南方某市饮用水源三氯乙醛生成特性

Chloral hydrate formation characteristics of drinking water sources of a city in the south of China

以我国南方某市饮用水源为研究对象,分析了不同反应条件下的三氯乙醛（CH）生成情况、CH与常规消毒副产物（DBPs）的相关关系及水质指标与CH生成势（CHFP）的相关关系。结果表明,5-35℃温度范围内,CH生成量随着温度的升高而逐渐升高,45℃时,反应约30 h后CH降解速率大于生成速率,生成量逐渐减少;CH生成量随着pH的升高而逐渐降低,当pH=11时,CH已经完全降解;Cl2∶TOC=1∶1-4∶1（质量比）时,CH的生成量随着加氯量的增加而增加,但是当Cl2∶TOC〉4∶1时,CH的生成量基本保持不变。CH与两类常规DBPs（三卤甲烷（THMs）和卤乙酸（HAAs））之间均为正相关关系,且CH与卤乙酸（HAAs）的相关关系更为显著。与UV254和SUVA254相比,CHFP与TOC线性关系更为显著,可以根据原水的TOC来简单预测水体中的CHFP。

We analyzed the chloral hydrate（ CH） formation under different reaction conditions,the relationship between CH and conventional disinfection by-products（ DBPs） and the relationship between water quality indicators and CH formation potential（ CHFP） for drinking water sources of a city in the south of China. The results indicated that CH yields increased with the increase of temperature from 5℃ to 35℃. CH degradation rate was greater than its formation rate when the temperature was 45℃ after about 30 h of chlorination reaction,and CH yields began to decrease correspondingly. CH yields decreased with the increase of pH,and it decreased to zero when pH was 11. As Cl2∶ TOC（ mass ratio） was from 1∶ 1 to 4∶ 1,CH yields increased with the increase of chlorine dose. However,CH yields did not increse as Cl2∶ TOC was greater than 4∶ 1. The positive correlation was detected between CH and conventional DBPs,i. e.,THMs and HAAs. Furthermore,the relationship between CH and HAAs was more outstanding than that between CH and THMs. The linear relationship between CH formation potential（ CHFP） and TOC of raw water was more outstanding compared with UV254 and SUVA254,hence,CHFP could be predicted by TOC approximately.