Design of optimum Response Surface Model for the Treatment of Chromium Contaminated Groundwater at TCCL Site of Ranipet, TamilNadu, India

Vanitha Murugaiyan, Saif Ullah Khan

Abstract: A statistical model using Central Composite Design (CCD) of surface response analysis was employed for the optimization of parameters in the removal of Cr (VI) from contaminated ground water at laboratory scale. Different concentrations of Sodium dithionite have been used in synthetic chromium water to optimize the initial concentration, pH and dosage for complete removal of Cr (VI). Analysis of variance showed a high coefficient of determination value (R2 = 0.9670) and a satisfactory prediction quadratic regression model was derived. The optimum reduction pH, dosage and the maximum removal of Cr (VI) from the initial concentration of 1335.4 mg/L of synthetic contaminated water were found to be 2.80, 3.68 g/L and 99.62 %, respectively. Based on the optimized conditions, trials have been extended to chromium contaminated groundwater. The results are compared. Ex-situ treatment using Na2S2O4 for treating the groundwater is a suitable choice for effective field implementation.

Keywords: TCCL, Ranipet, hexavalent Cr (VI), reduction and precipitation, response surface methodology