Enhancement of Phenol Biodegradation by South Magnetic Field Exposure

1. Enhancement of Phenol Biodegradation by South Magnetic Field Exposure • Jongtai Jung • (Professor/Ph. D) • Major of Environmental Engineering • Division of Urban and Environmental Engineering • University of Incheon

2. Objectives • To determine • - if acclimation in the presence of south pole • magnetic field enhanced degradation, • - and if this enhancement varied at different • magnetic field strengths. • Due to the large size of a 0.49 tesla magnet, • the region between zero and 0.49 is examined • in this study

3. Microorganism • 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

4. Experiments to be performed TABLE 1. Summary of Experiments Performed (series A and B were designed to investigate the effects of acclimation, while B,C and D were designed to test further exposure to preacclimated bacteria).

5. Acclimation • - Physiological adjustment by an organism • to environmental change • Acclimating microorganisms to a given toxic • chemical can have positive effect on the treatment • of that chemical

6. Parameters to be monitored • Rate of oxygen consumption • (nmol/min∙ml) • 2) Secreted protein concentration (㎍/ml) • 3) Rate of phenol biodegradation(ppm/hr)

7. Analytical Methods • Oxygen consumption : • - Clark-type dissolved oxygen probe • -Chart recorder • 2) Phenol Concentration : • - Varian 3300 Gas Chromatograph, • -Detector : FID • Protein concentration : • - Standard Lowry test(color response measurement) • - Bovine serum albumin (Sigma Chemicals) • as a protein standard

8. Results and Discussions • Figure 2,3 and 4 summarize the data obtained from analysis • of phenol, DO and extracellular enzyme concentration • during biodegradation experiments. • Curve "A" represents experiments conducted with bacteria • not acclimated with the south pole magnetic field, and • not exposed during the runs in the course of the experiment. • This is the control experiment. • Curve "B" represents magnetically acclimated bacteria which • were not exposed to magnetic fields during subsequent runs. • Curve "C" and curve "D" represent experiments conducted • with magnetically acclimated bacteria in the presence of a • south pole magnetic field, and further exposed during runs, • curve "C" with 0.35 tesla and curve "D" with 0.15 tesla.

9. Fig 2. Effect of magnetic field exposure on biodegradation rate. Biodegradation of phenol is enhanced by exposure during acclimation (B,C,D), and further increased(C,D) by additional magnetic exposure during runs. Runs A-D are further described in Table 1.

10. Effect on rate of biodegradation • Biodegradation rates in all cases gradually increased as the system stabilized • after 2 or 3 days. The degradation rates for phenol were in the range of 2.5 to • 4.25 ppm/hr with microbes not acclimated and not exposed to magnetic • fields(A). • With magnetically preacclimated bacteria without exposure to magnetic field • after immobilization the rates were in the range 2.8 to 8.96 ppm/hr (Fig2.) • This suggests that the preacclimation step enhanced the maximum rate • approximately twofold. • Further enhancement of oxidation rates was achieved when magnetically • preacclimated bacteria were used to degrade phenol in the presence of • additional magnetic irradiation after the beads had been immobilized. • With a field strength of 0.35 tesla(curve “C”), the maximum rates ranged • from 3.96 to 14.4ppm/hr with an enhancement of four-fold over the control • experiment • With a field strength of 0.15 tesla(curve "D“) the rates ranged from 2.7 to • 25.6ppm/hrwith an enhancement of 7.5 times the rates observed in the • control experiment

11. Effect on rate of oxygen consumption • Figure 3 shows results from the analysis of oxygen consumption rates. • Curve A,B,C and D follow the same trend as was in the analysis of phenol • consumption. • Oxygen consumption rates of microbes not pre-acclimated with the magnetic • field, and without exposure to magnetic field during biodegradation • experiments were the lowest, in the range of 1.35 to 2.0 nmol/min/ml • (curve "A"). • Oxygen uptake rate for microbes pre-acclimated with south pole magnetic • field were a little higher than control experiments. They ranged from 2.5 to • 4.23 nmol/min/ml(curve"B"). • The oxygen uptake rates for pre-acclimated microbes with further exposure to • magnetic field during biodegradation are significantly high. • Curve "C" shows oxygen consumption rates in the presence of 0.35 tesla of • magnetic field. The rates ranged from 5.87 to 16.04 nmol/min/ml, a maximum • enhancement of eight times over the control. • Curve "D" shows rates in the presence of 0.15 tesla of magnetic field. • The rates ranged from 3.03 to 27.48 nmol/min/ml, a maximum enhancement of • 13.5 times over the control experiment.

12. Fig 3. Effect of magnetic field exposure on rate of consumption. Acclimation (B,C,D) increases oxidation rate, which is further enhanced by subsequent exposure (C,D) during runs.

13. Effect on release of extracellular proteins • Figure 4 shows results from analysis of extracellular protein • concentration. • The observed trend followed an identical pattern to that seen in • the analysis of oxygen consumption and phenol disappearance. • With essentially no extracellular protein present at the start, • protein concentration increased as the microbes were challenged • with phenol. • Maximum concentration of extracellular proteinobserved in • the control was 205㎍/ml. • Where acclimated microbes were exposed to the magnetic field • during biodegradation the maximum extracellular protein • concentration was 465㎍/ml with 0.35 teslafield strength and • 2250㎍/ml with 0.15 teslafield strength, and increase by one • order of magnitude from the control experiment.

14. Fig 4. Effect of magnetic field exposure on extracellular protein production. Acclimation (B,C,D) increases protein production, which is further enhanced by subsequent exposure (C,D) to magnetic fields during runs.

15. Effect of field strength and time(1) • Results from the analysis of phenol, oxygen and extracellular • protein concentrations all show that south pole magnetic filed • increased biological activity among microorganisms from • activated sludge. • This increase in activity can be obtained by pre-acclimating • the microbes in the magnetic filed, and also by continuous • exposure of the microbes to the field during biodegradation • experiments. • Table 2 summarizes the results. Acclimation with, as well as • subsequent continuous application of, south magnetic fields • enhanced biodegradation as measured by phenol disappearance, • oxidation rate, and protein synthesis. • For reference, all three phenol degradation rates were higher • than reported previously for 0.49 tesla, unacclimated(5.9ppm/hr)

16. Effect of field strength and time(2) - Two observations can be made from this analysis. • First, biological activity in the control and in the pre-acclimated • microbes not exposed to the magnetic field increased gradually • as the system stabilized, and then the activity stabilized. • When the pre-acclimated microbes were exposed to the magnetic • south field(0.15 and 0.35 tesla) the biological activity increased • significantly and reached a maximum(10days) after which it • decreased. This could be due to inhibition from extended • exposure to the magnetic field. • Secondly, the enhancement of biological activity changed as the • strength of the magnetic field varied. As shown in Table 2, • biological activity against phenol was most enhanced in the • presence of 0.15 tesla, indicating that the higher intensities may • not have been as productive and that there appeared to be an • optimum value of field strength.

17. TABLE 2. Summary of Data, acclimation (B versus A)demonstrated general stimulation, as did subsequent exposure (C and D) to south magnetic fields during runs).

18. Conclusions - For treating many waste streams, biological treatment methods • have often been described as offering a complete and cost • effective solution.Biological treatment may be enhanced by • use of immobilized cell bioreactors. • Acclimation of free cells to a south pole magnetic field prior to • immobilization increases bio-oxidatonand phenol destruction • in the order of 100%. • Optimum strength and exposure time are important • since higher magnetic irradiation decreases the rate of • biodegradaton. • The maximum observed enhancement with twice irradiated • cells is 750% higher than control runs.

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