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Indexed by:Journal Papers

Date of Publication:2015-12-01

Journal:FRONTIERS OF ENVIRONMENTAL SCIENCE & ENGINEERING

Included Journals:SCIE、Scopus

Volume:9

Issue:6

Page Number:1084-1095

ISSN No.:2095-2201

Key Words:biocathode; microbial electrolysis cell; microbial fuel cell; Cu(II) removal; Co(II) removal

Abstract:Cobalt and copper recovery from aqueous Co (II) and Cu(II) is one critical step for cobalt and copper wastewaters treatment. Previous tests have primarily examined Cu(II) and Co(II) removal in microbial electrolysis cells (MECs) with abiotic cathodes and driven by microbial fuel cell (MFCs). However, Cu(II) and Co(II) removal rates were still slow. Here we report MECs with biocathodes and driven by MFCs where enhanced removal rates of 6.0 +/- 0.2 mg center dot L-1 center dot h(-1) for Cu(II) at an initial concentration of 50 mg center dot L-1 and 5.3 +/- 0.4 mg center dot L-1 h(-1) for Co(II) at an initial 40 mg center dot L-1 were achieved, 1.7 times and 3.3 times as high as those in MECs with abiotic cathodes and driven by MFCs. Species of Cu(II) was reduced to pure copper on the cathodes of MFCs whereas Co(II) was removed associated with microorganisms on the cathodes of the connected MECs. Higher Cu(II) concentrations and smaller working volumes in the cathode chambers of MFCs further improved removal rates of Cu(II) (115.7 mg center dot L-1 center dot h(-1)) and Co(II) (6.4 mg center dot L-1 center dot h(-1)) with concomitantly achieving hydrogen generation (0.05 +/- 0.00 mol center dot moL(-1) COD). Phylogenetic analysis on the biocathodes indicates Proteobacteria dominantly accounted for 67.9% of the total reads, followed by Firmicutes (14.0%), Bacteroidetes (6.1%), Tenericutes (2.5%), Lentisphaerae (1.4%), and Synergistetes (1.0%). This study provides a beneficial attempt to achieve simultaneous enhanced Cu(II) and Co(II) removal, and efficient Cu(II) and Co(II) wastewaters treatment without any external energy consumption.