Bacterial Oxidation of Organic Carbons Electrochemically Coupled to Bacterial Denitrification in Wastwater Treatment System

Abstract

The aerobic bioreactor was electrochemically coupled to anaerobic bioreactor in bioelectrochemical system. 5 volt of electric oxidation and reduction potential were charged to anodic biofilm media and cathodic biofilm media of bioelectrochemical system but were not those of normal system. The bacterial oxidation efficiency of organic carbons and bacterial denitrification were measured in bioelectrochemical system and compared with those in normal system. The bacterial oxidation efficiency of organic carbons in bioelectrochemical system was about 1.5 times higher than that in normal system. The dentrifier capable of oxidizing H2 in coupling with the reduction of NO3 - to N2 was applied to the anaerobic bioreactor in bioelectrochemical and normal system, respectively. The denitrification efficiency was less than 22% in normal system and more than 77% in bioelectrochemical system. This result indicates that the electrochemical oxidation reactions of aerobic bioreactor coupling with electrochemical reduction at anaerobic bioreactor may be a useful tool for the improvement of wastewater treatment efficiencies at oxidation of organic wastes, and denitrification, without MLSS returning, C/N ratio control, and biofilm refreshi