Y El maguana N Elhadiri M Bouchdoug M Benchanaaand A Boussetta ldquoOptimization of preparation conditions ofnovel adsorbent from sugar scum using response surfacemethodology for removal of methylene bluerdquo Journal ofChemistry vol 2018 Article ID 2093654 10 pages 2018

[4] A M Elgarahy K Z Elwakeel G A Elshoubaky andS H Mohammad ldquoUntapped sepia shellndashbased composite forthe sorption of cationic and anionic dyesrdquo Water Air amp SoilPollution vol 230 p 217 2019

[5] R Kant ldquoAdsorption of dye eosin from an aqueous solutionon two different samples of activated carbon by static batchmethodrdquo Journal of Water Resource and Protection vol 4no 2 pp 93ndash98 2012

[6] K Z Elwakeel G O El-Sayed and S M Abo El-NassrldquoRemoval of ferrous and manganous from water by activatedcarbon obtained from sugarcane bagasserdquo Desalination andWater Treatment vol 55 no 2 pp 471ndash483 2015

[7] K Ennaciri A Baccedilaoui M Sergent and A YaacoubildquoApplication of fractional factorial and Doehlert designs foroptimizing the preparation of activated carbons from Arganshellsrdquo Chemometrics and Intelligent Laboratory Systemsvol 139 pp 48ndash57 2014

[8] K Y Foo and B H Hameed ldquoMesoporous activated carbonfrom wood sawdust by K2CO3 activation using microwaveheatingrdquo Bioresource Technology vol 111 pp 425ndash432 2012

[9] A Kausar M Iqbal A Javed et al ldquoDyes adsorption usingclay and modified clay a reviewrdquo Journal of Molecular Liq-uids vol 256 pp 395ndash407 2018

[10] S Babel ldquoLow-cost adsorbents for heavy metals uptake fromcontaminated water a reviewrdquo Journal of Hazardous Mate-rials vol 97 no 1-3 pp 219ndash243 2003

[11] M Besbes N Fakhfakh andM Benzina ldquoCharacterization ofsilica gel prepared by using sol-gel processrdquo Physics Procediavol 2 no 3 pp 1087ndash1095 2009

[12] B Sun and A Chakraborty ldquo)ermodynamic frameworks ofadsorption kinetics modeling dynamic water uptakes on silicagel for adsorption cooling applicationsrdquo Energy vol 84pp 296ndash302 2015

[13] S K Alpat O patref S Alpat and H Akccedilay ldquo)e adsorptionkinetics and removal of cationic dye Toluidine Blue O from

Table 5 Adsorption capacities of MO onto various materials

Adsorbents qMO (mgg) ReferencesActivated carbon nanotubes 149 [51]Mesoporous carbon 2941 [52]Surfactants modified montmorillonite 14925 [53]Ammonium-functionalized silica nanoparticle 1054 [54]Lead oxide nanoparticles loaded activated carbon 33333 [55]Gold nanoparticles loaded on activated carbon 161 [56]Activated carbon 797 [57]Chitosan modified magnetic kaolin 3497 [58]Polyanilineactivated carbon composite 285 [59]Chitosan microspheres 207 [60]Activated carbon 33612 )is work

Journal of Chemistry 7

aqueous solution with Turkish zeoliterdquo Journal of HazardousMaterials vol 151 no 1 pp 213ndash220 2008

[14] D Caputo and F Pepe ldquoExperiments and data processing ofion exchange equilibria involving Italian natural zeolites areviewrdquo Microporous and Mesoporous Materials vol 105no 3 pp 222ndash231 2007

[15] A Wasti and M Ali Awan ldquoAdsorption of textile dye ontomodified immobilized activated aluminardquo Journal of theAssociation of Arab Universities for Basic and Applied Sciencesvol 20 no 1 pp 26ndash31 2016

[16] K Z Elwakeel ldquoRemoval of Reactive Black 5 from aqueoussolutions using magnetic chitosan resinsrdquo Journal of Haz-ardous Materials vol 167 no 1-3 pp 383ndash392 2009

[17] K Z Elwakeel A A El-Bindary A Ismail andA M Morshidy ldquoSorptive removal of Remazol Brilliant BlueR from aqueous solution by diethylenetriamine functionalizedmagnetic macro-reticular hybrid materialrdquo RSC Advancesvol 6 no 27 pp 22395ndash22410 2016

[18] T Shahnaz C Patra V Sharma andN Selvaraju ldquoA comparativestudy of raw acid-modified and EDTA-complexed Acaciaauriculiformis biomass for the removal of hexavalent chromiumrdquoChemistry and Ecology vol 36 no 4 pp 360ndash381 2020

[19] C Patra R M N Medisetti K Pakshirajan andS Narayanasamy ldquoAssessment of raw acid-modified andchelated biomass for sequestration of hexavalent chromiumfrom aqueous solution using Sterculia villosa Roxb shellsrdquoEnvironmental Science and Pollution Research vol 26 no 23pp 23625ndash23637 2019

[20] C Patra T Shahnaz S Subbiah and S NarayanasamyldquoComparative assessment of raw and acid-activated prepa-rations of novel Pongamia pinnata shells for adsorption ofhexavalent chromium from simulated wastewaterrdquo Envi-ronmental Science and Pollution Research vol 27 no 13pp 14836ndash14851 2020

[21] Y El Maguana N Elhadiri M Bouchdoug andM Benchanaa ldquoStudy of the influence of some factors on thepreparation of activated carbon from walnut cake using thefractional factorial designrdquo Journal of EnvironmentalChemical Engineering vol 6 no 1 pp 1093ndash1099 2018

[22] P Ammendola F Raganati and R Chirone ldquoCO2 adsorptionon a fine activated carbon in a sound assisted fluidized bedthermodynamics and kineticsrdquo Chemical Engineering Journalvol 322 pp 302ndash313 2017

[23] F Raganati P Ammendola and R Chirone ldquoOn improvingthe CO2 recovery efficiency of a conventional TSA process in asound assisted fluidized bed by separating heating andpurgingrdquo Separation and Purification Technology vol 167pp 24ndash31 2016

[24] F Raganati P Ammendola and R Chirone ldquoRole of acousticfields in promoting the gas-solid contact in a fluidized bed offine particlesrdquo KONA Powder and Particle Journal vol 32pp 23ndash40 2015

[25] K Z Elwakeel M A Abd El-Ghaffar S M El-kousy andH G El-Shorbagy ldquoSynthesis of new ammonium chitosanderivatives and their application for dye removal fromaqueous mediardquo Chemical Engineering Journal vol 203pp 458ndash468 2012

[26] A A Yakout M A Shaker K Z Elwakeel and W AlshitarildquoLauryl sulfatemagnetic graphene oxide nanosorbent forfast methylene blue recovery from aqueous solutionsrdquo Journalof Dispersion Science and Technology vol 40 no 5pp 707ndash715 2019

[27] I A W Tan A L Ahmad and B H Hameed ldquoPreparationof activated carbon from coconut husk optimization study

on removal of 246-trichlorophenol using response surfacemethodologyrdquo Journal of Hazardous Materials vol 153no 1-2 pp 709ndash717 2008

[28] J Yang and K Qiu ldquoPreparation of activated carbons fromwalnut shells via vacuum chemical activation and their ap-plication for methylene blue removalrdquo Chemical EngineeringJournal vol 165 no 1 pp 209ndash217 2010

[29] M L Martınez M M Torres C A Guzman andD M Maestri ldquoPreparation and characteristics of activatedcarbon from olive stones and walnut shellsrdquo Industrial Cropsand Products vol 23 no 1 pp 23ndash28 2006

[30] P Nowicki R Pietrzak and H Wachowska ldquoSorptionproperties of active carbons obtained from walnut shells bychemical and physical activationrdquo Catalysis Today vol 150no 1-2 pp 107ndash114 2010

[31] T-H Liou ldquoDevelopment of mesoporous structure and highadsorption capacity of biomass-based activated carbon byphosphoric acid and zinc chloride activationrdquo ChemicalEngineering Journal vol 158 no 2 pp 129ndash142 2010

[32] B S Girgis and M F Ishak ldquoActivated carbon from cottonstalks by impregnation with phosphoric acidrdquo MaterialsLetters vol 39 no 2 pp 107ndash114 1999

[33] Y El Maguana N Elhadiri M Bouchdoug M Benchanaaand A Jaouad ldquoActivated carbon from prickly pear seed cakeoptimization of preparation conditions using experimentaldesign and its application in dye removalrdquo InternationalJournal of Chemical Engineering vol 2019 Article ID8621951 12 pages 2019

[34] Y El maguana N Elhadiri M Benchanaa and R ChikrildquoAdsorption thermodynamic and kinetic studies of methylorange onto sugar scum powder as a low-cost inorganicadsorbentrdquo Journal of Chemistry vol 2020 Article ID9165874 10 pages 2020

[35] K V Kumar ldquoLinear and non-linear regression analysis forthe sorption kinetics of methylene blue onto activated car-bonrdquo Journal of Hazardous Materials vol 137 no 3pp 1538ndash1544 2006

[36] S Lagergren ldquoZur theorie der sogenannten adsorptiongeloster stoffe Kungliga Svenska VetenskapsakademiensrdquoHandlingar vol 24 pp 1ndash39 1898

[37] Y S Ho and G McKay ldquoPseudo-second order model forsorption processesrdquo Process Biochemistry vol 34 no 5pp 451ndash465 1999

[38] A G Ritchie ldquoAlternative to the Elovich equation for thekinetics of adsorption of gases on solidsrdquo Journal of theChemical Society Faraday Transactions 1 Physical Chemistryin Condensed Phases vol 73 pp 1650ndash1653 1977

[39] J W Weber and J C Morris ldquoKinetics of adsorption oncarbon from solutionrdquo Journal of the Sanitary EngineeringDivision vol 89 pp 31ndash60 1963

[40] A Gurses C Dogar M Yalcin M Acikyildiz R Bayrak andS Karaca ldquo)e adsorption kinetics of the cationic dyemethylene blue onto clayrdquo Journal of Hazardous Materialsvol 131 no 1-3 pp 217ndash228 2006

[41] G B Oguntimein ldquoBiosorption of dye from textile wastewatereffluent onto alkali treated dried sunflower seed hull anddesign of a batch adsorberrdquo Journal of EnvironmentalChemical Engineering vol 3 no 4 pp 2647ndash2661 2015

[42] G-B Hong and Y-KWang ldquoSynthesis of low-cost adsorbentfrom rice bran for the removal of reactive dye based on theresponse surface methodologyrdquo Applied Surface Sciencevol 423 pp 800ndash809 2017

[43] C H Giles T HMacewan S N Nakhwa and D Smith ldquo786Studies in adsorption Part XI A system of classification of

8 Journal of Chemistry

solution adsorption isotherms and its use in diagnosis ofadsorption mechanisms and in measurement of specificsurface areas of solidsrdquo Journal of the Chemical Society(Resumed) vol 10 pp 3973ndash3993 1960

[44] I Langmuir ldquo)e constitution and fundamental properties ofsolids and liquids Part I Solidsrdquo Journal of the AmericanChemical Society vol 38 no 11 pp 2221ndash2295 1916

[45] H Freundlish ldquoOver the adsorption in solutionrdquo Journal ofPhysical Chemistry vol 57 pp 385ndash470 1906

[46] D Kavitha and C Namasivayam ldquoExperimental and kineticstudies on methylene blue adsorption by coir pith carbonrdquoBioresource Technology vol 98 no 1 pp 14ndash21 2007

[47] H N Tran S-J You and H-P Chao ldquo)ermodynamicparameters of cadmium adsorption onto orange peel calcu-lated from various methods a comparison studyrdquo Journal ofEnvironmental Chemical Engineering vol 4 no 3 pp 2671ndash2682 2016

[48] T A Khan E A Khan and Shahjahan ldquoRemoval of basicdyes from aqueous solution by adsorption onto binary iron-manganese oxide coated kaolinite non-linear isotherm andkinetics modelingrdquo Applied Clay Science vol 107 pp 70ndash772015

[49] T N V de Souza S M L de Carvalho M G A VieiraM G C da Silva and D d S B Brasil ldquoAdsorption of basicdyes onto activated carbon experimental and theoreticalinvestigation of chemical reactivity of basic dyes using DFT-based descriptorsrdquo Applied Surface Science vol 448pp 662ndash670 2018

[50] S Wang and Z Zhu ldquoEffects of acidic treatment of activatedcarbons on dye adsorptionrdquoDyes and Pigments vol 75 no 2pp 306ndash314 2007

[51] J Ma F Yu L Zhou et al ldquoEnhanced adsorptive removal ofmethyl orange and methylene blue from aqueous solution byalkali-activated multiwalled carbon nanotubesrdquo ACS AppliedMaterials amp Interfaces vol 4 no 11 pp 5749ndash5760 2012

[52] N Mohammadi H Khani V K Gupta E Amereh andS Agarwal ldquoAdsorption process of methyl orange dye ontomesoporous carbon material-kinetic and thermodynamicstudiesrdquo Journal of Colloid and Interface Science vol 362no 2 pp 457ndash462 2011

[53] D Chen J Chen X Luan H Ji and Z Xia ldquoCharacterizationof anion-cationic surfactants modified montmorillonite andits application for the removal of methyl orangerdquo ChemicalEngineering Journal vol 171 no 3 pp 1150ndash1158 2011

[54] J Liu S Ma and L Zang ldquoPreparation and characterizationof ammonium-functionalized silica nanoparticle as a newadsorbent to remove methyl orange from aqueous solutionrdquoApplied Surface Science vol 265 pp 393ndash398 2013

[55] S Agarwal I Tyagi V K Gupta et al ldquoRETRACTED ki-netics and thermodynamics of methyl orange adsorption fromaqueous solutions-artificial neural network-particle swarmoptimization modelingrdquo Journal of Molecular Liquidsvol 218 pp 354ndash362 2016

[56] M Ghaedi A M Ghaedi A Ansari F Mohammadi andA Vafaei ldquoArtificial neural network and particle swarmoptimization for removal of methyl orange by gold nano-particles loaded on activated carbon and Tamariskrdquo Spec-trochimica Acta Part A Molecular and BiomolecularSpectroscopy vol 132 pp 639ndash654 2014

[57] V Yonten N K Sanyurek and M R Kivanccedil ldquoA thermo-dynamic and kinetic approach to adsorption of methyl orangefrom aqueous solution using a low cost activated carbonprepared from Vitis vinifera Lrdquo Surfaces and Interfacesvol 20 Article ID 100529 2020

[58] D-M Liu C Dong J Zhong S Ren Y Chen and T QiuldquoFacile preparation of chitosan modified magnetic kaolin byone-pot coprecipitation method for efficient removal ofmethyl orangerdquo Carbohydrate Polymers vol 245 Article ID116572 2020

[59] M Hasan M M Rashid M M Hossain et al ldquoFabrication ofpolyanilineactivated carbon composite and its testing formethyl orange removal optimization equilibrium isothermand kinetic studyrdquo Polymer Testing vol 77 Article ID 1059092019

[60] L Zhai Z Bai Y Zhu B Wang and W Luo ldquoFabrication ofchitosan microspheres for efficient adsorption of methylorangerdquo Chinese Journal of Chemical Engineering vol 26no 3 pp 657ndash666 2018

Journal of Chemistry 9

process [34] )e overall adsorption process may be con-trolled by either external or film diffusion pore diffusion andadsorption on the pore surface or a combination of morethan one step [34] In order to predict the mechanism of theadsorption process of methyl orange onto the activatedcarbon the experimental data were fitted with differentkinetic models In a first step the experimental kinetic datawere fitted by pseudo-first-order and pseudo-second-orderkinetic models We employed pseudo-first-order andpseudo-second-order models in their nonlinear forms todetermine the kinetic parameters because in this way thekinetic parameters are predicted better than in the linearizedforms of these models [33 35]

)e nonlinear form of pseudo-first-order model [36] isgiven by the following equation

qt qe 1 minus eminus k1t

1113872 1113873 (3)

)e nonlinear form of pseudo-second-order model [37]is given as follows

qt k2q

2et

1 + k2qet (4)

where qe (mgg) is the adsorption amount at equilibriumqt (mgg) is the adsorption amount at time t (min) and k1(1min) and k2 (gmg min) are the adsorption rate con-stants of pseudo-first-order and pseudo-second-ordermodels respectively Kinetic parameters qe k1 and k2can be calculated from the plots of qe versus t

)e validity of these models was evaluated by the co-efficient of regression R2 and by the normalized standarddeviation ∆q () which is defined as follows

Δq () 100

1113936 qexp minus qcal1113872 1113873qexp1113960 11139612

N minus 1

1113971

(5)

where qexp and qcal are the experimental and calculatedequilibrium adsorption capacity value respectively and N isthe number of data points

Figure 2 shows the plots for pseudo-first-order andpseudo-second-ordermodels)e calculated values of k1 k2 qe

correlation coefficient (R2) and normalized standard deviation∆q are presented in Table 1 It can be seen that both pseudo-first-order and pseudo-second-order models have a good fit tothe experimental data (R2 greater than 099 and ∆q lower than5) Moreover the equilibrium adsorption capacities (qecal)calculated by the pseudo-first order and pseudo-second orderare closer to the experimental value (qeexp 19408mgg)According to these results we can say that both pseudo-first-order and pseudo-second-order models could be used to de-scribe the adsorption process of methyl orange onto activatedcarbon However ∆q for pseudo-second order was lower thanthat for pseudo-first order thus suggesting an order kineticgreater than 1 Taking into account that the kinetic order cantake a decimal value the kinetic data were fitted with a pseudo-n order kinetic model [38] expressed as follows

qt qe 1 minus 1 +(n minus 1)knt1113858 111385911minus n

1113960 1113961 (6)

where qe (mgg) is the adsorption amount at equilibriumqt (mgg) is the adsorption amount at time t (min) and kn(1min) is the adsorption rate constant of pseudo-n-ordermodel

)e plot corresponding to the nonlinear fit of pseudo-n-order kinetic model for methyl orange adsorption ontoactivated carbon is presented in Figure 3 )e kineticparameters obtained from the pseudo-n-order kinetic modelare listed in Table 2 )e results show that the values of R2

and ∆q obtained by pseudo-n-order kinetic model are equalto those for pseudo-second order Moreover the equilib-rium adsorption capacities (qecal) calculated by pseudo-n-order and pseudo-second-order kinetic models are similarand the value of n is almost equal to 2 (n 197) )ereforethe adsorption process of methyl orange on the activatedcarbon can be well described by pseudo-second-ordermodel suggesting that the boundary layer resistance was notthe rate-limiting step [33] So if the pseudo-first-orderkinetic parameters are closer to those for pseudo-secondorder then we cannot deduce the kinetic model which can

0

50

100

150

200

MO

adso

rptio

n (m

gg)

150 2000 50 100t (min)

Figure 1 Effect of contact time on the MO adsorption onto ac-tivated carbon (C0 100mgL adsorbent dose 02 gL pH sim 7T 20degC)

Experimental dataPseudo-first orderPseudo-second order

0

50

100

150

200

q t (m

gg)

150 2000 50 100t (min)

Figure 2 Nonlinear fits of pseudo-first-order and pseudo-second-order kinetics for MO adsorption onto activated car-bon (C0 100 mgL adsorbent dose 02 gL pH sim 7 T 20degC)

