饮用水中嗅味物质N-氯代亚胺的分布规律研究

Investigation on the distribution of N-chloroaldimine odorants in drinking water

N-氯代亚胺是水中氨基酸经氯(胺)消毒后衍生的一类重要副产物。这类消毒副产物嗅阈值很低,易引起饮用水强烈的氯嗅问题。为明晰N-氯代亚胺在供水系统中的浓度水平和季节变化规律,对华东地区某自来水厂出厂水以及某供水管网末梢龙头水连续采样监测。结果表明:供水系统中N-氯代亚胺广泛存在出厂水和管网水中,其浓度范围为195.45~1048.71ng/L,检出频率为100%;N-氯代亚胺的浓度随季节变化明显,最高浓度水平出现在高藻期7、8月;在出厂水和龙头水所检样品中,N-氯代亚胺浓度超出嗅阈值的频率最高可达53.3%,对饮用水水质安全和品质提升构成严重威胁。

Chlor(am)ination-derived organic odorants N-chloroaldimine is one of the main disinfection by-products(DBPs)of amino acid production during chlor(am)ination process,which can cause odorous problem with low odor threshold.In order to clarify the concentration levels and seasonal distribution of N-chloroaldimine in water system,continuous sampling and monitoring methods were conducted for a typical drinking water treatment plant(DWTP)and tap water in east of China.The results indicated that N-chloroaldimine was widely present in finished water and tap water of the water supply system.Its concentration range was 195.45~1048.71ng/L,and the detection frequency was 100%.The concentration of N-chloroaldimine varied significantly in terms of season that the maximum concentration level occurred in July and August.The frequency of N-chloroaldimine concentration exceeding the odor threshold was up to 53.3%in samples,posing a serious risks to the quality and safety of drinking water.