OPTIMIZATION OF THE ELECTRO-FENTON PROCESS FOR COD REDUCTION FROM REFINERY WASTEWATER
Ammar S. Abbas, Zainab I. Abbas
Abstract
This study shows the results of the experimental investigation of refinery wastewater treatment by the electro-Fenton process.The experiments were designed using Taguchi design approach with an orthogonal array (OA) of L16 runs.Four process variables (current density (CD), temperature (T), Fe 2+ concentration (Fe 2+ ), and time (t)) at four different levels were considered for the present design.Regression analysis was performed to predict a correlation for the response function (chemical oxygen demand (COD) reduction efficiency) of the treatment process by the electro-Fenton technique.Analysis of variance (ANOVA) was carried out to verify the significant variables that control COD reduction.Moreover, a linear model analysis was implemented for the signal to noise (S/N) ratios with "larger the better" and for means.Based on S/N ratios and means responses, the operating conditions for optimum COD reduction were: CD = 8 mA/cm 2 , T = 60°C, Fe 2+ = 0.4 mM, and t = 6 h, at which 87.35% of COD was reduced.ANOVA shows that the operating temperature had the most significant impact on COD reduction efficiency.The R-square value for the predicted COD reduction correlation was 90.00%.Considering ranks based on delta statistics, the relative magnitude of effects of the process variables were: T, Fe 2+ , t, and CD.