The Study on the Change of Iron Concentration and the Reaction Mechanism of the 1,4-Dioxane Degradation using Zero Valent Iron and UV

영가철(Fe$^0$)과 UV를 이용한 1,4-dioxane 분해 반응시 철농도의 변화와 반응 메커니즘의 연구

  • Son, Hyun-Seok (Institute of Health & Environment, Seoul National University) ;
  • Im, Jong-Kwon (Department of Environmental Health, Graduate School of Public Health, Seoul National University) ;
  • Zoh, Kyung-Duk (Department of Environmental Health, Graduate School of Public Health, Seoul National University)
  • 손현석 (서울대학교 보건환경연구소) ;
  • 임종권 (서울대학교 보건대학원 환경보건학과) ;
  • 조경덕 (서울대학교 보건대학원 환경보건학과)
  • Published : 2008.03.31

Abstract

The study presents the results of 1,4-dioxane degradation using zero valent (Fe$^0$) or Fe$^{2+}$ ions with and without UV. During the reaction, the change of [Fe$^{2+}$] and [Fe$^{2+}$]/[Fe(t)], the concentration ratio of ferrous ion to total iron ion in solution was measured. Less than 10% degradation of 1,4-dioxane was observed by UV-only, Fe$^0$-only, and Fe$^{2+}$-only conditions, and also the changes of [Fe$^{2+}$] and [Fe$^{2+}$]/[Fe(t)] were minimal in each reaction. However, the oxidation of Fe$^0$ was enhanced with the irradiation of UV by approximately 25% and the improvement of 1,4-dioxane degradation was observed. Fenton reaction ($Fe^{2+}+H_2O_2$) showed higher degradation efficiency of 1,4-dioxane until 90 min, which of the degradation was stopped after that time. In the reaction of Fe$^{2+}$ and UV, the ratio of [Fe$^{2+}$]/[Fe(t)] decreased then slowly increased after a certain time indicating the reduction of Fe3+ to Fe$^{2+}$. In case of Fe$^0$ in the presence of UV, the first-order rate constant was found to be 1.84$\times$10$^{-3}$ min$^{-1}$ until 90 min, and then changed to 9.33$\times$10$^{-3}$ min$^{-1}$ when the oxidation of Fe$^{2+}$ mainly occurred. In this case [Fe$^{2+}$]/[Fe(t)] kept decreasing for the reaction. However, the addition of perchlortae (ClO$_4^-$) in the reaction of Fe$^0$ and UV induced the continuous increase of [Fe$^{2+}$]/[Fe(t)] ratio. The results mean the primary degradation factor of 1,4-dioxane is the oxidation by the radicals generated from the redox reaction between Fe$^{2+}$ and Fe$^{3+}$. Also, both UV and ClO$_4^-$ played the role inducing the reduction of Fe$^{3+}$, which is important to degrade 1,4-dioxane by enhancing the generation of radicals.

