title: Electrocoagulation removal of Cr(VI) from simulated wastewater using response surface methodology.
abstract: The present study envisages the performance of a laboratory scale electrocoagulation system for the removal of Cr(VI) from 100 mg l(-1) solution using Al-Al electrodes with an effective surface area of 100 cm(2), and placed 15 mm apart. The interaction between voltage x time, and amperage x time best explained the Cr(VI) reduction efficiency with the coefficient of determination (R(2)) being 0.8873 and 0.9270 respectively. Similarly, the square root of energy consumption in Cr(VI) reduction had a linear correlation with voltage x time (R(2)=0.8949), whereas, amperage x time better explained energy consumption (R(2)=0.9400). Response surface methodology was used for the optimization of process variables (pH, voltage and treatment time), response modeling and predictions. Maximum Cr(VI) reduction efficiency of 90.4% was achieved at pH 5, 24 V and 24 min treatment time, and the treatment consumed 137.2 KWh m(-3) of electrical energy. Multiple response optimization for maximizing Cr(VI) reduction efficiency and minimizing energy consumption showed 49.6% Cr(VI) removal at pH 5, 12.8 V and 24 min treatment time. The response models developed explained 95.2% variability for Cr(VI) reduction efficiency and 99.4% variability for energy consumption. Results of the prediction models were validated through laboratory scale batch experiments.
authors.affiliation: Department of Botanical & Environmental Sciences, Guru Nanak Dev University, Amritsar 143005, India. mbhatti73@bsnl.in
authors.forename: Manpreet S
authors.initials: MS
authors.lastname: Bhatti
authors.forename: Akepati S
authors.initials: AS
authors.lastname: Reddy
authors.forename: Ashwani K
authors.initials: AK
authors.lastname: Thukral
mesh_terms: D002857:Chromium / Q000302:isolation & purification*; D019411:Clinical Laboratory Techniques; D004564:Electrocoagulation / Q000379:methods*; D004566:Electrodes; D007220:Industrial Waste; D010084:Oxidation-Reduction; D014865:Waste Disposal, Fluid; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods*
chemical_list: D007220:Industrial Waste; D014874:Water Pollutants, Chemical; D002857:Chromium; C074702:chromium hexavalent ion