Journal of Chemistry 3

be used to predict the mechanism of the adsorption processHence it appears that the use of a general kinetic model(pseudo-n order) with no preset reaction order is advisablewhenR2 and∆q of pseudo-first-order and pseudo-second-ordermodels are comparable

)e possibility of intraparticle diffusion resistance wasexplored by using the intraparticle diffusion model proposedby Weber and Morris [39] expressed as follows

qt kidt12

+ c (7)

where qt (mgg) is the adsorption amount at time t (min) kid(mggmin12) is the adsorption rate constant of intraparticlediffusion model and c is a constant related to the thicknessof the boundary layer

If the plot of qt versus t12 is linear and passes through theorigin then intraparticle diffusion is the sole rate-limitingstep of the adsorption process Figure 4 shows the plot of theintraparticle diffusion model which is not linear and did notpass through the origin indicating that intraparticle diffu-sion was not the only rate-limiting step of the adsorptionprocess of methyl orange onto the activated carbon but alsoother mechanisms may control the rate of the adsorption allof which may be operating simultaneously [8 34 40] )e

first portion of the plot is attributed to the transport of solutefrom bulk solution through liquid film to the adsorbentexterior surface)ereafter the second part is ascribed to theintraparticle diffusion as slower process In fact the slope ofthe linear portion indicates the rate of the adsorptionprocess the lower slope corresponds to a slower adsorptionprocess [34 41] )us the rate of the diffusion of methylorange molecules through boundary layer film in the initialstage of the adsorption process was faster than the rate of theintraparticle diffusion because the slope of the first linearportion was higher than of the second linear portion Ini-tially the methyl orange molecules are quickly adsorbedonto the surface of the activated carbon and when satu-ration is reached the methyl orange molecules are diffusedinto the interior of adsorbent particles [34] Finally the lastportion is attributed to the final equilibrium stage for whichthe intraparticle diffusion slows down due to the low con-centration dye in the aqueous solution [42]

32 Equilibrium Adsorption Adsorption equilibrium isestablished between the adsorbed molecules and the ad-sorbent surface when an adsorbate is in contact with theadsorbent )e equilibrium relationship between theadsorbed amount of adsorbate (qe) and the residual ad-sorbate concentration (Ce) at constant temperature is de-scribed by the adsorption isotherm )is last is very usefulfor understanding the adsorption mechanism In generaladsorption isotherms provide information on the affinityand the binding energy between the adsorbate and theadsorbent on the adsorption capacity and on the surfacephase which may be considered as a monolayer or multi-layer All this information can be extracted from equilibrium

Table 1 Pseudo-first-order and pseudo-second-order kinetic parameters (C0 100mgL adsorbent dose 02 gL pH sim 7 T 20degC)

qeexp (mgg)Pseudo-first order Pseudo-second order

qecal (mgg) k1 (1min) R2 Δq () qecal (mgg) k2 (gmgmin) R2 Δq ()19408 18842 795 10minus2 0990 383 20034 715 10minus4 0998 160

Experimental dataPseudo-n order

0

50

100

150

200

q t (m

gg)

50 100 150 2000t (min)

Figure 3 Nonlinear fit of pseudo-n-order kinetic model for MOadsorption onto activated carbon (C0 100mgL adsorbentdose 02 gL pH sim 7 T 20degC)

Table 2 Pseudo-n-order kinetic parameters (C0 100mgLadsorbent dose 02 gL pH sim 7 T 20degC)

qeexp (mgg)Pseudo-n order

qecal (mgg) kn (1min) n R2 Δq ()19408 19978 1407 10minus2 197 0998 159

Experimental data

0

50

100

150

200

q t (m

gg)

25 50 75 100 125 15000t12 (min12)

Figure 4 Plot of the intraparticle diffusion model for MO ad-sorption onto sugar scum (C0 100mgL adsorbent dose 02 gLpH sim 7 T 20degC)

4 Journal of Chemistry

isotherm models describing the adsorption process Severalisotherm models are presented in the literature whichpermit a better understanding of the adsorption phenom-enon of chemical species on the adsorbent )e modeling ofthe adsorption isotherms consists in describing the exper-imental data using theoretical or empirical mathematicalequations and allowing determination of isotherm param-eters to compare the efficiency of different adsorbents

To investigate the adsorption isotherm the adsorptioncapacity of the activated carbon prepared from pricklypear seed cake for methyl orange is studied at temperature20degC and pH sim 7 for an adsorbent dose of 1 gL Figure 5shows the adsorption isotherm of methyl orange onto theactivated carbon which indicates a significant adsorptionat low concentrations According to Giles classification[43] this isotherm displayed an H curve pattern indi-cating that the methyl orange and activated carbon have ahigh affinity

In the first step the experimental data of adsorptionisotherm were fitted to the Langmuir and Freundlich modelsto find which one can be used to describe the adsorptionprocess of methyl orange onto the surface of the activatedcarbon Langmuir equation assumes the monolayer ad-sorption on a homogenous surface without interactionbetween adsorbates [44] while the Freundlich isotherm wasbased on the assumption of the multilayer adsorption onheterogeneous surface [45]

)e Langmuir isotherm equation is expressed as follows

qe qmKLCe

1 + KLCe (8)

)e Freundlich isotherm equation is given as follows

qe KFC1ne (9)

where Ce (mgL) is the equilibrium concentration of ad-sorbate qe (mgg) is the amount of adsorption at theequilibrium qm (mgg) is the monolayer adsorption ca-pacity n is the Freundlich intensity constant and KL and KFare the Langmuir and Freundlich constants respectively

Figure 6 shows the Freundlich and Langmuir curvesgenerated using (8) and (9) It can be seen from this figurethat the adsorption isotherm of methyl orange onto theactivated carbon was well described by the Freundlichequation Calculated parameters of Langmuir and Freund-lich isotherms along with R2 values obtained by the non-linear fitting method are listed in Table 3 Via comparison ofthe R2 values Freundlich equation represents a better fit ofequilibrium experimental data than Langmuir )ereforethe adsorption process of methyl orange onto the activatedcarbon can be described more appropriately by theFreundlich isotherm indicating the multilayer adsorptionon the heterogeneous surface with a different energy dis-tribution Freundlich constant n is a measure of adsorptionintensity As seen from Table 3 a value of 1n was foundbetween 0 and 1 indicating the favorable adsorption ofmethyl orange on the activated carbon [33]

)e experimental data of the adsorption isotherm werealso fitted to Temkin isotherm equation to approach

energetic aspects Temkin isotherm is based on the as-sumption that the heat of adsorption of all the molecules inthe layer decreased linearly with coverage and adsorption ischaracterized by a uniform distribution of binding energies[46]

)e Temkin isotherm equation is expressed as

qe RTb

ln KTCe( 1113857 (10)

0

100

200

300

q e (m

gg)

150 2502000 50 100Ce (mgL)

Experimental data

Figure 5 Adsorption isotherm of MO onto activated carbon(tcontact 2 h adsorbent dose 1 gL pH sim 7 T 20degC)

0

100

200

300q e

(mg

g)

150 2502000 50 100Ce (mgL)

Experimental dataLangmuirFreundlich

Figure 6 Nonlinear fits of the Langmuir and Freundlich isothermsfor MO adsorption onto activated carbon (tcontact 2 h adsorbentdose 1 gL pH sim 7 T 20degC)

Table 3 Langmuir and Freundlich isotherm parameters(tcontact 2 h adsorbent dose 1 gL pH sim 7 T 20degC)

Langmuir Freundlichqm (mgg) KL (Lmg) R2 1n KF ((mgg) (Lmg)1n) R2

31906 00748 093 029 6982 099

Journal of Chemistry 5

where qe (mgg) is the amount of adsorption at the equi-librium Ce (mgL) is the equilibrium concentration ofadsorbate T (K) is the temperature R is the universal gasconstant and KT is the equilibrium binding constant cor-responding to the maximum binding energy )e constant b(Jmol) is related to the heat of adsorption )e Temkinisotherm parameters were obtained by plotting qe versus Ceshown in Figure 7 and summarized in Table 4 According tothe R2 value the Temkin isothermmodel did not fit well withthe experimental data indicating the energetic heterogeneityof the adsorption sites

Besides the Langmuir Freundlich and Temkin modelsthe DubininndashRadushkevich isotherm model was alsoemployed for the estimation of the adsorption energy (E)and further finding the nature of the adsorption [41 47] Itsequation is given as follows

qe qm exp minusKDR RT ln 1 +1

Ce1113888 11138891113890 1113891

2⎡⎣ ⎤⎦ (11)

where qe (mgg) is the amount of adsorption at the equi-librium Ce (mgL) is the equilibrium concentration ofadsorbate qm is the monolayer adsorption capacity KDR isthe D-R constant which gives the adsorption energy (E)T (K) is the temperature and R is the universal gas constant)e adsorption energy can be computed using the followingrelationship

E 12B

radic (12)

)e adsorption energy (E) value gives information aboutadsorption mechanism and more specifically its physical orchemical nature When E is lower than 8 kJmol the type ofadsorption can be explained by physisorption and it can becontrolled by ion-exchange or chemical adsorption when Eis higher than 8 kJmol [48]

Figure 8 shows the fitting curve of DubininndashRadushkevichisotherm and the obtained parameters are listed in Table 4)ecalculated adsorption energy (E 057 kJmol) reveals that thetype of adsorption of methyl orange onto activated carbon canbe explained by physisorption indicating that the adsorption isillustrated by the formation of week physical attraction forcessuch as hydrogen-bonding and van der Waals forces betweenadsorbate molecules and solid surface and thus adsorption isreversible )is result indicates that the adsorption of methylorange onto the surface of the prepared activated carbon is amultilayer adsorption which confirms that this process followsthe Freundlich isotherm

)e results of the previous [33] and present studyshowed that the activated carbon prepared from prickly pearseed cake by phosphoric acid activation is effective for re-moving cationic and anionic dyes such as methylene blueand methyl orange from aqueous solution )is can beexplained by the presence of a variety of functional groupson the adsorbent surface which have enhanced the ad-sorption capacity [33] )e activated carbon simultaneously

presents acidic and basic sites able to fix cationic and anionicdyes by electrostatic interactions )e adsorption mecha-nism can also be explained by the interactions betweendelocalized π-electrons of the activated carbon surface andthe free electrons of the dye molecules present in the aro-matic rings and multiple bonds [49 50] )e adsorptioncapacities of MO onto various materials are given in Table 5

Table 4 Temkin and DubininndashRadushkevich isotherm parameters(tcontact 2 h adsorbent dose 1 gL pH sim 7 T 20degC)

Temkin DubininndashRadushkevichb KT R2 qm KDR E R2(Jmol) (Lmg) mgg mol2kJ kJmol5966 609 095 19380 153 057 084

0

100

200

300

q e (m

gg)

150 2502000 50 100Ce (mgL)

Experimental data

Figure 7 Nonlinear fit of the Temkin isotherm for MO adsorptiononto activated carbon (tcontact 2 h adsorbent dose 1 gL pH sim 7T 20degC)

600 20 40Ce (mgL)

Experimental data

q e (m

gg)

0

100

200

300

Figure 8 Nonlinear fit of the DubininndashRadushkevich isotherm forMO adsorption onto activated carbon (tcontact 2 h adsorbentdose 1 gL pH sim 7 T 20degC)

6 Journal of Chemistry

in order to evaluate the performance of the activated carbonprepared from prickly pear seed cake

4 Conclusion

In this study the use of the activated carbon preparedfrom prickly pear seed cake by thermo chemical processusing phosphoric acid for the removal of methyl orangefrom aqueous solution has been studied )e kineticof adsorbate-adsorbent interactions can be represented bythe pseudo-second-order model )e equilibriumadsorption data are best fitted by the Freundlich model ascompared to Langmuir and Temkin models )e ad-sorption capacity for methyl orange was found to be33612mgg at temperature 20degC and pH sim 7 indicatingthat the activated carbon may be an efficient adsorbentwith great adsorptive capacity DubininndashRadushkevichisotherm reveals that the adsorption of methyl orangeonto the activated carbon was a physisorption process innature )e results demonstrated that the prickly pear seedcake is a suitable precursor for the preparation of anadequate activated carbon for dyes removal from indus-trial effluents

Data Availability

All the data used to support the findings of this study areincluded within the article

Conflicts of Interest

)e authors declare that they have no conflicts of interest

Acknowledgments

)e authors are grateful to the Center of Analyses andCharacterization (CAC) of University Caddy Ayyad Mo-rocco Also the authors also extend their appreciation toprofessors of REMATOP LCOA and REMINEX ManagemLaboratories in Marrakech Morocco

References

[1] S Kumar C Patra S Narayanasamy and P V RajaramanldquoPerformance of acid-activated water caltrop (Trapa natans)

shell in fixed bed column for hexavalent chromium removalfrom simulated wastewaterrdquo Environmental Science andPollution Research vol 27 no 22 pp 28042ndash28052 2020

[2] T Shahnaz V Sharma S Subbiah and S NarayanasamyldquoMultivariate optimisation of Cr (VI) Co (III) and Cu (II)adsorption onto nanobentonite incorporated nanocellulosechitosan aerogel using response surface methodologyrdquoJournal of Water Process Engineering vol 36 p 101283 2020

[3] Y El maguana N Elhadiri M Bouchdoug M Benchanaaand A Boussetta ldquoOptimization of preparation conditions ofnovel adsorbent from sugar scum using response surfacemethodology for removal of methylene bluerdquo Journal ofChemistry vol 2018 Article ID 2093654 10 pages 2018

[4] A M Elgarahy K Z Elwakeel G A Elshoubaky andS H Mohammad ldquoUntapped sepia shellndashbased composite forthe sorption of cationic and anionic dyesrdquo Water Air amp SoilPollution vol 230 p 217 2019

[5] R Kant ldquoAdsorption of dye eosin from an aqueous solutionon two different samples of activated carbon by static batchmethodrdquo Journal of Water Resource and Protection vol 4no 2 pp 93ndash98 2012

[6] K Z Elwakeel G O El-Sayed and S M Abo El-NassrldquoRemoval of ferrous and manganous from water by activatedcarbon obtained from sugarcane bagasserdquo Desalination andWater Treatment vol 55 no 2 pp 471ndash483 2015

[7] K Ennaciri A Baccedilaoui M Sergent and A YaacoubildquoApplication of fractional factorial and Doehlert designs foroptimizing the preparation of activated carbons from Arganshellsrdquo Chemometrics and Intelligent Laboratory Systemsvol 139 pp 48ndash57 2014

[8] K Y Foo and B H Hameed ldquoMesoporous activated carbonfrom wood sawdust by K2CO3 activation using microwaveheatingrdquo Bioresource Technology vol 111 pp 425ndash432 2012

[9] A Kausar M Iqbal A Javed et al ldquoDyes adsorption usingclay and modified clay a reviewrdquo Journal of Molecular Liq-uids vol 256 pp 395ndash407 2018

[10] S Babel ldquoLow-cost adsorbents for heavy metals uptake fromcontaminated water a reviewrdquo Journal of Hazardous Mate-rials vol 97 no 1-3 pp 219ndash243 2003

[11] M Besbes N Fakhfakh andM Benzina ldquoCharacterization ofsilica gel prepared by using sol-gel processrdquo Physics Procediavol 2 no 3 pp 1087ndash1095 2009

[12] B Sun and A Chakraborty ldquo)ermodynamic frameworks ofadsorption kinetics modeling dynamic water uptakes on silicagel for adsorption cooling applicationsrdquo Energy vol 84pp 296ndash302 2015

[13] S K Alpat O patref S Alpat and H Akccedilay ldquo)e adsorptionkinetics and removal of cationic dye Toluidine Blue O from

Table 5 Adsorption capacities of MO onto various materials

Adsorbents qMO (mgg) ReferencesActivated carbon nanotubes 149 [51]Mesoporous carbon 2941 [52]Surfactants modified montmorillonite 14925 [53]Ammonium-functionalized silica nanoparticle 1054 [54]Lead oxide nanoparticles loaded activated carbon 33333 [55]Gold nanoparticles loaded on activated carbon 161 [56]Activated carbon 797 [57]Chitosan modified magnetic kaolin 3497 [58]Polyanilineactivated carbon composite 285 [59]Chitosan microspheres 207 [60]Activated carbon 33612 )is work

Journal of Chemistry 7

aqueous solution with Turkish zeoliterdquo Journal of HazardousMaterials vol 151 no 1 pp 213ndash220 2008

[14] D Caputo and F Pepe ldquoExperiments and data processing ofion exchange equilibria involving Italian natural zeolites areviewrdquo Microporous and Mesoporous Materials vol 105no 3 pp 222ndash231 2007

[15] A Wasti and M Ali Awan ldquoAdsorption of textile dye ontomodified immobilized activated aluminardquo Journal of theAssociation of Arab Universities for Basic and Applied Sciencesvol 20 no 1 pp 26ndash31 2016

[16] K Z Elwakeel ldquoRemoval of Reactive Black 5 from aqueoussolutions using magnetic chitosan resinsrdquo Journal of Haz-ardous Materials vol 167 no 1-3 pp 383ndash392 2009

[17] K Z Elwakeel A A El-Bindary A Ismail andA M Morshidy ldquoSorptive removal of Remazol Brilliant BlueR from aqueous solution by diethylenetriamine functionalizedmagnetic macro-reticular hybrid materialrdquo RSC Advancesvol 6 no 27 pp 22395ndash22410 2016

[18] T Shahnaz C Patra V Sharma andN Selvaraju ldquoA comparativestudy of raw acid-modified and EDTA-complexed Acaciaauriculiformis biomass for the removal of hexavalent chromiumrdquoChemistry and Ecology vol 36 no 4 pp 360ndash381 2020

[19] C Patra R M N Medisetti K Pakshirajan andS Narayanasamy ldquoAssessment of raw acid-modified andchelated biomass for sequestration of hexavalent chromiumfrom aqueous solution using Sterculia villosa Roxb shellsrdquoEnvironmental Science and Pollution Research vol 26 no 23pp 23625ndash23637 2019

[20] C Patra T Shahnaz S Subbiah and S NarayanasamyldquoComparative assessment of raw and acid-activated prepa-rations of novel Pongamia pinnata shells for adsorption ofhexavalent chromium from simulated wastewaterrdquo Envi-ronmental Science and Pollution Research vol 27 no 13pp 14836ndash14851 2020

[21] Y El Maguana N Elhadiri M Bouchdoug andM Benchanaa ldquoStudy of the influence of some factors on thepreparation of activated carbon from walnut cake using thefractional factorial designrdquo Journal of EnvironmentalChemical Engineering vol 6 no 1 pp 1093ndash1099 2018

[22] P Ammendola F Raganati and R Chirone ldquoCO2 adsorptionon a fine activated carbon in a sound assisted fluidized bedthermodynamics and kineticsrdquo Chemical Engineering Journalvol 322 pp 302ndash313 2017

[23] F Raganati P Ammendola and R Chirone ldquoOn improvingthe CO2 recovery efficiency of a conventional TSA process in asound assisted fluidized bed by separating heating andpurgingrdquo Separation and Purification Technology vol 167pp 24ndash31 2016

[24] F Raganati P Ammendola and R Chirone ldquoRole of acousticfields in promoting the gas-solid contact in a fluidized bed offine particlesrdquo KONA Powder and Particle Journal vol 32pp 23ndash40 2015

[25] K Z Elwakeel M A Abd El-Ghaffar S M El-kousy andH G El-Shorbagy ldquoSynthesis of new ammonium chitosanderivatives and their application for dye removal fromaqueous mediardquo Chemical Engineering Journal vol 203pp 458ndash468 2012

