State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, 100084, China; College of Civil Engineering, Huaqiao University, Xiamen, 361021, China.
State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, 100084, China.
Water Res. 2015 Dec 15;87:292-8. doi: 10.1016/j.watres.2015.09.040. Epub 2015 Sep 28.
Some N-nitrosamines (NAs) have been identified as emerging disinfection by-products during water treatment. Thus, it is essential to understand the characteristics of the NA precursors. In this study, the polarity rapid assessment method (PRAM) and the classical resin fractionation method were studied as methods to fractionate the NA precursors during drinking water treatment. The results showed that PRAM has much higher selectivity for NA precursors than the resin approach. The normalized N-nitrosodimethylamine formation potential (NDMA FP) and N-nitrosodiethylamine (NDEA) FP of four resin fractions was at the same level as the average yield of the bulk organic matter whereas that of the cationic fraction by PRAM showed 50 times the average. Thus, the cationic fraction was shown to be the most important NDMA precursor contributor. The PRAM method also helped understand which portions of the NA precursor were removed by different water treatment processes. Activated carbon (AC) adsorption removed over 90% of the non-polar PRAM fraction (that sorbs onto the C18 solid phase extraction [SPE] cartridge) of NDMA and NDEA precursors. Bio-treatment removed 80-90% of the cationic fraction of PRAM (that is retained on the cation exchange SPE cartridge) and 40-60% of the non-cationic fractions. Ozonation removed 50-60% of the non-polar PRAM fraction of NA precursors and transformed part of them into the polar fraction. Coagulation and sedimentation had very limited removal of various PRAM fractions of NA precursors.
一些 N-亚硝胺（NAs）已被确定为水处理过程中新兴的消毒副产物。因此，了解 NA 前体的特性至关重要。在这项研究中，极性快速评估方法（PRAM）和经典树脂分级方法被研究作为在饮用水处理过程中分级 NA 前体的方法。结果表明，PRAM 对 NA 前体的选择性远高于树脂方法。四种树脂级分的归一化二甲基亚硝胺形成潜能（NDMA FP）和二乙基亚硝胺（NDEA）FP 与总有机物质的平均产率相当，而 PRAM 阳离子级分的产率则为平均产率的 50 倍。因此，阳离子级分被认为是最重要的 NDMA 前体贡献者。PRAM 方法还有助于了解不同水处理工艺去除了哪些 NA 前体部分。活性炭（AC）吸附去除了超过 90%的非极性 PRAM 级分（即吸附到 C18 固相萃取 [SPE] 小柱上的部分）的 NDMA 和 NDEA 前体。生物处理去除了 PRAM 阳离子级分的 80-90%（即保留在阳离子交换 SPE 小柱上的部分）和 40-60%的非阳离子级分。臭氧氧化去除了 50-60%的非极性 PRAM 级分的 NA 前体，并将部分前体转化为极性级分。混凝和沉淀对各种 PRAM 级分的 NA 前体去除率非常有限。
