Treatment method of high-salt content and refractory oil exploitation wastewater

Abstract

The invention discloses a method for treating high-salt content and refractory oil exploitation wastewater, which specifically comprises the following steps of acidifying the high-salt content, high-oil content and refractory oil exploitation wastewater treated by a natural settling coarse graining efficient coalescence separation process, an air floatation process and a coagulating settling process by using an acid material, and adjusting the pH value of the beneficiation wastewater; sequentially adding a proper amount of proper ferrous sulfate and a small amount of hydrogen peroxide to form an efficient oxidant Fenton reagent; neutralizing with an alkaline material; separating the floc with a sedimentation tank; finally, reducing the content of the COD (chemical oxygen demand) in the wastewater through active carbon adsorption. The treated wastewater reaches the national standard of Integrated Wastewater Discharge Standard of Liaoning (DB21 / 1627-2008). With simple processes, the method disclosed by the invention can remove the suspended particles and organic matters left in the wastewater, needs relatively small equipment and space, and can better solve the problem in deep purification of the high-salt content and refractory oil exploitation wastewater.

Description

technical field [0001] The invention belongs to the technical field of advanced treatment of industrial wastewater, in particular to a treatment method for high-salt and refractory petroleum exploitation wastewater. Background technique [0002] Oil extraction wastewater mainly comes from different sections of drilling, oil production, well washing, and downhole operations. The wastewater discharged from these sections contains petroleum, volatile phenol, sulfide, SS and other pollutants. Among them, the wastewater discharge during the oil extraction process is the largest, and the most polluting is petroleum. Petroleum is a biodegradable substance, which can cause difficulty in breathing and slow growth of organisms, affect the normal operation of biochemistry, and lead to BOD 5 , The removal rate of COD decreases, and the quality of effluent water deteriorates, so that the normal and stable operation of the recycling device is affected. [0003] At the same time, water i...

AI Technical Summary

Problems solved by technology

The biological treatment of oil extraction wastewater with high salt content is more difficult, and the activity of salt-tolerant microorganisms decreases with the increase of salt content. At the same time, the biodegradability of wastewater is low, and BOD 5 / COD value is lower than 0.3, difficult to biodegrade

[0005] To sum up, the treatment process of high-salt and refractory petroleum extraction wastewater is relatively complicated, and due to the influence of high salinity, large fluctuations in water quality components and other factors, the water quality after treatment cannot be stably discharged up to the standard. The advanced treatment of wastewater for these problems is particularly important important

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