title: Spontaneous electrochemical treatment for sulfur recovery by a sulfide oxidation/vanadium(V) reduction galvanic cell.
abstract: Sulfide is the product of the biological sulfate reduction process which gives toxicity and odor problems. Wastewaters or bioreactor effluents containing sulfide can cause severe environmental impacts. Electrochemical treatment can be an alternative approach for sulfide removal and sulfur recovery from such sulfide rich solutions. This study aims to develop a spontaneous electrochemical sulfide oxidation/vanadium(V) reduction cell with a graphite electrode system to recover sulfide as elemental sulfur. The effects of the internal and external resistance on the sulfide removal efficiency and electrical current produced were investigated at different pH. A high surface area of the graphite electrode is required in order to have as less internal resistance as possible. In this study, graphite powder was added (contact area >633 cm(2)) in order to reduce the internal resistance. A sulfide removal efficiency up to 91% and electrical charge of more than 400 C were achieved when using five graphite rods supplemented with graphite powder as the electrode at an external resistance of 30 Ω and a sulfide concentration of 250 mg L(-1).
authors.affiliation: UNESCO-IHE Institute for Water Education, Westvest 7, 2611 AX Delft, The Netherlands; Department of Environmental Engineering, Faculty of Engineering, Chiang Mai University, Chiang Mai 50200, Thailand. Electronic address: pimluck@eng.cmu.ac.th.
authors.forename: Pimluck
authors.initials: P
authors.lastname: Kijjanapanich
authors.affiliation: Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand.
authors.forename: Pairoje
authors.initials: P
authors.lastname: Kijjanapanich
authors.affiliation: Environmental Engineering and Management, Asian Institute of Technology, PO Box 4, Klongluang, Pathumthani 12120, Thailand.
authors.forename: Ajit P
authors.initials: AP
authors.lastname: Annachhatre
authors.affiliation: Department of Civil and Mechanical Engineering, University of Cassino and Southern Lazio, Via Di Biasio, 43 03043 Cassino (FR), Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Esposito
authors.affiliation: UNESCO-IHE Institute for Water Education, Westvest 7, 2611 AX Delft, The Netherlands.
authors.forename: Piet N L
authors.initials: PN
authors.lastname: Lens
mesh_terms: D004560:Electricity; D055664:Electrochemical Techniques / Q000379:methods*; D004566:Electrodes; D006108:Graphite; D010084:Oxidation-Reduction; D013440:Sulfides / Q000737:chemistry*; D013455:Sulfur / Q000302:isolation & purification*; D013696:Temperature; D014639:Vanadium / Q000737:chemistry*; D062065:Wastewater / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*
chemical_list: D006108:Graphite; D013440:Sulfides; D013455:Sulfur; D014639:Vanadium; D062065:Wastewater
keywords: Dissolved sulfide; Electrochemical treatment; Graphite electrode; Sulfide oxidation; Sulfur recovery