title: Bioreduction of para-chloronitrobenzene in drinking water using a continuous stirred hydrogen-based hollow fiber membrane biofilm reactor.
abstract: para-Chloronitrobenzene (p-CNB) is particularly harmful and persistent in the environment and is one of the priority pollutants. A feasible degradation pathway for p-CNB is bioreduction under anaerobic conditions. Bioreduction of p-CNB using a hydrogen-based hollow fiber membrane biofilm reactor (HFMBfR) was investigated in the present study. The experiment results revealed that p-CNB was firstly reduced to para-chloraniline (p-CAN) as an intermediate and then reduced to aniline that involves nitro reduction and reductive dechlorination with H(2) as the electron donor. The HFMBfR had reduced p-CNB to a major extent with a maximum removal percentage of 99.3% at an influent p-CNB concentration of 2mg/L and a hydraulic residence time of 4.8h, which corresponded to a p-CNB flux of 0.058g/m(2) d. The H(2) availability, p-CNB loading, and the presence of competing electron acceptors affected the p-CNB reduction. Flux analysis indicated that the reduction of p-CNB and p-CAN could consume fewer electrons than that of nitrate and sulfate. The HFMBfR had high average hydrogen utilization efficiencies at different steady states in this experiment, with a maximum efficiency at 98.2%.
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China. siqingxia@gmail.com
authors.forename: Siqing
authors.initials: S
authors.lastname: Xia
authors.forename: Haixiang
authors.initials: H
authors.lastname: Li
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Zhang
authors.forename: Yanhao
authors.initials: Y
authors.lastname: Zhang
authors.forename: Xin
authors.initials: X
authors.lastname: Yang
authors.forename: Renyong
authors.initials: R
authors.lastname: Jia
authors.forename: Kang
authors.initials: K
authors.lastname: Xie
authors.forename: Xiaotian
authors.initials: X
authors.lastname: Xu
mesh_terms: D018441:Biofilms; D003470:Culture Media; D006859:Hydrogen / Q000378:metabolism*; D008567:Membranes, Artificial; D009578:Nitrobenzenes / Q000378:metabolism*; D010084:Oxidation-Reduction; D014881:Water Supply
chemical_list: D003470:Culture Media; D008567:Membranes, Artificial; D009578:Nitrobenzenes; D006859:Hydrogen; C010407:4-chloronitrobenzene