[26] A A Yakout M A Shaker K Z Elwakeel and W AlshitarildquoLauryl sulfatemagnetic graphene oxide nanosorbent forfast methylene blue recovery from aqueous solutionsrdquo Journalof Dispersion Science and Technology vol 40 no 5pp 707ndash715 2019

[27] I A W Tan A L Ahmad and B H Hameed ldquoPreparationof activated carbon from coconut husk optimization study

on removal of 246-trichlorophenol using response surfacemethodologyrdquo Journal of Hazardous Materials vol 153no 1-2 pp 709ndash717 2008

[28] J Yang and K Qiu ldquoPreparation of activated carbons fromwalnut shells via vacuum chemical activation and their ap-plication for methylene blue removalrdquo Chemical EngineeringJournal vol 165 no 1 pp 209ndash217 2010

[29] M L Martınez M M Torres C A Guzman andD M Maestri ldquoPreparation and characteristics of activatedcarbon from olive stones and walnut shellsrdquo Industrial Cropsand Products vol 23 no 1 pp 23ndash28 2006

[30] P Nowicki R Pietrzak and H Wachowska ldquoSorptionproperties of active carbons obtained from walnut shells bychemical and physical activationrdquo Catalysis Today vol 150no 1-2 pp 107ndash114 2010

[31] T-H Liou ldquoDevelopment of mesoporous structure and highadsorption capacity of biomass-based activated carbon byphosphoric acid and zinc chloride activationrdquo ChemicalEngineering Journal vol 158 no 2 pp 129ndash142 2010

[32] B S Girgis and M F Ishak ldquoActivated carbon from cottonstalks by impregnation with phosphoric acidrdquo MaterialsLetters vol 39 no 2 pp 107ndash114 1999

[33] Y El Maguana N Elhadiri M Bouchdoug M Benchanaaand A Jaouad ldquoActivated carbon from prickly pear seed cakeoptimization of preparation conditions using experimentaldesign and its application in dye removalrdquo InternationalJournal of Chemical Engineering vol 2019 Article ID8621951 12 pages 2019

[34] Y El maguana N Elhadiri M Benchanaa and R ChikrildquoAdsorption thermodynamic and kinetic studies of methylorange onto sugar scum powder as a low-cost inorganicadsorbentrdquo Journal of Chemistry vol 2020 Article ID9165874 10 pages 2020

[35] K V Kumar ldquoLinear and non-linear regression analysis forthe sorption kinetics of methylene blue onto activated car-bonrdquo Journal of Hazardous Materials vol 137 no 3pp 1538ndash1544 2006

[36] S Lagergren ldquoZur theorie der sogenannten adsorptiongeloster stoffe Kungliga Svenska VetenskapsakademiensrdquoHandlingar vol 24 pp 1ndash39 1898

[37] Y S Ho and G McKay ldquoPseudo-second order model forsorption processesrdquo Process Biochemistry vol 34 no 5pp 451ndash465 1999

[38] A G Ritchie ldquoAlternative to the Elovich equation for thekinetics of adsorption of gases on solidsrdquo Journal of theChemical Society Faraday Transactions 1 Physical Chemistryin Condensed Phases vol 73 pp 1650ndash1653 1977

[39] J W Weber and J C Morris ldquoKinetics of adsorption oncarbon from solutionrdquo Journal of the Sanitary EngineeringDivision vol 89 pp 31ndash60 1963

[40] A Gurses C Dogar M Yalcin M Acikyildiz R Bayrak andS Karaca ldquo)e adsorption kinetics of the cationic dyemethylene blue onto clayrdquo Journal of Hazardous Materialsvol 131 no 1-3 pp 217ndash228 2006

[41] G B Oguntimein ldquoBiosorption of dye from textile wastewatereffluent onto alkali treated dried sunflower seed hull anddesign of a batch adsorberrdquo Journal of EnvironmentalChemical Engineering vol 3 no 4 pp 2647ndash2661 2015

[42] G-B Hong and Y-KWang ldquoSynthesis of low-cost adsorbentfrom rice bran for the removal of reactive dye based on theresponse surface methodologyrdquo Applied Surface Sciencevol 423 pp 800ndash809 2017

[43] C H Giles T HMacewan S N Nakhwa and D Smith ldquo786Studies in adsorption Part XI A system of classification of

8 Journal of Chemistry

solution adsorption isotherms and its use in diagnosis ofadsorption mechanisms and in measurement of specificsurface areas of solidsrdquo Journal of the Chemical Society(Resumed) vol 10 pp 3973ndash3993 1960

[44] I Langmuir ldquo)e constitution and fundamental properties ofsolids and liquids Part I Solidsrdquo Journal of the AmericanChemical Society vol 38 no 11 pp 2221ndash2295 1916

[45] H Freundlish ldquoOver the adsorption in solutionrdquo Journal ofPhysical Chemistry vol 57 pp 385ndash470 1906

[46] D Kavitha and C Namasivayam ldquoExperimental and kineticstudies on methylene blue adsorption by coir pith carbonrdquoBioresource Technology vol 98 no 1 pp 14ndash21 2007

[47] H N Tran S-J You and H-P Chao ldquo)ermodynamicparameters of cadmium adsorption onto orange peel calcu-lated from various methods a comparison studyrdquo Journal ofEnvironmental Chemical Engineering vol 4 no 3 pp 2671ndash2682 2016

[48] T A Khan E A Khan and Shahjahan ldquoRemoval of basicdyes from aqueous solution by adsorption onto binary iron-manganese oxide coated kaolinite non-linear isotherm andkinetics modelingrdquo Applied Clay Science vol 107 pp 70ndash772015

[49] T N V de Souza S M L de Carvalho M G A VieiraM G C da Silva and D d S B Brasil ldquoAdsorption of basicdyes onto activated carbon experimental and theoreticalinvestigation of chemical reactivity of basic dyes using DFT-based descriptorsrdquo Applied Surface Science vol 448pp 662ndash670 2018

[50] S Wang and Z Zhu ldquoEffects of acidic treatment of activatedcarbons on dye adsorptionrdquoDyes and Pigments vol 75 no 2pp 306ndash314 2007

[51] J Ma F Yu L Zhou et al ldquoEnhanced adsorptive removal ofmethyl orange and methylene blue from aqueous solution byalkali-activated multiwalled carbon nanotubesrdquo ACS AppliedMaterials amp Interfaces vol 4 no 11 pp 5749ndash5760 2012

[52] N Mohammadi H Khani V K Gupta E Amereh andS Agarwal ldquoAdsorption process of methyl orange dye ontomesoporous carbon material-kinetic and thermodynamicstudiesrdquo Journal of Colloid and Interface Science vol 362no 2 pp 457ndash462 2011

[53] D Chen J Chen X Luan H Ji and Z Xia ldquoCharacterizationof anion-cationic surfactants modified montmorillonite andits application for the removal of methyl orangerdquo ChemicalEngineering Journal vol 171 no 3 pp 1150ndash1158 2011

[54] J Liu S Ma and L Zang ldquoPreparation and characterizationof ammonium-functionalized silica nanoparticle as a newadsorbent to remove methyl orange from aqueous solutionrdquoApplied Surface Science vol 265 pp 393ndash398 2013

[55] S Agarwal I Tyagi V K Gupta et al ldquoRETRACTED ki-netics and thermodynamics of methyl orange adsorption fromaqueous solutions-artificial neural network-particle swarmoptimization modelingrdquo Journal of Molecular Liquidsvol 218 pp 354ndash362 2016

[56] M Ghaedi A M Ghaedi A Ansari F Mohammadi andA Vafaei ldquoArtificial neural network and particle swarmoptimization for removal of methyl orange by gold nano-particles loaded on activated carbon and Tamariskrdquo Spec-trochimica Acta Part A Molecular and BiomolecularSpectroscopy vol 132 pp 639ndash654 2014

[57] V Yonten N K Sanyurek and M R Kivanccedil ldquoA thermo-dynamic and kinetic approach to adsorption of methyl orangefrom aqueous solution using a low cost activated carbonprepared from Vitis vinifera Lrdquo Surfaces and Interfacesvol 20 Article ID 100529 2020

[58] D-M Liu C Dong J Zhong S Ren Y Chen and T QiuldquoFacile preparation of chitosan modified magnetic kaolin byone-pot coprecipitation method for efficient removal ofmethyl orangerdquo Carbohydrate Polymers vol 245 Article ID116572 2020

[59] M Hasan M M Rashid M M Hossain et al ldquoFabrication ofpolyanilineactivated carbon composite and its testing formethyl orange removal optimization equilibrium isothermand kinetic studyrdquo Polymer Testing vol 77 Article ID 1059092019

[60] L Zhai Z Bai Y Zhu B Wang and W Luo ldquoFabrication ofchitosan microspheres for efficient adsorption of methylorangerdquo Chinese Journal of Chemical Engineering vol 26no 3 pp 657ndash666 2018

Journal of Chemistry 9

be used to predict the mechanism of the adsorption processHence it appears that the use of a general kinetic model(pseudo-n order) with no preset reaction order is advisablewhenR2 and∆q of pseudo-first-order and pseudo-second-ordermodels are comparable

)e possibility of intraparticle diffusion resistance wasexplored by using the intraparticle diffusion model proposedby Weber and Morris [39] expressed as follows

qt kidt12

+ c (7)

where qt (mgg) is the adsorption amount at time t (min) kid(mggmin12) is the adsorption rate constant of intraparticlediffusion model and c is a constant related to the thicknessof the boundary layer

If the plot of qt versus t12 is linear and passes through theorigin then intraparticle diffusion is the sole rate-limitingstep of the adsorption process Figure 4 shows the plot of theintraparticle diffusion model which is not linear and did notpass through the origin indicating that intraparticle diffu-sion was not the only rate-limiting step of the adsorptionprocess of methyl orange onto the activated carbon but alsoother mechanisms may control the rate of the adsorption allof which may be operating simultaneously [8 34 40] )e

first portion of the plot is attributed to the transport of solutefrom bulk solution through liquid film to the adsorbentexterior surface)ereafter the second part is ascribed to theintraparticle diffusion as slower process In fact the slope ofthe linear portion indicates the rate of the adsorptionprocess the lower slope corresponds to a slower adsorptionprocess [34 41] )us the rate of the diffusion of methylorange molecules through boundary layer film in the initialstage of the adsorption process was faster than the rate of theintraparticle diffusion because the slope of the first linearportion was higher than of the second linear portion Ini-tially the methyl orange molecules are quickly adsorbedonto the surface of the activated carbon and when satu-ration is reached the methyl orange molecules are diffusedinto the interior of adsorbent particles [34] Finally the lastportion is attributed to the final equilibrium stage for whichthe intraparticle diffusion slows down due to the low con-centration dye in the aqueous solution [42]

32 Equilibrium Adsorption Adsorption equilibrium isestablished between the adsorbed molecules and the ad-sorbent surface when an adsorbate is in contact with theadsorbent )e equilibrium relationship between theadsorbed amount of adsorbate (qe) and the residual ad-sorbate concentration (Ce) at constant temperature is de-scribed by the adsorption isotherm )is last is very usefulfor understanding the adsorption mechanism In generaladsorption isotherms provide information on the affinityand the binding energy between the adsorbate and theadsorbent on the adsorption capacity and on the surfacephase which may be considered as a monolayer or multi-layer All this information can be extracted from equilibrium

Table 1 Pseudo-first-order and pseudo-second-order kinetic parameters (C0 100mgL adsorbent dose 02 gL pH sim 7 T 20degC)

qeexp (mgg)Pseudo-first order Pseudo-second order

qecal (mgg) k1 (1min) R2 Δq () qecal (mgg) k2 (gmgmin) R2 Δq ()19408 18842 795 10minus2 0990 383 20034 715 10minus4 0998 160

Experimental dataPseudo-n order

0

50

100

150

200

q t (m

gg)

50 100 150 2000t (min)

Figure 3 Nonlinear fit of pseudo-n-order kinetic model for MOadsorption onto activated carbon (C0 100mgL adsorbentdose 02 gL pH sim 7 T 20degC)

Table 2 Pseudo-n-order kinetic parameters (C0 100mgLadsorbent dose 02 gL pH sim 7 T 20degC)

qeexp (mgg)Pseudo-n order

qecal (mgg) kn (1min) n R2 Δq ()19408 19978 1407 10minus2 197 0998 159

Experimental data

0

50

100

150

200

q t (m

gg)

25 50 75 100 125 15000t12 (min12)

Figure 4 Plot of the intraparticle diffusion model for MO ad-sorption onto sugar scum (C0 100mgL adsorbent dose 02 gLpH sim 7 T 20degC)

4 Journal of Chemistry

isotherm models describing the adsorption process Severalisotherm models are presented in the literature whichpermit a better understanding of the adsorption phenom-enon of chemical species on the adsorbent )e modeling ofthe adsorption isotherms consists in describing the exper-imental data using theoretical or empirical mathematicalequations and allowing determination of isotherm param-eters to compare the efficiency of different adsorbents

To investigate the adsorption isotherm the adsorptioncapacity of the activated carbon prepared from pricklypear seed cake for methyl orange is studied at temperature20degC and pH sim 7 for an adsorbent dose of 1 gL Figure 5shows the adsorption isotherm of methyl orange onto theactivated carbon which indicates a significant adsorptionat low concentrations According to Giles classification[43] this isotherm displayed an H curve pattern indi-cating that the methyl orange and activated carbon have ahigh affinity

In the first step the experimental data of adsorptionisotherm were fitted to the Langmuir and Freundlich modelsto find which one can be used to describe the adsorptionprocess of methyl orange onto the surface of the activatedcarbon Langmuir equation assumes the monolayer ad-sorption on a homogenous surface without interactionbetween adsorbates [44] while the Freundlich isotherm wasbased on the assumption of the multilayer adsorption onheterogeneous surface [45]

)e Langmuir isotherm equation is expressed as follows

qe qmKLCe

1 + KLCe (8)

)e Freundlich isotherm equation is given as follows

qe KFC1ne (9)

where Ce (mgL) is the equilibrium concentration of ad-sorbate qe (mgg) is the amount of adsorption at theequilibrium qm (mgg) is the monolayer adsorption ca-pacity n is the Freundlich intensity constant and KL and KFare the Langmuir and Freundlich constants respectively

Figure 6 shows the Freundlich and Langmuir curvesgenerated using (8) and (9) It can be seen from this figurethat the adsorption isotherm of methyl orange onto theactivated carbon was well described by the Freundlichequation Calculated parameters of Langmuir and Freund-lich isotherms along with R2 values obtained by the non-linear fitting method are listed in Table 3 Via comparison ofthe R2 values Freundlich equation represents a better fit ofequilibrium experimental data than Langmuir )ereforethe adsorption process of methyl orange onto the activatedcarbon can be described more appropriately by theFreundlich isotherm indicating the multilayer adsorptionon the heterogeneous surface with a different energy dis-tribution Freundlich constant n is a measure of adsorptionintensity As seen from Table 3 a value of 1n was foundbetween 0 and 1 indicating the favorable adsorption ofmethyl orange on the activated carbon [33]

)e experimental data of the adsorption isotherm werealso fitted to Temkin isotherm equation to approach

energetic aspects Temkin isotherm is based on the as-sumption that the heat of adsorption of all the molecules inthe layer decreased linearly with coverage and adsorption ischaracterized by a uniform distribution of binding energies[46]

)e Temkin isotherm equation is expressed as

qe RTb

ln KTCe( 1113857 (10)

0

100

200

300

q e (m

gg)

150 2502000 50 100Ce (mgL)

Experimental data

Figure 5 Adsorption isotherm of MO onto activated carbon(tcontact 2 h adsorbent dose 1 gL pH sim 7 T 20degC)

0

100

200

300q e

(mg

g)

150 2502000 50 100Ce (mgL)

Experimental dataLangmuirFreundlich

Figure 6 Nonlinear fits of the Langmuir and Freundlich isothermsfor MO adsorption onto activated carbon (tcontact 2 h adsorbentdose 1 gL pH sim 7 T 20degC)

Table 3 Langmuir and Freundlich isotherm parameters(tcontact 2 h adsorbent dose 1 gL pH sim 7 T 20degC)

Langmuir Freundlichqm (mgg) KL (Lmg) R2 1n KF ((mgg) (Lmg)1n) R2

31906 00748 093 029 6982 099

Journal of Chemistry 5

where qe (mgg) is the amount of adsorption at the equi-librium Ce (mgL) is the equilibrium concentration ofadsorbate T (K) is the temperature R is the universal gasconstant and KT is the equilibrium binding constant cor-responding to the maximum binding energy )e constant b(Jmol) is related to the heat of adsorption )e Temkinisotherm parameters were obtained by plotting qe versus Ceshown in Figure 7 and summarized in Table 4 According tothe R2 value the Temkin isothermmodel did not fit well withthe experimental data indicating the energetic heterogeneityof the adsorption sites

Besides the Langmuir Freundlich and Temkin modelsthe DubininndashRadushkevich isotherm model was alsoemployed for the estimation of the adsorption energy (E)and further finding the nature of the adsorption [41 47] Itsequation is given as follows

qe qm exp minusKDR RT ln 1 +1

Ce1113888 11138891113890 1113891

2⎡⎣ ⎤⎦ (11)

where qe (mgg) is the amount of adsorption at the equi-librium Ce (mgL) is the equilibrium concentration ofadsorbate qm is the monolayer adsorption capacity KDR isthe D-R constant which gives the adsorption energy (E)T (K) is the temperature and R is the universal gas constant)e adsorption energy can be computed using the followingrelationship

E 12B

radic (12)

)e adsorption energy (E) value gives information aboutadsorption mechanism and more specifically its physical orchemical nature When E is lower than 8 kJmol the type ofadsorption can be explained by physisorption and it can becontrolled by ion-exchange or chemical adsorption when Eis higher than 8 kJmol [48]

Figure 8 shows the fitting curve of DubininndashRadushkevichisotherm and the obtained parameters are listed in Table 4)ecalculated adsorption energy (E 057 kJmol) reveals that thetype of adsorption of methyl orange onto activated carbon canbe explained by physisorption indicating that the adsorption isillustrated by the formation of week physical attraction forcessuch as hydrogen-bonding and van der Waals forces betweenadsorbate molecules and solid surface and thus adsorption isreversible )is result indicates that the adsorption of methylorange onto the surface of the prepared activated carbon is amultilayer adsorption which confirms that this process followsthe Freundlich isotherm

)e results of the previous [33] and present studyshowed that the activated carbon prepared from prickly pearseed cake by phosphoric acid activation is effective for re-moving cationic and anionic dyes such as methylene blueand methyl orange from aqueous solution )is can beexplained by the presence of a variety of functional groupson the adsorbent surface which have enhanced the ad-sorption capacity [33] )e activated carbon simultaneously

presents acidic and basic sites able to fix cationic and anionicdyes by electrostatic interactions )e adsorption mecha-nism can also be explained by the interactions betweendelocalized π-electrons of the activated carbon surface andthe free electrons of the dye molecules present in the aro-matic rings and multiple bonds [49 50] )e adsorptioncapacities of MO onto various materials are given in Table 5

Table 4 Temkin and DubininndashRadushkevich isotherm parameters(tcontact 2 h adsorbent dose 1 gL pH sim 7 T 20degC)

Temkin DubininndashRadushkevichb KT R2 qm KDR E R2(Jmol) (Lmg) mgg mol2kJ kJmol5966 609 095 19380 153 057 084

