Effects of salinity anions on the anode performance in bioelectrochemical systems

• Published in: Desalination Vol. 351; pp. 77 - 81
• Main Authors: Liu, Guangli, Yu, Shuxian, Luo, Haiping, Zhang, Renduo, Fu, Shiyu, Luo, Xiaonan
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.10.2014; Elsevier
• Subjects: Anion composition; Anions; Anode effect; Anodes; Applied sciences; Bioelectrochemical systems; Density; Desalination; Drinking water and swimming-pool water. Desalination; Electricity generation performance; Energy; Energy. Thermal use of fuels; Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc; Exact sciences and technology; Fuel cells; General purification processes; Geobacter; Microbial community structure; Microorganisms; Mycobacterium fortuitum; Pollution; Salinity; Voltage; Wastewaters; Water treatment and pollution; Bioelectrochemical systems; Electricity generation performance; Anion composition; Microbial community structure; Community structure; Desalination; Production; Biofilm; Waste water purification; Density; Microbial community; Fuel cell
• ISSN: 0011-9164; 1873-4464
• DOI: 10.1016/j.desal.2014.07.026

To study the feasibility to utilize the microbial desalination cell (MDC) to desalinate complex saltwater, the objective of this study was to investigate the effects of different salinity anions on anode performance. Experiments were conducted using three different salinity anions (Cl−, SO42−, and HCO3−) with different concentrations in the anode of two-chamber microbial fuel cell (MFC). Results showed that the supplement of anions, with concentration ranges of 25–50mM for Cl−, 25mM for SO42−, and 25–100mM for HCO3−, into the substrate increased the voltage output of the MFC. With the HCO3− concentrations from 0 to 100mM, the coulombic efficiencies increased from 29% to 44%, and the power densities increased from 465 to 1064mW/m2. At the same conductivity, the electron production in the MFC with the anions was in the order: HCO3−>Cl−>SO42−. The presence of HCO3− enhanced the buffer capacity of the anolyte and maintained the activity of the anode biofilm, in which the dominant species included Geobacter uraniireducens, Desulfofaba fastidiosa, and Mycobacterium fortuitum. This study suggests that the MDC can be used to desalinate complex saltwater to improve wastewater treatment in the anode chamber. •With HCO3− from 0 to 100mM, the coulombic efficiencies increased from 29% to 44%.•The power density increased from 465 to 676mW/m2 by adding Cl− from 0 to 50mM.•With the presence of 100mM SO42−, the power density decreased to 56mW/cm2.•At the same conductivity, the best performance was obtained with HCO3− supplement.