본 논문은 1,4-dioxane의 분해를 위한 Fe$^0$와 Fe$^{2+}$의 반응에서 UV의 영향을 평가하기 위해 반응 중 [Fe$^{2+}$]와 용액 중 총철이온 농도에 대한 [Fe$^{2+}$]의 비([Fe$^{2+}$]/[Fe(t)])의 변화를 조사하였다. UV, Fe$^0$, 그리고 Fe$^{2+}$의 단독반응에 의한 1,4-dioxane의 분해효율은 10% 이하였으며 그 반응 동안 [Fe$^{2+}$]와 [Fe$^{2+}$]/[Fe(t)]의 변화 또한 거의 일어나지 않았다. 그러나 UV 조사에 의해 Fe$^0$의 산화는 약 25% 정도 증가하였을 뿐만 아니라 1,4-dioxane의 분해 효율 또한 개선되었다. Fenton 반응($Fe^{2+}+H_2O_2$)의 경우 반응초기 90분까지는 매우 빠른 분해율을 보인 반면 90분 이후에는 1,4-dioxane의 분해가 거의 정지되었다. Fe$^{2+}$와 UV 반응에서는 [Fe$^{2+}$]/[Fe(t)]가 반응 시작부터 감소하다가 90분 이후부터 완만한 증가를 보였다. Fe$^0$와 UV 반응의 경우 반응속도 상수는 반응시작 90분 동안 1.84$\times$10$^{-3}$ min$^{-1}$에서 Fe$^{2+}$의 변화가 일어나는 시간인 90분 이후 9.33$\times$10$^{-3}$ min$^{-1}$로 큰 상승을 보였고 이 변화는 [Fe$^{2+}$]/[Fe(t)]이 감소이후에 일어났다. [Fe$^{2+}$]/[Fe(t)]는 Fe$^{2+}$와 UV 반응에서 계속적으로 감소하였다. 그러나 그 반응에 ClO$_4^-$를 첨가한 경우 [Fe$^{2+}$]/[Fe(t)]는 완만한 상승을 보였다. 이 결과들은 1,4-dioxane의 분해는 주로 Fe$^0$이 Fe$^{2+}$로 산화되는 기간이 아닌 Fe$^{2+}$가 Fe$^{3+}$로 산화, 환원되는 반응 동안 일어났음을 보여준다. 즉, 1,4-dioxane의 주요 분해는 철순환에서 생성되는 라디칼에 의한 산화작용이라 할 수 있다. 또한 UV와 ClO$_4^-$는 Fe$^{3+}$의 환원에 큰 작용을 하는 것으로 관찰되었고 이는 radical의 지속적인 생산이라는 측면에서 1,4-dioxane의 분해효율을 증가시키기 위해 매우 중요한 부분이라 할 수 있다.

