PERFORMANCE EVALUATION OF A SIMPLE ELECTROCHEMICAL TREATMENT MODEL FOR SALINE WASTEWATERS: PART A

Abstract

This paper investigated the performance of the electrochemical treatment technique in removing chloride from saline (salty) wastewaters (brine). Saline wastewaters (between 10 x 103 mg/l and 40 x 103 mg/l of chloride) were prepared and subjected to electrochemical treatment using developed carbon–resin (anode) and aluminium (cathode) electrodes. Electrochemical treatment of the simulated brine was conducted on a laboratory scale. The influence of selected factors on the performance of the electrochemical process was monitored using fractional factorial experiments. These selected factors were optimized using steepest descent technique (between the minimum and maximum concentrations) and rate change of chloride removal efficacy through Microsoft Excel Solver. The optimum values of these selected factors were used to purify typical raw saline water. Efficacies of the process in removing chloride ions from the typical raw saline water was used to predict efficacy of the system using typical chloride concentration in seawater based on literature and previous studies. The study revealed the relationship between chloride removal efficacy (%), initial concentration of chloride, current through the wastewater and separation distance between the electrodes were best in the form of exponentials with coefficient of determination of 0.979, 0.920 and 0.977, respectively. The optimum values of these selected factors such as current, pH, treatment period and separation distance between the electrode (centre to centre of the electrode) were 10.5 A equivalent to 0.795 A cm-2 , 6.7, 2.75 hr and 42mm, respectively. It was concluded that electrochemical treatment with carbon electrodes is an effective tool for removing chloride from saline wastewater during electrochemical treatment.