Simultaneous removal of organic matter and salt ions from saline wastewater in bioelectrochemical systems

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• 作者：Younggy Kim¹ ; Bruce E. Logan ; ^{blogan@psu.edu}
• 关键词：Saline wastewater ; Ionic separation ; Microbial electrolysis cells ; Ion-exchange membranes ; Bioelectrochemical systems
• 刊名：Desalination
• 出版年：2013
• 出版时间：2 January, 2013
• 年：2013
• 卷：308
• 期：Complete
• 页码：115-121
• 全文大小：937 K

文摘

A new bioelectrochemical system is proposed for simultaneous removal of salinity and organic matter. In this process, exoelectrogenic microorganisms oxidize organic matter and transfer electrons to the anode, hydrogen is evolved at the cathode by supplying additional voltage, and salt is removed from the wastewater due to the electric potential generated and the use of two ion-exchange membranes. Salinity removal (initial conductivity ~ 40 mS/cm) increased from 21 to 84 % by increasing the substrate (sodium acetate) from 2 to 8 g/L. A total of 72-94 % of the chemical oxygen demand was degraded in the anode and cathode chambers, with 1-4 % left in the anode chamber and the balance lost through the anion-exchange membrane into the concentrate waste chamber. The maximum hydrogen production rate was 3.6 m³-H₂/m³-electrolyte per day at an applied potential of 1.2 V. The Coulombic efficiency was ~ 100 % , while the cathode recovery varied from 57 to 100 % , depending on the extent of methanogenesis. Exoelectrogenic microbes generated high current densities (7.8 mA/cm²) at ¡Ü 36 g/L of total dissolved solids, but > 41 g/L eliminated current. These results provide a new method for achieving simultaneous removal of salinity and organic matter from a saline wastewater with H₂ production.