Optimization of Electrocoagulation Process for the Removal of Chromium from Simulated Water Using the Response Surface Methodology

This work is an attempt to remove Cr(VI) from simulated wastewater using electrocoagulation (EC) process where stainless steel (SS) is used as a sacrificial electrode. The central composite design (CCD) of response surface methodology (RSM) is used to optimize different operating parameters including initial pH (pH(i): 1.5-9.5), current density (j: 20.75-104.15 A/m(2)), electrode gap (g: 1.5-2.5 cm), and treatment time (t: 0-30 min), with respect to the removal of Cr(VI) from simulated water. The high coefficient of determination for Cr(VI) (R-2 = 0.9922) was found by the analysis of variance (ANOVA) between the experimental data and the predicted data using a second-order regression model. The maximum Cr(VI) removal of 88.9% was achieved at optimum conditions (pH 3.5, j = 83.3 A/m(2), g = 1.75 cm, and t = 24 min) as reflected by ANOVA analysis. A foam and residues analysis has also been incorporated.