Formation of disinfection byproducts upon chlorine dioxide preoxidation followed by chlorination or chloramination of natural organic matter

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• 作者：Xin Yang^a ; ^b ; ^{yangx36@mail.sysu.edu.cn} ; Wanhong Guo^a ; Wontae Lee^c ; ^{wtlee@kumoh.ac.kr}
• 关键词：Chlorine dioxide (ClO2) ; Disinfection byproducts (DBPs) ; Natural organic matter (NOM) ; Chlorination ; Chloramination
• 刊名：Chemosphere
• 出版年：2013
• 出版时间：June, 2013
• 年：2013
• 卷：91
• 期：11
• 页码：1477-1485
• 全文大小：625 K

文摘

Chlorine dioxide (ClO₂) is often used as an oxidant to remove taste, odor and color during water treatment. Due to the concerns of the chlorite formation, chlorination or chloramination is often applied after ClO₂ preoxidation. We investigated the formation of regulated and emerging disinfection byproducts (DBPs) in sequential ClO₂-chlorination and ClO₂-chloramination processes. To clarify the relationship between the formation of DBPs and the characteristics of natural organic matter (NOM), changes in the properties of NOM before and after ClO₂ oxidation were characterized by fluorescence, Fourier transform infrared spectroscopy (FTIR), and size and resin fractionation techniques. ClO₂ preoxidation destroyed the aromatic and conjugated structures of NOM and transformed large aromatic and long aliphatic chain organics to small and hydrophilic organics. Treatment with ClO₂ alone did not produce significant amount of trihalomethanes (THMs) and haloacetic acids (HAAs), but produced chlorite. ClO₂ preoxidation reduced THMs, HAAs, haloacetonitriles (HANs) and chloral hydrate (CH) during subsequent chlorination, but no reduction of THMs was observed during chloramination. Increasing ClO₂ doses enhanced the reduction of most DBPs except halonitromethanes (HNMs) and haloketones (HKs). The presence of bromide increased the formation of total amount of DBPs and also shifted DBPs to more brominated ones. Bromine incorporation was higher in ClO₂ treated samples. The results indicated that ClO₂ preoxidation prior to chlorination is applicable for control of THM, HAA and HAN in both pristine and polluted waters, but chlorite formation is a concern and HNMs and HKs are not effectively controlled by ClO₂ preoxidation.