EFFECT OF CHLORIDE ON THE FORMATION OF POLYCHLORINATED DIBENZO-P-DIOXIONS DURING PHOTOTRANSFORMATION OF PENTACHLOROPHENOL
Most of the mass balance discrepancy of polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/F) is due to the octachlorinated dibenzo-p-dioxin (OCDD) congener, and photochemical synthesis of OCDD from pentachlorophenol (PCP) is suggested to be one of the most significant sources of OCDD in the environment. This paper first investigated the effect of chloride on OCDD formation from PCP under simulated sunlight irradiation. OCDD formation was relatively low when PCP was irradiated in Milli-Q water or saline water, whereas, OCDD formed rapidly in coexistence of Fe(III) and Cl– with a significant amount. OCDD, OCDF and 2-hydroxynonachlorodiphenyl ether was detected at 1.5 h irradiation, and the mass of OCDD is 10 times higher than that only Fe(III) existed. Formation of OCDD increased when Cl– increasing in the presence of Fe(III), and the amount of OCDD with 0.4 M Cl– was three times higher than that with 0.04 M Cl–. That is because chlorine radical (Cl·/Cl2 ·–), generated through irradiation of chloride in the presence of Fe(III), abstracted hydrogen from PCP to yield pentachlorophenoxy radical (PCP·), which then dimerized to OCDD. This study indicates the high possibility of OCDD formation from PCP in saline water with Fe(III).
Liu Hui Zhao Huimin Zhang Yaobin Quan Xie
Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education,China),School of Environmental and Biological Science and Technology,Dalian University of Technology,Dalian 116024,China
国际会议
北京
英文
1-6
2009-08-24（万方平台首次上网日期，不代表论文的发表时间）