Impact of UV/H2O2 Pre-Oxidation on the Formation of Haloacetamides and Other Nitrogenous Disinfection Byproducts during Chlorination

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• 作者：Wenhai Chu ; Naiyun Gao ; Daqiang Yin ; Stuart W. Krasner ; William A. Mitch
• 刊名：Environmental Science & Technology
• 出版年：2014
• 出版时间：October 21, 2014
• 年：2014
• 卷：48
• 期：20
• 页码：12190-12198
• 全文大小：347K
• ISSN：1520-5851

文摘

Haloacetamides (HAcAms), an emerging class of nitrogen-based disinfection byproducts (N-DBPs) of health concern in drinking water, have been found in drinking waters at 渭g/L levels. However, there is a limited understanding about the formation, speciation, and control of halogenated HAcAms. Higher ultraviolet (UV) doses and UV advanced oxidation (UV/H₂O₂) processes (AOPs) are under consideration for the treatment of trace organic pollutants. The objective of this study was to examine the potential of pretreatment with UV irradiation, H₂O₂ oxidation, and a UV/H₂O₂ AOP for minimizing the formation of HAcAms, as well as other emerging N-DBPs, during postchlorination. We investigated changes in HAcAm formation and speciation attributed to UV, H₂O₂ or UV/H₂O₂ followed by the application of free chlorine to quench any excess hydrogen peroxide and to provide residual disinfection. The results showed that low-pressure UV irradiation alone (19.5鈥?85 mJ/cm²) and H₂O₂ preoxidation alone (2鈥?0 mg/L) did not significantly change total HAcAm formation during subsequent chlorination. However, H₂O₂ preoxidation alone resulted in diiodoacetamide formation in two iodide-containing waters and increased bromine utilization. Alternatively, UV/H₂O₂ preoxidation using UV (585 mJ/cm²) and H₂O₂ (10 mg/L) doses typically employed for trace contaminant removal controlled the formation of HAcAms and several other N-DBPs in drinking water.