Reinforced nitrite supplement by cathode nitrate reduction with a bio-electrochemical system coupled anammox reactor

Liang Qiao; Ye Yuan; Chang Mei; Wanxin Yin; Chao Zou; Yanan Yin; Qingyuan Guo; Tianming Chen; Cheng Ding

doi:10.1016/j.envres.2021.112051

Reinforced nitrite supplement by cathode nitrate reduction with a bio-electrochemical system coupled anammox reactor

Environ Res. 2022 Mar;204(Pt B):112051. doi: 10.1016/j.envres.2021.112051. Epub 2021 Sep 13.

Authors

Liang Qiao¹, Ye Yuan², Chang Mei³, Wanxin Yin³, Chao Zou³, Yanan Yin⁴, Qingyuan Guo¹, Tianming Chen⁵, Cheng Ding¹

Affiliations

¹ School of Environmental Science and Engineering, Yancheng Institute of Technology, Yancheng, 224051, China; Jiangsu Province Engineering Research Center of Intelligent Environmental Protection Equipment, Yancheng Institute of Technology, Yancheng, 224051, China.
² School of Environmental Science and Engineering, Yancheng Institute of Technology, Yancheng, 224051, China; Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; Jiangsu Province Engineering Research Center of Intelligent Environmental Protection Equipment, Yancheng Institute of Technology, Yancheng, 224051, China. Electronic address: yuanye_19840915@163.com.
³ School of Environmental Science and Engineering, Yancheng Institute of Technology, Yancheng, 224051, China.
⁴ Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an, 710055, China.
⁵ School of Environmental Science and Engineering, Yancheng Institute of Technology, Yancheng, 224051, China; Jiangsu Province Engineering Research Center of Intelligent Environmental Protection Equipment, Yancheng Institute of Technology, Yancheng, 224051, China. Electronic address: ycchentm@163.com.

PMID: 34529971
DOI: 10.1016/j.envres.2021.112051

Abstract

Anammox has been widely used for the treatment of nitrogen wastewater. However, the problem of stable NO₂^- supplement becomes one of the limiting factors. It is an effective method to obtain NO₂^- by denitrifying the NO₃^-, including the by-product of Anammox. In this study, NO₂^- was reinforced by bio-electrochemical system (BES) through the reaction of partial denitrification in situ in an Anammox reactor. Our results showed that both NO₃^- and NO₂^- can be reduced on the cathode with different Coulombic efficiencies. The reduction of NO₃^- amount increased with an increase in Inf-NO₃^-, which was greater than that of NO₂^-. The conversion amount of NO₃^- was 2.50% ± 17.25% to the theoretical Eff-NO₃^-, and the maximum reduction amount was 23.24% with the highest Coulombic efficiency of 3.56%. High throughput results showed that denitrifying bacteria, such as Limnobacter, Thauera, Denitratisoma, Nitrosomonas and Nitrospira, were attached to the cathode surface and in Anammox granular sludge. This study showed that NO₂^- can be supplied by reducing the by-product NO₃^- with denitrification cathode at Anammox environment in-situ.

Keywords: Anammox; Denitrification efficiency; Denitrifying bacteria; Electrode cathode; NO(3)(−) reduction.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Anaerobic Ammonia Oxidation
Bioreactors
Denitrification
Electrodes
Nitrates* / analysis
Nitrites*
Nitrogen
Oxidation-Reduction
Sewage
Wastewater

Substances

Nitrates
Nitrites
Sewage
Waste Water
Nitrogen