0

100

200

300

q e (m

gg)

150 2502000 50 100Ce (mgL)

Experimental data

Figure 7 Nonlinear fit of the Temkin isotherm for MO adsorptiononto activated carbon (tcontact 2 h adsorbent dose 1 gL pH sim 7T 20degC)

600 20 40Ce (mgL)

Experimental data

q e (m

gg)

0

100

200

300

Figure 8 Nonlinear fit of the DubininndashRadushkevich isotherm forMO adsorption onto activated carbon (tcontact 2 h adsorbentdose 1 gL pH sim 7 T 20degC)

6 Journal of Chemistry

in order to evaluate the performance of the activated carbonprepared from prickly pear seed cake

4 Conclusion

In this study the use of the activated carbon preparedfrom prickly pear seed cake by thermo chemical processusing phosphoric acid for the removal of methyl orangefrom aqueous solution has been studied )e kineticof adsorbate-adsorbent interactions can be represented bythe pseudo-second-order model )e equilibriumadsorption data are best fitted by the Freundlich model ascompared to Langmuir and Temkin models )e ad-sorption capacity for methyl orange was found to be33612mgg at temperature 20degC and pH sim 7 indicatingthat the activated carbon may be an efficient adsorbentwith great adsorptive capacity DubininndashRadushkevichisotherm reveals that the adsorption of methyl orangeonto the activated carbon was a physisorption process innature )e results demonstrated that the prickly pear seedcake is a suitable precursor for the preparation of anadequate activated carbon for dyes removal from indus-trial effluents

Data Availability

All the data used to support the findings of this study areincluded within the article

Conflicts of Interest

)e authors declare that they have no conflicts of interest

Acknowledgments

)e authors are grateful to the Center of Analyses andCharacterization (CAC) of University Caddy Ayyad Mo-rocco Also the authors also extend their appreciation toprofessors of REMATOP LCOA and REMINEX ManagemLaboratories in Marrakech Morocco

References

[1] S Kumar C Patra S Narayanasamy and P V RajaramanldquoPerformance of acid-activated water caltrop (Trapa natans)

shell in fixed bed column for hexavalent chromium removalfrom simulated wastewaterrdquo Environmental Science andPollution Research vol 27 no 22 pp 28042ndash28052 2020

[2] T Shahnaz V Sharma S Subbiah and S NarayanasamyldquoMultivariate optimisation of Cr (VI) Co (III) and Cu (II)adsorption onto nanobentonite incorporated nanocellulosechitosan aerogel using response surface methodologyrdquoJournal of Water Process Engineering vol 36 p 101283 2020

[3] Y El maguana N Elhadiri M Bouchdoug M Benchanaaand A Boussetta ldquoOptimization of preparation conditions ofnovel adsorbent from sugar scum using response surfacemethodology for removal of methylene bluerdquo Journal ofChemistry vol 2018 Article ID 2093654 10 pages 2018

[4] A M Elgarahy K Z Elwakeel G A Elshoubaky andS H Mohammad ldquoUntapped sepia shellndashbased composite forthe sorption of cationic and anionic dyesrdquo Water Air amp SoilPollution vol 230 p 217 2019

[5] R Kant ldquoAdsorption of dye eosin from an aqueous solutionon two different samples of activated carbon by static batchmethodrdquo Journal of Water Resource and Protection vol 4no 2 pp 93ndash98 2012

[6] K Z Elwakeel G O El-Sayed and S M Abo El-NassrldquoRemoval of ferrous and manganous from water by activatedcarbon obtained from sugarcane bagasserdquo Desalination andWater Treatment vol 55 no 2 pp 471ndash483 2015

[7] K Ennaciri A Baccedilaoui M Sergent and A YaacoubildquoApplication of fractional factorial and Doehlert designs foroptimizing the preparation of activated carbons from Arganshellsrdquo Chemometrics and Intelligent Laboratory Systemsvol 139 pp 48ndash57 2014

[8] K Y Foo and B H Hameed ldquoMesoporous activated carbonfrom wood sawdust by K2CO3 activation using microwaveheatingrdquo Bioresource Technology vol 111 pp 425ndash432 2012

[9] A Kausar M Iqbal A Javed et al ldquoDyes adsorption usingclay and modified clay a reviewrdquo Journal of Molecular Liq-uids vol 256 pp 395ndash407 2018

[10] S Babel ldquoLow-cost adsorbents for heavy metals uptake fromcontaminated water a reviewrdquo Journal of Hazardous Mate-rials vol 97 no 1-3 pp 219ndash243 2003

[11] M Besbes N Fakhfakh andM Benzina ldquoCharacterization ofsilica gel prepared by using sol-gel processrdquo Physics Procediavol 2 no 3 pp 1087ndash1095 2009

[12] B Sun and A Chakraborty ldquo)ermodynamic frameworks ofadsorption kinetics modeling dynamic water uptakes on silicagel for adsorption cooling applicationsrdquo Energy vol 84pp 296ndash302 2015

[13] S K Alpat O patref S Alpat and H Akccedilay ldquo)e adsorptionkinetics and removal of cationic dye Toluidine Blue O from

Table 5 Adsorption capacities of MO onto various materials

Adsorbents qMO (mgg) ReferencesActivated carbon nanotubes 149 [51]Mesoporous carbon 2941 [52]Surfactants modified montmorillonite 14925 [53]Ammonium-functionalized silica nanoparticle 1054 [54]Lead oxide nanoparticles loaded activated carbon 33333 [55]Gold nanoparticles loaded on activated carbon 161 [56]Activated carbon 797 [57]Chitosan modified magnetic kaolin 3497 [58]Polyanilineactivated carbon composite 285 [59]Chitosan microspheres 207 [60]Activated carbon 33612 )is work

Journal of Chemistry 7

aqueous solution with Turkish zeoliterdquo Journal of HazardousMaterials vol 151 no 1 pp 213ndash220 2008

[14] D Caputo and F Pepe ldquoExperiments and data processing ofion exchange equilibria involving Italian natural zeolites areviewrdquo Microporous and Mesoporous Materials vol 105no 3 pp 222ndash231 2007

[15] A Wasti and M Ali Awan ldquoAdsorption of textile dye ontomodified immobilized activated aluminardquo Journal of theAssociation of Arab Universities for Basic and Applied Sciencesvol 20 no 1 pp 26ndash31 2016

[16] K Z Elwakeel ldquoRemoval of Reactive Black 5 from aqueoussolutions using magnetic chitosan resinsrdquo Journal of Haz-ardous Materials vol 167 no 1-3 pp 383ndash392 2009

[17] K Z Elwakeel A A El-Bindary A Ismail andA M Morshidy ldquoSorptive removal of Remazol Brilliant BlueR from aqueous solution by diethylenetriamine functionalizedmagnetic macro-reticular hybrid materialrdquo RSC Advancesvol 6 no 27 pp 22395ndash22410 2016

[18] T Shahnaz C Patra V Sharma andN Selvaraju ldquoA comparativestudy of raw acid-modified and EDTA-complexed Acaciaauriculiformis biomass for the removal of hexavalent chromiumrdquoChemistry and Ecology vol 36 no 4 pp 360ndash381 2020

[19] C Patra R M N Medisetti K Pakshirajan andS Narayanasamy ldquoAssessment of raw acid-modified andchelated biomass for sequestration of hexavalent chromiumfrom aqueous solution using Sterculia villosa Roxb shellsrdquoEnvironmental Science and Pollution Research vol 26 no 23pp 23625ndash23637 2019

[20] C Patra T Shahnaz S Subbiah and S NarayanasamyldquoComparative assessment of raw and acid-activated prepa-rations of novel Pongamia pinnata shells for adsorption ofhexavalent chromium from simulated wastewaterrdquo Envi-ronmental Science and Pollution Research vol 27 no 13pp 14836ndash14851 2020

[21] Y El Maguana N Elhadiri M Bouchdoug andM Benchanaa ldquoStudy of the influence of some factors on thepreparation of activated carbon from walnut cake using thefractional factorial designrdquo Journal of EnvironmentalChemical Engineering vol 6 no 1 pp 1093ndash1099 2018

[22] P Ammendola F Raganati and R Chirone ldquoCO2 adsorptionon a fine activated carbon in a sound assisted fluidized bedthermodynamics and kineticsrdquo Chemical Engineering Journalvol 322 pp 302ndash313 2017

[23] F Raganati P Ammendola and R Chirone ldquoOn improvingthe CO2 recovery efficiency of a conventional TSA process in asound assisted fluidized bed by separating heating andpurgingrdquo Separation and Purification Technology vol 167pp 24ndash31 2016

[24] F Raganati P Ammendola and R Chirone ldquoRole of acousticfields in promoting the gas-solid contact in a fluidized bed offine particlesrdquo KONA Powder and Particle Journal vol 32pp 23ndash40 2015

[25] K Z Elwakeel M A Abd El-Ghaffar S M El-kousy andH G El-Shorbagy ldquoSynthesis of new ammonium chitosanderivatives and their application for dye removal fromaqueous mediardquo Chemical Engineering Journal vol 203pp 458ndash468 2012

[26] A A Yakout M A Shaker K Z Elwakeel and W AlshitarildquoLauryl sulfatemagnetic graphene oxide nanosorbent forfast methylene blue recovery from aqueous solutionsrdquo Journalof Dispersion Science and Technology vol 40 no 5pp 707ndash715 2019

[27] I A W Tan A L Ahmad and B H Hameed ldquoPreparationof activated carbon from coconut husk optimization study

on removal of 246-trichlorophenol using response surfacemethodologyrdquo Journal of Hazardous Materials vol 153no 1-2 pp 709ndash717 2008

[28] J Yang and K Qiu ldquoPreparation of activated carbons fromwalnut shells via vacuum chemical activation and their ap-plication for methylene blue removalrdquo Chemical EngineeringJournal vol 165 no 1 pp 209ndash217 2010

[29] M L Martınez M M Torres C A Guzman andD M Maestri ldquoPreparation and characteristics of activatedcarbon from olive stones and walnut shellsrdquo Industrial Cropsand Products vol 23 no 1 pp 23ndash28 2006

[30] P Nowicki R Pietrzak and H Wachowska ldquoSorptionproperties of active carbons obtained from walnut shells bychemical and physical activationrdquo Catalysis Today vol 150no 1-2 pp 107ndash114 2010

[31] T-H Liou ldquoDevelopment of mesoporous structure and highadsorption capacity of biomass-based activated carbon byphosphoric acid and zinc chloride activationrdquo ChemicalEngineering Journal vol 158 no 2 pp 129ndash142 2010

[32] B S Girgis and M F Ishak ldquoActivated carbon from cottonstalks by impregnation with phosphoric acidrdquo MaterialsLetters vol 39 no 2 pp 107ndash114 1999

[33] Y El Maguana N Elhadiri M Bouchdoug M Benchanaaand A Jaouad ldquoActivated carbon from prickly pear seed cakeoptimization of preparation conditions using experimentaldesign and its application in dye removalrdquo InternationalJournal of Chemical Engineering vol 2019 Article ID8621951 12 pages 2019

[34] Y El maguana N Elhadiri M Benchanaa and R ChikrildquoAdsorption thermodynamic and kinetic studies of methylorange onto sugar scum powder as a low-cost inorganicadsorbentrdquo Journal of Chemistry vol 2020 Article ID9165874 10 pages 2020

[35] K V Kumar ldquoLinear and non-linear regression analysis forthe sorption kinetics of methylene blue onto activated car-bonrdquo Journal of Hazardous Materials vol 137 no 3pp 1538ndash1544 2006

[36] S Lagergren ldquoZur theorie der sogenannten adsorptiongeloster stoffe Kungliga Svenska VetenskapsakademiensrdquoHandlingar vol 24 pp 1ndash39 1898

[37] Y S Ho and G McKay ldquoPseudo-second order model forsorption processesrdquo Process Biochemistry vol 34 no 5pp 451ndash465 1999

[38] A G Ritchie ldquoAlternative to the Elovich equation for thekinetics of adsorption of gases on solidsrdquo Journal of theChemical Society Faraday Transactions 1 Physical Chemistryin Condensed Phases vol 73 pp 1650ndash1653 1977

[39] J W Weber and J C Morris ldquoKinetics of adsorption oncarbon from solutionrdquo Journal of the Sanitary EngineeringDivision vol 89 pp 31ndash60 1963

[40] A Gurses C Dogar M Yalcin M Acikyildiz R Bayrak andS Karaca ldquo)e adsorption kinetics of the cationic dyemethylene blue onto clayrdquo Journal of Hazardous Materialsvol 131 no 1-3 pp 217ndash228 2006

[41] G B Oguntimein ldquoBiosorption of dye from textile wastewatereffluent onto alkali treated dried sunflower seed hull anddesign of a batch adsorberrdquo Journal of EnvironmentalChemical Engineering vol 3 no 4 pp 2647ndash2661 2015

[42] G-B Hong and Y-KWang ldquoSynthesis of low-cost adsorbentfrom rice bran for the removal of reactive dye based on theresponse surface methodologyrdquo Applied Surface Sciencevol 423 pp 800ndash809 2017

[43] C H Giles T HMacewan S N Nakhwa and D Smith ldquo786Studies in adsorption Part XI A system of classification of

8 Journal of Chemistry

solution adsorption isotherms and its use in diagnosis ofadsorption mechanisms and in measurement of specificsurface areas of solidsrdquo Journal of the Chemical Society(Resumed) vol 10 pp 3973ndash3993 1960

[44] I Langmuir ldquo)e constitution and fundamental properties ofsolids and liquids Part I Solidsrdquo Journal of the AmericanChemical Society vol 38 no 11 pp 2221ndash2295 1916

[45] H Freundlish ldquoOver the adsorption in solutionrdquo Journal ofPhysical Chemistry vol 57 pp 385ndash470 1906

[46] D Kavitha and C Namasivayam ldquoExperimental and kineticstudies on methylene blue adsorption by coir pith carbonrdquoBioresource Technology vol 98 no 1 pp 14ndash21 2007

[47] H N Tran S-J You and H-P Chao ldquo)ermodynamicparameters of cadmium adsorption onto orange peel calcu-lated from various methods a comparison studyrdquo Journal ofEnvironmental Chemical Engineering vol 4 no 3 pp 2671ndash2682 2016

[48] T A Khan E A Khan and Shahjahan ldquoRemoval of basicdyes from aqueous solution by adsorption onto binary iron-manganese oxide coated kaolinite non-linear isotherm andkinetics modelingrdquo Applied Clay Science vol 107 pp 70ndash772015

[49] T N V de Souza S M L de Carvalho M G A VieiraM G C da Silva and D d S B Brasil ldquoAdsorption of basicdyes onto activated carbon experimental and theoreticalinvestigation of chemical reactivity of basic dyes using DFT-based descriptorsrdquo Applied Surface Science vol 448pp 662ndash670 2018

[50] S Wang and Z Zhu ldquoEffects of acidic treatment of activatedcarbons on dye adsorptionrdquoDyes and Pigments vol 75 no 2pp 306ndash314 2007

[51] J Ma F Yu L Zhou et al ldquoEnhanced adsorptive removal ofmethyl orange and methylene blue from aqueous solution byalkali-activated multiwalled carbon nanotubesrdquo ACS AppliedMaterials amp Interfaces vol 4 no 11 pp 5749ndash5760 2012

[52] N Mohammadi H Khani V K Gupta E Amereh andS Agarwal ldquoAdsorption process of methyl orange dye ontomesoporous carbon material-kinetic and thermodynamicstudiesrdquo Journal of Colloid and Interface Science vol 362no 2 pp 457ndash462 2011

[53] D Chen J Chen X Luan H Ji and Z Xia ldquoCharacterizationof anion-cationic surfactants modified montmorillonite andits application for the removal of methyl orangerdquo ChemicalEngineering Journal vol 171 no 3 pp 1150ndash1158 2011

[54] J Liu S Ma and L Zang ldquoPreparation and characterizationof ammonium-functionalized silica nanoparticle as a newadsorbent to remove methyl orange from aqueous solutionrdquoApplied Surface Science vol 265 pp 393ndash398 2013

[55] S Agarwal I Tyagi V K Gupta et al ldquoRETRACTED ki-netics and thermodynamics of methyl orange adsorption fromaqueous solutions-artificial neural network-particle swarmoptimization modelingrdquo Journal of Molecular Liquidsvol 218 pp 354ndash362 2016

[56] M Ghaedi A M Ghaedi A Ansari F Mohammadi andA Vafaei ldquoArtificial neural network and particle swarmoptimization for removal of methyl orange by gold nano-particles loaded on activated carbon and Tamariskrdquo Spec-trochimica Acta Part A Molecular and BiomolecularSpectroscopy vol 132 pp 639ndash654 2014

[57] V Yonten N K Sanyurek and M R Kivanccedil ldquoA thermo-dynamic and kinetic approach to adsorption of methyl orangefrom aqueous solution using a low cost activated carbonprepared from Vitis vinifera Lrdquo Surfaces and Interfacesvol 20 Article ID 100529 2020

[58] D-M Liu C Dong J Zhong S Ren Y Chen and T QiuldquoFacile preparation of chitosan modified magnetic kaolin byone-pot coprecipitation method for efficient removal ofmethyl orangerdquo Carbohydrate Polymers vol 245 Article ID116572 2020

[59] M Hasan M M Rashid M M Hossain et al ldquoFabrication ofpolyanilineactivated carbon composite and its testing formethyl orange removal optimization equilibrium isothermand kinetic studyrdquo Polymer Testing vol 77 Article ID 1059092019

[60] L Zhai Z Bai Y Zhu B Wang and W Luo ldquoFabrication ofchitosan microspheres for efficient adsorption of methylorangerdquo Chinese Journal of Chemical Engineering vol 26no 3 pp 657ndash666 2018

Journal of Chemistry 9

isotherm models describing the adsorption process Severalisotherm models are presented in the literature whichpermit a better understanding of the adsorption phenom-enon of chemical species on the adsorbent )e modeling ofthe adsorption isotherms consists in describing the exper-imental data using theoretical or empirical mathematicalequations and allowing determination of isotherm param-eters to compare the efficiency of different adsorbents

To investigate the adsorption isotherm the adsorptioncapacity of the activated carbon prepared from pricklypear seed cake for methyl orange is studied at temperature20degC and pH sim 7 for an adsorbent dose of 1 gL Figure 5shows the adsorption isotherm of methyl orange onto theactivated carbon which indicates a significant adsorptionat low concentrations According to Giles classification[43] this isotherm displayed an H curve pattern indi-cating that the methyl orange and activated carbon have ahigh affinity

In the first step the experimental data of adsorptionisotherm were fitted to the Langmuir and Freundlich modelsto find which one can be used to describe the adsorptionprocess of methyl orange onto the surface of the activatedcarbon Langmuir equation assumes the monolayer ad-sorption on a homogenous surface without interactionbetween adsorbates [44] while the Freundlich isotherm wasbased on the assumption of the multilayer adsorption onheterogeneous surface [45]

)e Langmuir isotherm equation is expressed as follows

qe qmKLCe

1 + KLCe (8)

)e Freundlich isotherm equation is given as follows

qe KFC1ne (9)

where Ce (mgL) is the equilibrium concentration of ad-sorbate qe (mgg) is the amount of adsorption at theequilibrium qm (mgg) is the monolayer adsorption ca-pacity n is the Freundlich intensity constant and KL and KFare the Langmuir and Freundlich constants respectively

