Key Laboratory of Yellow River Water Environment in Gansu Province, Lanzhou Jiaotong University, Lanzhou, 730070, China; College of Environment and Municipal Engineering, Lanzhou Jiaotong University, Lanzhou, 730070, China.
Key Laboratory of Yellow River Water Environment in Gansu Province, Lanzhou Jiaotong University, Lanzhou, 730070, China; College of Environment and Municipal Engineering, Lanzhou Jiaotong University, Lanzhou, 730070, China.
Chemosphere. 2024 Jun;358:142121. doi: 10.1016/j.chemosphere.2024.142121. Epub 2024 Apr 25.
Disinfection by-products (DBPs) are prevalent contaminants in drinking water and are primarily linked to issues regarding water quality. These contaminants have been associated with various adverse health effects. Among different treatment processes, nanofiltration (NF) has demonstrated superior performance in effectively reducing the levels of DBPs compared to conventional processes and ozone-biological activated carbon (O-BAC) processes. In this experiment, we systematically investigated the performance of three advanced membrane filtration treatment schemes, namely "sand filter + nanofiltration" (SF + NF), "sand filter + ozone-biological activated carbon + nanofiltration" (SF + O-BAC + NF), and "ultrafiltration + nanofiltration" (UF + NF), in terms of their ability to control disinfection by-product (DBP) formation in treated water, analyzed the source and fate of DBP precursors during chlorination, and elucidated the role of precursor molecular weight distribution during membrane filtration in relation to DBP formation potential (DBPFP). The results indicated that each treatment process reduced DBPFP, as measured by trihalomethane formation potential (THMFP) and haloacetic acid formation potential (HAAFP), with the SF + O-BAC + NF process being the most effective (14.27 μg/L and 14.88 μg/L), followed by the SF + NF process (21.04 μg/L and 16.29 μg/L) and the UF + NF process (26.26 μg/L and 21.75 μg/L). Tyrosine, tryptophan, and soluble microbial products were identified as the major DBP precursors during chlorination, with their fluorescence intensity decreasing gradually as water treatment progressed. Additionally, while large molecular weight organics (60-100,000 KDa) played a minor role in DBPFP, small molecular weight organics (0.2-5 KDa) were highlighted as key contributors to DBPFP, and medium molecular weight organics (5-60 KDa) could adhere to the membrane surface and reduce DBPFP. Based on these findings, the combined NF process can be reasonably selected for controlling DBP formation, with potential long-term benefits for human health.
消毒副产物（DBPs）是饮用水中的普遍污染物，主要与水质问题有关。这些污染物与各种不良健康影响有关。在不同的处理工艺中，与传统工艺和臭氧-生物活性炭（O-BAC）工艺相比，纳滤（NF）在有效降低 DBPs 水平方面表现出卓越的性能。在这项实验中，我们系统地研究了三种先进的膜过滤处理方案的性能，即“砂滤+纳滤”（SF+NF）、“砂滤+臭氧-生物活性炭+纳滤”（SF+O-BAC+NF）和“超滤+纳滤”（UF+NF），以控制处理水中消毒副产物（DBP）的形成，分析氯化过程中 DBPs 前体的来源和归宿，并阐明在与 DBP 形成潜力（DBPFP）相关的膜过滤过程中前体分子量分布的作用。结果表明，每个处理过程都降低了 DBPFP，以三卤甲烷形成潜力（THMFP）和卤乙酸形成潜力（HAAFP）衡量，SF+O-BAC+NF 工艺效果最佳（14.27μg/L 和 14.88μg/L），其次是 SF+NF 工艺（21.04μg/L 和 16.29μg/L）和 UF+NF 工艺（26.26μg/L 和 21.75μg/L）。酪氨酸、色氨酸和可溶微生物产物被确定为氯化过程中的主要 DBP 前体，随着水处理的进行，其荧光强度逐渐降低。此外，虽然大分子量有机物（60-100,000KDa）在 DBPFP 中作用较小，但小分子量有机物（0.2-5KDa）是 DBPFP 的关键贡献者，中分子量有机物（5-60KDa）可附着在膜表面并降低 DBPFP。基于这些发现，纳滤组合工艺可合理选择用于控制 DBP 的形成，对人类健康具有潜在的长期益处。
