Korean Journal of Environmental Agriculture (한국환경농학회지)

The Korean Society of Environmental Agriculture (한국환경농학회)
권호 표지
DOI QR코드

DOI QR Code

Kinetics of Metolachlor Degradation by Zerovalent Iron

Zerovalent Iron에 의한 Metolachlor의 분해 Kinetics

  • Kim, Su-Jung (Division of Biological Environment, Kangwon National University) ;
  • Oh, Sang-Eun (Division of Biological Environment, Kangwon National University) ;
  • Yang, Jae-E. (Division of Biological Environment, Kangwon National University)
  • 김수정 (강원대학교 자원생물환경학과) ;
  • 오상은 (강원대학교 자원생물환경학과) ;
  • 양재의 (강원대학교 자원생물환경학과)
  • Published : 2007.03.27
Download PDF
⟨ Previous Next ⟩

Abstract

Metolachlor may pose a threat to surface and ground water qualities due to its high solubility in water, Zerovalent iron (ZVI) releases $e^-$ which can degrade the organochlorinated compounds. The objective of this research was to evaluate the kinetics of metolachlor degradation as affected by ZVI sources [Peerless unannealed (PU) and Peerless annealed (PA)] and ZVI levels (1 and 5%) under batch conditions at different metolachlor concentrations (200 and 1000 mg/l) and temperatures (15, 25, and $35^{\circ}C$). The effectiveness of ZVI on metolachlor degradation was assessed by characterizing the dechlorinated metolachlor byproduct molecules. Metolachlor degradation by ZVI followed the first-ordered kinetics with a higher rate constant at higher level of ZVI treatment. At 5% (w/v) of PU and PA treatment, the half-lives of metolachlor degradation were 9.93 and 6.51 h and all of the initial metolachlor were degraded in 72 and 48 h, respectively. Rate constants (k) of metolachlor degradation were higher at the lower initial metolachlor concentration. The metolachlor degradation by ZVI was temperature dependent showing that the rate constant (k) at 15, 25, and $35^{\circ}C$ were 0.0805, 0.1017, and 0.3116 /h, respectively. The ZVI-mediated metolachlor degradation yielded two byproduct molecules identified as dechlorinated metolachlor $(C_{13}H_{18}NO)$ and dechlorinated-dealkylated metolachlor $(C_{12}H_{17}NO)$. The PA ZVI was more effective than PU ZVI in metolachlor degradation.

본 연구에서는 ZVI 종류[Peerless unannealed(PU), Peerless annealed(PA)]별 처리농도(1, 5%, w/v), 초기 metolachlor 농도(200, 1000 mg/l) 및 온도(15, 25, $35^{\circ}C$)가 metolachlor의 분해에 미치는 kinetics를 평가하였다. ZVI에 의한 metolachlor의 분해는 first order kinetics모델로 설명할 수 있었다. ZVI의 처리 농도가 증가할수록 metolachlor 의 분해속도가 빨랐다. 5%(w/v)의 PU와 PA ZVI를 처리시 metolachlor의 분해 반감기는 각각 9.9와 6.5 h 이었고 metolachlor는 72 및 48 h 에 모두 분해되었다. metolachlor의 분해상수(k)는 초기 metolachlor 농도가 낮을 때 컸다. ZVI에 의한 metolachlor의 분해는 온도가 높을수록 증가되었고 15, 25, $35^{\circ}C$에서 metolachlor의 분해상수(k)는 각각 0.0805, 0.1017, 0.3116 /h 이었다. ZVI에 의한 metolachlor 분해 시 2종류의 분해산물이 동정되었는데 이는 탈염소화된 metolachlor$(C_{13}H_{18}NO)$, 탈염소화-탈알킬화된 metolachlor$(C_{12}H_{17}NO)$이었다. PA ZVI가 PU ZVI 보다 metolachlor를 분해하는데 효율적임을 알 수 있었다. ZVI는 탈염소화기작에 의해 metolachlor를 분해함을 알 수 있었다.

