Reductive potential from cathode electrode as an option for the achievement of short-cut nitrification in bioelectrochemical systems. (October 2021)

• Record Type: Journal Article
• Authors: Xia, Jiaohui; Chen, Dan; Hou, Cheng; Li, Yan; Jiang, Xinbai; Shen, Jinyou
• Is Part Of: Bioresource technology. Volume 338(2021)
• Publication Date: 2021-10
• Subjects: Bioelectrochemical system -- Reductive potential -- Short-cut nitrification -- Biological nitrogen removal -- Activities of key enzymes; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2021.125553
• Languages: English
• ISSNs: 0960-8524

Abstract

Graphical abstract: Highlights: Reductive potential improved nitrite accumulation ratio. Applied potential had little impact on the ammonia oxidation rate. Total nitrogen removal was enhanced without organic carbon source. The activities of key enzymes and functional bacteria were studied. Abstract: Nitrogen removal based on short-cut nitrification (SCN) have attract more attentions, in which stable nitrite accumulation is prerequisite. In this study, different reductive potential was applied to inhibit nitrite oxidizing bacteria for achievement of SCN in aerobic cathode chamber of bioelectrochemical systems with dissolved oxygen concentration of 3.5 mg/L. The results demonstrated that the applied potential facilitated nitrite accumulation with high ammonia oxidation rates. The maximum nitrate accumulation rate of 87.61% was obtained at −800 mV. The abundance of Nitrosomonas and Thauera increased while Nitrospira abundance declined with more negative reductive potentials. The activity of nitric oxide reductase was also evidently inhibited. The above-mentioned three genera were the keystone taxa in co-occurrence network with high degree and closeness centrality. Interestingly, total nitrogen (TN) removal was enhanced simultaneously in the absence of external organic carbon. Reductive potential would be a promising approach for achieving SCN and simultaneously TN removal.