控制饮用水处理工艺及配水管网中卤乙酸的研究

A Study on Haloacetic Acids Control in Drinking Water Treatment Process and Distribution System

研究了北京市第九水厂处理工艺过程中卤乙酸的去除特性，并测定了五个水厂配水管网中卤乙酸的变化情况。结果表明：①传统水处理工艺对卤乙酸的去除率仅在２０％以下；活性炭对卤乙酸的去除效果较好，不同运行时期的炭床对其进水中的卤乙酸去除率为５０％～８５％，去除的卤乙酸占预氯化后水厂进水中卤乙酸总量的４０％～７０％，其去除作用包括活性炭的吸附和炭床中的生物分解，两者所去除的卤乙酸量基本相同。②配水管网中影响卤乙酸变化的因素较多，如清水池停留时间较短，出水余氯较高，则可能在管网前部继续生成卤乙酸，使其浓度升高；在管网末梢，余氯较低，在微生物的作用下卤乙酸浓度将降低。

Characteristics of haloacetic acids (HAAs) removal were studied in Beijing No. 9 Water words. Changes of HAAs concentration in five distrbubion systems served by five water works were also measured. The results showed that: (1) HAAs removal efficiency was low by conventional treatment process, with a removal of less than 20 % . Activated carbon had a satisfactory removal for HAAs, with a removal of 50 % ～85 % depending on operation time of carbon bed, which consists of 40 % ～70 % of total HAAs in the raw water after pre chlorination. Both carbon adsorption and biological degradation in the carbon bed had roughly the same contrbution to the HAAs removal. (2) HAAs in the distribution system was influenced by many factors. In the front part of pipe networks, HAAs concentration could increase in the situation of short hydraulic retention time in clear well and high residual chloring, while in the end part where low residual chlorine concentration existed, HAAs concentration was reduced by microbilogical degradation in the pipe networks.