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Efficient treatment of alizarin yellow R contained wastewater in an electrostimulated anaerobic-oxic integrated system

Li, Zhi-Ling, Sun, Kai, Chen, Fan, Lin, Xiao-Qiu, Huang, Cong, Yao, Zheng, Chen, Dan, Xia, Ting, Xiao, Zhi-Xing, Wang, Ai-Jie
Environmental research 2020 v.185 pp. 109403
Comamonas, Desulfovibrio, Propionispira, Rhodocyclus, alizarin, amination, ammonia, ammonification, biofilm, chemical oxygen demand, corrosion, decolorization, denitrification, electrons, fermentation, heat treatment, metabolites, mineralization, nitrates, nitrification, nitrogen, oxidation, stainless steel, toxicity, wastewater
An electrostimulated anaerobic-oxic integrated system was constructed for treating alizarin yellow R (AYR) containing wastewater. In electro-stimulated anaerobic unit, AYR decolorization efficiency improved from 51.2% to 96.6%. Two amination metabolites, p-phenylenediamine and 5-aminosalicylic acid, went through oxidation, ammonification and mineralization in oxic unit. Electro-stimulation promoted denitrification and COD removal efficiencies by 15.5% and 8.6%, respectively. A 20% improved nitrification efficiency was observed in oxic unit, due to elimination of AYR toxicity inhibition. No corrosion of heat-treated stainless steel occurred during the 60 days of continuous operation. Electrons sunk in denitrification and decolorization accounted for 34.4–36.8% of those released from COD removal, and 7.3% increase of removed nitrogen in nitrogenous compounds (AYR, nitrate and ammonia) was found. Electro-stimulated anaerobic unit predominated with fermentation and denitrification genera (Propionispira, Rhodocyclus, etc.) and aboundance of electro-active decolorization genus (Desulfovibrio, etc.) increased. Ammonia-oxidizing genus, Comamonas, was the most abundant in aerobic unit. Compared to the suspension, the electrostimulation could increased the abundance of electro-active genera in cathodic biofilm. This study revealed the feasibility of applying electro-stimulation and the conversion laws of nitrogenous organics in secondary bio-treatment system for treating toxic nitrogenous organics-contained wastewater.