combination of electrocoagulation and electrooxidation for produced water treatment

To reduce the risk of long-term exposure of toxic chemicals being discharge into the sea, produced water was treated by combination of electrocoagulation (ec) and electrooxidation (eo) processes. box-behnken design (bbd) technique, was optimized ec conditions in ph=6.2, cd=12.28 ma/cm2 and electrode distances=1 cm by applying aluminum as sacrificial anode and 30 minutes electrolysis duration. at this condition, chemical oxygen demand (cod) removal was 25% corresponding to energy efficiency of 137 g/kwh. the pw treatment was then completed using electrochemical oxidation process, which was used modified tin oxide as anode. comprehensive eo tests were designed by bbd technique and 100% removal of cod were achieved after 200 min. eo optimized conditions was cd=10 ma/cm2, ph=4.00 and electrode distances of 10 mm. in combined process, cod removal rate equation was a pseudo-first order with a constant rate of 0.006 min-1 and 10% of cost saving was achieved for total pw treatment.