Initial Formation and Accumulation of Manganese Deposits in Drinking Water Pipes: Investigating the Role of Microbial-Mediated Processes.
Initial Formation and Accumulation of Manganese Deposits in Drinking Water Pipes: Investigating the Role of Microbial-Mediated Processes.
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DOI：
10.1021/acs.est.1c08293
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发表时间：
2022-04
影响因子：
11.4
通讯作者：
Guiwei Li;Yuliang Su;Bin Wu;Guohang Han;Jianwei Yu;Min Yang;Baoyou Shi
中科院分区：
文献类型：
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作者：
Guiwei Li;Yuliang Su;Bin Wu;Guohang Han;Jianwei Yu;Min Yang;Baoyou Shi
微生物Mn（II）氧化发生在饮用水分配系统中消毒剂不足的地区。然而，微生物介导的锰存款形成的整体过程尚不清楚。本研究调查了初始锰（II）氧化，存款积累，和生物膜的发展，在管回路与非消毒成品水喂养300天。结果表明，在连续接受100 μg/L Mn（II）的新管道中，微生物Mn（II）的氧化和沉积需要20 d才能明显开始。一旦启动，存款的积累就加速了。一个伪一级动力学模型可以模拟Mn（II）在良好混合的管回路水中的消失。观察到的速率常数达到2.81 h-1 [对应于Mn（II）的半衰期为0.25 h]后，136天的操作。在没有氧气的情况下，水中的Mn（II）也通过吸附沉积物迅速下降至1.0 μg/L，表明在最初的微生物形成MnOx之后，随后的MnOx积累可归因于微生物和物理化学过程的组合。与无锰条件相比，Mn（II）输入导致生物膜形成增加1个数量级。这项研究揭示了越来越快的过程中锰积累的水管内表面上的锰（II）氧化生物膜的生物活性和MnOx的建立具有较强的吸附能力。
Microbial Mn(II) oxidation occurs in areas with insufficient disinfectants in drinking water distribution systems. However, the overall processes of microbial-mediated Mn deposit formation are unclear. This research investigated the initial Mn(II) oxidation, deposit accumulation, and biofilm development in pipe loops fed with nondisinfected finished water for 300 days. The results show that it took 20 days for microbial Mn(II) oxidation and deposition to be initiated visibly in new pipes continuously receiving 100 μg/L Mn(II). Once started, the deposit accumulation accelerated. A pseudo-first-order kinetic model could simulate the disappearance of Mn(II) in well-mixed pipe loop water. The observed rate constant reached 2.81 h-1 [corresponding to a Mn(II) half-life of 0.25 h] after 136 days of operation. Without oxygen, Mn(II) in the water also decreased rapidly to 1.0 μg/L through adsorption to deposits, indicating that after the initial microbial formation of MnOx, subsequent MnOx accumulation was attributable to a combination of microbial and physicochemical processes. Compared to the no-Mn condition, Mn(II) input resulted in 1 order of magnitude increase in biofilm formation. This study sheds light on the increasingly rapid processes of Mn accumulation on the inner surfaces of water pipes resulting from the biological activity of Mn(II)-oxidizing biofilms and the build-up of MnOx with strong adsorption capacity.