Figure 6 shows the Freundlich and Langmuir curvesgenerated using (8) and (9) It can be seen from this figurethat the adsorption isotherm of methyl orange onto theactivated carbon was well described by the Freundlichequation Calculated parameters of Langmuir and Freund-lich isotherms along with R2 values obtained by the non-linear fitting method are listed in Table 3 Via comparison ofthe R2 values Freundlich equation represents a better fit ofequilibrium experimental data than Langmuir )ereforethe adsorption process of methyl orange onto the activatedcarbon can be described more appropriately by theFreundlich isotherm indicating the multilayer adsorptionon the heterogeneous surface with a different energy dis-tribution Freundlich constant n is a measure of adsorptionintensity As seen from Table 3 a value of 1n was foundbetween 0 and 1 indicating the favorable adsorption ofmethyl orange on the activated carbon [33]

)e experimental data of the adsorption isotherm werealso fitted to Temkin isotherm equation to approach

energetic aspects Temkin isotherm is based on the as-sumption that the heat of adsorption of all the molecules inthe layer decreased linearly with coverage and adsorption ischaracterized by a uniform distribution of binding energies[46]

)e Temkin isotherm equation is expressed as

qe RTb

ln KTCe( 1113857 (10)

0

100

200

300

q e (m

gg)

150 2502000 50 100Ce (mgL)

Experimental data

Figure 5 Adsorption isotherm of MO onto activated carbon(tcontact 2 h adsorbent dose 1 gL pH sim 7 T 20degC)

0

100

200

300q e

(mg

g)

150 2502000 50 100Ce (mgL)

Experimental dataLangmuirFreundlich

Figure 6 Nonlinear fits of the Langmuir and Freundlich isothermsfor MO adsorption onto activated carbon (tcontact 2 h adsorbentdose 1 gL pH sim 7 T 20degC)

Table 3 Langmuir and Freundlich isotherm parameters(tcontact 2 h adsorbent dose 1 gL pH sim 7 T 20degC)

Langmuir Freundlichqm (mgg) KL (Lmg) R2 1n KF ((mgg) (Lmg)1n) R2

31906 00748 093 029 6982 099

Journal of Chemistry 5

where qe (mgg) is the amount of adsorption at the equi-librium Ce (mgL) is the equilibrium concentration ofadsorbate T (K) is the temperature R is the universal gasconstant and KT is the equilibrium binding constant cor-responding to the maximum binding energy )e constant b(Jmol) is related to the heat of adsorption )e Temkinisotherm parameters were obtained by plotting qe versus Ceshown in Figure 7 and summarized in Table 4 According tothe R2 value the Temkin isothermmodel did not fit well withthe experimental data indicating the energetic heterogeneityof the adsorption sites

Besides the Langmuir Freundlich and Temkin modelsthe DubininndashRadushkevich isotherm model was alsoemployed for the estimation of the adsorption energy (E)and further finding the nature of the adsorption [41 47] Itsequation is given as follows

qe qm exp minusKDR RT ln 1 +1

Ce1113888 11138891113890 1113891

2⎡⎣ ⎤⎦ (11)

where qe (mgg) is the amount of adsorption at the equi-librium Ce (mgL) is the equilibrium concentration ofadsorbate qm is the monolayer adsorption capacity KDR isthe D-R constant which gives the adsorption energy (E)T (K) is the temperature and R is the universal gas constant)e adsorption energy can be computed using the followingrelationship

E 12B

radic (12)

)e adsorption energy (E) value gives information aboutadsorption mechanism and more specifically its physical orchemical nature When E is lower than 8 kJmol the type ofadsorption can be explained by physisorption and it can becontrolled by ion-exchange or chemical adsorption when Eis higher than 8 kJmol [48]

Figure 8 shows the fitting curve of DubininndashRadushkevichisotherm and the obtained parameters are listed in Table 4)ecalculated adsorption energy (E 057 kJmol) reveals that thetype of adsorption of methyl orange onto activated carbon canbe explained by physisorption indicating that the adsorption isillustrated by the formation of week physical attraction forcessuch as hydrogen-bonding and van der Waals forces betweenadsorbate molecules and solid surface and thus adsorption isreversible )is result indicates that the adsorption of methylorange onto the surface of the prepared activated carbon is amultilayer adsorption which confirms that this process followsthe Freundlich isotherm

)e results of the previous [33] and present studyshowed that the activated carbon prepared from prickly pearseed cake by phosphoric acid activation is effective for re-moving cationic and anionic dyes such as methylene blueand methyl orange from aqueous solution )is can beexplained by the presence of a variety of functional groupson the adsorbent surface which have enhanced the ad-sorption capacity [33] )e activated carbon simultaneously

presents acidic and basic sites able to fix cationic and anionicdyes by electrostatic interactions )e adsorption mecha-nism can also be explained by the interactions betweendelocalized π-electrons of the activated carbon surface andthe free electrons of the dye molecules present in the aro-matic rings and multiple bonds [49 50] )e adsorptioncapacities of MO onto various materials are given in Table 5

Table 4 Temkin and DubininndashRadushkevich isotherm parameters(tcontact 2 h adsorbent dose 1 gL pH sim 7 T 20degC)

Temkin DubininndashRadushkevichb KT R2 qm KDR E R2(Jmol) (Lmg) mgg mol2kJ kJmol5966 609 095 19380 153 057 084

0

100

200

300

q e (m

gg)

150 2502000 50 100Ce (mgL)

Experimental data

Figure 7 Nonlinear fit of the Temkin isotherm for MO adsorptiononto activated carbon (tcontact 2 h adsorbent dose 1 gL pH sim 7T 20degC)

600 20 40Ce (mgL)

Experimental data

q e (m

gg)

0

100

200

300

Figure 8 Nonlinear fit of the DubininndashRadushkevich isotherm forMO adsorption onto activated carbon (tcontact 2 h adsorbentdose 1 gL pH sim 7 T 20degC)

6 Journal of Chemistry

in order to evaluate the performance of the activated carbonprepared from prickly pear seed cake

4 Conclusion

In this study the use of the activated carbon preparedfrom prickly pear seed cake by thermo chemical processusing phosphoric acid for the removal of methyl orangefrom aqueous solution has been studied )e kineticof adsorbate-adsorbent interactions can be represented bythe pseudo-second-order model )e equilibriumadsorption data are best fitted by the Freundlich model ascompared to Langmuir and Temkin models )e ad-sorption capacity for methyl orange was found to be33612mgg at temperature 20degC and pH sim 7 indicatingthat the activated carbon may be an efficient adsorbentwith great adsorptive capacity DubininndashRadushkevichisotherm reveals that the adsorption of methyl orangeonto the activated carbon was a physisorption process innature )e results demonstrated that the prickly pear seedcake is a suitable precursor for the preparation of anadequate activated carbon for dyes removal from indus-trial effluents

Data Availability

All the data used to support the findings of this study areincluded within the article

Conflicts of Interest

)e authors declare that they have no conflicts of interest

Acknowledgments

)e authors are grateful to the Center of Analyses andCharacterization (CAC) of University Caddy Ayyad Mo-rocco Also the authors also extend their appreciation toprofessors of REMATOP LCOA and REMINEX ManagemLaboratories in Marrakech Morocco

References

[1] S Kumar C Patra S Narayanasamy and P V RajaramanldquoPerformance of acid-activated water caltrop (Trapa natans)

shell in fixed bed column for hexavalent chromium removalfrom simulated wastewaterrdquo Environmental Science andPollution Research vol 27 no 22 pp 28042ndash28052 2020

[2] T Shahnaz V Sharma S Subbiah and S NarayanasamyldquoMultivariate optimisation of Cr (VI) Co (III) and Cu (II)adsorption onto nanobentonite incorporated nanocellulosechitosan aerogel using response surface methodologyrdquoJournal of Water Process Engineering vol 36 p 101283 2020

[3] Y El maguana N Elhadiri M Bouchdoug M Benchanaaand A Boussetta ldquoOptimization of preparation conditions ofnovel adsorbent from sugar scum using response surfacemethodology for removal of methylene bluerdquo Journal ofChemistry vol 2018 Article ID 2093654 10 pages 2018

[4] A M Elgarahy K Z Elwakeel G A Elshoubaky andS H Mohammad ldquoUntapped sepia shellndashbased composite forthe sorption of cationic and anionic dyesrdquo Water Air amp SoilPollution vol 230 p 217 2019

[5] R Kant ldquoAdsorption of dye eosin from an aqueous solutionon two different samples of activated carbon by static batchmethodrdquo Journal of Water Resource and Protection vol 4no 2 pp 93ndash98 2012

[6] K Z Elwakeel G O El-Sayed and S M Abo El-NassrldquoRemoval of ferrous and manganous from water by activatedcarbon obtained from sugarcane bagasserdquo Desalination andWater Treatment vol 55 no 2 pp 471ndash483 2015

[7] K Ennaciri A Baccedilaoui M Sergent and A YaacoubildquoApplication of fractional factorial and Doehlert designs foroptimizing the preparation of activated carbons from Arganshellsrdquo Chemometrics and Intelligent Laboratory Systemsvol 139 pp 48ndash57 2014

[8] K Y Foo and B H Hameed ldquoMesoporous activated carbonfrom wood sawdust by K2CO3 activation using microwaveheatingrdquo Bioresource Technology vol 111 pp 425ndash432 2012

[9] A Kausar M Iqbal A Javed et al ldquoDyes adsorption usingclay and modified clay a reviewrdquo Journal of Molecular Liq-uids vol 256 pp 395ndash407 2018

[10] S Babel ldquoLow-cost adsorbents for heavy metals uptake fromcontaminated water a reviewrdquo Journal of Hazardous Mate-rials vol 97 no 1-3 pp 219ndash243 2003

[11] M Besbes N Fakhfakh andM Benzina ldquoCharacterization ofsilica gel prepared by using sol-gel processrdquo Physics Procediavol 2 no 3 pp 1087ndash1095 2009

[12] B Sun and A Chakraborty ldquo)ermodynamic frameworks ofadsorption kinetics modeling dynamic water uptakes on silicagel for adsorption cooling applicationsrdquo Energy vol 84pp 296ndash302 2015

[13] S K Alpat O patref S Alpat and H Akccedilay ldquo)e adsorptionkinetics and removal of cationic dye Toluidine Blue O from

Table 5 Adsorption capacities of MO onto various materials

Adsorbents qMO (mgg) ReferencesActivated carbon nanotubes 149 [51]Mesoporous carbon 2941 [52]Surfactants modified montmorillonite 14925 [53]Ammonium-functionalized silica nanoparticle 1054 [54]Lead oxide nanoparticles loaded activated carbon 33333 [55]Gold nanoparticles loaded on activated carbon 161 [56]Activated carbon 797 [57]Chitosan modified magnetic kaolin 3497 [58]Polyanilineactivated carbon composite 285 [59]Chitosan microspheres 207 [60]Activated carbon 33612 )is work

Journal of Chemistry 7

aqueous solution with Turkish zeoliterdquo Journal of HazardousMaterials vol 151 no 1 pp 213ndash220 2008

[14] D Caputo and F Pepe ldquoExperiments and data processing ofion exchange equilibria involving Italian natural zeolites areviewrdquo Microporous and Mesoporous Materials vol 105no 3 pp 222ndash231 2007

[15] A Wasti and M Ali Awan ldquoAdsorption of textile dye ontomodified immobilized activated aluminardquo Journal of theAssociation of Arab Universities for Basic and Applied Sciencesvol 20 no 1 pp 26ndash31 2016

[16] K Z Elwakeel ldquoRemoval of Reactive Black 5 from aqueoussolutions using magnetic chitosan resinsrdquo Journal of Haz-ardous Materials vol 167 no 1-3 pp 383ndash392 2009

[17] K Z Elwakeel A A El-Bindary A Ismail andA M Morshidy ldquoSorptive removal of Remazol Brilliant BlueR from aqueous solution by diethylenetriamine functionalizedmagnetic macro-reticular hybrid materialrdquo RSC Advancesvol 6 no 27 pp 22395ndash22410 2016

[18] T Shahnaz C Patra V Sharma andN Selvaraju ldquoA comparativestudy of raw acid-modified and EDTA-complexed Acaciaauriculiformis biomass for the removal of hexavalent chromiumrdquoChemistry and Ecology vol 36 no 4 pp 360ndash381 2020

[19] C Patra R M N Medisetti K Pakshirajan andS Narayanasamy ldquoAssessment of raw acid-modified andchelated biomass for sequestration of hexavalent chromiumfrom aqueous solution using Sterculia villosa Roxb shellsrdquoEnvironmental Science and Pollution Research vol 26 no 23pp 23625ndash23637 2019

[20] C Patra T Shahnaz S Subbiah and S NarayanasamyldquoComparative assessment of raw and acid-activated prepa-rations of novel Pongamia pinnata shells for adsorption ofhexavalent chromium from simulated wastewaterrdquo Envi-ronmental Science and Pollution Research vol 27 no 13pp 14836ndash14851 2020

[21] Y El Maguana N Elhadiri M Bouchdoug andM Benchanaa ldquoStudy of the influence of some factors on thepreparation of activated carbon from walnut cake using thefractional factorial designrdquo Journal of EnvironmentalChemical Engineering vol 6 no 1 pp 1093ndash1099 2018

[22] P Ammendola F Raganati and R Chirone ldquoCO2 adsorptionon a fine activated carbon in a sound assisted fluidized bedthermodynamics and kineticsrdquo Chemical Engineering Journalvol 322 pp 302ndash313 2017

[23] F Raganati P Ammendola and R Chirone ldquoOn improvingthe CO2 recovery efficiency of a conventional TSA process in asound assisted fluidized bed by separating heating andpurgingrdquo Separation and Purification Technology vol 167pp 24ndash31 2016

[24] F Raganati P Ammendola and R Chirone ldquoRole of acousticfields in promoting the gas-solid contact in a fluidized bed offine particlesrdquo KONA Powder and Particle Journal vol 32pp 23ndash40 2015

[25] K Z Elwakeel M A Abd El-Ghaffar S M El-kousy andH G El-Shorbagy ldquoSynthesis of new ammonium chitosanderivatives and their application for dye removal fromaqueous mediardquo Chemical Engineering Journal vol 203pp 458ndash468 2012

[26] A A Yakout M A Shaker K Z Elwakeel and W AlshitarildquoLauryl sulfatemagnetic graphene oxide nanosorbent forfast methylene blue recovery from aqueous solutionsrdquo Journalof Dispersion Science and Technology vol 40 no 5pp 707ndash715 2019

[27] I A W Tan A L Ahmad and B H Hameed ldquoPreparationof activated carbon from coconut husk optimization study

on removal of 246-trichlorophenol using response surfacemethodologyrdquo Journal of Hazardous Materials vol 153no 1-2 pp 709ndash717 2008

[28] J Yang and K Qiu ldquoPreparation of activated carbons fromwalnut shells via vacuum chemical activation and their ap-plication for methylene blue removalrdquo Chemical EngineeringJournal vol 165 no 1 pp 209ndash217 2010

[29] M L Martınez M M Torres C A Guzman andD M Maestri ldquoPreparation and characteristics of activatedcarbon from olive stones and walnut shellsrdquo Industrial Cropsand Products vol 23 no 1 pp 23ndash28 2006

[30] P Nowicki R Pietrzak and H Wachowska ldquoSorptionproperties of active carbons obtained from walnut shells bychemical and physical activationrdquo Catalysis Today vol 150no 1-2 pp 107ndash114 2010

[31] T-H Liou ldquoDevelopment of mesoporous structure and highadsorption capacity of biomass-based activated carbon byphosphoric acid and zinc chloride activationrdquo ChemicalEngineering Journal vol 158 no 2 pp 129ndash142 2010

[32] B S Girgis and M F Ishak ldquoActivated carbon from cottonstalks by impregnation with phosphoric acidrdquo MaterialsLetters vol 39 no 2 pp 107ndash114 1999

[33] Y El Maguana N Elhadiri M Bouchdoug M Benchanaaand A Jaouad ldquoActivated carbon from prickly pear seed cakeoptimization of preparation conditions using experimentaldesign and its application in dye removalrdquo InternationalJournal of Chemical Engineering vol 2019 Article ID8621951 12 pages 2019

[34] Y El maguana N Elhadiri M Benchanaa and R ChikrildquoAdsorption thermodynamic and kinetic studies of methylorange onto sugar scum powder as a low-cost inorganicadsorbentrdquo Journal of Chemistry vol 2020 Article ID9165874 10 pages 2020

[35] K V Kumar ldquoLinear and non-linear regression analysis forthe sorption kinetics of methylene blue onto activated car-bonrdquo Journal of Hazardous Materials vol 137 no 3pp 1538ndash1544 2006

[36] S Lagergren ldquoZur theorie der sogenannten adsorptiongeloster stoffe Kungliga Svenska VetenskapsakademiensrdquoHandlingar vol 24 pp 1ndash39 1898

[37] Y S Ho and G McKay ldquoPseudo-second order model forsorption processesrdquo Process Biochemistry vol 34 no 5pp 451ndash465 1999

[38] A G Ritchie ldquoAlternative to the Elovich equation for thekinetics of adsorption of gases on solidsrdquo Journal of theChemical Society Faraday Transactions 1 Physical Chemistryin Condensed Phases vol 73 pp 1650ndash1653 1977

[39] J W Weber and J C Morris ldquoKinetics of adsorption oncarbon from solutionrdquo Journal of the Sanitary EngineeringDivision vol 89 pp 31ndash60 1963

[40] A Gurses C Dogar M Yalcin M Acikyildiz R Bayrak andS Karaca ldquo)e adsorption kinetics of the cationic dyemethylene blue onto clayrdquo Journal of Hazardous Materialsvol 131 no 1-3 pp 217ndash228 2006

[41] G B Oguntimein ldquoBiosorption of dye from textile wastewatereffluent onto alkali treated dried sunflower seed hull anddesign of a batch adsorberrdquo Journal of EnvironmentalChemical Engineering vol 3 no 4 pp 2647ndash2661 2015

[42] G-B Hong and Y-KWang ldquoSynthesis of low-cost adsorbentfrom rice bran for the removal of reactive dye based on theresponse surface methodologyrdquo Applied Surface Sciencevol 423 pp 800ndash809 2017

[43] C H Giles T HMacewan S N Nakhwa and D Smith ldquo786Studies in adsorption Part XI A system of classification of

8 Journal of Chemistry

solution adsorption isotherms and its use in diagnosis ofadsorption mechanisms and in measurement of specificsurface areas of solidsrdquo Journal of the Chemical Society(Resumed) vol 10 pp 3973ndash3993 1960

[44] I Langmuir ldquo)e constitution and fundamental properties ofsolids and liquids Part I Solidsrdquo Journal of the AmericanChemical Society vol 38 no 11 pp 2221ndash2295 1916

[45] H Freundlish ldquoOver the adsorption in solutionrdquo Journal ofPhysical Chemistry vol 57 pp 385ndash470 1906

[46] D Kavitha and C Namasivayam ldquoExperimental and kineticstudies on methylene blue adsorption by coir pith carbonrdquoBioresource Technology vol 98 no 1 pp 14ndash21 2007

[47] H N Tran S-J You and H-P Chao ldquo)ermodynamicparameters of cadmium adsorption onto orange peel calcu-lated from various methods a comparison studyrdquo Journal ofEnvironmental Chemical Engineering vol 4 no 3 pp 2671ndash2682 2016

