Utilization of 2k Factorial Experiments For the Determination of Factors That Influence Electrochemical Process
Keywords:
factorial experiments, electrochemical treatment process, efficiency, wastewater, factors, interactions, mathematical modelAbstract
As a follow up of previous studies, in this paper a report on a two-level factorial experiment that provides information on the impact of selected operational variables on efficiency of electrochemical method using aluminium/carbon-resin electrodes in a synthetic wastewater was presented. Carbon –resin electrodes were developed from used dry cells using a non-heat treatment process. 24 factorial experiments were used to determine the influence of selected factors (volume of the wastewater, distance between the electrodes, contact surface area and current through the electrodes) on efficiency of an electrochemical treatment process. Factors with significant effects were optimized using a steepest ascent method. The results of the optimization were analyzed using least squares method and confirmed with further studies.
The study revealed that volume of the wastewater and clear distance between the electrodes had negative effects on efficiency of an electrochemical treatment process, while contact surface area and current through the electrodes had positive effects. The significant factors at 90.0 % significant level (p<0.0005) were distance between the electrodes (F = 6.91; 12.28), contact surface area (F = 16.83; 30.08) and current through the electrodes (F = 13.00; 23.10), while volume of the wastewater used was not a significant factor at the same level (F = 1.62; 2.91). Optimization values for current, separation distance, volume and contact surface area were 1.85 A, 0.50 cm, 0.60 L and 0.240 cm2 respectively. Results of the verification showed that the mathematical model agreed with experimental responses and an optimum model had correlation coefficients (R2) of 0.984 for first order model.
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