Method and device for pre-treating oil field sewage by ultrasonic oxidation united with electrochemical oxidation

Abstract

The invention relates to a method and a device for pre-treating oil field sewage by ultrasonic oxidation united with electrochemical oxidation, and belongs to the sewage treatment of oil field exploration and production. The invention discloses (1) an ultrasonic and electrochemical cooperated composite oxidation method for oxidizing and degrading organic pollutants in an oil field, wherein the frequency of the ultrasonic wave is 20 to 500Hz; and current density is 50 to 5000A / m<2>; and the invention also discloses (2) an ultrasonic washing method for washing cathode scales which are oxidized in a united electrochemical mode. The device is a composite oxidizing electrolytic bath device, wherein an electrolytic bath, an anode and a cathode are arranged in the composite oxidizing electrolytic bath device; and particularly an ultrasonic device is arranged on the electrolytic bath. The invention has the advantages of reducing and avoiding medicament doping, avoiding the medicament resistance of biological species in a water body and the phenomena of a discontinuous electrolysis process, a poor electrolysis effect and the like caused by the cathode scales in the traditional electrochemical electrolysis, ensuring the stable quality of discharged water and a better purification effect, and lowering water treatment cost.

Description

technical field [0001] The invention relates to a method for continuous treatment of oilfield sewage by ultrasonic chemistry and electrochemistry, and belongs to the technical field of sewage treatment in oilfield exploitation and production. Background technique [0002] A large amount of oily sewage will be produced in the process of oilfield production and exploitation, especially in the process of oilfield exploitation. my country's oilfields have basically entered the secondary exploitation period, and the content of crude oil produced is less than 30%, or even lower, producing a large amount of complex components. The highly harmful sewage must be further treated before it can be re-injected into the underground layer. [0003] At present, the typical treatment processes and methods of oilfield sewage mainly include dosing coagulation, flocculation sedimentation, filtration; or dosing coagulation, air flotation, filtration and other methods. The above methods and proce...

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Problems solved by technology

Electrochemical oxidation of oilfield sewage is through ionization, electron action, electrode chemical reaction, electric buoyancy, and electric excitation resonance to make the suspended solids in the water form larger flocs, so as to achieve the purpose of separation and purification. The purified water after treatment reduces the potential It improves the activation performance of the solution components, and kills various bacteria in the water in an extraordinary way, which slows down the occurrence of bacterial corrosion to a certain extent. In actual use, although there is a certain effect, but due to the slow formation of After scaling, the electrolysis efficiency will gradually decrease, and even the electrode between the cathode and the anode will be completely blocked, and finally the machine must be shut down to remove the scaling, resulting in unsatisfactory results

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