Electrode effects on temporal changes in electrolyte pH and redox potential for water treatment
Open Access
- 14 March 2012
- journal article
- research article
- Published by Taylor & Francis Ltd in Journal of Environmental Science and Health, Part A
- Vol. 47 (5), 718-726
- https://doi.org/10.1080/10934529.2012.660088
Abstract
The performance of electrochemical remediation methods could be optimized by controlling the physicochemical conditions of the electrochemical redox system. The effects of anode type (reactive or inert), current density and electrolyte composition on the temporal changes in pH and redox potential of the electrolyte were evaluated in divided and mixed electrolytes. Two types of electrodes were used: iron as a reactive electrode and mixed metal oxide coated titanium (MMO) as an inert electrode. Electric currents of 15, 30, 45 and 60 mA (37.5 mA L−1, 75 mA L−1, 112.5 mA L−1 and 150 mA L−1) were applied. Solutions of NaCl, Na2SO4 and NaHCO3 were selected to mimic different wastewater or groundwater compositions. Iron anodes resulted in highly reducing electrolyte conditions compared to inert anodes. Electrolyte pH was dependent on electrode type, electrolyte composition and current density. The pH of mixed-electrolyte was stable when MMO electrodes were used. When iron electrodes were used, the pH of electrolyte with relatively low current density (37.5 mA L−1) did not show significant changes but the pH increased sharply for relatively high current density (150 mA L−1). Sulfate solution showed more basic and relatively more reducing electrolyte conditions compared to bicarbonate and chloride solution. The study shows that a highly reducing environment could be achieved using iron anodes in divided or mixed electrolytes and the pH and redox potential could be optimized using appropriate current and polarity reversal.Keywords
This publication has 32 references indexed in Scilit:
- Redox Control for Electrochemical Dechlorination of Trichloroethylene in Bicarbonate Aqueous MediaEnvironmental Science & Technology, 2011
- Electrochemical chlorine evolution at rutile oxide (110) surfacesPhysical Chemistry Chemical Physics, 2009
- Treatment of tannery liming drum wastewater by electrocoagulationJournal of Hazardous Materials, 2009
- Kinetics of trichloroethene dechlorination and methane formation by a mixed anaerobic culture in a bio-electrochemical systemElectrochimica Acta, 2008
- Electrocoagulation Combined with the Use of an Intermittently Aerating Bioreactor to enhance Phosphorus RemovalEnvironmental Technology, 2006
- Reductive Dehalogenation of Aqueous-Phase Chlorinated Hydrocarbons in an Electrochemical ReactorIndustrial & Engineering Chemistry Research, 2004
- Electrochemical technologies in wastewater treatmentSeparation and Purification Technology, 2004
- Electrochemical Oxidation of Aqueous Phenol Wastes Using Active and Nonactive ElectrodesJournal of the Electrochemical Society, 2002
- Electrochemical treatment of phenolic wastewater: Efficiency, design considerations and economic evaluationJournal of Environmental Science and Health . Part A: Environmental Science and Engineering and Toxicology, 1997
- Removal of phenolic compounds by electrooxidation methodJournal of Environmental Science and Health . Part A: Environmental Science and Engineering and Toxicology, 1995