Electrochemical effect on denitrification in different microenvironments around anodes and cathodes.
A bio-anode reactor and a bio-cathode reactor were developed to investigate the microenvironments around anodes and cathodes and their effects on denitrification. With an applied current of 40 mA, the oxidation-reduction potentials (ORPs) in the bio-cathode and bio-anode reactors were 100-200 mV lower and 50 mV higher, respectively, than that in the control reactor (a normal bio-reactor). The cathode reaction enhanced denitrification and the anode reaction inhibited denitrification. At 40 mA, the denitrification rate in the bio-cathode reactor was 55.1% higher than that in the control reactor. At 75 mA, the denitrification rate in the bio-anode reactor was just 33.5% of that in control reactor. Electric current of less than 20 mA had no effect on the most probable number (MPN) of denitrifiers, but at 75 mA, the MPN of denitrifiers decreased by 90% in the bio-anode reactor. In the bio-cathode reactor, the MPN of denitrifiers increased more than 100% for the lower ORP environment produced by a cathode reaction at 75 mA.
Zhang
Le-hua
LH
School of Environmental Science and Engineering, Shanghai Jiaotong University, Shanghai 200240, PR China. zhanglehua@sjtu.edu.cn
Jia
Jin-ping
JP
Ying
Di-wen
DW
Zhu
Nan-wen
NW
Zhu
You-chun
YC
D001419:Bacteria / Q000378:metabolism*; D019149:Bioreactors; D004563:Electrochemistry; D004566:Electrodes; D004572:Electrolysis; D017672:Nitrogen Compounds / Q000378:metabolism*; D014871:Water Microbiology; D014877:Water Pollution, Chemical
D017672:Nitrogen Compounds