The Mechanistic and Oxidative Study of Methomyl and Parathion Degradation by Fenton Process
The purpose of this study is to investigate the chemical
degradation of the organophosphorus pesticide of parathion and
carbamate insecticide of methomyl in the aqueous phase through
Fenton process. With the employment of batch Fenton process, the
degradation of the two selected pesticides at different pH, initial
concentration, humic acid concentration, and Fenton reagent dosages
was explored. The Fenton process was found effective to degrade
parathion and methomyl. The optimal dosage of Fenton reagents (i.e.,
molar concentration ratio of H2O2 to Fe2+) at pH 7 for parathion
degradation was equal to 3, which resulted in 50% removal of
parathion. Similarly, the optimal dosage for methomyl degradation
was 1, resulting in 80% removal of methomyl. This study also found
that the presence of humic substances has enhanced pesticide
degradation by Fenton process significantly. The mass spectroscopy
results showed that the hydroxyl free radical may attack the single
bonds with least energy of investigated pesticides to form smaller
molecules which is more easily to degrade either through
physio-chemical or bilolgical processes.
[1] R. S. Adams, "Factors influencing soil adsorption and bioactivity of
pesticides," Residue Reviews, vol 47, pp. 1-54, 1973.
[2] W. D. Guenzi, J. L. Ahlrichs, M. E. Bloodworth, G. Chester, R. G. Nash,
Pesticides in soil and water, Soil Science Society of America, Wisconsin,
562, 1974.
[3] E. Neyens, J. Baeyens, "A review of classic Fenton's peroxidation as an
advanced oxidation technique," J. Hazard. Mater., vol. 98, pp. 33-55,
2003.
[4] R. J. Watts, M. D. Udell, P. A. Rauch, "Treatment of
pentachlorophenolcontaminated soils using Fenton's reagent," Hazard.
Waste Hazard. Mater., vol. 7, pp. 335-345, 1990.
[5] B. W. Tyre, R. J. Watts, G. C. Miller, "Treatment of four biorefractory
contaminants in soil using catalyzed hydrogen peroxide," J. Environ.
Qual., vol. 20, pp. 832-838, 1991.
[6] R. J. Watts, S. Kong, M. Dippre, W. T. Barnes, "Oxidation of sorbed
hexachlorobenzene in soils using catalyzed hydrogen peroxide," J.
Hazard. Mater., vol. 39, pp. 33-47, 1994.
[7] G. Chen, G. E. Hoag, P. Chedda, "The mechanism and applicability of in
situ oxidation of trichloroethylene with Fenton's reagent," J. Hazard.
Mater., vol. 87, pp. 171-86, 2001.
[8] D. D. Gates, R. L. Siegrist, "In-situ chemical oxidation of
trichloroethylene using hydrogen peroxide," J. Environ. Eng.-Asce., vol.
121, pp. 639-44, 1995.
[9] B. Utset, J. Garcia, J. Casado, X. Domenech, J. Peral, "Replacement of
H2O2 in Fenton and photo-Fenton reactions," Chemosphere, vol. 41, pp.
1187-92, 2000.
[10] G. W. vanLoon, S. J. Duffy, Environmental chemistry. New York: Oxford
University Press, 2000. pp. 370-410.
[1] R. S. Adams, "Factors influencing soil adsorption and bioactivity of
pesticides," Residue Reviews, vol 47, pp. 1-54, 1973.
[2] W. D. Guenzi, J. L. Ahlrichs, M. E. Bloodworth, G. Chester, R. G. Nash,
Pesticides in soil and water, Soil Science Society of America, Wisconsin,
562, 1974.
[3] E. Neyens, J. Baeyens, "A review of classic Fenton's peroxidation as an
advanced oxidation technique," J. Hazard. Mater., vol. 98, pp. 33-55,
2003.
[4] R. J. Watts, M. D. Udell, P. A. Rauch, "Treatment of
pentachlorophenolcontaminated soils using Fenton's reagent," Hazard.
Waste Hazard. Mater., vol. 7, pp. 335-345, 1990.
[5] B. W. Tyre, R. J. Watts, G. C. Miller, "Treatment of four biorefractory
contaminants in soil using catalyzed hydrogen peroxide," J. Environ.
Qual., vol. 20, pp. 832-838, 1991.
[6] R. J. Watts, S. Kong, M. Dippre, W. T. Barnes, "Oxidation of sorbed
hexachlorobenzene in soils using catalyzed hydrogen peroxide," J.
Hazard. Mater., vol. 39, pp. 33-47, 1994.
[7] G. Chen, G. E. Hoag, P. Chedda, "The mechanism and applicability of in
situ oxidation of trichloroethylene with Fenton's reagent," J. Hazard.
Mater., vol. 87, pp. 171-86, 2001.
[8] D. D. Gates, R. L. Siegrist, "In-situ chemical oxidation of
trichloroethylene using hydrogen peroxide," J. Environ. Eng.-Asce., vol.
121, pp. 639-44, 1995.
[9] B. Utset, J. Garcia, J. Casado, X. Domenech, J. Peral, "Replacement of
H2O2 in Fenton and photo-Fenton reactions," Chemosphere, vol. 41, pp.
1187-92, 2000.
[10] G. W. vanLoon, S. J. Duffy, Environmental chemistry. New York: Oxford
University Press, 2000. pp. 370-410.
@article{"International Journal of Chemical, Materials and Biomolecular Sciences:57899", author = "Chihhao Fan and Ming-Chu Liao", title = "The Mechanistic and Oxidative Study of Methomyl and Parathion Degradation by Fenton Process", abstract = "The purpose of this study is to investigate the chemical
degradation of the organophosphorus pesticide of parathion and
carbamate insecticide of methomyl in the aqueous phase through
Fenton process. With the employment of batch Fenton process, the
degradation of the two selected pesticides at different pH, initial
concentration, humic acid concentration, and Fenton reagent dosages
was explored. The Fenton process was found effective to degrade
parathion and methomyl. The optimal dosage of Fenton reagents (i.e.,
molar concentration ratio of H2O2 to Fe2+) at pH 7 for parathion
degradation was equal to 3, which resulted in 50% removal of
parathion. Similarly, the optimal dosage for methomyl degradation
was 1, resulting in 80% removal of methomyl. This study also found
that the presence of humic substances has enhanced pesticide
degradation by Fenton process significantly. The mass spectroscopy
results showed that the hydroxyl free radical may attack the single
bonds with least energy of investigated pesticides to form smaller
molecules which is more easily to degrade either through
physio-chemical or bilolgical processes.", keywords = "Fenton Process, humic acid, methomyl, parathion,pesticides", volume = "3", number = "11", pages = "619-5", }