Synergistic Control of Nitrogenous Disinfection By-products and Opportunistic Pathogens in Drinking Water by Iron-Modified Quartz Sand Filtration
Synergistic Control of Nitrogenous Disinfection By-products and Opportunistic Pathogens in Drinking Water by Iron-Modified Quartz Sand Filtration
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DOI：
10.13227/j.hjkx.202106098
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发表时间：
2022-02-15
期刊：
影响因子：
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通讯作者：
Li Ze-song
中科院分区：
文献类型：
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作者：
Qi Peng;Hu Chun;Li Ze-song
石英砂在饮用水处理中的主要作用一直是去除浊度，而其固液界面的微生物作用一直被忽视。为了解决铁对普通石英砂中消毒副产物（DBPs）和机会致病菌（OPs）控制的局限性，将普通石英砂改性为铁砂。采用气相色谱-电子捕获检测器（ECD）测定了典型含氮消毒副产物（N-DBPs）和含碳消毒副产物的最大DBPs生成潜力。与砂相比，铁砂对卤代硝基甲烷、卤代乙酰胺和卤代乙腈的缓蚀效果提高了51。51%，43. 66%，90。6%，分别。此外，蠕虫状哈特曼氏菌，军团菌属，分枝杆菌属，M. avium和耐格里属（Naegleria spp.）通过定量qPCR检测，结果表明铁砂确实对OP具有类似的显著抑制作用。铁砂对NOM的去除效果有限，但能有效抑制生物膜对N-DBPs和条件致病菌的持续贡献。铁砂滤料表面生物膜分布均匀，不易脱落，且较为稳定，但出水中悬浮生物膜较难聚集。此外，胞外蛋白二级结构的α-螺旋在铁砂的流出物中消失。因此，整个悬浮生物膜很容易被氯气穿透。铁砂固液界面确实显著改变了微生物群落结构和悬浮生物膜特性，为保障饮用水水质安全提供了新的理念，对饮用水处理厂现有工艺的改进和改造起到了良好的理论支撑作用。
The main function of quartz sand in drinking water treatment has been to remove turbidity, while the microbial effect of its solid-liquid interface has been ignored. In order to iron solve the limitations of control of the disinfection by-products (DBPs) and opportunistic pathogens (OPs) in common quartz sand, the common quartz sand was modified to iron sand. The maximum DBPs formation potential of typical nitrogenous disinfection by-products ( N-DBPs ) and carbonaceous disinfection by-products was determined using gas chromatography-ECD. Compared with those of sand, the inhibition effects of halonitromethanes, haloacetamides, and haloacetonitriles by the Fe-sand were increased by 51. 51% , 43. 66% , and 90. 6% , respectively. In addition, the gene copy numbers of Hartmanella vermiformis , Legionella spp., Mycobacterium spp., M. avium, and Naegleria spp. were detected via quantitative qPCR, and the results indicated that the Fe-sand did have a similar significant inhibitory effect on OPs. The Fe-sand had limited ability to enhance the removal of NOM. However, the Fe-sand effectively inhibited the continuous contribution of biofilm to N-DBPs and opportunistic pathogens. The distribution of biofilms on the surface of the Fe-sand filter media was uniform, not likely to fall off, and more stable; however, the suspended biofilms in the effluent were more difficult to aggregate. In addition, the alpha-helix of the secondary structure in the extracellular protein disappeared in the effluent of the Fe-sand. Therefore, the whole suspended biofilm was easily penetrated by chlorine. The Fe-sand solid-liquid interface did significantly change the microbial community structure and suspended biofilm characteristics, which provides a new concept to ensure the safety of drinking water quality and plays a good theoretical supporting role in the improvement and transformation of the existing process in drinking water treatment plants.