ABSTRACT
Using a combined zero-valent iron (ZVI) and anaerobic sludge system as the platform, the hydrogen utilization and reductive mechanism of p-chloronitrobenzene (p-ClNB) were investigated in the study. Results showed that the corrosion of ZVI could be used as a source of electron donor for anaerobic microorganisms, and then enhanced reductive transformation of p-ClNB and production of methane. Thereinto, the transformation of p-ClNB was observed to have priority for the utilization of H(2). The enhancement factors (Q') for the reductive transformation of p-ClNB with exogenous H(2), reduced ZVI (RZVI), industrial ZVI (IZVI), and nanoscale ZVI (NZVI) as electron donors were 4.1-5.6, 14.8-35.1, 2.8-4.6, and 1.5-5.7, respectively. Results demonstrated that RZVI was the most effective type of electron donors, which was attributed to the production and utilization of H(2)/[H] simultaneously via the ZVI corrosion and microbial metabolism. It is hopeful for the application of ZVI to enhance the reductive transformation of analogous persistent organic pollutants in the anaerobic sludge system.
Subject(s)
Hydrogen/metabolism , Iron/metabolism , Nitrobenzenes/chemistry , Sewage/microbiology , Waste Disposal, Fluid/methods , Anaerobiosis , Biodegradation, Environmental , Corrosion , Iron/chemistry , Methane/chemistry , Methane/metabolism , Nitrobenzenes/metabolism , Water Pollutants, Chemical/chemistry , Water Pollutants, Chemical/metabolismABSTRACT
Lake and reservoir' s eutrophication and its produced microcystins (MCs) have enormous threats to ecological environment and human health. Because the conventional water pollution control techniques have definite limitations, it' s quite urgent to develop new technique to remove the MCs from water environment. MCs can be effectively degraded by specific microbes, and its intermediate and terminal products are non-toxic or low-toxic. This paper summarized the MCs-degrading microbial strains, biodegradation processes, mechanisms, and affecting factors, degraded products and their structural characteristics, and the applications of MCs-degrading microbial strains in water environment restoration. The further research directions were also proposed. It was hoped that this review could provide technical ideas for restoring MCs-polluted lakes and reservoirs and ensuring drinking water safety in China.
