CITRUS FRUIT WASTE-BASED ADSORPTION TECHNOLOGY FOR THE TREATMENT OF HEAVY METAL BEARING WASTEWATER...
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Transcript of CITRUS FRUIT WASTE-BASED ADSORPTION TECHNOLOGY FOR THE TREATMENT OF HEAVY METAL BEARING WASTEWATER...
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CITRUS FRUIT WASTE-BASED ADSORPTION TECHNOLOGY FOR THE TREATMENT OF HEAVY METAL BEARING WASTEWATER
Asma Saeed and Muhammad Iqbal T.I
Bioresource Utilization Group, Food and Biotechnology Research Centre
PCSIR Laboratories Complex Lahore
What is Pollution?
Introduction of contaminants into natural environment that cause instability, disorder, harm or discomfort to the ecosystem. It may be in the form of chemical substances or energy like heat, light and noise.
ORGANIC INORGANIC
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ECOSYSTEM
All organisms living in a particular area interacting with physical components like soil, water, air and sunlight
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SOURCES OF ENVIRONMENTAL CONTAMINATION
AirNoiseLightWater
Water contamination is the most serious issue as it is vital for life
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ROUTES OF WATER CONTAMINATION
Direct Discharge
Sewage
Dumping toxins
Industrial water
Indirect Discharge
Urban runoff
Agricultural runoff
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HEAVY METALSAmong various pollutants, heavy metals impart deleterious effect on the ecosystem due to their persistent and non-biodegrable nature that ultimately led them to enter into food chain
Dangerous Substances Directive by the European Union (76/464/EEC)
Red List Grey List
1. Hg 1. Zn 2. Cu 3. Ni2. Cd 4. Cr 5. Pb 6. As
7. Sb 8. Mo 9. Ti10. Sn11. Ba12. Be13. B 14. U 15. V16. Co17. Ag 18. Tl19. Se 20. Ti
GREY LIST before 1997PbCuNiCrZn
HEAVY METAL CONTAMINATION OF FRESH WATER
Electroplating (Cu, Zn, Cr, Pb, Ni)
Metal finishing (Cd, Cr, Cu, Pb, Ni, Zn, Ag)
Petroleum (Pb and Organic compounds)
Steel works (Al, Co, Cu, Ce, Ti, Ni, Cr, Mo etc)
Vehicle and aircrafts (Oils, Emulsifiers, Al, Pb)
Storage batteries (Pb, Cu, Sb)
Mining (Zn, Pb)
Pulp and Paper (Cu)
Glass, ceramics and cement (Pb, W)
Textile and Leather (Dyes, Cr)
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WATER TREATMENT TECHNOLOGIES
Conventional technologies for heavy metal remediation include:1. Chemical precipitation2. Coagulation3. Oxidation-reduction4. Osmosis5. Reverse osmosis6. Evaporation7. Ion Exchange
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TECHNO-ECONOMICAL CONSTRAINTS
Expensive/costlyInefficient/ineffective for the removal of
heavy metals at low concentrationHazardous/generate toxic sludge
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BIOSORPTION-AN ALTERNATE TECHNOLOGY
Biosorption is the passive accumulation of the adsorbate e.g. metal ions, organic molecules, colour ions etc., to biologically inactive material
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ADVANTAGES OF BIOSORPTIONBiosorption is a combination of several phenomena having several advantages:1. Cost effective2. Efficient3. Reusability in repeated cycles4. Low operational cost5. Environment-friendly6. Applicable over wide-range of physicochemical
conditions7. Non-selective work under multi-metal conditions
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Biosorption as an Alternative Technique
Biosorption
Microbial Biomass Agro-waste Materials
Bacteria, Algae, Fungi, Yeast
Purposefully Cultured Biomass
Waste from Fermentation and Pharmaceutical
Industry
Plant Waste Biomass
Food Industry Waste
Crop Residues, Grains/Fruit Wastes
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Small particles Very fragile/delicates Low mechanical strength Difficulty of separation Process can not be scaled up
Technical Limitations Towards TheirCommercial Applications
SOLUTION ?
Immobilization/Entrapment
A physical or chemical process used to fix micro-organisms on to a solid support or trap them in
a solid matrix.
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Biostructural Fibrous Network as an Alternative Immobilization Matrix
Loofa Sponge Papaya Wood Palm Trunk Fibers
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Biowastes used as Biosorbent
Petiolar felt-sheet of Palm
Papaya wood
Black gram husk
Orange peel
Now I will discuss more about the application of citrus peel waste in the treatmentof metal contaminated water
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Citrus Peel as a Biosorbent
wet wt dry wt Component (%) (%)
~ 6 25 - 35sugars
~ 5 20 - 25cellulose & hemicellulose
~ 4 15 - 25soluble fiber (pectin)
~ 1 04 - 06flavanones (hesperidin, naringin, etc)
~ 0.05 0.1 - 0.5 polymethoxylated flavones
~ 0.05 0.1 - 0.3 limonoids (limonin+glucosides)
~ 1 3 - 5 ash
~ 1 3 - 4 protein
~ 1 limonene/peel oil
~ 80 water
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Citrus Peel as a BiosorbentExperimental Equilibrium
BiosorptionLangmuir and Freundlich
Models
Metal ions Langmuir isotherm model Freundlich isotherm model qmax b r2 KF n r2 (mg g-1) (l mg-1)
Cd2+ 67.08 0.085 0.998 6.3 2.22 0.952
Pb2+ 96.32 0.101 0.996 7.26 1.94 0.975
Pb qeq = 99.05 mgg-1
Cd qeq = 68.92 mgg-1
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FTIR Spectrum of CPW and Functional Moieties
a
b
c
Native CPW
Cd-loaded CPW
Pb-loaded CPW
-OH stretch
-CH stretch C=O stretch
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Biosorption and Ion-Exchange SEM-EDX
Ion Exchange Equation:M+n + BHn ↔ BM + nH+
SEM-EDX of Native CPW SEM-EDX of Pb-Loaded CPW
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PROPOSED MECHANISM OF METAL BINDING
II) Lignin moieties
I) Cellulosic moieties
III) Protein moieties
Mn2+
Mn2+
Mn2+
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Citrus Peel as a Biosorbent
a, Maximum acceptable concentration for health reasonsb, Limits for aesthetic or consumer oriented reasonsc, Provisional value for health reasons
Metal ions
Before biosorption
(mg/L)
After biosorption
(mg/L)
Limits recommended by WHO for drinking
water (mg/L)
NEQS maximum limits for effluent
discharge (mg/L)
Cd(II)Pb(II)Cu(II)Zn(II)Cr(III)Ni(II)
10.029.9810.0410.3610.0110.06
0.001±0.0020.06±0.0150.43±0.00410.19±0.0020.78±0.0120.69±0.037
0.003a
0.01a
1.00a,b
0.1a,b
0.05c
0.07a
0.10.51.05.01.01.0
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Fixed Bed Column Bioreactor Studies
ColumnDescription
Schematic diagram of fixed bed column bioreactor, packed with CPW designed to function as a continuous flow system for biosorption of heavy metals.
1. metal solution reservoir; 2. peristaltic pump; 3. flow control; 4. glass column reactor;5. cpw biosorbent;6. enlarged view of column
packing; 7. extension for secondary column; and 8. effluent storage.
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Thanks to:
University of Alaska Fairbanks, USA
University of Sheffield, UK
Forschungszentrum Karlsruhe, Germany