Separation and Purification Technology, Vol.180, 133-141, 2017
An integrated biological and electrochemical process for recovery of sulfur from an industrial effluent contaminated pond water and its preliminary application in high performance battery
A new combined approach has been made for the recovery of sulfur by reducing in the concentration of sulfate contaminated pond water via an integrated approach of biological (sulfate reducing bacteria) and electro oxidation process. Three different types of dominating facultative anaerobic and micro aerobic bacteria such as Stenotrophomonas maltophilia (CECRI-BESRB1), Bacillus cereus (CECRI-BESRB2) and Bacillus licheniformis (CECRI-BESRB3) were isolated from contaminated pond water for reduction of sulfate to sulfide and formed as transition metal sulfide residue. The biological metal sulfide residue was converted into alkaline metal sulfide and oxidized into sulfur by the electrochemical process. Ti-TiO2/IrO2/RuO2 mixed metal oxide coated standard electrode was used as anode for electrochemical sulfide oxidation process at low current density of 20 mA/cm(2). Sulfur was recovered and confirmed by XRD. The purity of sulfur (100%) was observed by EDAX analysis. The recovered sulfur was evaluated as cathode in energy storage device (Li-S battery). The cyclic voltammetry and charge -discharge profile indicated that the recovered sulfur can be employed as an active cathode material for Li-S battery. (C) 2017 Elsevier B.V. All rights reserved.
Keywords:Sulfate contaminated wastewater;SRB;Sulfide;Electrochemical membrane cell;Sulfur;Li-S battery