State Key laboratory of Pollution Control & Resources Reuse, School of the Environment, Nanjing University, 163, Xianlin Avenue, Nanjing 210023, Jiangsu, PR China; Ecology and Environmental Science Research & Design Institute of Zhejiang Province, 109, Tianmushan Road, Hangzhou 310007, Zhejiang, PR China.
State Key laboratory of Pollution Control & Resources Reuse, School of the Environment, Nanjing University, 163, Xianlin Avenue, Nanjing 210023, Jiangsu, PR China.
J Hazard Mater. 2023 Jun 5;451:131027. doi: 10.1016/j.jhazmat.2023.131027. Epub 2023 Feb 17.
Pathogens in natural water can pose great threat to public health and challenge water quality. In sunlit surface water, dissolved organic matters (DOMs) can inactivate pathogens due to their photochemical activity. However, the photoreactivity of autochthonous DOM derived from different source and their interaction with nitrate on photo-inactivation remained limited understood. In this study, the composition and photoreactivity of DOM extracted from Microcystis (ADOM), submerged aquatic plant (PDOM) and river water (RDOM) were studied. Results revealed that lignin and tannin-like polyphenols and polymeric aromatic compounds negatively correlated with quantum yield of DOM*, whilst lignin like molecules positively correlated with •OH generation. ADOM had highest photoinactivation efficiency of E. coli, followed by RDOM and PDOM. Both the photogenerated •OH and low energy DOM* could inactivate bacteria damaging cell membrane and causing increase of intracellular reactive species. PDOM with more phenolic or polyphenols compounds not only weaken its photoreactivity, also increase regrowth potential of bacteria after photodisinfection. The presence of nitrate counteracted with autochthonous DOMs on photogeneration of •OH and photodisinfection activity, as well as increased the reactivation rate of PDOM and ADOM, which might be attributed to the increase of survival bacteria and more bioavailable fractions provided in systems.
天然水中的病原体对公众健康构成极大威胁，并对水质构成挑战。在阳光照射的地表水，溶解有机物（DOM）由于其光化学活性而使病原体失活。然而，源自不同来源的土著 DOM 的光反应性及其对光失活过程中硝酸盐的相互作用仍知之甚少。在本研究中，研究了从微囊藻（ADOM）、水下植物（PDOM）和河水（RDOM）中提取的 DOM 的组成和光反应性。结果表明，木质素和单宁类多酚以及聚合芳香族化合物与 DOM的量子产率呈负相关，而木质素样分子与•OH 的生成呈正相关。ADOM 对大肠杆菌的光灭活效率最高，其次是 RDOM 和 PDOM。光生成的•OH 和低能量 DOM均可破坏细胞膜，使细胞内活性物质增加，从而灭活细菌。具有更多酚类或多酚类化合物的 PDOM 不仅削弱了其光反应性，而且还增加了细菌在光消毒后的再生潜力。硝酸盐的存在会与土著 DOM 相互作用，从而抑制•OH 的生成和光消毒活性，并增加 PDOM 和 ADOM 的复活率，这可能是由于系统中提供了更多的存活细菌和更具生物利用度的分数。
