Treatment of Spent Caustic from Ethylene Plant Using Electro-Fenton Technique

The treatment of sulfidic spent caustic produced from ethylene plant by electro fenton technique using iron and stainless steel electrodes was investigated. The effect of operating conditions such as current density, H2O2 concentration, reaction time, initial pH and H2O2 feeding mode on the efficiency of electro fenton method was studied. The results show that maximum COD removal of 83.4% was achieved at current density = 3.3 mA/cm2, H2O2 concentration = 1875 mg H2O2/L and initial pH=3. Multi steps and continuous addition mode were employed; it was found that a highest COD removal achieved 89.7% at continuous addition of H2O2. It is demonstrated that electro fenton method can effectively treat spent caustic.