氯、氯胺消毒下钱江源水源水消毒副产物形成特征研究

以钱江源水源水为研究对象,以氯、氯胺为消毒方式,研究了不同消毒条件下,三卤甲烷(THMs)、卤乙腈(HANs)、氯代酮(CKs)、二卤乙酸(DHAAs)、三卤乙酸(THAAs)等消毒副产物(DBPs)的形成情况,以便为水务工作者监测钱江源建库前后水质、DBPs形成的变化提供基础数据.结果显示,氯消毒下DBPs的产量比氯胺消毒高出3~7倍甚至1个数量级,但不管是氯消毒还是氯胺消毒,THMs、HAAs形成量均在我国饮用水标准范围内.氯消毒下,大部分DBPs产量为中、碱性条件酸性条件(除了CKs),氯胺消毒则呈现不同的情况(所有DBPs的产量均为p H=6、p H=7p H=8).消毒剂量对所有DBPs形成具有明显的促进作用;溴离子对THMs、DHANs、DHAAs的形成有明显的促进作用.进一步研究表明,钱江源水源水的水质比钱塘江下游九溪水源水好,DBPs形成也较低,某些指标(如有机碳、有机氮、HANs形成量等)甚至比同省水质较好的金兰水库还要好;而且由于其较高的比紫外吸收值(SUVA),DBPs的溴嵌入能力均比九溪水源水、金兰水库低.此外,就目前的钱江源水源水来说,控制消毒剂量(氯、或氯胺)是控制DBPs形成的有效策略.

Formation of disinfection by-products upon chlorination/chloramination of Qianjiang source water

In order to provide basic data for water department to monitor the changes of water quality and DBPs formation before and after the construction of the Qianjiang source reservoir, present study investigated the formation of disinfection by-products (DBPs), i.e. trihalomethanes (THMs), haloacetonitriles (HANs), chloroketones (CKs), dihaloacetic acids (DHAAs) and trihaloacetic aceids (THAAs), upon chlorination/chloramination of Qianjiang source water. The results showed that the DBPs yields under chlorine disinfection were 3~7 times higher or 1 order of magnitude higher than that of chloramine disinfection. However, whether for chlorination or chloramination, THMs and HAAs levels were within the scope of drinking water standards in China. For chlorination, most DBPs (except CKs) showed higher yields in neutral/alkaline condition than acid condition, but different situation was observed in chloramination (DBPs yields in pH=6, pH=7>pH=8). All DBPs yields increased with chlorine/chloramine dose; Bromine ion also showed a promotion effect on the formation of THMs, DHANs and DHAAs. Further study showed that water qualities of Qianjiang source water were much better than those in Jiuxi source water, which located in the downstream of Qiantang River. The formation of DBPs was also low, and some parameters (such as organic carbon, organic nitrogen, HANs formation, etc) were even better than Jinlan Reservoir, which had good water quality and located in the same province. Moreover, the bromide incorporation ability of DBPs formation in Qianjiang source water was relatively lower than that in Jiuxi source water and Jinlan Reservoir water due to it higher specific ultraviolet absorbance (SUVA). In addition, controlling chlorine/chloramine dose was an effective way for controlling DBPs formation of Qianjiang source water at present.