Acclimated sediment microbial fuel cells from a eutrophic lake for the in situ denitrification proce
Title:Acclimated sediment microbial fuel cells from a eutrophic lake for the in situ denitrification process
Author:Yuan Wang,Jiangjun Hu, Longmian Wang,Dan Shan, Xu Wang,Yimin Zhang,Xuhui Mao,Lei Xing, Dihua Wang
Publication:RSC Advancesvolume:83:6: 80079–80085 DOI: 10.1039/C6RA16510ATime:2016
Abstract:Sediment microbial fuel cells (SMFCs) with various external resistances were acclimated at the north of Lake Taihu for two months. Then, each SMFC was transferred to a container and operated in batch mode for evaluating its electrochemical and denitrification performances. The nitrate removal efficiencies of SMFCs that were connected to the external resistances of 510, 100, 51, 10 and 1Ωwere 12%, 20%, 32%, 42.1% and 60%, respectively. Conversely, the nitrate concentration increased by 0.05 mg L-1 for the SMFC with 1000Ωexternal resistance. The microbial community of the biocathode in the SMFC with 1Ωexternal resistance was determined. Proteobacteria (48.04%), Bacteroidetes (9.87%) and Chloroflexi (9.8%) were identified as the dominant phyla. The microbial community analysis and half-cell tests revealed that the acclimated biocathode could simultaneously promote a denitrification reaction and an oxygen reduction reaction. In addition, Nitrosomonadales and Nitrospirales on the biocathode facilitated the ammonia oxidation reaction which caused a mixed potential. The mixed potential was enhanced by increasing ammonia concentration and decreased the biocathode performance.