Biodegradation of Phenol : A Comparative Study With and Without Applying Magnetic Fields

Jongtai Jung (Professor/Ph. D) Dept. of Environmental Engineering Division of Urban and Environmental Engineering University of Incheon

Biodegradation of Phenol : A Comparative Study With and With-

out Applying Magnetic Fields

Jongtai Jung (Professor/Ph. D)

Major of Environmental EngineeringDivision of Urban and Environmental

EngineeringUniversity of Incheon


• Every community produces both liquid and solid wastes• The Liquid portion –wastewater – is essentially the water supply of the community after it has been fouled by a variety of uses

• From the stand point of sources of generation, wastewater is defined as a combination of the liquid or water-carried wastes removed from residences, institution, and commercial and industrial establishment, together with such groundwater, surface water, and storm water as may be present

Wastewater


Treatment Descriptions

Preliminary

Removal of wastewater constituents such as rags, stick, floatables, grit, and grease that may cause

maintenance or operational problems with the treatment operations, processes,

and ancillary systems

Primary Removal of a portion of the suspended solids and organic matter from the wastewater

Advanced Primary

Enhanced removal of suspended solids and organic matter from the wastewater.

Typically accomplished by chemical addition or Filtration


Treatment Descriptions

Secondary

Removal of biodegradable organic matter (in solution or suspension) and suspended solids.

Disinfection is also typically included in the definition of conventional secondary treatment

Secondary with nutrient

Removal

Removal of biodegradable organics, suspended solidsAnd nutrients (nitrogen, phosphorus, or both nitrogen

and phosphorus)

Tertiary

Removal of residual suspended solids (after secondary treatment), usually by granular

medium filtration or microscreen. Disinfection is also typically a part of tertiary treatment,

Nutrient removal is often included in this definition

AdvancedRemoval of dissolved and suspended materials

remaining after normal biological treatment when required for various water reuse applications


1) Physical Treatment Method

- Screening, Comminution, Aeration, Mixing, Flocculation, - Sedimentation, Filtration, Adsorption, Gas Stripping, - Membrane Processes, etc

2) Chemical Treatment method

- Disinfection, Precipitation, Coagulation, - Chemical oxidation, Ion exchange, etc

Wastewater Treatment Methods(1)


3) Biological treatment Method

- Conventional Activated Sludge Processes, - Trickling Filter Processes - Rotating Biological Contactor Processes - Oxidation Pond Process - Anaerobic Biological Treatment, - A/O (Advanced Oxidation) Process a) Phostrip Process b) Bardenpho Process ** Nitrogen and Phosphate removal process

Wastewater Treatment Methods(2)


1) Purpose - To convert the colloidal and dissolved carbonaceous organic matter into various gases and into cell tissue.

2) Advantages - Less operation cost - Byproduct (CH4 etc)

Biological Treatment Process


1. Depends on supplying oxygen – Aerobic process : presence of oxygen – Facultative process : indifferent to the presence of DO – Anaerobic process : absence of oxygen – A combination of the aerobic/anoxic or anaerobic process2. Microorganisms 1) Suspended-growth processes 2) Immobilized-growth process - Attached microorganism - Entrapped microorganism

Biological treatment Process


1) Techniques – Entrapment in a gel, polymer matrix (like alginate, carageenan and polyurethane) – Attachment on the surface of inert supports (like diatomaceous earth, glass bead, and polymeric membranes)

2) Advantages - No wash out - Reuse of biomass - Operation flexibility (Possible to choose the different operating mode for reactors) - Protected from high concentrations of toxic compounds which are inhibitory - A desirable change in biological activity of the biomass

Immobilization Techniques and Advantages


To study the effect of magnetic fields

on the rate of phenol biodegradation using immobilized activated sludge with a recirculation flow bioreactor.

The objective of this work


Fig.1 Batch recirculation flow biomagnetic reactor with immobilized microorganism

Schematic Diagram


Experimental Set-up(1)

1) Recirculation flow-type bioreactor, - Reactor size : 6.4 cm in diameter 20 cm in length.. 2) Reservoir - Reservoir size : 11.4 cm in diameter 25.4 cm in length3) Total reaction volume - 2 liters including the reservoir.


Experimental Set-up(2)

1) Culture medium - 100 ppm MgCl2, - 0.5 ppm FeCl3

- 10 ppm MgSO4, - 10 ppm K2PO4

2) Air flow rate : 1.5 liter/min.3) Recirculation flow rate : 325ml/min.4) Magnets size - Rectangular block , - Dimension 5x15x1 cm.


Experiments set-up and Run(3)

• Chosen Substrate : Phenol

• Operating period : 1200 hr

• Magnet strength : 0.49 Tesla


• Activated sludge(Mixed microbial population) from Waste water treatment plant• 100 g alginate-immobilized activated sludge• How to immobilize - Distilled water - Concentrated sludge(50 mg dry biomass/ g of pallet) - 0.5% sodium chloride - 1% sodium alginate - 0.1 mol/liter CaCl2

- Distilled water and Conc. Pellets in a ratio 5:2 mixed with NaCl and Sodium Alginate in a blender - The homogeneous cell suspension was then extruded using a syringe pump into CaCl2 solution to obtain the immobilized bacterial beads

Microorganism


1) Control experiment without applying magnetic field, 2) Experiments with magnetic south pole applied to the reactor,

3) Experiments with magnetic north pole applied to the reactor,

4) Experiments with alternating magnetic north and south poles.