[48] T A Khan E A Khan and Shahjahan ldquoRemoval of basicdyes from aqueous solution by adsorption onto binary iron-manganese oxide coated kaolinite non-linear isotherm andkinetics modelingrdquo Applied Clay Science vol 107 pp 70ndash772015

[49] T N V de Souza S M L de Carvalho M G A VieiraM G C da Silva and D d S B Brasil ldquoAdsorption of basicdyes onto activated carbon experimental and theoreticalinvestigation of chemical reactivity of basic dyes using DFT-based descriptorsrdquo Applied Surface Science vol 448pp 662ndash670 2018

[50] S Wang and Z Zhu ldquoEffects of acidic treatment of activatedcarbons on dye adsorptionrdquoDyes and Pigments vol 75 no 2pp 306ndash314 2007

[51] J Ma F Yu L Zhou et al ldquoEnhanced adsorptive removal ofmethyl orange and methylene blue from aqueous solution byalkali-activated multiwalled carbon nanotubesrdquo ACS AppliedMaterials amp Interfaces vol 4 no 11 pp 5749ndash5760 2012

[52] N Mohammadi H Khani V K Gupta E Amereh andS Agarwal ldquoAdsorption process of methyl orange dye ontomesoporous carbon material-kinetic and thermodynamicstudiesrdquo Journal of Colloid and Interface Science vol 362no 2 pp 457ndash462 2011

[53] D Chen J Chen X Luan H Ji and Z Xia ldquoCharacterizationof anion-cationic surfactants modified montmorillonite andits application for the removal of methyl orangerdquo ChemicalEngineering Journal vol 171 no 3 pp 1150ndash1158 2011

[54] J Liu S Ma and L Zang ldquoPreparation and characterizationof ammonium-functionalized silica nanoparticle as a newadsorbent to remove methyl orange from aqueous solutionrdquoApplied Surface Science vol 265 pp 393ndash398 2013

[55] S Agarwal I Tyagi V K Gupta et al ldquoRETRACTED ki-netics and thermodynamics of methyl orange adsorption fromaqueous solutions-artificial neural network-particle swarmoptimization modelingrdquo Journal of Molecular Liquidsvol 218 pp 354ndash362 2016

[56] M Ghaedi A M Ghaedi A Ansari F Mohammadi andA Vafaei ldquoArtificial neural network and particle swarmoptimization for removal of methyl orange by gold nano-particles loaded on activated carbon and Tamariskrdquo Spec-trochimica Acta Part A Molecular and BiomolecularSpectroscopy vol 132 pp 639ndash654 2014

[57] V Yonten N K Sanyurek and M R Kivanccedil ldquoA thermo-dynamic and kinetic approach to adsorption of methyl orangefrom aqueous solution using a low cost activated carbonprepared from Vitis vinifera Lrdquo Surfaces and Interfacesvol 20 Article ID 100529 2020

[58] D-M Liu C Dong J Zhong S Ren Y Chen and T QiuldquoFacile preparation of chitosan modified magnetic kaolin byone-pot coprecipitation method for efficient removal ofmethyl orangerdquo Carbohydrate Polymers vol 245 Article ID116572 2020

[59] M Hasan M M Rashid M M Hossain et al ldquoFabrication ofpolyanilineactivated carbon composite and its testing formethyl orange removal optimization equilibrium isothermand kinetic studyrdquo Polymer Testing vol 77 Article ID 1059092019

[60] L Zhai Z Bai Y Zhu B Wang and W Luo ldquoFabrication ofchitosan microspheres for efficient adsorption of methylorangerdquo Chinese Journal of Chemical Engineering vol 26no 3 pp 657ndash666 2018

Journal of Chemistry 9

where qe (mgg) is the amount of adsorption at the equi-librium Ce (mgL) is the equilibrium concentration ofadsorbate T (K) is the temperature R is the universal gasconstant and KT is the equilibrium binding constant cor-responding to the maximum binding energy )e constant b(Jmol) is related to the heat of adsorption )e Temkinisotherm parameters were obtained by plotting qe versus Ceshown in Figure 7 and summarized in Table 4 According tothe R2 value the Temkin isothermmodel did not fit well withthe experimental data indicating the energetic heterogeneityof the adsorption sites

Besides the Langmuir Freundlich and Temkin modelsthe DubininndashRadushkevich isotherm model was alsoemployed for the estimation of the adsorption energy (E)and further finding the nature of the adsorption [41 47] Itsequation is given as follows

qe qm exp minusKDR RT ln 1 +1

Ce1113888 11138891113890 1113891

2⎡⎣ ⎤⎦ (11)

where qe (mgg) is the amount of adsorption at the equi-librium Ce (mgL) is the equilibrium concentration ofadsorbate qm is the monolayer adsorption capacity KDR isthe D-R constant which gives the adsorption energy (E)T (K) is the temperature and R is the universal gas constant)e adsorption energy can be computed using the followingrelationship

E 12B

radic (12)

)e adsorption energy (E) value gives information aboutadsorption mechanism and more specifically its physical orchemical nature When E is lower than 8 kJmol the type ofadsorption can be explained by physisorption and it can becontrolled by ion-exchange or chemical adsorption when Eis higher than 8 kJmol [48]

Figure 8 shows the fitting curve of DubininndashRadushkevichisotherm and the obtained parameters are listed in Table 4)ecalculated adsorption energy (E 057 kJmol) reveals that thetype of adsorption of methyl orange onto activated carbon canbe explained by physisorption indicating that the adsorption isillustrated by the formation of week physical attraction forcessuch as hydrogen-bonding and van der Waals forces betweenadsorbate molecules and solid surface and thus adsorption isreversible )is result indicates that the adsorption of methylorange onto the surface of the prepared activated carbon is amultilayer adsorption which confirms that this process followsthe Freundlich isotherm

)e results of the previous [33] and present studyshowed that the activated carbon prepared from prickly pearseed cake by phosphoric acid activation is effective for re-moving cationic and anionic dyes such as methylene blueand methyl orange from aqueous solution )is can beexplained by the presence of a variety of functional groupson the adsorbent surface which have enhanced the ad-sorption capacity [33] )e activated carbon simultaneously

presents acidic and basic sites able to fix cationic and anionicdyes by electrostatic interactions )e adsorption mecha-nism can also be explained by the interactions betweendelocalized π-electrons of the activated carbon surface andthe free electrons of the dye molecules present in the aro-matic rings and multiple bonds [49 50] )e adsorptioncapacities of MO onto various materials are given in Table 5

Table 4 Temkin and DubininndashRadushkevich isotherm parameters(tcontact 2 h adsorbent dose 1 gL pH sim 7 T 20degC)

Temkin DubininndashRadushkevichb KT R2 qm KDR E R2(Jmol) (Lmg) mgg mol2kJ kJmol5966 609 095 19380 153 057 084

0

100

200

300

q e (m

gg)

150 2502000 50 100Ce (mgL)

Experimental data

Figure 7 Nonlinear fit of the Temkin isotherm for MO adsorptiononto activated carbon (tcontact 2 h adsorbent dose 1 gL pH sim 7T 20degC)

600 20 40Ce (mgL)

Experimental data

q e (m

gg)

0

100

200

300

Figure 8 Nonlinear fit of the DubininndashRadushkevich isotherm forMO adsorption onto activated carbon (tcontact 2 h adsorbentdose 1 gL pH sim 7 T 20degC)

6 Journal of Chemistry

in order to evaluate the performance of the activated carbonprepared from prickly pear seed cake

4 Conclusion

In this study the use of the activated carbon preparedfrom prickly pear seed cake by thermo chemical processusing phosphoric acid for the removal of methyl orangefrom aqueous solution has been studied )e kineticof adsorbate-adsorbent interactions can be represented bythe pseudo-second-order model )e equilibriumadsorption data are best fitted by the Freundlich model ascompared to Langmuir and Temkin models )e ad-sorption capacity for methyl orange was found to be33612mgg at temperature 20degC and pH sim 7 indicatingthat the activated carbon may be an efficient adsorbentwith great adsorptive capacity DubininndashRadushkevichisotherm reveals that the adsorption of methyl orangeonto the activated carbon was a physisorption process innature )e results demonstrated that the prickly pear seedcake is a suitable precursor for the preparation of anadequate activated carbon for dyes removal from indus-trial effluents

Data Availability

All the data used to support the findings of this study areincluded within the article

Conflicts of Interest

)e authors declare that they have no conflicts of interest

Acknowledgments

)e authors are grateful to the Center of Analyses andCharacterization (CAC) of University Caddy Ayyad Mo-rocco Also the authors also extend their appreciation toprofessors of REMATOP LCOA and REMINEX ManagemLaboratories in Marrakech Morocco

References

[1] S Kumar C Patra S Narayanasamy and P V RajaramanldquoPerformance of acid-activated water caltrop (Trapa natans)

shell in fixed bed column for hexavalent chromium removalfrom simulated wastewaterrdquo Environmental Science andPollution Research vol 27 no 22 pp 28042ndash28052 2020

[2] T Shahnaz V Sharma S Subbiah and S NarayanasamyldquoMultivariate optimisation of Cr (VI) Co (III) and Cu (II)adsorption onto nanobentonite incorporated nanocellulosechitosan aerogel using response surface methodologyrdquoJournal of Water Process Engineering vol 36 p 101283 2020

[3] Y El maguana N Elhadiri M Bouchdoug M Benchanaaand A Boussetta ldquoOptimization of preparation conditions ofnovel adsorbent from sugar scum using response surfacemethodology for removal of methylene bluerdquo Journal ofChemistry vol 2018 Article ID 2093654 10 pages 2018

[4] A M Elgarahy K Z Elwakeel G A Elshoubaky andS H Mohammad ldquoUntapped sepia shellndashbased composite forthe sorption of cationic and anionic dyesrdquo Water Air amp SoilPollution vol 230 p 217 2019

[5] R Kant ldquoAdsorption of dye eosin from an aqueous solutionon two different samples of activated carbon by static batchmethodrdquo Journal of Water Resource and Protection vol 4no 2 pp 93ndash98 2012

[6] K Z Elwakeel G O El-Sayed and S M Abo El-NassrldquoRemoval of ferrous and manganous from water by activatedcarbon obtained from sugarcane bagasserdquo Desalination andWater Treatment vol 55 no 2 pp 471ndash483 2015

[7] K Ennaciri A Baccedilaoui M Sergent and A YaacoubildquoApplication of fractional factorial and Doehlert designs foroptimizing the preparation of activated carbons from Arganshellsrdquo Chemometrics and Intelligent Laboratory Systemsvol 139 pp 48ndash57 2014

[8] K Y Foo and B H Hameed ldquoMesoporous activated carbonfrom wood sawdust by K2CO3 activation using microwaveheatingrdquo Bioresource Technology vol 111 pp 425ndash432 2012

[9] A Kausar M Iqbal A Javed et al ldquoDyes adsorption usingclay and modified clay a reviewrdquo Journal of Molecular Liq-uids vol 256 pp 395ndash407 2018

[10] S Babel ldquoLow-cost adsorbents for heavy metals uptake fromcontaminated water a reviewrdquo Journal of Hazardous Mate-rials vol 97 no 1-3 pp 219ndash243 2003

[11] M Besbes N Fakhfakh andM Benzina ldquoCharacterization ofsilica gel prepared by using sol-gel processrdquo Physics Procediavol 2 no 3 pp 1087ndash1095 2009

[12] B Sun and A Chakraborty ldquo)ermodynamic frameworks ofadsorption kinetics modeling dynamic water uptakes on silicagel for adsorption cooling applicationsrdquo Energy vol 84pp 296ndash302 2015

[13] S K Alpat O patref S Alpat and H Akccedilay ldquo)e adsorptionkinetics and removal of cationic dye Toluidine Blue O from

Table 5 Adsorption capacities of MO onto various materials

Adsorbents qMO (mgg) ReferencesActivated carbon nanotubes 149 [51]Mesoporous carbon 2941 [52]Surfactants modified montmorillonite 14925 [53]Ammonium-functionalized silica nanoparticle 1054 [54]Lead oxide nanoparticles loaded activated carbon 33333 [55]Gold nanoparticles loaded on activated carbon 161 [56]Activated carbon 797 [57]Chitosan modified magnetic kaolin 3497 [58]Polyanilineactivated carbon composite 285 [59]Chitosan microspheres 207 [60]Activated carbon 33612 )is work

Journal of Chemistry 7

aqueous solution with Turkish zeoliterdquo Journal of HazardousMaterials vol 151 no 1 pp 213ndash220 2008

[14] D Caputo and F Pepe ldquoExperiments and data processing ofion exchange equilibria involving Italian natural zeolites areviewrdquo Microporous and Mesoporous Materials vol 105no 3 pp 222ndash231 2007

[15] A Wasti and M Ali Awan ldquoAdsorption of textile dye ontomodified immobilized activated aluminardquo Journal of theAssociation of Arab Universities for Basic and Applied Sciencesvol 20 no 1 pp 26ndash31 2016

[16] K Z Elwakeel ldquoRemoval of Reactive Black 5 from aqueoussolutions using magnetic chitosan resinsrdquo Journal of Haz-ardous Materials vol 167 no 1-3 pp 383ndash392 2009

[17] K Z Elwakeel A A El-Bindary A Ismail andA M Morshidy ldquoSorptive removal of Remazol Brilliant BlueR from aqueous solution by diethylenetriamine functionalizedmagnetic macro-reticular hybrid materialrdquo RSC Advancesvol 6 no 27 pp 22395ndash22410 2016

[18] T Shahnaz C Patra V Sharma andN Selvaraju ldquoA comparativestudy of raw acid-modified and EDTA-complexed Acaciaauriculiformis biomass for the removal of hexavalent chromiumrdquoChemistry and Ecology vol 36 no 4 pp 360ndash381 2020

[19] C Patra R M N Medisetti K Pakshirajan andS Narayanasamy ldquoAssessment of raw acid-modified andchelated biomass for sequestration of hexavalent chromiumfrom aqueous solution using Sterculia villosa Roxb shellsrdquoEnvironmental Science and Pollution Research vol 26 no 23pp 23625ndash23637 2019

[20] C Patra T Shahnaz S Subbiah and S NarayanasamyldquoComparative assessment of raw and acid-activated prepa-rations of novel Pongamia pinnata shells for adsorption ofhexavalent chromium from simulated wastewaterrdquo Envi-ronmental Science and Pollution Research vol 27 no 13pp 14836ndash14851 2020

[21] Y El Maguana N Elhadiri M Bouchdoug andM Benchanaa ldquoStudy of the influence of some factors on thepreparation of activated carbon from walnut cake using thefractional factorial designrdquo Journal of EnvironmentalChemical Engineering vol 6 no 1 pp 1093ndash1099 2018

[22] P Ammendola F Raganati and R Chirone ldquoCO2 adsorptionon a fine activated carbon in a sound assisted fluidized bedthermodynamics and kineticsrdquo Chemical Engineering Journalvol 322 pp 302ndash313 2017

[23] F Raganati P Ammendola and R Chirone ldquoOn improvingthe CO2 recovery efficiency of a conventional TSA process in asound assisted fluidized bed by separating heating andpurgingrdquo Separation and Purification Technology vol 167pp 24ndash31 2016

[24] F Raganati P Ammendola and R Chirone ldquoRole of acousticfields in promoting the gas-solid contact in a fluidized bed offine particlesrdquo KONA Powder and Particle Journal vol 32pp 23ndash40 2015

[25] K Z Elwakeel M A Abd El-Ghaffar S M El-kousy andH G El-Shorbagy ldquoSynthesis of new ammonium chitosanderivatives and their application for dye removal fromaqueous mediardquo Chemical Engineering Journal vol 203pp 458ndash468 2012

[26] A A Yakout M A Shaker K Z Elwakeel and W AlshitarildquoLauryl sulfatemagnetic graphene oxide nanosorbent forfast methylene blue recovery from aqueous solutionsrdquo Journalof Dispersion Science and Technology vol 40 no 5pp 707ndash715 2019

[27] I A W Tan A L Ahmad and B H Hameed ldquoPreparationof activated carbon from coconut husk optimization study

on removal of 246-trichlorophenol using response surfacemethodologyrdquo Journal of Hazardous Materials vol 153no 1-2 pp 709ndash717 2008

[28] J Yang and K Qiu ldquoPreparation of activated carbons fromwalnut shells via vacuum chemical activation and their ap-plication for methylene blue removalrdquo Chemical EngineeringJournal vol 165 no 1 pp 209ndash217 2010

[29] M L Martınez M M Torres C A Guzman andD M Maestri ldquoPreparation and characteristics of activatedcarbon from olive stones and walnut shellsrdquo Industrial Cropsand Products vol 23 no 1 pp 23ndash28 2006

[30] P Nowicki R Pietrzak and H Wachowska ldquoSorptionproperties of active carbons obtained from walnut shells bychemical and physical activationrdquo Catalysis Today vol 150no 1-2 pp 107ndash114 2010

[31] T-H Liou ldquoDevelopment of mesoporous structure and highadsorption capacity of biomass-based activated carbon byphosphoric acid and zinc chloride activationrdquo ChemicalEngineering Journal vol 158 no 2 pp 129ndash142 2010

[32] B S Girgis and M F Ishak ldquoActivated carbon from cottonstalks by impregnation with phosphoric acidrdquo MaterialsLetters vol 39 no 2 pp 107ndash114 1999

[33] Y El Maguana N Elhadiri M Bouchdoug M Benchanaaand A Jaouad ldquoActivated carbon from prickly pear seed cakeoptimization of preparation conditions using experimentaldesign and its application in dye removalrdquo InternationalJournal of Chemical Engineering vol 2019 Article ID8621951 12 pages 2019

[34] Y El maguana N Elhadiri M Benchanaa and R ChikrildquoAdsorption thermodynamic and kinetic studies of methylorange onto sugar scum powder as a low-cost inorganicadsorbentrdquo Journal of Chemistry vol 2020 Article ID9165874 10 pages 2020

[35] K V Kumar ldquoLinear and non-linear regression analysis forthe sorption kinetics of methylene blue onto activated car-bonrdquo Journal of Hazardous Materials vol 137 no 3pp 1538ndash1544 2006

[36] S Lagergren ldquoZur theorie der sogenannten adsorptiongeloster stoffe Kungliga Svenska VetenskapsakademiensrdquoHandlingar vol 24 pp 1ndash39 1898

[37] Y S Ho and G McKay ldquoPseudo-second order model forsorption processesrdquo Process Biochemistry vol 34 no 5pp 451ndash465 1999

[38] A G Ritchie ldquoAlternative to the Elovich equation for thekinetics of adsorption of gases on solidsrdquo Journal of theChemical Society Faraday Transactions 1 Physical Chemistryin Condensed Phases vol 73 pp 1650ndash1653 1977

[39] J W Weber and J C Morris ldquoKinetics of adsorption oncarbon from solutionrdquo Journal of the Sanitary EngineeringDivision vol 89 pp 31ndash60 1963

[40] A Gurses C Dogar M Yalcin M Acikyildiz R Bayrak andS Karaca ldquo)e adsorption kinetics of the cationic dyemethylene blue onto clayrdquo Journal of Hazardous Materialsvol 131 no 1-3 pp 217ndash228 2006

[41] G B Oguntimein ldquoBiosorption of dye from textile wastewatereffluent onto alkali treated dried sunflower seed hull anddesign of a batch adsorberrdquo Journal of EnvironmentalChemical Engineering vol 3 no 4 pp 2647ndash2661 2015

