COD Removal from High Salinity Petrochemical Wastewater Using Photo-assisted Peroxi-coagulation

Abstract

Photo-assisted peroxi-coagulation (PPC) was investigated for treatment of high TDS (total dissolved solids) wastewater. The most important characteristics of the studied wastewater were high TDS of around 16428 mg L–1 and BOD5/COD ratio of 0.07. Effective operating parameters, including initial pH values of 3–8, reaction time of 60–240 min, electrode distance values of 2–6 cm, and voltage values of 0.5–3 V were investigated in batch mode experiments. Optimum conditions were obtained at pH = 3, voltage = 1.5 V, electrode distance = 2 cm, and reaction time = 420 min, corresponding to 89.44 % COD removal, which meets the Iran environmental discharge legislation (COD = 100 mg L–1). Kinetic analysis showed that pseudo first-order kinetic model was best fitted (R2 = 0.97). GC mass chromatograms before and after treatment showed degradation of complex compounds to more simple constituents.

Keywords

• photo-assisted peroxi-coagulation
• Fenton oxidation
• high salinity wastewater
• petrochemical industries
• degradation