OPTIMIZATION OF COD REMOVAL FROM POLYVINYL ALCOHOL AQUEOUS SOLUTION VIA ELECTROCOAGULATION USING RESPONSE SURFACE METHODOLOGY

We investigated the influence of experimental factors on the removal polyvinyl alcohol (PVA) in a batch reactor by electrocoagulation (EC) using response surface methodology (RSM). Central composite design (CCD) was used to evaluate influence of three operating factors of the response surface on the COD removal efficiency of PVA: current density, supporting electrolyte concentration, and temperature. Analysis of variance (ANOVA) showed a high coefficient of determination value (R-2) and an insignificant lack of fit for the quadratic response surface model. The current density was found to be more significant than the supporting electrolyte concentration and temperature. The optimal conditions to achieve over 90% COD removal efficiency were established as a current density of 7.05 mA/cm(2), a supporting electrolyte concentration of 0.012 N, and a temperature of 304.98 K. The experimental values agreed with the theoretical results very well, indicating that the models employed to optimize the EC removal of PVA were effective. The results show that process optimization using CCD was reliable and removed PVA at the desired performance level.