Aniline Degradation Coupled with Removal and Recovery of the Chemically Bound Nitrogen in a Bioelectrochemical System with a Micro-oxygen Bioanode

Eliminating the environmental impact of aromatic aminesin traditionalwastewater treatment processes requires more than one unit to allowboth removal of organic components and the chemically bound nitrogen(CBN). Herein, we report, for the first time, that a bioelectrochemicalsystem with a micro-oxygen bioanode can be a one-stage process torealize the co-removal of organic carbon and CBN derived from aniline(a mode aromatic amine) as well as recover the CBN as value-addedammonium salt. The micro-oxygen condition in the bioanode chamberwas demonstrated to promote current output with aniline as the soleelectron donor (0.95 & PLUSMN; 0.07 mA, which was 6.78 times higher comparedto the anaerobic condition). Accompanied by the 91.92% degradationof aniline, 75.24% of total nitrogen was found to be simultaneouslyremoved. Thereinto, the 54.87% removal was the fact that the producedammonium was migrated to the cathode chamber and finally recoveredby stripping into a sulfuric acid absorber, while the remaining 20.37%removal was a result of denitrification in the anode chamber. Electronbalance analysis revealed that 2.14% and 3.92% of the released electronsduring aniline degradation contributed to the ammonium recovery anddenitrification, respectively. This study opens an opportunity totreat aromatic amine-bearing wastewater in a more compact and sustainablemanner.