Keywords

References

  1. Southwick, L. M., Willis, G. H., Bengston, R. L., and Lormand, T. J. (1990) Atrazine and metolachlor in subsurface drain water in Louisiana. J. Irrig. Drain. Eng. 116, 16-23 https://doi.org/10.1061/(ASCE)0733-9437(1990)116:1(16)
  2. Kruger, E. L., Zhu, B., and Coats, J. R. (1996) Relative mobility of atrazine, five atrazine degradates, metolachlor, and simazine in soils of Iowa. Environ. Taxicol Chem. 15, 691-695 https://doi.org/10.1897/1551-5028(1996)015<0691:RMOAFA>2.3.CO;2
  3. Novak, S. M., Portal, J. M., and Schiavon, M. (2001) Effects of soil type upon metolachlor losses in subsurface drainage. Chemosphere 42, 235-244 https://doi.org/10.1016/S0045-6535(00)00089-8
  4. Funari, E., Donati, L., Sandroni, D., and Vighi, M. (1995) Pesticide levels in groundwater: value and limitations of monitoring. In Pesticide Risk in Groundwater. Vighi, M. and Funari, E. (eds.) pp. 3-44. CRC Press, Boca Raton, FL
  5. Senseman, S. A., Lavy, T. L., Mattice, J. D., Gbur, E. E., and Briggs, W. S. (1997) Trace level pesticide detections in Arkansas surface waters. Environ. Sci. Technol. 31, 395-401 https://doi.org/10.1021/es960244c
  6. Yang, J. E., Chung, D. Y., Kim, J. G., and Chung, J. B. (2001) Soil contamination and agricultural environment. In Agricultural environment. Yang, J. E. and Lee, K. S. (eds) pp. 85-125. The Korean Society of Agriculture and Environment, Suwon, Korea
  7. Rock, M. L., Kearney, P. C., and Hetz, G. R. (1998) Innovative remediation technology. In Pesticide remediation in soils and water. Keamey, P. C and Roberts, T. (eds.) pp. 285-306. John Wiley & Sons, New York
  8. Singh, J., Comfort, S. D., and Shea, P. J. (1998) Remediating RDX-contaminated water and soil using zero-valent iron. J. Environ. Qual. 27, 1240-1245 https://doi.org/10.2134/jeq1998.00472425002700050032x
  9. Comfort, S. D., Shea, P. J., Machacek, T. A., Gaber, H., and Oh, B. T. (2001) Field-scale remediation of a metolachlor-contaminated spill site using zerovalent iron. J. Environ. Qual. 30, 1636-1643 https://doi.org/10.2134/jeq2001.3051636x
  10. Blowes, D. W., Ptacek, C. J., and Jabor, J. L. (1997) In situ remediation of Cr(VI)-contaminated groundwater using permeable reactive walls: Laboratory studies. Environ. Sci. Technol. 31, 3348-3357 https://doi.org/10.1021/es960844b
  11. Fiedor, J. N., Bostick, W. D., Jarabek, R. J., and Farrel, J. (1998) Understanding the mechanism of uranium removal from groundwater by zero-valent iron using X-ray photoelectron spectroscopy. Environ. Sci. Technol. 32, 1466-1473 https://doi.org/10.1021/es970385u
  12. Yang, J. E., Kim, J. S., Ok, Y. S., Kim, S. J., and Yoo, K. Y. (2006) Capacity of Cr(VI) reduction in an aqueous solution using different sources of zerovalent irons. Korean J. Chem. Eng. 23, 935-939 https://doi.org/10.1007/s11814-006-0011-5
  13. Hundal, L. S., Singh, J., Bier, E. L., Shea, P. J., Comfort, S. D., and Powers, W. L. (1997) Removal of TNT and RDX from water and soil using iron metal. Environ. Pollut. 97, 55-64 https://doi.org/10.1016/S0269-7491(97)00081-X
  14. Park, J., Comfort, S. D., Shea, P. J., and Machacek, T. A. (2004) Remediating munitions-contaminated soil with zerovalent iron and cationic surfactants. J. Environ. Qual. 33, 1305-1313 https://doi.org/10.2134/jeq2004.1305
  15. Leah, J. M. and Paul, G. T. (1994) Reductive dehalogenation of chlorinated methanes by iron metal. Environ. Sci. Technol. 28, 2045-2053 https://doi.org/10.1021/es00061a012
  16. Bae, B. (2000) The effects of environmental conditions on the reduction rate of TNT by $Fe^0$. J. Korean Soil Environ. Sci. 5, 82-97
  17. Kim, J. S. (2001) Reduction of Cr(VI) using zerovalent iron (ZVI). MS Thesis, Kangwon National University, Chuncheon, Korea
  18. Gotpagar, J. E., Grulke, T., and Bhattacharyya, D. (1997) Reductive dehalrogenation of trichloroethene using zero-valent iron. Environ. Prog. 16, 137-143 https://doi.org/10.1002/ep.3300160221
  19. Johnson, T. L., Scherer, M., and Tratnyek, P. G. (1996) Kinetics of halogenated organic compound degradation by iron metal. Environ. Sci. Technol. 30, 2634-2640 https://doi.org/10.1021/es9600901
  20. Gerald, R. E. and Douglas, T. D. (1998) Dechlorination of the chloroacetanilide herbicides alachlor and metolachlor by iron metal. Environ. Sci. Technol. 32, 1482-1487 https://doi.org/10.1021/es970678n
  21. Timothy M. V., Craig, S. C., and Perry, L. M. (1987) Transformations of halogenated aliphatic compounds. Environ. Sci. Technol. 21, 722-736 https://doi.org/10.1021/es00162a001

Cited by

  1. Determining Kinetic Parameters and Stabilization Efficiency of Heavy Metals with Various Chemical Amendment vol.44, pp.6, 2011, https://doi.org/10.7745/KJSSF.2011.44.6.1063
  2. Accelerated Metolachlor Degradation in Soil by Zerovalent Iron and Compost Amendments vol.84, pp.4, 2010, https://doi.org/10.1007/s00128-010-9963-6