High nitrate(NO_3^-)loading in water bodies is a crucial factor inducing the eutrophication of lakes.We tried to enhance NO_3^-reduction in overlying water by coupling sediment microbial fuel cells(SMFCs)with submerge...High nitrate(NO_3^-)loading in water bodies is a crucial factor inducing the eutrophication of lakes.We tried to enhance NO_3^-reduction in overlying water by coupling sediment microbial fuel cells(SMFCs)with submerged aquatic plant Ceratophyllum demersum.A comparative study was conducted by setting four treatments:open-circuit SMFC(Control),closed-circuit SMFC(SMFC-c),open-circuit SMFC with C.demersum(Plant),and closed-circuit SMFC with C.demersum(P-SMFC-c).The electrochemical parameters were documented to illustrate the bio-electrochemical characteristics of SMFC-c and P-SMFC-c.Removal pathways of NO_3^- in different treatments were studied by adding quantitative^(15)NO_3^- to water column.The results showed that the cathodic reaction in SMFC-c was mainly catalyzed by aerobic organisms attached on the cathode,including algae,Pseudomonas,Bacillus,and Albidiferax.The oxygen secreted by plants significantly improved the power generation of SMFC-c.Both electrogenesis and plants enhanced the complete removal of NO_3^- from the sediment–water system.The complete removal rates of added^(15)N increased by 17.6% and 10.2% for SMFC-c and plant,respectively,when compared with control at the end of experiment.The electrochemical/heterotrophic and aerobic denitrification on cathodes mainly drove the higher reduction of NO_3^- in SMFC-c and plant,respectively.The coexistence of electrogenesis and plants further increased the complete removal of NO_3^- with a rate of 23.1%.The heterotrophic and aerobic denitrifications were simultaneously promoted with a highest abundance of Flavobacterium,Bacillus,Geobacter,Pseudomonas,Rhodobacter,and Arenimonas on the cathode.展开更多
基金supported by the National Key Research and Development Plan of China (No. 2016YFC0500403-03)the Science and Technology Service Network Initiative of the Chinese Academy of Sciences (No. KFJ-STS-ZDTP-038)
文摘High nitrate(NO_3^-)loading in water bodies is a crucial factor inducing the eutrophication of lakes.We tried to enhance NO_3^-reduction in overlying water by coupling sediment microbial fuel cells(SMFCs)with submerged aquatic plant Ceratophyllum demersum.A comparative study was conducted by setting four treatments:open-circuit SMFC(Control),closed-circuit SMFC(SMFC-c),open-circuit SMFC with C.demersum(Plant),and closed-circuit SMFC with C.demersum(P-SMFC-c).The electrochemical parameters were documented to illustrate the bio-electrochemical characteristics of SMFC-c and P-SMFC-c.Removal pathways of NO_3^- in different treatments were studied by adding quantitative^(15)NO_3^- to water column.The results showed that the cathodic reaction in SMFC-c was mainly catalyzed by aerobic organisms attached on the cathode,including algae,Pseudomonas,Bacillus,and Albidiferax.The oxygen secreted by plants significantly improved the power generation of SMFC-c.Both electrogenesis and plants enhanced the complete removal of NO_3^- from the sediment–water system.The complete removal rates of added^(15)N increased by 17.6% and 10.2% for SMFC-c and plant,respectively,when compared with control at the end of experiment.The electrochemical/heterotrophic and aerobic denitrification on cathodes mainly drove the higher reduction of NO_3^- in SMFC-c and plant,respectively.The coexistence of electrogenesis and plants further increased the complete removal of NO_3^- with a rate of 23.1%.The heterotrophic and aerobic denitrifications were simultaneously promoted with a highest abundance of Flavobacterium,Bacillus,Geobacter,Pseudomonas,Rhodobacter,and Arenimonas on the cathode.