Keywords

References

  1. Budavari, S., "Merck Index. An encyclopedia of chemicals, drugs, and biological," 13th ed.; Merck and Co. Inc.: Rahway, NJ, pp. 1204-1210(2001)
  2. Beckett, M. A., and Hua, I., "Elucidation of the 1,4-dioxane decomposition pathway at discrete ultrasonic frequencies," Environ. Sci. Technol., 34, 3944-3953(2000) https://doi.org/10.1021/es000928r
  3. Lesage, S., Jackson, R. E., Priddle, M. W., and Riemann, P. G., "Occurrence and fate of organic solvent residues in anoxic groundwater at the gloucester landfill," Environ. Sci. Technol., 24, 559-566(1990) https://doi.org/10.1021/es00074a016
  4. Tom, M., "GRA's 1,4-dioxane conference profiles national challenge of emerging and unregulated contaminants," in proceedings of the 2003 GRA's ninth symposium on groundwater contaminants focused 1,4-dioxane & other solvent stabilizer compounds in the environment, Groundwater Resource Association, San Jose, pp. 164-168(2003)
  5. Chemical Safety Information from Intergovernmental Orgainzations Home Page, http://www.inchem.org/documents/iarc/vol71/019-dioxane.html, July(1999)
  6. Urbansky, E. T. and Schock, M. R., "Issues in managing the risks associated with Perchlorate in drinking water," J. Environ. Mange., 56, 79-95(1999) https://doi.org/10.1006/jema.1999.0274
  7. Wolff, J., "Perchlorate and the Thyroid Gland," Pharmacol. Rev., 50(1), 89-105(1998)
  8. Renner, R., "High Levels of perchlorate found in US mothers' milk," Environ. Sci. Technol. A-Pages, 39(7), 144-145(2005) https://doi.org/10.1021/es0532279
  9. U.S. Environmental Protection Agency homepage, http://www.epa.gov/iris/subst/1007.htm, February(2005)
  10. Mantha, R., Talyor, K. E., and Bewtra, J. K., "A Continuous system for $Fe^{0}$ reduction of nitrobenzene in synthetic Wastewater," Environ. Sci. Technol., 35, 3231-3236(2001) https://doi.org/10.1021/es0014943
  11. Moor, J. K., Doney, S. C., Glover, D. M., and Fung, I. Y., "Iron cycling and nutrient-limitation patteres in surface waters of world ocean," Deep-Sea Research II, 49, 493-507(2002)
  12. Pignatello, J. J., "Dark and photoassisted $Fe^{3+}$-catalyzed degradation of chlorophenoxy herbicides by hydrogen peroxide," Environ. Sci. Technol., 26(5), 944-951(1992) https://doi.org/10.1021/es00029a012
  13. Walling, C. and Goosen, A., "Mechanism of the ferric ion catalyzed decomposition of hydrogen peroxide. Effect of organic substrates," J. Am. Chem. Soc., 95, 2987-2991(1973) https://doi.org/10.1021/ja00790a042
  14. 박성호, 한인섭, "$Fe^{0}, Fe^{2+}, Fe^{3+}/H_{2}O_{2}$ 시스템을 이용한 침출수의 Fenton 산화반응," 대한환경공학회지, 27(4), 402-408(2005)
  15. Wust, W. F., Kober, R., Schlicker, O., and Dahmke, A., "Combined zero- and First-order kinetic model of the degradadtion TCE and cis-DCE with commercial iron," Environ. Sci. Technol., 33, 4304-4309(1999) https://doi.org/10.1021/es980439f
  16. Arnold, W. and Roberts, A. L., "Pathway and kinetics of chllorinated Ethylene and chlorinated acetylene reaction with $Fe^{0}$ Particles," Environ. Sci. Technol., 34, 1794-1805(2000) https://doi.org/10.1021/es990884q
  17. APHA, AWWA, and WEF, "Standard Methods for the examination of water and Wastewater: 20th Edition," APHA, 3.75-3.78(1998)
  18. Devlin, J. F., Klausen, J., and Schwarzenbch, R. P., "Kinetics of nitroaromatic reduction on granular iron in recirculating bactch experiments," Environ. Sci. Technol., 32, 1941-1947(1998) https://doi.org/10.1021/es970896g
  19. Legrinl, O., Oliveros, E., and Braun, A. M., "Photochemical Processes for water treatment," Chem. Rev., 93, 671-698(1993) https://doi.org/10.1021/cr00018a003
  20. Lopes, L., de Laat, J., and Legube, B., "Charge Transfer of iron(III) monomeric and oligomeric aqua hydroxo complexes: Semiempirical investigation into photoactivity," Inorg. Chem., 41, 2505-2517(2002) https://doi.org/10.1021/ic011029m
  21. Chen, F., He, J. J., and Zhao, J. C., "Fenton degradation of malachite green catalyzed by aromatic additives," J. Phys. Chem. A., 106(41), 9485-9490(2002) https://doi.org/10.1021/jp0144350
  22. Pignatello, J. J., "Dark and photoassisted $Fe^{3+}$-catalyzed degradation of chlorophenoxy herbicides by hydrogen peroxide," Environ. Sci. Technol., 26(5), 944-951(1992) https://doi.org/10.1021/es00029a012
  23. Mater, L., Rosa, E. V. C., Berto, J., Correa, A. X. R., Schwingel, P.R., and Radetski, C. M., "A simple methodology to evaluate influence of $H_{2}O_{2}$ and $Fe^{2+}$ concentrations on the mineralization and biodegradability of organic compounds in water and soil contaminated with crude petroleum," J. Hazard. Mater., 149, 379-386(2007) https://doi.org/10.1016/j.jhazmat.2007.04.005
  24. Rush, J. D., Bielski, B. H. J., "Pulse radiolytic studies of the reactions of $HO_{2}/O_{2}^{-}$ with Fe(II)/Fe(III) ions. The reactivity of $HO_{2}/O_{2}^{-}$ with ferric ions and its implication on the Haber-Weiss reaction," J. phys. Chem., 89, 5062-5066(1985) https://doi.org/10.1021/j100269a035
  25. Song, W., Ma, W., Ma, J., Chen, C., Zhao, J., Huang, Y., and Xu, Y., "Photochemical oscillation of Fe(II)/Fe(III) ratio induced by periodic flux of dissolved organic matter," Environ. Sci. Technol., 39, 3121-3127(2005) https://doi.org/10.1021/es0483701