Experimental Study on COD Composition and Electrochemical Degradation of Wastewater in Offshore Oilfields

摘要

COD standard discharge of wastewater in offshore oilfields is an important part of oilfield wastewater treatment. The polymer-contained oily wastewater from oilfields in Bohai Sea was taken as the object. Combining with the wastewater treatment experiments, the major composition of COD as oils, polymer and chemical agents are researched. Under certain conditions, the two-dimensional PFR electrochemical reactor was used to treat wastewater and a linear relation between COD and concentration was established in a low concentration range. A primary study was carried out on the main factors of COD removal, the results showed that compared to the polymer, the oils were easier to be electrolyzed and the chemical agents were more difficult to be electrolyzed. The highest COD removal by electrochemical treatment of wastewater was 75.34% and the residual COD in wastewater was mainly contributed by the chemical agents and polymer which were not degraded completely.