[42] G-B Hong and Y-KWang ldquoSynthesis of low-cost adsorbentfrom rice bran for the removal of reactive dye based on theresponse surface methodologyrdquo Applied Surface Sciencevol 423 pp 800ndash809 2017

[43] C H Giles T HMacewan S N Nakhwa and D Smith ldquo786Studies in adsorption Part XI A system of classification of

8 Journal of Chemistry

solution adsorption isotherms and its use in diagnosis ofadsorption mechanisms and in measurement of specificsurface areas of solidsrdquo Journal of the Chemical Society(Resumed) vol 10 pp 3973ndash3993 1960

[44] I Langmuir ldquo)e constitution and fundamental properties ofsolids and liquids Part I Solidsrdquo Journal of the AmericanChemical Society vol 38 no 11 pp 2221ndash2295 1916

[45] H Freundlish ldquoOver the adsorption in solutionrdquo Journal ofPhysical Chemistry vol 57 pp 385ndash470 1906

[46] D Kavitha and C Namasivayam ldquoExperimental and kineticstudies on methylene blue adsorption by coir pith carbonrdquoBioresource Technology vol 98 no 1 pp 14ndash21 2007

[47] H N Tran S-J You and H-P Chao ldquo)ermodynamicparameters of cadmium adsorption onto orange peel calcu-lated from various methods a comparison studyrdquo Journal ofEnvironmental Chemical Engineering vol 4 no 3 pp 2671ndash2682 2016

[48] T A Khan E A Khan and Shahjahan ldquoRemoval of basicdyes from aqueous solution by adsorption onto binary iron-manganese oxide coated kaolinite non-linear isotherm andkinetics modelingrdquo Applied Clay Science vol 107 pp 70ndash772015

[49] T N V de Souza S M L de Carvalho M G A VieiraM G C da Silva and D d S B Brasil ldquoAdsorption of basicdyes onto activated carbon experimental and theoreticalinvestigation of chemical reactivity of basic dyes using DFT-based descriptorsrdquo Applied Surface Science vol 448pp 662ndash670 2018

[50] S Wang and Z Zhu ldquoEffects of acidic treatment of activatedcarbons on dye adsorptionrdquoDyes and Pigments vol 75 no 2pp 306ndash314 2007

[51] J Ma F Yu L Zhou et al ldquoEnhanced adsorptive removal ofmethyl orange and methylene blue from aqueous solution byalkali-activated multiwalled carbon nanotubesrdquo ACS AppliedMaterials amp Interfaces vol 4 no 11 pp 5749ndash5760 2012

[52] N Mohammadi H Khani V K Gupta E Amereh andS Agarwal ldquoAdsorption process of methyl orange dye ontomesoporous carbon material-kinetic and thermodynamicstudiesrdquo Journal of Colloid and Interface Science vol 362no 2 pp 457ndash462 2011

[53] D Chen J Chen X Luan H Ji and Z Xia ldquoCharacterizationof anion-cationic surfactants modified montmorillonite andits application for the removal of methyl orangerdquo ChemicalEngineering Journal vol 171 no 3 pp 1150ndash1158 2011

[54] J Liu S Ma and L Zang ldquoPreparation and characterizationof ammonium-functionalized silica nanoparticle as a newadsorbent to remove methyl orange from aqueous solutionrdquoApplied Surface Science vol 265 pp 393ndash398 2013

[55] S Agarwal I Tyagi V K Gupta et al ldquoRETRACTED ki-netics and thermodynamics of methyl orange adsorption fromaqueous solutions-artificial neural network-particle swarmoptimization modelingrdquo Journal of Molecular Liquidsvol 218 pp 354ndash362 2016

[56] M Ghaedi A M Ghaedi A Ansari F Mohammadi andA Vafaei ldquoArtificial neural network and particle swarmoptimization for removal of methyl orange by gold nano-particles loaded on activated carbon and Tamariskrdquo Spec-trochimica Acta Part A Molecular and BiomolecularSpectroscopy vol 132 pp 639ndash654 2014

[57] V Yonten N K Sanyurek and M R Kivanccedil ldquoA thermo-dynamic and kinetic approach to adsorption of methyl orangefrom aqueous solution using a low cost activated carbonprepared from Vitis vinifera Lrdquo Surfaces and Interfacesvol 20 Article ID 100529 2020

[58] D-M Liu C Dong J Zhong S Ren Y Chen and T QiuldquoFacile preparation of chitosan modified magnetic kaolin byone-pot coprecipitation method for efficient removal ofmethyl orangerdquo Carbohydrate Polymers vol 245 Article ID116572 2020

[59] M Hasan M M Rashid M M Hossain et al ldquoFabrication ofpolyanilineactivated carbon composite and its testing formethyl orange removal optimization equilibrium isothermand kinetic studyrdquo Polymer Testing vol 77 Article ID 1059092019

[60] L Zhai Z Bai Y Zhu B Wang and W Luo ldquoFabrication ofchitosan microspheres for efficient adsorption of methylorangerdquo Chinese Journal of Chemical Engineering vol 26no 3 pp 657ndash666 2018

Journal of Chemistry 9

in order to evaluate the performance of the activated carbonprepared from prickly pear seed cake

4 Conclusion

In this study the use of the activated carbon preparedfrom prickly pear seed cake by thermo chemical processusing phosphoric acid for the removal of methyl orangefrom aqueous solution has been studied )e kineticof adsorbate-adsorbent interactions can be represented bythe pseudo-second-order model )e equilibriumadsorption data are best fitted by the Freundlich model ascompared to Langmuir and Temkin models )e ad-sorption capacity for methyl orange was found to be33612mgg at temperature 20degC and pH sim 7 indicatingthat the activated carbon may be an efficient adsorbentwith great adsorptive capacity DubininndashRadushkevichisotherm reveals that the adsorption of methyl orangeonto the activated carbon was a physisorption process innature )e results demonstrated that the prickly pear seedcake is a suitable precursor for the preparation of anadequate activated carbon for dyes removal from indus-trial effluents

Data Availability

All the data used to support the findings of this study areincluded within the article

Conflicts of Interest

)e authors declare that they have no conflicts of interest

Acknowledgments

)e authors are grateful to the Center of Analyses andCharacterization (CAC) of University Caddy Ayyad Mo-rocco Also the authors also extend their appreciation toprofessors of REMATOP LCOA and REMINEX ManagemLaboratories in Marrakech Morocco

References

[1] S Kumar C Patra S Narayanasamy and P V RajaramanldquoPerformance of acid-activated water caltrop (Trapa natans)

shell in fixed bed column for hexavalent chromium removalfrom simulated wastewaterrdquo Environmental Science andPollution Research vol 27 no 22 pp 28042ndash28052 2020

[2] T Shahnaz V Sharma S Subbiah and S NarayanasamyldquoMultivariate optimisation of Cr (VI) Co (III) and Cu (II)adsorption onto nanobentonite incorporated nanocellulosechitosan aerogel using response surface methodologyrdquoJournal of Water Process Engineering vol 36 p 101283 2020

[3] Y El maguana N Elhadiri M Bouchdoug M Benchanaaand A Boussetta ldquoOptimization of preparation conditions ofnovel adsorbent from sugar scum using response surfacemethodology for removal of methylene bluerdquo Journal ofChemistry vol 2018 Article ID 2093654 10 pages 2018

[4] A M Elgarahy K Z Elwakeel G A Elshoubaky andS H Mohammad ldquoUntapped sepia shellndashbased composite forthe sorption of cationic and anionic dyesrdquo Water Air amp SoilPollution vol 230 p 217 2019

[5] R Kant ldquoAdsorption of dye eosin from an aqueous solutionon two different samples of activated carbon by static batchmethodrdquo Journal of Water Resource and Protection vol 4no 2 pp 93ndash98 2012

[6] K Z Elwakeel G O El-Sayed and S M Abo El-NassrldquoRemoval of ferrous and manganous from water by activatedcarbon obtained from sugarcane bagasserdquo Desalination andWater Treatment vol 55 no 2 pp 471ndash483 2015

[7] K Ennaciri A Baccedilaoui M Sergent and A YaacoubildquoApplication of fractional factorial and Doehlert designs foroptimizing the preparation of activated carbons from Arganshellsrdquo Chemometrics and Intelligent Laboratory Systemsvol 139 pp 48ndash57 2014

[8] K Y Foo and B H Hameed ldquoMesoporous activated carbonfrom wood sawdust by K2CO3 activation using microwaveheatingrdquo Bioresource Technology vol 111 pp 425ndash432 2012

[9] A Kausar M Iqbal A Javed et al ldquoDyes adsorption usingclay and modified clay a reviewrdquo Journal of Molecular Liq-uids vol 256 pp 395ndash407 2018

[10] S Babel ldquoLow-cost adsorbents for heavy metals uptake fromcontaminated water a reviewrdquo Journal of Hazardous Mate-rials vol 97 no 1-3 pp 219ndash243 2003

[11] M Besbes N Fakhfakh andM Benzina ldquoCharacterization ofsilica gel prepared by using sol-gel processrdquo Physics Procediavol 2 no 3 pp 1087ndash1095 2009

[12] B Sun and A Chakraborty ldquo)ermodynamic frameworks ofadsorption kinetics modeling dynamic water uptakes on silicagel for adsorption cooling applicationsrdquo Energy vol 84pp 296ndash302 2015

[13] S K Alpat O patref S Alpat and H Akccedilay ldquo)e adsorptionkinetics and removal of cationic dye Toluidine Blue O from

Table 5 Adsorption capacities of MO onto various materials

Adsorbents qMO (mgg) ReferencesActivated carbon nanotubes 149 [51]Mesoporous carbon 2941 [52]Surfactants modified montmorillonite 14925 [53]Ammonium-functionalized silica nanoparticle 1054 [54]Lead oxide nanoparticles loaded activated carbon 33333 [55]Gold nanoparticles loaded on activated carbon 161 [56]Activated carbon 797 [57]Chitosan modified magnetic kaolin 3497 [58]Polyanilineactivated carbon composite 285 [59]Chitosan microspheres 207 [60]Activated carbon 33612 )is work

Journal of Chemistry 7

aqueous solution with Turkish zeoliterdquo Journal of HazardousMaterials vol 151 no 1 pp 213ndash220 2008

[14] D Caputo and F Pepe ldquoExperiments and data processing ofion exchange equilibria involving Italian natural zeolites areviewrdquo Microporous and Mesoporous Materials vol 105no 3 pp 222ndash231 2007

[15] A Wasti and M Ali Awan ldquoAdsorption of textile dye ontomodified immobilized activated aluminardquo Journal of theAssociation of Arab Universities for Basic and Applied Sciencesvol 20 no 1 pp 26ndash31 2016

[16] K Z Elwakeel ldquoRemoval of Reactive Black 5 from aqueoussolutions using magnetic chitosan resinsrdquo Journal of Haz-ardous Materials vol 167 no 1-3 pp 383ndash392 2009

[17] K Z Elwakeel A A El-Bindary A Ismail andA M Morshidy ldquoSorptive removal of Remazol Brilliant BlueR from aqueous solution by diethylenetriamine functionalizedmagnetic macro-reticular hybrid materialrdquo RSC Advancesvol 6 no 27 pp 22395ndash22410 2016

[18] T Shahnaz C Patra V Sharma andN Selvaraju ldquoA comparativestudy of raw acid-modified and EDTA-complexed Acaciaauriculiformis biomass for the removal of hexavalent chromiumrdquoChemistry and Ecology vol 36 no 4 pp 360ndash381 2020

[19] C Patra R M N Medisetti K Pakshirajan andS Narayanasamy ldquoAssessment of raw acid-modified andchelated biomass for sequestration of hexavalent chromiumfrom aqueous solution using Sterculia villosa Roxb shellsrdquoEnvironmental Science and Pollution Research vol 26 no 23pp 23625ndash23637 2019

[20] C Patra T Shahnaz S Subbiah and S NarayanasamyldquoComparative assessment of raw and acid-activated prepa-rations of novel Pongamia pinnata shells for adsorption ofhexavalent chromium from simulated wastewaterrdquo Envi-ronmental Science and Pollution Research vol 27 no 13pp 14836ndash14851 2020

[21] Y El Maguana N Elhadiri M Bouchdoug andM Benchanaa ldquoStudy of the influence of some factors on thepreparation of activated carbon from walnut cake using thefractional factorial designrdquo Journal of EnvironmentalChemical Engineering vol 6 no 1 pp 1093ndash1099 2018

[22] P Ammendola F Raganati and R Chirone ldquoCO2 adsorptionon a fine activated carbon in a sound assisted fluidized bedthermodynamics and kineticsrdquo Chemical Engineering Journalvol 322 pp 302ndash313 2017

[23] F Raganati P Ammendola and R Chirone ldquoOn improvingthe CO2 recovery efficiency of a conventional TSA process in asound assisted fluidized bed by separating heating andpurgingrdquo Separation and Purification Technology vol 167pp 24ndash31 2016

[24] F Raganati P Ammendola and R Chirone ldquoRole of acousticfields in promoting the gas-solid contact in a fluidized bed offine particlesrdquo KONA Powder and Particle Journal vol 32pp 23ndash40 2015

[25] K Z Elwakeel M A Abd El-Ghaffar S M El-kousy andH G El-Shorbagy ldquoSynthesis of new ammonium chitosanderivatives and their application for dye removal fromaqueous mediardquo Chemical Engineering Journal vol 203pp 458ndash468 2012

[26] A A Yakout M A Shaker K Z Elwakeel and W AlshitarildquoLauryl sulfatemagnetic graphene oxide nanosorbent forfast methylene blue recovery from aqueous solutionsrdquo Journalof Dispersion Science and Technology vol 40 no 5pp 707ndash715 2019

[27] I A W Tan A L Ahmad and B H Hameed ldquoPreparationof activated carbon from coconut husk optimization study

on removal of 246-trichlorophenol using response surfacemethodologyrdquo Journal of Hazardous Materials vol 153no 1-2 pp 709ndash717 2008

[28] J Yang and K Qiu ldquoPreparation of activated carbons fromwalnut shells via vacuum chemical activation and their ap-plication for methylene blue removalrdquo Chemical EngineeringJournal vol 165 no 1 pp 209ndash217 2010

[29] M L Martınez M M Torres C A Guzman andD M Maestri ldquoPreparation and characteristics of activatedcarbon from olive stones and walnut shellsrdquo Industrial Cropsand Products vol 23 no 1 pp 23ndash28 2006

[30] P Nowicki R Pietrzak and H Wachowska ldquoSorptionproperties of active carbons obtained from walnut shells bychemical and physical activationrdquo Catalysis Today vol 150no 1-2 pp 107ndash114 2010

[31] T-H Liou ldquoDevelopment of mesoporous structure and highadsorption capacity of biomass-based activated carbon byphosphoric acid and zinc chloride activationrdquo ChemicalEngineering Journal vol 158 no 2 pp 129ndash142 2010

[32] B S Girgis and M F Ishak ldquoActivated carbon from cottonstalks by impregnation with phosphoric acidrdquo MaterialsLetters vol 39 no 2 pp 107ndash114 1999

[33] Y El Maguana N Elhadiri M Bouchdoug M Benchanaaand A Jaouad ldquoActivated carbon from prickly pear seed cakeoptimization of preparation conditions using experimentaldesign and its application in dye removalrdquo InternationalJournal of Chemical Engineering vol 2019 Article ID8621951 12 pages 2019

[34] Y El maguana N Elhadiri M Benchanaa and R ChikrildquoAdsorption thermodynamic and kinetic studies of methylorange onto sugar scum powder as a low-cost inorganicadsorbentrdquo Journal of Chemistry vol 2020 Article ID9165874 10 pages 2020

[35] K V Kumar ldquoLinear and non-linear regression analysis forthe sorption kinetics of methylene blue onto activated car-bonrdquo Journal of Hazardous Materials vol 137 no 3pp 1538ndash1544 2006

[36] S Lagergren ldquoZur theorie der sogenannten adsorptiongeloster stoffe Kungliga Svenska VetenskapsakademiensrdquoHandlingar vol 24 pp 1ndash39 1898

[37] Y S Ho and G McKay ldquoPseudo-second order model forsorption processesrdquo Process Biochemistry vol 34 no 5pp 451ndash465 1999

[38] A G Ritchie ldquoAlternative to the Elovich equation for thekinetics of adsorption of gases on solidsrdquo Journal of theChemical Society Faraday Transactions 1 Physical Chemistryin Condensed Phases vol 73 pp 1650ndash1653 1977

[39] J W Weber and J C Morris ldquoKinetics of adsorption oncarbon from solutionrdquo Journal of the Sanitary EngineeringDivision vol 89 pp 31ndash60 1963

[40] A Gurses C Dogar M Yalcin M Acikyildiz R Bayrak andS Karaca ldquo)e adsorption kinetics of the cationic dyemethylene blue onto clayrdquo Journal of Hazardous Materialsvol 131 no 1-3 pp 217ndash228 2006

[41] G B Oguntimein ldquoBiosorption of dye from textile wastewatereffluent onto alkali treated dried sunflower seed hull anddesign of a batch adsorberrdquo Journal of EnvironmentalChemical Engineering vol 3 no 4 pp 2647ndash2661 2015

[42] G-B Hong and Y-KWang ldquoSynthesis of low-cost adsorbentfrom rice bran for the removal of reactive dye based on theresponse surface methodologyrdquo Applied Surface Sciencevol 423 pp 800ndash809 2017

[43] C H Giles T HMacewan S N Nakhwa and D Smith ldquo786Studies in adsorption Part XI A system of classification of

8 Journal of Chemistry

solution adsorption isotherms and its use in diagnosis ofadsorption mechanisms and in measurement of specificsurface areas of solidsrdquo Journal of the Chemical Society(Resumed) vol 10 pp 3973ndash3993 1960

[44] I Langmuir ldquo)e constitution and fundamental properties ofsolids and liquids Part I Solidsrdquo Journal of the AmericanChemical Society vol 38 no 11 pp 2221ndash2295 1916

[45] H Freundlish ldquoOver the adsorption in solutionrdquo Journal ofPhysical Chemistry vol 57 pp 385ndash470 1906

[46] D Kavitha and C Namasivayam ldquoExperimental and kineticstudies on methylene blue adsorption by coir pith carbonrdquoBioresource Technology vol 98 no 1 pp 14ndash21 2007

[47] H N Tran S-J You and H-P Chao ldquo)ermodynamicparameters of cadmium adsorption onto orange peel calcu-lated from various methods a comparison studyrdquo Journal ofEnvironmental Chemical Engineering vol 4 no 3 pp 2671ndash2682 2016

[48] T A Khan E A Khan and Shahjahan ldquoRemoval of basicdyes from aqueous solution by adsorption onto binary iron-manganese oxide coated kaolinite non-linear isotherm andkinetics modelingrdquo Applied Clay Science vol 107 pp 70ndash772015

[49] T N V de Souza S M L de Carvalho M G A VieiraM G C da Silva and D d S B Brasil ldquoAdsorption of basicdyes onto activated carbon experimental and theoreticalinvestigation of chemical reactivity of basic dyes using DFT-based descriptorsrdquo Applied Surface Science vol 448pp 662ndash670 2018

[50] S Wang and Z Zhu ldquoEffects of acidic treatment of activatedcarbons on dye adsorptionrdquoDyes and Pigments vol 75 no 2pp 306ndash314 2007

