Coagulate-catalytic oxidation treatment of high concentrated drilling wastewater
高浓度钻井废水的混凝-催化氧化处理

The experiments investigated the treatment efficiency of high concentrated drilling wastewater with COD concentration of 14 460.0 mg/L from Huabei oilfield using the combined processes with acidification, coagulation, catalytic oxidation and adsorption. The Ni-based catalyst was carefully developed, and the effects of calcium hypochlorite (Ca(ClO)2) dosage, Ni-based catalysts dosage, pH value and reaction time on COD and color removal efficiency were studied. The treatment conditions of the catalytic oxidation process were also mainly studied. Under the optimum conditions of pH value of 4, Ca(ClO)2 dosage of 4.4 g/L, Ni-based catalysts dosage of 1.6 g/L, the COD concentration decreased to 403.5 mg/L. The adsorption method with modified fly ash was used for the drilling wastewater advanced treatment, and under the optimal conditions, the COD concentration declined to 139.9 mg/L, chroma was 30 times, petroleum content was 3.8 mg/L, pH value was 8.0 and the SS concentration was 52 mg/L, the quality of final effluent water met the standards of wastewater discharge (GB8978-1996). The processing cost is 84.8 yuan/m3.