Aerobic Denitrification Is Enhanced Using Biocathode of SMFC in Low-Organic Matter Wastewater

Water

Shuai Zhang¹  Dengfeng Hou²  Xian Cao²  Xianning Li²  Haochi Zhang²  Hui Wang³ 

[1] Collaborative Innovation Center of Atmospheric Environment and Equipment Technology (CIC-AEET), Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control (AEMPC), Nanjing University of Information Science & Technology, Nanjing 210044, China;School of Energy and Environment, Southeast University, Nanjing 210096, China;State Key Laboratory of Eco-Hydraulics in Northwest Arid Region, Xi’an University of Technology, Xi’an 710048, China;

关键词: heterotrophic denitrification;    sediment microbial fuel cell;    nitrate removal;    microbial community;   

DOI  :  10.3390/w13243512

来源: DOAJ

【 摘 要 】

Nitrate (NO₃⁻) in wastewater is a rising global threat to ecological and health safety. A sufficient carbon source, as the electron donor, is essential in the conventional biological denitrification process. It is not appropriate to add extra carbon sources into specific water bodies in terms of material cost and secondary pollution. Thus, innovative NO₃⁻ removal technologies that are independent of carbon sources, are urgently needed. This study constructed sediment microbial fuel cells (SMFCs) for aerobic denitrification in low-organic matter wastewater and explored the key factors affecting denitrification efficiencies. The SMFC treatments removed 72–91% NO₃⁻ through two main denitrifying stages which were driven by carbon sources (COD) and generated electrons, respectively. After COD was fully consumed, denitrification efficiencies were enhanced in SMFC treatments by 24–47% using the generated electrons within 3 days. In this stage, the NO₃⁻ removal efficiencies were positively correlated with external current intensities (p < 0.05). The improved denitrification efficiencies were attributed to two enriched phyla in the SMFC cathode. The dominant genera also demonstrated the heterotrophic denitrifying capacity of the SMFC biocathode. Furthermore, electrical characteristics could be used to monitor or regulate the denitrification process in the SMFC system. In conclusion, this study presents an innovative treatment strategy that is economical and eco-friendly compared with conventional physicochemical methods.

【 授权许可】

Unknown