Current intensities altered the performance and microbial community structure of a bio-electrochemical system

Minghan Zhu; Jingkai Fan; Minglu Zhang; Zhenyang Li; Jingdan Yang; Xiaotong Liu; Xiaohui Wang

doi:10.1016/j.chemosphere.2020.129069

Current intensities altered the performance and microbial community structure of a bio-electrochemical system

Chemosphere. 2021 Feb:265:129069. doi: 10.1016/j.chemosphere.2020.129069. Epub 2020 Nov 21.

Authors

Minghan Zhu¹, Jingkai Fan¹, Minglu Zhang², Zhenyang Li³, Jingdan Yang¹, Xiaotong Liu¹, Xiaohui Wang⁴

Affiliations

¹ Beijing Engineering Research Center of Environmental Material for Water Purification, College of Chemical Engineering, Beijing University of Chemical Technology, Beijing, 100029, China.
² Key Laboratory of Cleaner Production and Integrated Resource Utilization of China National Light Industry, Beijing Technology and Business University, Beijing, 100048, China.
³ Airport New City in Xixian New Area Management Commission of Shaanxi Province, Xi'an, 712034, China.
⁴ Beijing Engineering Research Center of Environmental Material for Water Purification, College of Chemical Engineering, Beijing University of Chemical Technology, Beijing, 100029, China. Electronic address: xhwang@mail.buct.edu.cn.

PMID: 33257046
DOI: 10.1016/j.chemosphere.2020.129069

Abstract

A novel integrated bio-electrochemical system with sulfur autotrophic denitrification (SAD) and electrocoagulation (BESAD-EC) system was established to remove nitrate (NO₃^--N) and phosphorus from contaminated groundwater. The impacts of a current intensity gradient on the system's performance and microbial community were investigated. The results showed that NO₃^--N and total phosphorus (TP) could be effectively removed with maximum NO₃^--N reduction and TP removal efficiencies of 94.2% and 75.8% at current intensities of 200 and 400 mA, respectively. Lower current intensities could improve the removal efficiencies of NO₃^--N (≤200 mA) and phosphorus (≤400 mA), while higher current intensity (600 mA) caused the inhibition of nutrients removal in the system. MiSeq sequencing analysis revealed that low electrical stimulation improved the diversity and richness of microbial community, while high electrical stimulation reduced their diversity and richness. The relative abundance of some genus involved in denitrification and phosphorus removal processes such as Rhizobium, Hydrogenophaga, Denitratisoma and Gemmobacter, significantly (P < 0.05) reduced under high current conditions. This could be one of the main reasons for the deterioration of denitrification and phosphorus removal performance. The results of this study could be helpful to enhance the nutrient removal performance of bio-electrochemical systems in groundwater treatment processes.

Keywords: Bio-electrochemical system; Current intensities; Groundwater; Microbial communities; Nitrate and phosphorus removal.

MeSH terms

Autotrophic Processes
Bioreactors
Denitrification*
Microbiota*
Nitrates
Nitrogen

Substances

Nitrates
Nitrogen