Comparison of Different Anodes and Investigation of Energy Consumption on Electrooxidation COD and Turbidity Removal Efficiency of Paper Industry Wastewater: The Effect of Support Electrolyte Type and Concentration

Abstract

 In the studies, different experimental settings were investigated for the treatment of wastewater from the paper industry using the electrooxidation method, one of the electrochemical treatment methods in the batch system. In the 2000 mL volume jacketed glass reactor used for the treatment of wastewater from the paper industry, 4 anodes and 4 cathodes sieve type plates with dimensions of 7 cm x 10 cm were positioned at 0,5 cm intervals, and 1200 mL wastewater was used in the tests. Coated sieve type Ti/IrO2/RuO2 and Ti/Pt electrodes were used as the anode material and uncoated sieve type Ti electrodes as the cathode material in the electrooxidation tests. The active anodic wet surface area of all plates was calculated as 1078 cm2 . In the trials, the removal efficiency of pollutant parameters such as COD (Chemical Oxygen Demand) and turbidity; The effects of supporting electrolyte types and concentrations such as NaNO3, Na2SO4, NaCl and KCl were investigated. According to the results obtained, for both anode types (Ti/IrO2/RuO2 and Ti/Pt); wastewater natural pH (~7.5) was the most effective pH value at 400 rpm mixing speed, 18.55 mA/cm2 was the most effective current density, 0.50 M NaCl was the most effective supporting electrolyte type and concentration. 73.20% COD and 97.50% turbidity for Ti/IrO2/RuO2 anode at optimum conditions; For Ti/Pt anode, 52.96% COD and 95.38% turbidity removal efficiencies were obtained. While the energy consumption value for the Ti/IrO2/RuO2 anode was calculated as 154.08 kWhour/kg COD, it was obtained as 312.05 kW-hour/kg COD for the Ti/Pt anode