期刊
ENVIRONMENTAL SCIENCE & TECHNOLOGY
卷 56, 期 9, 页码 5497-5507出版社
AMER CHEMICAL SOC
DOI: 10.1021/acs.est.1c08293
关键词
Mn(II) oxidation; microbial-mediated processes; kinetics; adsorption; Mn deposits; Mn(II)-oxidizing bacteria; biofilms
资金
- National Natural Science Foundation of China [51978652]
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences [20Z02KLDWST]
This study investigates the processes of microbial-mediated Mn(II) oxidation and deposit formation in pipeline loops. The results show that it takes 20 days for the microbial oxidation and deposition to be initiated in new pipes continuously receiving Mn(II). The accumulation of deposits accelerates once started. Without oxygen, Mn(II) rapidly decreases through adsorption to deposits. Compared to no Mn condition, the input of Mn(II) results in a significant increase in biofilm formation.
Microbial Mn(II) oxidation occurs in areas withinsufficient disinfectants in drinking water distribution systems.However, the overall processes of microbial-mediated Mn depositformation are unclear. This research investigated the initial Mn(II)oxidation, deposit accumulation, and biofilm development in pipeloops fed with nondisinfectedfinished water for 300 days. Theresults show that it took 20 days for microbial Mn(II) oxidationand deposition to be initiated visibly in new pipes continuouslyreceiving 100 mu g/L Mn(II). Once started, the deposit accumu-lation accelerated. A pseudo-first-order kinetic model couldsimulate the disappearance of Mn(II) in well-mixed pipe loopwater. The observed rate constant reached 2.81 h-1[correspond-ing 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 mu g/L through adsorption to deposits, indicating that after theinitial microbial formation of MnOx, subsequent MnOxaccumulation was attributable to a combination of microbial andphysicochemical processes. Compared to the no-Mn condition, Mn(II) input resulted in 1 order of magnitude increase in biofilmformation. This study sheds light on the increasingly rapid processes of Mn accumulation on the inner surfaces of water pipesresulting from the biological activity of Mn(II)-oxidizing biofilms and the build-up of MnOxwith strong adsorption capacity.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据