Decolorization and COD removal from real textile wastewater by chemical and electrochemical Fenton processes: a comparative study

BACKGROUND Due to the presence of non-biodegradable and toxic compounds, textile wastewater is difficult to treat by conventional methods. In the present study, Electrochemical Fenton (EF) and Chemical Fenton (CF) processes were studied and compared for the treatment of real textile wastewater. The effects of electrical current, ferrous ion, hydrogen peroxide concentration and reaction time on the removal efficiencies of COD and color were investigated. All the experiments were carried out at pH = 3. RESULTS Both EF and CF processes were mostly efficient within hydrogen peroxide concentration of 1978 mg/L (H2O2: COD ~ 1.1). The highest COD and color removal efficiencies were 70.6% and 72.9% respectively which were obtained through the EF process in 350 mA electrical current, 1978 mg/L hydrogen peroxide and 60 minutes reaction time. Furthermore, the operational costs of EF and CF processes were 17.56 and 8.6 US$ per kilogram of the removed COD respectively. CONCLUSION It was concluded that the electrochemical Fenton process was more efficient than the chemical Fenton process in the degradation of textile wastewater. Likewise, Although EF process imposed higher operational costs than the CF; it dramatically decreased the reaction time to gain the highest degradation efficiency.