Autotrophic biocathode for high efficient sulfate reduction in microbial electrolysis cells

• Published in: Bioresource technology Vol. 167; pp. 462 - 468
• Main Authors: Luo, Haiping, Fu, Shiyu, Liu, Guangli, Zhang, Renduo, Bai, Yaoping, Luo, Xiaonan
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01-09-2014; Elsevier
• Subjects: Autotrophic Processes; Batch Cell Culture Techniques; Biocathode; Biodegradation, Environmental; Bioelectric Energy Sources - microbiology; Biofilms; Biological and medical sciences; Cathodes; Continuous flow; Electricity; Electrodes; Electrolysis; Electrolytic cells; Fundamental and applied biological sciences. Psychology; Hydrogen-Ion Concentration; Microbial electrolysis cell; Microorganisms; Oxidation-Reduction; Sulfate reducing bacteria; Sulfate reduction; Sulfates; Sulfates - isolation & purification; Sulfides; Time Factors; Waste water; Microbial electrolysis cell; Sulfate reduction; Sulfate reducing bacteria; Biocathode; Chemical reduction; Sulfate-reducing bacteria; Cathode; Bioelectrochemistry; Autotrophy; Electrolysis cell; Microorganism; Sulfates
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2014.06.058

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•Autotrophic biocathode was used to remove sulfate in microbial electrolysis cell.•Sulfate removal rate under continuous flow was 49% higher than the fed-batch mode.•The highest sulfate removal was obtained at cathode potential of −0.9V.
The aim of this study was to utilize the biocathode microbial electrolysis cell (MEC) for sulfate removal from wastewater. Experiments were conducted using the two-chambered MEC under fed-batch and continuous flow modes, respectively, with different cathode potentials. With the fed-batch operation, the average reductive rate of sulfate was 0.49mgd−1 and the sulfide concentration increased to 3.1±0.7mgL−1 in the catholyte. Sulfate removal rate and electron production rate in the continuous flow mode were 49% and 11 times higher than in the fed-batch mode. With cathode potentials from −0.6 to −1.0V, electron recovery efficiencies ranged from 5.3% to 50% with the maximum obtained at −0.8V. The maximum sulfate removal efficiency of (39±9.2)% was achieved at −0.9V. This study suggests the MEC can be a valuable alternative to remove sulfate in wastewater treatment.