Qi Peng, Hu Chun, Xing Xue-Ci, Bi Zhi-Hao, Li Ze-Song
Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Institute of Environmental Research at Greater Bay, Guangzhou University, Guangzhou 510006, China.
Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
Huan Jing Ke Xue. 2022 Feb 8;43(2):887-895. doi: 10.13227/j.hjkx.202106098.
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 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 spp., spp., , and 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 -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.
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效应却被忽视。为了解决普通石英砂在控制消毒副产物（DBPs）和机会性病原体（OPs）方面的局限性，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抑制效果分别提高了51.51%、43.66%和90.6%。此外，通过定量qPCR检测了某些菌属的基因拷贝数，结果表明铁砂对OPs确实具有类似的显著抑制作用。铁砂增强天然有机物（NOM）去除的能力有限。然而，铁砂有效地抑制了生物膜对N - DBPs和机会性病原体的持续贡献。铁砂滤料表面生物膜的分布均匀，不易脱落，更稳定；然而，出水中的悬浮生物膜更难聚集。此外，铁砂出水中细胞外蛋白质二级结构中的α - 螺旋消失。因此，整个悬浮生物膜很容易被氯穿透。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，这为确保饮用水水质安全提供了新的理念，并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。
