The effects of operational parameters on the removal of pollutants from simulated tannery wastewater by electrocoagulation process

• Main Author: Lieu, Uyen Tu
• Format: text
• Language: English
• Published: Animo Repository 2012
• Online Access: https://animorepository.dlsu.edu.ph/etd_masteral/4284
• Institution: De La Salle University

The applicability of Electrocoagulation (EC) process in the treatment of simulated tannery wastewater was studied. Wastewater had an initial sulfide S2-, COD, total chromium content of 76.277.16 mg/L, 1145.651.2 mgO2/L, and 18.20.3 mg/L, respectively. The electrode material Fe/Al as anode/cathode gave the most effective treatment as compared to Fe/Fe and Al/Al in the 1-L beaker tests. In the 18-L reactor employing Fe/Al electrodes, the effects of operational parameters, such as current density (9.6 - 48 A/m2), inner-electrode distance (10 43 mm) and recirculation flow rate (0.4 4 L/min) on the removal of sulfide, COD, total chromium, and other characteristics including pH, temperature, conductivity, dissolved oxygen, applied voltage, electrode dissolution and energy consumption was investigated. When current was applied, there was a quick change in the color of wastewater from turbid greenish blue to totally black and finally to colorless solution the pollutant abatement was obtained at 95 % of S2-, 83 90 % of COD, and 99 % of total Cr. The experiments showed that very high current density led to passivation of electrodes and ineffective treatment of wastewater. EC was suitable to work in a low mixing regime. The relationships of operational parameters and the responses, namely the removal of S2-, COD, Cr and the energy consumption, were achieved via Response Surface Methodology (RSM) employing a central composite design. The effective EC run with the minimum energy consumption was 1.052 kWh/m3 when the process was performed at 19.2 A/m2 of current density, 16 mm of inner-electrode distance, 1L/min of recirculation flow rate and 90 minutes of electrolysis time. Overall, the EC process was effective in the treatment of tannery wastewater.