| 长距离供水系统中消毒副产物分布特征及二次加氯的影响 |
| 摘要点击 1531 全文点击 540 投稿时间：2020-01-02 修订日期：2020-02-09 |
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| 中文关键词 消毒副产物 长距离供水管网 二次加氯 DBPs生成势 水质安全 |
| 英文关键词 disinfection by-products long-distance water supply network booster chlorination DBPs formation potential water quality safety |
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| 中文摘要 |
| 供水管网覆盖区域大，导致出厂消毒剂量不足以维持管网末梢余氯量，需进行途中二次投氯.以H市供水管网为目标，通过均匀布点采样分析，考察二次加氯消毒型管网中消毒副产物（disinfection by-products，DBPs）的分布特征.结果表明，管网中检出DBPs包括三氯甲烷（TCM）、一溴二氯甲烷（BDCM）、二溴一氯甲烷（DBCM）、三溴甲烷（TBM）、二氯乙酸（DCAA）、三氯乙酸（TCAA）、二氯乙腈（DCAN）、溴氯乙腈（BCAN）和三氯硝基甲烷（TCNM）等，所检水样中DBPs浓度均低于《生活饮用水卫生标准》（GB 5749-2006）规定的标准限值.二次加氯前检出质量浓度（以平均值±偏差表示）分别为：（8.08±3.34）、（9.77±2.91）、（7.38±4.82）、（2.65±2.02）、（2.95±3.26）、（6.02±6.06）、（3.13±2.48）、（1.61±2.05）和（0.15±0.10）μg·L-1.二次加氯后检出质量浓度分别为：（10.30±4.55）、（11.73±3.60）、（8.23±5.22）、（2.95±2.45）、（3.29±3.60）、（8.15±7.58）、（3.31±2.61）、（1.33±2.04）和（0.12±0.06）μg·L-1.二次加氯后DBPs含量相较于出厂水至二次加氯点呈明显上升趋势，三卤甲烷（THMs）和卤乙酸（HAAs）分别比前段管网含量升高6.32%~26.60%和5.32%~42.71%.此外，原水水质和季节变化对DBPs的形成有一定影响，夏季DBPs的水平普遍高于春季或秋季.出厂水及管网水DBPs生成势分析表明，H市供水系统中DBPs可能存在超标风险，后续需考虑进一步优化处理工艺以保障供水水质. |
| 英文摘要 |
| It is difficult for waterworks that add chlorine into finished water once to maintain sufficient residual chlorine at unfavorable points of the pipe network that supply water for large areas of coverage. Therefore, booster chlorination was employed for a long-distance water distribution system. The study was performed in H City with a water supply system serving about 400 km2 of downtown and rural areas. The purpose of this work is to obtain the distribution characteristics of disinfection by-products (DBPs) in the booster chlorination disinfection pipe network through uniformly distributed sampling analysis. The results showed that detected DBPs include trichloromethane (TCM), bromodichloromethane (BDCM), dibromochloromethane (DBCM) and tribromomethane (TBM), dichloroacetic acid (DCAA), trichloroacetic acid (TCAA), dichloroacetonitrile (DCAN), bromochloroacetonitrile (BCAN), and trichloronitromethane (TCNM). The concentrations of the regulated DBPs were found to be lower than the standard limits specified in the Sanitary Standard for Drinking Water (GB5749-2006). Before booster chlorination, the average concentrations of the DBPs mentioned (expressed as mean±deviation) were (8.08±3.34), (9.77±2.91), (7.38±4.82), (2.65±2.02), (2.95±3.26), (6.02±6.06), (3.13±2.48), (1.61±2.05), and (0.15±0.10) μg·L-1, while afterwards, they were increased to (10.30±4.55), (11.73±3.60), (8.23±5.22), (2.95±2.45), (3.29±3.60), (8.15±7.58), (3.31±2.61), (1.33±2.04), and (0.12±0.06) μg·L-1, respectively. Trihalomethanes (THMs) and haloacetic acids (HAAs) increased by 6.32%-26.60% and 5.32%-42.71%, respectively, after booster chlorination. In addition, raw water quality and seasonal changes had a certain impact on the occurrence of DBPs. The levels of DBPs in summer were generally higher than those in spring or autumn. According to the analysis of DBP formation potential of source water, finished water, and tap water, it was found that the risk of DBPs exceeding the standard limit may exist in the water supply system of H City; therefore, further optimization of the treatment process should be considered to ensure water quality. |
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