Positive effects of concomitant heavy metals and their reduzates on hexavalent chromium removal in microbial fuel cells

Xiayuan Wu; Chunrui Li; Zuopeng Lv; Xiaowei Zhou; Zixuan Chen; Honghua Jia; Jun Zhou; Xiaoyu Yong; Ping Wei; Yan Li

doi:10.1039/d0ra01471k

Positive effects of concomitant heavy metals and their reduzates on hexavalent chromium removal in microbial fuel cells

RSC Adv. 2020 Apr 17;10(26):15107-15115. doi: 10.1039/d0ra01471k. eCollection 2020 Apr 16.

Authors

Xiayuan Wu¹, Chunrui Li¹, Zuopeng Lv², Xiaowei Zhou³, Zixuan Chen¹, Honghua Jia¹, Jun Zhou¹, Xiaoyu Yong¹, Ping Wei¹, Yan Li¹

Affiliations

¹ College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University No. 30 Puzhu Road(S) Nanjing 211816 Jiangsu China liyan@njtech.edu.cn +86 25 58139929 +86 25 58139929.
² The Key Laboratory of Biotechnology for Medicinal Plants of Jiangsu Province, Jiangsu Normal University Xuzhou 221116 China.
³ Department of Philosophy, Nanjing University Nanjing 210023 China.

Abstract

Cr(vi) laden wastewaters generally comprise a range of multiple heavy metals such as Au(iii) and Cu(ii) with great toxicity. In the present study, cooperative cathode modification by biogenic Au nanoparticles (BioAu) reduced from aqueous Au(iii) and in situ Cu(ii) co-reduction were investigated for the first time to enhance Cr(vi) removal in microbial fuel cells (MFCs). With the co-existence of Cu(ii) in the catholyte, the MFC with carbon cloth modified with nanocomposites of multi-walled carbon nanotubes blended with BioAu (BioAu/MWCNT) obtained the highest Cr(vi) removal rate (4.07 ± 0.01 mg L^-1 h^-1) and power density (309.34 ± 17.65 mW m^-2), which were 2.73 and 3.30 times as high as those for the control, respectively. The enhancements were caused by BioAu/MWCNT composites and deposited reduzates of Cu(ii) on the cathode surface, which increased the adsorption capacity, electronic conductivity and electrocatalytic activity of the cathode. This study provides an alternative approach for efficiently remediating co-contamination of multiple heavy metals and simultaneous bioenergy recovery.