Pretreatment of high concentration dyeing wastewater by coupling technique of internal electrolysis and electrochemical oxidation

Taking the high concentration dyeing wastewater as research subject,the feasibility and effect of pretreatment by internal electrolysis and electrochemical oxidation composited technology is studied.The impacts of the influencing factors such as solid-to-liquid ratio,carbon/ iron volume ratio,current density,initial pH value and reaction time on the chemical oxygen demand(COD) removal efficiency and decoloration rate are analyzed in order to determine the optimal conditions.The results show that up to 58.4% COD and 93.6% color could be eliminated under the optimum conditions of solid-to-liquid and carbon/iron volume ratio of 38% and 1 ∶ 1 respectively,current density of 9 mA/cm2,for a run time of 36 h at pH 3.This demonstrates that the coupling technique of internal electrolysis and electrochemical oxidation for pretreating high concentration dyeing wastewater is effective and feasible.