Cobalt removal from wastewater using electrocoagulation process

In this thesis study, a batch electrocoagulation process using aluminum (Al-Al) or iron (Fe-Fe) electrodes as monopolar-parallel connected anode and cathode was applied for the removal of cobalt (II) (Co(II)) from aqueous solutions. Response surface methodology (RSM) was used to analyze the process. The effects of operating parameters such as current density (4-20 mA/cm2), initial Co(II) concentration (mg/L) and electrocoagulation time (10-100 min) on Co(II) removal were investigated. The experimental design consisted of 20 studies determined using a central composite design (CCD). A quadratic model was used to estimate the Co(II) removal under different experimental conditions. The significance of each independent variable was calculated by analysis of variance (ANOVA). According to RSM results, all independent parameters are important in Co(II) removal efficiency. The optimum conditions for Co(II) removal are; for Fe electrodes, the current density was 16.67 mA/cm2, the initial Co(II) concentration was 50.45 mg/L and the reaction time was 79.39 min, and a Co(II) removal efficiency of 99.11% was achieved. For Al electrodes, the optimum conditions were current density 16.13 mA/cm2, initial Co(II) concentration 54.25 mg/L and reaction time 76.61 min, and a Co(II) removal efficiency of 99.05% was achieved. When the results obtained were evaluated, it was shown that the electrocoagulation process could be used successfully in the removal of Co(II) from aqueous solutions when both Fe electrodes and Al electrodes were used.