Treatment of turnip juice wastewater by electrocoagulation/electroflotation and electrooxidation with aluminum, iron, boron-doped diamond, and graphite electrodes

Abstract

The significant increase in the turnip sector has brought a wastewater problem that needs to be managed. In this study, turnip juice wastewater treatment was studied using the electrocoagulation/electroflotation and electrooxidation processes. Independent process parameters such as electrode type (aluminum-aluminum, iron-iron, boron-doped diamond-platinum and graphite-platinum), current density (25-100 A/m(2)) and retention time (15-180 min) were investigated for the optimization of treatment conditions. Removal efficiencies of chemical oxygen demand and total phenol were studied. It was determined that the optimum removal efficiencies in both electrocoagulation/electroflotation and electrooxidation processes were the same under the conditions of 100 A/m(2) current density, pH 5.4, and 45 min reaction time. Here, 100% removal efficiencies were achieved for both chemical oxygen demand and total phenol. The operating cost of the electrocoagulation/electroflotation process was calculated as 1.58 $/m(3), while it was determined as 0.61 $/m(3) for electrooxidation for the optimum removal parameters. It is seen in laboratory scale test results that electrocoagulation/electroflotation and electrooxidation processes are applicable/feasible for the treatment of turnip juice wastewater.