State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China.
Molecules. 2022 Nov 2;27(21):7454. doi: 10.3390/molecules27217454.
Natural organic matter (NOM) has always been considered the main precursor of disinfection by-products (DBPs) during the chlorine disinfection of drinking water. This research focuses on investigating the correlation between the functional group (carboxyl and carbonyl groups) content of NOM and the formation of trichloromethane (TCM) and chloral hydrate (CH). The quantitative determination of carboxyl groups, carbonyl groups, TCM, and CH were conducted during the drinking water treatment processes with different coagulant dosages and with/without pre-oxidation by KMnO or NaClO. The most appropriate coagulant for the removal of conventional components was polyaluminum chloride (PAC), and the dosage was 110 mg/L. Up to 43.7% and 14.5% of the carboxyl and carbonyl groups, respectively, were removed through the coagulation and sedimentation processes, which can be enhanced by increasing PAC dosage. The filtration process further increased the removal rates of these two functional groups to 59.8% and 33.5%, respectively. The formation potential of the TCM and CH decreased as the PAC dosage increased. Pre-oxidation by KMnO (0.8-1.0 mg/L) effectively controlled the formation of DBPs while increasing the carboxyl and carbonyl group content. Pre-oxidation by NaClO decreased the formation of TCM rather than CH, and a suitable amount (0.5-1.0 mg/L) decreased the carboxyl and carbonyl groups. It was found that there was a good linear correlation between carboxyl groups and TCM and CH. The linear fit R values of the carboxyl groups to TCM and CH were 0.6644 and 0.7957, respectively. The linear fit R values of the carbonyl groups to TCM and CH were 0.5373 and 0.7595, respectively.
天然有机物（NOM）一直被认为是饮用水氯消毒过程中消毒副产物（DBPs）的主要前体。本研究重点研究了 NOM 中官能团（羧基和羰基）含量与三氯甲烷（TCM）和氯仿（CH）形成之间的相关性。在不同混凝剂剂量和/或用 KMnO 或 NaClO 进行预氧化的饮用水处理过程中，对羧基、羰基、TCM 和 CH 进行了定量测定。去除常规成分的最适宜混凝剂是聚合氯化铝（PAC），剂量为 110mg/L。通过混凝和沉淀过程，分别去除了 43.7%和 14.5%的羧基和羰基，增加 PAC 剂量可以增强这一效果。过滤过程进一步将这两种官能团的去除率提高到 59.8%和 33.5%。随着 PAC 剂量的增加，TCM 和 CH 的生成潜能降低。用 KMnO（0.8-1.0mg/L）预氧化可有效控制 DBPs 的形成，同时增加羧基和羰基含量。用 NaClO 预氧化降低了 TCM 的生成而不是 CH 的生成，适量（0.5-1.0mg/L）则降低了羧基和羰基。发现羧基与 TCM 和 CH 之间存在良好的线性相关性。羧基与 TCM 和 CH 的线性拟合 R 值分别为 0.6644 和 0.7957。羰基与 TCM 和 CH 的线性拟合 R 值分别为 0.5373 和 0.7595。
