城市污水中卤代乙腈、卤代硝基甲烷、卤代乙酰胺类消毒副产物的探讨

Discussion on Disinfection By-Products of Halogenoacetonitrile,Halonitromethane and Haloacetamide in Urban Wastewater

分析统计了某市中心城区7家典型污水处理厂连续3个月的进水样品及出水样品中卤代乙腈、卤代硝基甲烷、卤代乙酰胺3类消毒副产物,结果表明,3类消毒副产物在进水及出水样品中均有检出,其中,进水样品中消毒副产物检出结果为:卤代乙腈类的质量浓度为0~28.1μg/L,卤代硝基甲烷类的质量浓度为0~1.9μg/L,卤代乙酰胺类的质量浓度为0~30.6μg/L。出水样品中消毒副产物检出结果为:卤代乙腈类的质量浓度为0.1~561.1μg/L,卤代硝基甲烷类的质量浓度为0~13.0μg/L,卤代乙酰胺类的质量浓度为0~144.8μg/L。7家典型污水处理厂出水水质中3类消毒副产物均有检出且含量较高,其中卤代乙腈类质量浓度达到561.1μg/L;其次为卤代乙酰胺类质量浓度可达到144.8μg/L;卤代硝基甲烷质量浓度为13.0μg/L。从以上消毒副产物检出结果来看,目前污水处理厂的消毒处理工艺过程中使用的消毒药剂在消毒过程中可能存在分解或转化从而导致出水中消毒副产物含量偏高,污水处理厂的出水如不经处理直接排入水环境中,可能对目前的生态环境造可能造成一定的潜在风险。该调查研究可以为污水处理厂优化或改善消毒工艺技术流程提供数据技术支撑,污水处理厂可以在现有的工艺基础上进行适当的调整,以降低出水中高含量的消毒副产物可能对目前的生态环境带来的潜在风险。

Three kinds of disinfection byproducts such as halogenoacetonitrile,halonitromethane and haloacetamide were analyzed and counted in influent samples and effluent samples of seven typical wastewater treatment plants(WWTPs)in central urban area of a city for three consecutive months.The results showed that three kinds of disinfection byproducts were detected in both influent and effluent samples.Among them,the detection results of disinfection byproducts in influent samples were as follows.The mass concentration of halogenoacetonitrile ranged from O to 28.1μg/L,the mass concentration of halonitromethane ranged from 0 to 1.9μg/L,the mass concentration of haloacetamide ranged from 0 to 30.6μg/L.The results showed that the mass concentration of halogenoacetonitrile ranged from 0.1μg/L to 561.1μg/L,that of halonitromethane ranged from 0 to 13.0μg/L,and that of haloacetamide ranged from 0 to 144.8μg/L.Three kinds of disinfection byproducts were detected in the effluent water of 7 typical WWTPs,and the mass concentration of halogenoacetonitrile was 561.1μg/L.The mass concentration of haloacetamide was 144.8μg/L.The mass concentration of halonitromethane was 13.0μg/L.According to the above detection results of disinfection byproducts,the disinfection agents used in the disinfection treatment process of the current WWTP may decompose or transform during the disinfection process,resulting in a high content of disinfection byproducts in the efluent.If effluent from WWTP is discharged directly into the water environment without treatment,it may cause certain potential risks to the current ecological environment.This study can provide data technical support for WWTPs to optimize or improve the disinfection process technical flow,and WWTPs can make appropriate adjustments on the basis of the existing process to reduce the potential risks that high levels of disinfection byproducts in effluent may bring to the current ecological environment.