Research Center for Environmental Quality Management, Graduate School of Engineering, Kyoto University, 1-2 Yumihama, Otsu, Shiga 520-0811, Japan.
Research Center for Environmental Quality Management, Graduate School of Engineering, Kyoto University, 1-2 Yumihama, Otsu, Shiga 520-0811, Japan.
Water Res. 2021 Mar 1;191:116827. doi: 10.1016/j.watres.2021.116827. Epub 2021 Jan 10.
The contribution of specific precursors to N-nitrosodimethylamine formation potential (NDMA FP) upon chloramination depends not only on their NDMA molar yields but also on their concentrations in the actual environment. We investigated the seasonal and diurnal patterns of the NDMA precursor N,N-dimethylformamide (DMF) and NDMA FP in the Yodo River basin, Japan, by examining water samples taken from inside the basin's largest sewage treatment plant (STP) as well as samples from five final effluents from four STPs, two main stream sites, and two tributary sites in the same basin. DMF and NDMA FP were found to be high in influent (raw sewage), and were found to be mostly removed during the STP treatment processes (especially with biological treatment). Nevertheless, DMF was found in concentrations of 0.06 to 31.7 µg/L in chlorinated effluents and in receiving rivers, while NDMA FP was detected in concentrations of 3.57 to 306 ng/L. Thus, STPs were shown to be an important source of DMF and NDMA FP to rivers. A strong positive correlation between NDMA FP and DMF was confirmed in the receiving river (K-M), indicating that DMF was an important NDMA precursor in the Yodo River basin. The contribution of DMF to NDMA FP was 15.8±11.2% (n = 4) in summer and 82.1±10.2% (n = 4) in winter in the main stream (site K-M) of the river due to insufficient dilution of chlorinated effluents from the largest STP. From the viewpoint of NDMA and NDMA FP control at downstream sites, monitoring and control of DMF at upstream sites are important.
在氯胺消毒过程中，特定前驱物对 N-亚硝基二甲胺形成潜力（NDMA FP）的贡献不仅取决于它们的 NDMA 摩尔产率，还取决于它们在实际环境中的浓度。我们通过检查日本与论河流域最大污水处理厂（STP）内部的水样以及来自四个 STP 的五个最终流出物、两个主要河流站点和同一流域的两个支流站点的水样，研究了 NDMA 前驱物 N，N-二甲基甲酰胺（DMF）和 NDMA FP 的季节性和日变化模式。DMF 和 NDMA FP 在进水（原污水）中含量较高，并且在 STP 处理过程中（特别是在生物处理过程中）大部分被去除。尽管如此，在氯化流出物和受纳河流中仍发现 DMF 的浓度为 0.06 至 31.7 µg/L，而 NDMA FP 的浓度为 3.57 至 306 ng/L。因此，STP 被证明是河流中 DMF 和 NDMA FP 的重要来源。在受纳河流（K-M）中证实了 NDMA FP 和 DMF 之间存在很强的正相关，表明 DMF 是与论河流域中重要的 NDMA 前驱物。由于最大 STP 的氯化流出物稀释不足，DMF 对 NDMA FP 的贡献在夏季为 15.8±11.2%（n=4），在冬季为 82.1±10.2%（n=4）。从下游站点 NDMA 和 NDMA FP 控制的角度来看，监测和控制上游站点的 DMF 非常重要。