Experiments to be performed


1) Rate of oxygen consumption (nmol/min∙ml)

2) Secreted protein concentration ( ㎍ /ml)

3) Rate of phenol biodegradation(ppm/hr)

Parameters to be monitored


1) Oxygen consumption : - Clark-type dissolved oxygen probe - Chart recorder2) Phenol Concentration : - Varian 3300 Gas Chromatograph, - Detector : FID3) Protein concentration : - Standard Lowry test(color response measurement) - Bovine serum albumin (Sigma Chemicals) as a protein standard

Analytical Methods


Results and Discussions(1)- Results obtained from the above studies under the influence of north pole, south pole and during the control experiments are given in Table 1.

- It can be seen that the highest average rate of phenol biodegradation and oxygen consumption occurred when the south pole was attached to the bioreactor. - When the magnetic south pole was applied, the biological oxidation activity (measured as dissolved oxygen consumption rate) increased by a factor of two as compared to the control experiment without magnetic field (0.615 to 1.546 nmol/min/ml).


Control South pole North pole

Rate of O2 consumption

[nmol/min∙ml]

0.615 ± 0.053

(±7.5%)

1.546 ± 0.165

(±11%)

0.365 ± 0.045

(±13%)

Secreted protein concentration

[㎍ /ml ]

170.5 ± 0.7

(1%)

2357 ± 46.2

(±2.5%)ND

Rate of phenol biodegradation

[ppm/hr ]

3.113 ± 0.02

(±1%)

4.437 ± 0.253

(±5%)

0.476 ± 0.043

(±10%)

Table 1. Effect of Magnetic North and South Pole Field on Phenol Biodegradation in Batch Recirculation Bioreactor

1) Value given represent mean±standard deviation of the mean. 2) The intervals of confidence are indicated in brackets. 3) The interval of confidence on the calculated values may be estimated at ±13% by maximizing the experiment errors.4) ND, Not detectable, Control means without any magnetic field.


Results and Discussions(2)- Figure 2 shows the effect of magnetic fields on the rate of dissolved oxygen consumption. It can be seen that the rate increases markedly after 4 days under the influence of south pole as compared to the control and the north pole.

- One of the measures of biodegradation is increase in activity (measured as rate of dissolved oxygen consumption) of the microbes in presence of a substrate such as phenol.

- An increase in dissolved oxygen consumption indicates that it is being utilized by the microorganisms to break down phenol into its metabolic products which ultimately are CO2 and water.

- The phenol consumption rate was faster by nearly 30% in the experiment with south pole as compared to the control.


Fig.2 The effect of magnetic south and north pole field on the rate of O2 consumption in batch recirculation bioreactor with immobilized activated sludge. Control means without magnet.


- Figure 3 indicates that the phenol concentration decreased rapidly under the influence of south pole in comparison to the north pole and the control.

- The observed trend compares closely with that for the rate of dissolved oxygen consumption and increase in extracellular protein concentration.

Results and Discussions(3)


Fig.3 The effect of magnetic south and north pole field on the rate of biodegradation when phenol was used as sole carbon source. Control means without magnet.


- Significant production of extracellular protein verified that biological activity was enhanced when a magnetic south pole was applied to the system as compared to the control as shown in Fig. 4.

- Microorganisms release enzymes extracellularly which in turn attack the substrate. A higher amount of proteins in the reaction medium is a positive measure of biodegradation.



Fig.4 The effect of magnetic south pole field on the protein concentration Protein was not detected in reactor with north pole. Control means without magnet.


- The poles were reversed several times. Initially no magnetic field was applied then the south pole was applied three times, and north pole twice alternately over the duration of the experiment.

- The north pole was consistently inhibitory and the south pole activating as seen from the dissolved oxygen consumption rates in Fig. 5.



Fig.5 The effect of alternating magnetic field on the rate of O2 consumption. AB control, BC with south pole, CD with north pole, DE with south pole, EF with north pole, FG with south pole.


1) When the magnetic north pole was applied to the system, the decrease in concentration of the phenol was extremely slow,2) There was a substantial decrease in oxygen consumption rate. This was due to an inhibitory effect on the microorganisms exposed to the magnetic north. 3) When magnetic south pole was applied to the system, the phenol concentration decreased rapidly and the rate of dissolved oxygen consumption along with excessive extracellular protein build-up were high. 4) This is due to an enhancing effect of the magnetic south pole.

Oxygen consumption and phenol disappearance are also positive signs.

Conclusions(1)


On this basis, we conclude

- Bio-oxidation of phenol was enhanced by magnetic field south pole

- Bio-oxidation of phenol inhibited by magnetic north pole irradiation

Conclusions(2)


Thank you very muchfor listening

Biodegradation of Phenol : A Comparative Study With and Without Applying Magnetic Fields

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