Yinfeng Xia and Wei Li
Zhejiang University, Institute of Industrial Ecology and Environment, Hangzhou, Zhejiang, China
Nitric oxides (NOx) are hazardous air pollutants that may cause acid rain, acid fog, photochemical smog, health risks of flora and fauna, etc. More and more attention has been paid to the control of NOx. Chemical absorption-biological reduction integrated system is one of the promising approaches which well integrates biological treatment with physicochemical methods.
According to the previous study, cathode electrons could enhance the reduction of Fe(III)EDTA via direct electrochemical reduction and indirect biological reduction using cathodic hydrogen as electron donor. Moreover, the denitrifiers could use hydrogen and inorganic carbon source to generate organics which could serve as electron donor and carbon source.
The reduction features of Fe(III)EDTA using glucose or cathode electrons as sole electron donor were studied respectively. It is noted that the reaction rate constant with cathode electrons was much higher than that with glucose. When the concentration of glucose was less than 300 mg/L, the relationship of cathode electrons and glucose was cooperation, and when the concentration of glucose was more than 300 mg/L, it changed to competition.
Keywords: NOx removal, biofilm electrode reactor, Fe(III)EDTA reduction, cooperation, competition.