Experimental Study on the Treatment of Tertiary Oil Recovery Wastewater via a Novel Electro-Coagulation Method

At present, methods for treating tertiary oil recovery wastewater via electro-coagulation are still in their early stage of development. In this study, a device for electro-coagulation wastewater treatment was built and tested in an oil field. The effects that the initial pH value, electrode type, and connection mode have on the coagulation and separation effect were assessed by measuring the mass fraction and turbidity of oil. The results have shown that when the electro-coagulation method is used, the effectiveness of the treatment can be significantly increased in neutral pH conditions (pH = 7), in acidic conditions, and in alkaline conditions. Compared to an Al electrode, the floc that is produced by an Fe electrode is smaller; thus, it does not easily coagulate and settle in a short time. Using the oil removal rate, turbidity removal rate and energy consumption as a basis to assess the performances, the results have demonstrated that the combined aluminum alloy iron composite electrode should be used as electrolytic electrode.