Efficient Removal of Chromium and Lead from Tanneries Effluent of Korangi Industrial Area Karachi Using Rotating Disk Mesh as Anode Electrode Electrocoagulation

Abstract

The aim of this study was to examine the best electrode design for the electrocoagulation process with the best removal performance, reduced passivation on the electrode surface, and lower energy consumption requirements for removing Chromium (Cr) and Lead (Pb) from leather tannery effluent. Three different electrodes were compared: non-rotating disk electrode (NRDE), rotating disk electrode (RDE) and rotating disk mesh electrode (RDME). All electrodes were used to observe a reduction in passivation on the electrode surface and its effects on the removal performance of Cr and Pb. The material used for the electrodes was iron. The maximum removal efficiency obtained was Cr = 87.9% and Pb = 97.5% under the following operating conditions: pH = 7, treatment time = 90 min, current density = 6.57 mA/cm², and RPM = 80. The results show that the electrical energy requirement for treating chromium and lead using RDME was 4.5 kWh/m³, which was found to be lower than the energy requirement observed in various other studies for treating tannery effluent. According to the results, RDME shows the highest removal performance with lower specific energy consumption compared to NRDE and RDE. RDME can be efficiently employed at a larger scale for treating leather tannery effluent.