Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
J Environ Sci (China). 2019 Feb;76:142-153. doi: 10.1016/j.jes.2018.04.017. Epub 2018 Apr 26.
Simulated drinking water distribution system (DWDS) treated with O-BAC-Cl (ozone-biological activated carbon-chlorine) was constructed to study its effects on the regrowth of five typical opportunistic pathogens (OPs). It was found that O-BAC-Cl could significantly reduce the regrowth of target OPs in the effluents of DWDS compared with Cl and O-Cl with the same residual chlorine levels. However, the effect of O-BAC-Cl on the average numbers of target OPs gene markers in the biofilms of DWDS was not apparent, suggesting that OPs in the biofilms of DWDS were tolerant to the upstream disinfection process. The quantification of target OPs in the BAC-filter column demonstrated that OPs decreased with the increase of depth, which was likely due to the organic nutrient gradient and microbial competition inside the BAC-filter. Increase in the ozone dose could further reduce the OPs at the bottom of the BAC-filter. Spearman correlation analysis demonstrated that some significant correlations existed between target microorganisms, suggesting potential microbial ecological relationships. Overall, our results demonstrated that the BAC-filter may act as a "battlefield" suppressing the OPs through microbial competition. O-BAC-Cl could be an effective multi-barrier process to suppress the proliferation of OPs in the bulk water of DWDS. However, OPs protected by the biofilms of DWDS should receive further attention because OPs may be detached and released from the biofilms.
构建了采用 O-BAC-Cl（臭氧-生物活性炭-氯）处理的模拟饮用水分配系统（DWDS），以研究其对五种典型机会性病原体（OPs）再生的影响。结果发现，与相同余氯水平的 Cl 和 O-Cl 相比，O-BAC-Cl 可显著降低 DWDS 出水中目标 OPs 的再生。然而，O-BAC-Cl 对 DWDS 生物膜中目标 OPs 基因标志物平均数量的影响并不明显，这表明 DWDS 生物膜中的 OPs 对上游消毒过程具有耐受性。BAC 滤柱中目标 OPs 的定量分析表明，OPs 随深度的增加而减少，这可能是由于 BAC 滤柱内有机营养物质梯度和微生物竞争所致。臭氧剂量的增加可进一步降低 BAC 滤柱底部的 OPs。Spearman 相关性分析表明，目标微生物之间存在一些显著的相关性，表明存在潜在的微生物生态关系。总体而言，我们的结果表明，BAC 滤柱可能通过微生物竞争充当抑制 OPs 的“战场”。O-BAC-Cl 可能是抑制 DWDS 水体中 OPs 增殖的有效多屏障工艺。然而，受 DWDS 生物膜保护的 OPs 应引起进一步关注，因为 OPs 可能会从生物膜中脱落和释放。