[51] J Ma F Yu L Zhou et al ldquoEnhanced adsorptive removal ofmethyl orange and methylene blue from aqueous solution byalkali-activated multiwalled carbon nanotubesrdquo ACS AppliedMaterials amp Interfaces vol 4 no 11 pp 5749ndash5760 2012

[52] N Mohammadi H Khani V K Gupta E Amereh andS Agarwal ldquoAdsorption process of methyl orange dye ontomesoporous carbon material-kinetic and thermodynamicstudiesrdquo Journal of Colloid and Interface Science vol 362no 2 pp 457ndash462 2011

[53] D Chen J Chen X Luan H Ji and Z Xia ldquoCharacterizationof anion-cationic surfactants modified montmorillonite andits application for the removal of methyl orangerdquo ChemicalEngineering Journal vol 171 no 3 pp 1150ndash1158 2011

[54] J Liu S Ma and L Zang ldquoPreparation and characterizationof ammonium-functionalized silica nanoparticle as a newadsorbent to remove methyl orange from aqueous solutionrdquoApplied Surface Science vol 265 pp 393ndash398 2013

[55] S Agarwal I Tyagi V K Gupta et al ldquoRETRACTED ki-netics and thermodynamics of methyl orange adsorption fromaqueous solutions-artificial neural network-particle swarmoptimization modelingrdquo Journal of Molecular Liquidsvol 218 pp 354ndash362 2016

[56] M Ghaedi A M Ghaedi A Ansari F Mohammadi andA Vafaei ldquoArtificial neural network and particle swarmoptimization for removal of methyl orange by gold nano-particles loaded on activated carbon and Tamariskrdquo Spec-trochimica Acta Part A Molecular and BiomolecularSpectroscopy vol 132 pp 639ndash654 2014

[57] V Yonten N K Sanyurek and M R Kivanccedil ldquoA thermo-dynamic and kinetic approach to adsorption of methyl orangefrom aqueous solution using a low cost activated carbonprepared from Vitis vinifera Lrdquo Surfaces and Interfacesvol 20 Article ID 100529 2020

[58] D-M Liu C Dong J Zhong S Ren Y Chen and T QiuldquoFacile preparation of chitosan modified magnetic kaolin byone-pot coprecipitation method for efficient removal ofmethyl orangerdquo Carbohydrate Polymers vol 245 Article ID116572 2020

[59] M Hasan M M Rashid M M Hossain et al ldquoFabrication ofpolyanilineactivated carbon composite and its testing formethyl orange removal optimization equilibrium isothermand kinetic studyrdquo Polymer Testing vol 77 Article ID 1059092019

[60] L Zhai Z Bai Y Zhu B Wang and W Luo ldquoFabrication ofchitosan microspheres for efficient adsorption of methylorangerdquo Chinese Journal of Chemical Engineering vol 26no 3 pp 657ndash666 2018

Journal of Chemistry 9

aqueous solution with Turkish zeoliterdquo Journal of HazardousMaterials vol 151 no 1 pp 213ndash220 2008

[14] D Caputo and F Pepe ldquoExperiments and data processing ofion exchange equilibria involving Italian natural zeolites areviewrdquo Microporous and Mesoporous Materials vol 105no 3 pp 222ndash231 2007

[15] A Wasti and M Ali Awan ldquoAdsorption of textile dye ontomodified immobilized activated aluminardquo Journal of theAssociation of Arab Universities for Basic and Applied Sciencesvol 20 no 1 pp 26ndash31 2016

[16] K Z Elwakeel ldquoRemoval of Reactive Black 5 from aqueoussolutions using magnetic chitosan resinsrdquo Journal of Haz-ardous Materials vol 167 no 1-3 pp 383ndash392 2009

[17] K Z Elwakeel A A El-Bindary A Ismail andA M Morshidy ldquoSorptive removal of Remazol Brilliant BlueR from aqueous solution by diethylenetriamine functionalizedmagnetic macro-reticular hybrid materialrdquo RSC Advancesvol 6 no 27 pp 22395ndash22410 2016

[18] T Shahnaz C Patra V Sharma andN Selvaraju ldquoA comparativestudy of raw acid-modified and EDTA-complexed Acaciaauriculiformis biomass for the removal of hexavalent chromiumrdquoChemistry and Ecology vol 36 no 4 pp 360ndash381 2020

[19] C Patra R M N Medisetti K Pakshirajan andS Narayanasamy ldquoAssessment of raw acid-modified andchelated biomass for sequestration of hexavalent chromiumfrom aqueous solution using Sterculia villosa Roxb shellsrdquoEnvironmental Science and Pollution Research vol 26 no 23pp 23625ndash23637 2019

[20] C Patra T Shahnaz S Subbiah and S NarayanasamyldquoComparative assessment of raw and acid-activated prepa-rations of novel Pongamia pinnata shells for adsorption ofhexavalent chromium from simulated wastewaterrdquo Envi-ronmental Science and Pollution Research vol 27 no 13pp 14836ndash14851 2020

[21] Y El Maguana N Elhadiri M Bouchdoug andM Benchanaa ldquoStudy of the influence of some factors on thepreparation of activated carbon from walnut cake using thefractional factorial designrdquo Journal of EnvironmentalChemical Engineering vol 6 no 1 pp 1093ndash1099 2018

[22] P Ammendola F Raganati and R Chirone ldquoCO2 adsorptionon a fine activated carbon in a sound assisted fluidized bedthermodynamics and kineticsrdquo Chemical Engineering Journalvol 322 pp 302ndash313 2017

[23] F Raganati P Ammendola and R Chirone ldquoOn improvingthe CO2 recovery efficiency of a conventional TSA process in asound assisted fluidized bed by separating heating andpurgingrdquo Separation and Purification Technology vol 167pp 24ndash31 2016

[24] F Raganati P Ammendola and R Chirone ldquoRole of acousticfields in promoting the gas-solid contact in a fluidized bed offine particlesrdquo KONA Powder and Particle Journal vol 32pp 23ndash40 2015

[25] K Z Elwakeel M A Abd El-Ghaffar S M El-kousy andH G El-Shorbagy ldquoSynthesis of new ammonium chitosanderivatives and their application for dye removal fromaqueous mediardquo Chemical Engineering Journal vol 203pp 458ndash468 2012

[26] A A Yakout M A Shaker K Z Elwakeel and W AlshitarildquoLauryl sulfatemagnetic graphene oxide nanosorbent forfast methylene blue recovery from aqueous solutionsrdquo Journalof Dispersion Science and Technology vol 40 no 5pp 707ndash715 2019

[27] I A W Tan A L Ahmad and B H Hameed ldquoPreparationof activated carbon from coconut husk optimization study

on removal of 246-trichlorophenol using response surfacemethodologyrdquo Journal of Hazardous Materials vol 153no 1-2 pp 709ndash717 2008

[28] J Yang and K Qiu ldquoPreparation of activated carbons fromwalnut shells via vacuum chemical activation and their ap-plication for methylene blue removalrdquo Chemical EngineeringJournal vol 165 no 1 pp 209ndash217 2010

[29] M L Martınez M M Torres C A Guzman andD M Maestri ldquoPreparation and characteristics of activatedcarbon from olive stones and walnut shellsrdquo Industrial Cropsand Products vol 23 no 1 pp 23ndash28 2006

[30] P Nowicki R Pietrzak and H Wachowska ldquoSorptionproperties of active carbons obtained from walnut shells bychemical and physical activationrdquo Catalysis Today vol 150no 1-2 pp 107ndash114 2010

[31] T-H Liou ldquoDevelopment of mesoporous structure and highadsorption capacity of biomass-based activated carbon byphosphoric acid and zinc chloride activationrdquo ChemicalEngineering Journal vol 158 no 2 pp 129ndash142 2010

[32] B S Girgis and M F Ishak ldquoActivated carbon from cottonstalks by impregnation with phosphoric acidrdquo MaterialsLetters vol 39 no 2 pp 107ndash114 1999

[33] Y El Maguana N Elhadiri M Bouchdoug M Benchanaaand A Jaouad ldquoActivated carbon from prickly pear seed cakeoptimization of preparation conditions using experimentaldesign and its application in dye removalrdquo InternationalJournal of Chemical Engineering vol 2019 Article ID8621951 12 pages 2019

[34] Y El maguana N Elhadiri M Benchanaa and R ChikrildquoAdsorption thermodynamic and kinetic studies of methylorange onto sugar scum powder as a low-cost inorganicadsorbentrdquo Journal of Chemistry vol 2020 Article ID9165874 10 pages 2020

[35] K V Kumar ldquoLinear and non-linear regression analysis forthe sorption kinetics of methylene blue onto activated car-bonrdquo Journal of Hazardous Materials vol 137 no 3pp 1538ndash1544 2006

[36] S Lagergren ldquoZur theorie der sogenannten adsorptiongeloster stoffe Kungliga Svenska VetenskapsakademiensrdquoHandlingar vol 24 pp 1ndash39 1898

[37] Y S Ho and G McKay ldquoPseudo-second order model forsorption processesrdquo Process Biochemistry vol 34 no 5pp 451ndash465 1999

[38] A G Ritchie ldquoAlternative to the Elovich equation for thekinetics of adsorption of gases on solidsrdquo Journal of theChemical Society Faraday Transactions 1 Physical Chemistryin Condensed Phases vol 73 pp 1650ndash1653 1977

[39] J W Weber and J C Morris ldquoKinetics of adsorption oncarbon from solutionrdquo Journal of the Sanitary EngineeringDivision vol 89 pp 31ndash60 1963

[40] A Gurses C Dogar M Yalcin M Acikyildiz R Bayrak andS Karaca ldquo)e adsorption kinetics of the cationic dyemethylene blue onto clayrdquo Journal of Hazardous Materialsvol 131 no 1-3 pp 217ndash228 2006

[41] G B Oguntimein ldquoBiosorption of dye from textile wastewatereffluent onto alkali treated dried sunflower seed hull anddesign of a batch adsorberrdquo Journal of EnvironmentalChemical Engineering vol 3 no 4 pp 2647ndash2661 2015

[42] G-B Hong and Y-KWang ldquoSynthesis of low-cost adsorbentfrom rice bran for the removal of reactive dye based on theresponse surface methodologyrdquo Applied Surface Sciencevol 423 pp 800ndash809 2017

[43] C H Giles T HMacewan S N Nakhwa and D Smith ldquo786Studies in adsorption Part XI A system of classification of

8 Journal of Chemistry

solution adsorption isotherms and its use in diagnosis ofadsorption mechanisms and in measurement of specificsurface areas of solidsrdquo Journal of the Chemical Society(Resumed) vol 10 pp 3973ndash3993 1960

[44] I Langmuir ldquo)e constitution and fundamental properties ofsolids and liquids Part I Solidsrdquo Journal of the AmericanChemical Society vol 38 no 11 pp 2221ndash2295 1916

[45] H Freundlish ldquoOver the adsorption in solutionrdquo Journal ofPhysical Chemistry vol 57 pp 385ndash470 1906

[46] D Kavitha and C Namasivayam ldquoExperimental and kineticstudies on methylene blue adsorption by coir pith carbonrdquoBioresource Technology vol 98 no 1 pp 14ndash21 2007

[47] H N Tran S-J You and H-P Chao ldquo)ermodynamicparameters of cadmium adsorption onto orange peel calcu-lated from various methods a comparison studyrdquo Journal ofEnvironmental Chemical Engineering vol 4 no 3 pp 2671ndash2682 2016

[48] T A Khan E A Khan and Shahjahan ldquoRemoval of basicdyes from aqueous solution by adsorption onto binary iron-manganese oxide coated kaolinite non-linear isotherm andkinetics modelingrdquo Applied Clay Science vol 107 pp 70ndash772015

[49] T N V de Souza S M L de Carvalho M G A VieiraM G C da Silva and D d S B Brasil ldquoAdsorption of basicdyes onto activated carbon experimental and theoreticalinvestigation of chemical reactivity of basic dyes using DFT-based descriptorsrdquo Applied Surface Science vol 448pp 662ndash670 2018

[50] S Wang and Z Zhu ldquoEffects of acidic treatment of activatedcarbons on dye adsorptionrdquoDyes and Pigments vol 75 no 2pp 306ndash314 2007

[51] J Ma F Yu L Zhou et al ldquoEnhanced adsorptive removal ofmethyl orange and methylene blue from aqueous solution byalkali-activated multiwalled carbon nanotubesrdquo ACS AppliedMaterials amp Interfaces vol 4 no 11 pp 5749ndash5760 2012

[52] N Mohammadi H Khani V K Gupta E Amereh andS Agarwal ldquoAdsorption process of methyl orange dye ontomesoporous carbon material-kinetic and thermodynamicstudiesrdquo Journal of Colloid and Interface Science vol 362no 2 pp 457ndash462 2011

[53] D Chen J Chen X Luan H Ji and Z Xia ldquoCharacterizationof anion-cationic surfactants modified montmorillonite andits application for the removal of methyl orangerdquo ChemicalEngineering Journal vol 171 no 3 pp 1150ndash1158 2011

[54] J Liu S Ma and L Zang ldquoPreparation and characterizationof ammonium-functionalized silica nanoparticle as a newadsorbent to remove methyl orange from aqueous solutionrdquoApplied Surface Science vol 265 pp 393ndash398 2013

[55] S Agarwal I Tyagi V K Gupta et al ldquoRETRACTED ki-netics and thermodynamics of methyl orange adsorption fromaqueous solutions-artificial neural network-particle swarmoptimization modelingrdquo Journal of Molecular Liquidsvol 218 pp 354ndash362 2016

[56] M Ghaedi A M Ghaedi A Ansari F Mohammadi andA Vafaei ldquoArtificial neural network and particle swarmoptimization for removal of methyl orange by gold nano-particles loaded on activated carbon and Tamariskrdquo Spec-trochimica Acta Part A Molecular and BiomolecularSpectroscopy vol 132 pp 639ndash654 2014

[57] V Yonten N K Sanyurek and M R Kivanccedil ldquoA thermo-dynamic and kinetic approach to adsorption of methyl orangefrom aqueous solution using a low cost activated carbonprepared from Vitis vinifera Lrdquo Surfaces and Interfacesvol 20 Article ID 100529 2020

[58] D-M Liu C Dong J Zhong S Ren Y Chen and T QiuldquoFacile preparation of chitosan modified magnetic kaolin byone-pot coprecipitation method for efficient removal ofmethyl orangerdquo Carbohydrate Polymers vol 245 Article ID116572 2020

[59] M Hasan M M Rashid M M Hossain et al ldquoFabrication ofpolyanilineactivated carbon composite and its testing formethyl orange removal optimization equilibrium isothermand kinetic studyrdquo Polymer Testing vol 77 Article ID 1059092019

[60] L Zhai Z Bai Y Zhu B Wang and W Luo ldquoFabrication ofchitosan microspheres for efficient adsorption of methylorangerdquo Chinese Journal of Chemical Engineering vol 26no 3 pp 657ndash666 2018

Journal of Chemistry 9

solution adsorption isotherms and its use in diagnosis ofadsorption mechanisms and in measurement of specificsurface areas of solidsrdquo Journal of the Chemical Society(Resumed) vol 10 pp 3973ndash3993 1960

[44] I Langmuir ldquo)e constitution and fundamental properties ofsolids and liquids Part I Solidsrdquo Journal of the AmericanChemical Society vol 38 no 11 pp 2221ndash2295 1916

[45] H Freundlish ldquoOver the adsorption in solutionrdquo Journal ofPhysical Chemistry vol 57 pp 385ndash470 1906

[46] D Kavitha and C Namasivayam ldquoExperimental and kineticstudies on methylene blue adsorption by coir pith carbonrdquoBioresource Technology vol 98 no 1 pp 14ndash21 2007

[47] H N Tran S-J You and H-P Chao ldquo)ermodynamicparameters of cadmium adsorption onto orange peel calcu-lated from various methods a comparison studyrdquo Journal ofEnvironmental Chemical Engineering vol 4 no 3 pp 2671ndash2682 2016

[48] T A Khan E A Khan and Shahjahan ldquoRemoval of basicdyes from aqueous solution by adsorption onto binary iron-manganese oxide coated kaolinite non-linear isotherm andkinetics modelingrdquo Applied Clay Science vol 107 pp 70ndash772015

[49] T N V de Souza S M L de Carvalho M G A VieiraM G C da Silva and D d S B Brasil ldquoAdsorption of basicdyes onto activated carbon experimental and theoreticalinvestigation of chemical reactivity of basic dyes using DFT-based descriptorsrdquo Applied Surface Science vol 448pp 662ndash670 2018

[50] S Wang and Z Zhu ldquoEffects of acidic treatment of activatedcarbons on dye adsorptionrdquoDyes and Pigments vol 75 no 2pp 306ndash314 2007

[51] J Ma F Yu L Zhou et al ldquoEnhanced adsorptive removal ofmethyl orange and methylene blue from aqueous solution byalkali-activated multiwalled carbon nanotubesrdquo ACS AppliedMaterials amp Interfaces vol 4 no 11 pp 5749ndash5760 2012

[52] N Mohammadi H Khani V K Gupta E Amereh andS Agarwal ldquoAdsorption process of methyl orange dye ontomesoporous carbon material-kinetic and thermodynamicstudiesrdquo Journal of Colloid and Interface Science vol 362no 2 pp 457ndash462 2011

[53] D Chen J Chen X Luan H Ji and Z Xia ldquoCharacterizationof anion-cationic surfactants modified montmorillonite andits application for the removal of methyl orangerdquo ChemicalEngineering Journal vol 171 no 3 pp 1150ndash1158 2011

[54] J Liu S Ma and L Zang ldquoPreparation and characterizationof ammonium-functionalized silica nanoparticle as a newadsorbent to remove methyl orange from aqueous solutionrdquoApplied Surface Science vol 265 pp 393ndash398 2013

[55] S Agarwal I Tyagi V K Gupta et al ldquoRETRACTED ki-netics and thermodynamics of methyl orange adsorption fromaqueous solutions-artificial neural network-particle swarmoptimization modelingrdquo Journal of Molecular Liquidsvol 218 pp 354ndash362 2016

[56] M Ghaedi A M Ghaedi A Ansari F Mohammadi andA Vafaei ldquoArtificial neural network and particle swarmoptimization for removal of methyl orange by gold nano-particles loaded on activated carbon and Tamariskrdquo Spec-trochimica Acta Part A Molecular and BiomolecularSpectroscopy vol 132 pp 639ndash654 2014

[57] V Yonten N K Sanyurek and M R Kivanccedil ldquoA thermo-dynamic and kinetic approach to adsorption of methyl orangefrom aqueous solution using a low cost activated carbonprepared from Vitis vinifera Lrdquo Surfaces and Interfacesvol 20 Article ID 100529 2020

[58] D-M Liu C Dong J Zhong S Ren Y Chen and T QiuldquoFacile preparation of chitosan modified magnetic kaolin byone-pot coprecipitation method for efficient removal ofmethyl orangerdquo Carbohydrate Polymers vol 245 Article ID116572 2020

[59] M Hasan M M Rashid M M Hossain et al ldquoFabrication ofpolyanilineactivated carbon composite and its testing formethyl orange removal optimization equilibrium isothermand kinetic studyrdquo Polymer Testing vol 77 Article ID 1059092019

[60] L Zhai Z Bai Y Zhu B Wang and W Luo ldquoFabrication ofchitosan microspheres for efficient adsorption of methylorangerdquo Chinese Journal of Chemical Engineering vol 26no 3 pp 657ndash666 2018

Journal of Chemistry 9