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Treatment of oilfield fracturing wastewater

ABSTRACT An integrated process was developed for treating an oilfield fracturing wastewater. Under the optimum conditions, the removal efficiencies of chemical oxygen demand, suspended solids (SS), and oil were higher than 98%, and the quality of the final effluent could satisfy the national discharge standard of China. The oxidation process significantly reduced the viscosity and altered the chemical structures of organics in the wastewater. The coagulation process removed a considerable proportion of SS associated with particulate organic matter. The upflow anaerobic sludge bed and biological aerated filter processes played an important role in the post-polish treatment of the wastewater.