A treatment method for crude oil electric desalination wastewater

Abstract

The invention provides a treatment method for crude oil electro-desalting waste water. The treatment method comprises: carrying out acidification aeration preprocessing on the crude oil electro-desalting waste water; performing an electric flocculation reaction on the preprocessed crude oil electro-desalting waste water; adding alkali liquor and a coagulant aid into the crude oil electro-desaltingwaste water subjected to electric flocculation to perform a mixed flocculation reaction; carrying out precipitation on the crude oil electro-desalting waste water subjected to mixed flocculation; adding acid into the precipitated crude oil electro-desalting waste water to regulate pH, and after filtering, adding hydrogen peroxide to perform a photo-catalytic oxidation reaction to complete treatment on the crude oil electro-desalting waste water. The treatment method provided by the invention is short in flow and high in treatment efficiency; the treated waste water can reach the external emission standard.

Description

technical field [0001] The invention relates to a wastewater treatment method, in particular to a treatment method for crude oil electric desalination wastewater, and belongs to the technical field of wastewater treatment. Background technique [0002] Crude oil usually contains water, inorganic salts, suspended solids and water-soluble trace metals. The first step in oil refining is to remove these substances through desalination and dehydration to reduce corrosion, blockage and fouling of equipment, while preventing catalyst poisoning in subsequent treatment units. Except for a few ultra-heavy oils that use three-stage electric desalting, most crude oils use two-stage electric desalting. [0003] Electric desalination wastewater generally contains petroleum, inorganic salts, sulfides, phenols, suspended particles and various organic substances, including demulsifiers added in desalination and dehydration. In recent years, the trend of heavy and inferior crude oil has bec...

AI Technical Summary

Problems solved by technology

However, many research results show that the important issue affecting the treatment of electric desalination wastewater is not the salt content, but the organic pollutants in it.

Among them, naphthenic acid is difficult to biochemically degrade, and the residual concentration in the biochemical treatment effluent is relatively high, which is the main reason why the COD of high-acid crude oil electric desalination wastewater is difficult to meet the standard; various surfactants and electric desalination wastewater added in the crude oil electric desalination treatment process The emulsified asphaltenes that may exist in the effluent also make it difficult to meet the effluent quality standards

[0005] Chinese patent application CN103755052B discloses a treatment method and system for electric desalination black liquor of petroleum refining waste water. It uses filtration and oil-water separator for treatment. Although it can improve the oil-water separation effect, it still cannot solve the problem of electric desalination waste water, especially high-acid crude oil. Emulsification of Electrodesalination Wastewater and Problems Rich in Naphthenic Acid

Chinese patent application CN106517510A discloses an activated sludge treatment method for electric desalination wastewater, which also cannot solve the problem of emulsification of electric desalination wastewater, especially if the naphthenic acid is not pretreated, it will have a great impact on the activated sludge

Chinese patent application CN103102035B discloses a treatment method for high-acid crude oil electric desalination wastewater. The high-acid crude oil electric desalination wastewater is sequentially subjected to oil removal and suspended solids treatment, sequenced batch activated sludge (SBR) treatment, flocculation treatment, and Fenton oxidation. Treatment and membrane bioreactor (MBR) treatment, the treatment effect is remarkable, but the process is too long, and a two-stage biochemical treatment process is applied, and the highly biotoxic naphthenic acid in the wastewater has a serious impact on the primary biochemical activated sludge

Chinese patent application CN103102037B discloses a treatment method for electric desalination wastewater. The electric desalination wastewater is sequentially subjected to oil removal and suspended solids treatment, membrane bioreactor (MBR) treatment and photocatalytic membrane reactor (PMR) treatment. milk problem, and pollutants in wastewater can easily lead to catalyst poisoning

Chinese patent application CN105540820A discloses a device and method for using ozone to treat electric desalination wastewater, but it is difficult to achieve COD emission up to standard by relying solely on the oxidation capacity of ozone

[0008] However, the existing electric desalination wastewater treatment is difficult to achieve efficient demulsification and oil removal and deep degradation of COD

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