High-efficiency oily sewage treatment device and method

Abstract

The invention provides a high-efficiency oily sewage treatment method, comprising the following steps: pressurizing to-be-treated oily sewage, and then delivering the pressurized oily sewage into an electric flocculation tank so as to generate a polynuclear hydroxy complex, hydroxide floccules and hydrogen gas bubbles; adding gas-dissolved water into the oily sewage after electrolysis to enable the polynuclear hydroxy complex to adsorb the floccules, sediment grains and large-particle oil drops in the sewage; wrapping the oil drops and the sediment grains with micro-bubbles and hydrogen gas bubbles in the gas-dissolved water; performing cyclone separation to remove the floccules, the large sediment grains and the oil drops; and performing flotation separation on the treated sewage in a full-water low-pressure state to remove the remaining polynuclear hydroxy complex-oil drops, hydroxide floccules-suspended particles, micro-bubbles-oil drops and sediment impurities, so as to obtain purified water. The device and the method provided by the invention can be used for removing oil drops, sediments, colloids, dissolved organic matters and heavy metal ions in sewage at the same time, bacteria and viruses in water can also be killed without adding chemical reagents, and the water quality after treatment is stable and reaches the standards.

Description

technical field [0001] The invention relates to an efficient oily sewage treatment device and method, in particular to a multi-process oilfield sewage treatment technology including electrocoagulation, hydrocyclone and air flotation. Background technique [0002] At present, my country's onshore oilfields basically adopt the water injection development method, that is, inject high-pressure water into the formation to drive crude oil to be extracted from the oil well. The produced sewage mainly includes dispersed oil and slick oil, mud particles, colloids, dissolved organic matter, Impurities such as heavy metal ions. Traditional oily sewage treatment methods (gravity sedimentation method, coagulation degreasing method, coarse granulation method, air flotation method, centrifugal sedimentation method, etc.) have many deficiencies, such as the inability to treat multiple impurities at the same time, the treatment process takes a long time, and the treatment equipment Large vol...

AI Technical Summary

Problems solved by technology

[0010] The technical problem to be solved by the present invention is to provide a treatment method that integrates the three processes of "electrocoagulation, hydrocyclone, and air flotation"; at the same time, it provides a simple structure and small volume efficient sewage treatment device. The device can complete three sewage treatment processes of electrocoagulation, hydrocyclone and air flotation at the same time, so as to solve the technical problems such as easy secondary pollution, low hydrocyclone velocity, short residence time and uneven distribution of microbubbles in the existing design scheme

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