Jia Aiyin, Wu Chunde, Duan Yan
School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China; The Key Laboratory of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou 510006, PR China.
School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China; The Key Laboratory of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou 510006, PR China; The Key Laboratory of Environmental Protection and Eco-Remediation of Guangdong Regular Higher Education Institutions, Guangzhou 510006, PR China.
J Hazard Mater. 2016 May 5;308:411-8. doi: 10.1016/j.jhazmat.2016.01.037. Epub 2016 Jan 18.
This study investigated the precursors and factors affecting formation of haloacetonitriles (HANs) and chloropicrin (TCNM) during chlorination/chloramination of eight amino acids in the effluent water of V-type clarifying filtration from a drinking water treatment plant. The yields of trichloroacetonitrile (TCAN), dichloroacetonitrile (DCAN) and TCNM were higher during chlorination than during chloramination. Tyrosine and tryptophan produced the greatest amount of DCAN and also generated a small amount of TCAN during chlorination process. Besides, the yields of DCAN were higher than TCNM during chlorination/chloramination. Contact time, Cl2:org-N molar ratios, pH, temperature and bromide ion affected nitrogenous disinfection by-products (N-DBPs) formation during chlorination of tryptophan in different degrees. TCAN, DCAN and TCNM formation showed the increasing and then decreasing with prolonged contact time. Higher Cl2:org-N molar ratios improved N-DBPs formation within a certain range. The pH affected N-DBPs formation differently. HANs increased with increasing pH from 5 to 6 and decreased with increasing pH from 6 to 9, while TCNM increased with increasing pH from 5 to 9. Higher temperatures enhanced TCNM formation, but reduced the formation of TCAN and DCAN. The presence of bromide ions improved the yields of HANs and TCNM and shifted N-DBPs to more brominated ones.
本研究调查了某饮用水处理厂V型澄清过滤出水中8种氨基酸在氯化/氯胺化过程中卤代乙腈（HANs）和三氯硝基甲烷（TCNM）的前体物质及影响其生成的因素。氯化过程中三氯乙腈（TCAN）、二氯乙腈（DCAN）和TCNM的生成量高于氯胺化过程。酪氨酸和色氨酸在氯化过程中产生的DCAN量最多，同时也生成少量TCAN。此外，在氯化/氯胺化过程中DCAN的生成量高于TCNM。接触时间、Cl2:有机氮摩尔比、pH值、温度和溴离子对色氨酸氯化过程中含氮消毒副产物（N-DBPs）的生成有不同程度的影响。随着接触时间延长，TCAN、DCAN和TCNM的生成呈现先增加后减少的趋势。在一定范围内，较高的Cl2:有机氮摩尔比促进N-DBPs的生成。pH值对N-DBPs生成的影响不同。HANs在pH值从5增加到6时增加，在pH值从6增加到9时减少，而TCNM在pH值从5增加到9时增加。较高的温度促进TCNM的生成，但减少TCAN和DCAN的生成。溴离子的存在提高了HANs和TCNM的生成量，并使N-DBPs向更多溴代产物转变。
