A standard discharge treatment method for high-acid crude oil electric desalination wastewater

Abstract

The present invention discloses a high acid crude oil electric desalting wastewater standard discharging treatment method, which comprises that: high acid crude oil electric desalting wastewater is sequentially subjected to an oil and suspended solid removing treatment, a sequencing batch reactor activated sludge treatment (SBR), a membrane bioreactor (MBR) treatment and a photocatalysis membrane reactor (PMR) treatment. The method is suitable for standard discharging treatments of electric desalting wastewater from high acid crude oil processing or polymer flooding oil field wastewater and various naphthenic acid-containing wastewater, wherein COD in the treated effluent is less than or equal to 35 mg / L, ammonia nitrogen in the treated effluent is less than or equal to 2 mg / L, petroleum in the treated effluent is less than or equal to 1 mg / L, and turbidity is less than 1 NTU, such that the stringent local discharging standard (COD is less than or equal to 60 mg / L) can be met so as to discharge the wastewater, and the effluent can be used as influent for reverse osmosis constant depth reuse treatments.

Description

technical field [0001] The invention belongs to the technical field of wastewater treatment, and in particular relates to a standard-reaching discharge treatment method for high-acid crude oil electric desalination wastewater. Background technique [0002] At present, oil refinery electrical desalination wastewater is generally treated by traditional oil separation-flotation-biochemical-clarification or sand filtration process. When this process treats high-acid crude oil electrical desalination wastewater, the COD of the effluent is usually higher than 200mg / L, and some high-acid The A / O treatment effluent of crude oil electric desalination wastewater is even as high as 700-800mg / L, far exceeding the national wastewater discharge standard (COD≤100mg / L). With the increasing processing volume of low-quality high-acid crude oil in my country and the implementation of stricter local wastewater discharge standards (COD≤60mg / L) in some areas, the contradiction of meeting the disc...

AI Technical Summary

Problems solved by technology

US5976366 uses a two-stage oil-water separation-gas stripping-activated carbon adsorption-flocculation process to treat electric desalination wastewater. The process is complicated and the operating cost is high, and the treatment effect of high-acid crude oil electric desalination wastewater has not been seen.

CN1078567C extracts naphthenic acid wastewater with a mixed solvent of tertiary amine and diesel oil, the extract is back-extracted with sodium hydroxide lye, and the extractant is separated and reused. The reagent consumption of this method is large, the cost is high, and the extraction process is easy to produce Emulsification, high COD of treated effluent

CN1209302C provides a method for treating naphthenic acid wastewater by flocculation-electroheterogeneous catalytic oxidation. The process of this method is relatively complicated, the energy consumption is high, and the treatment effect of naphthenic acid is limited

[0006] Although there are many kinds of sewage treatment units in the prior art, and the combined methods of different treatment units are used to treat sewage from different sources, when it is used to treat high-acid crude oil electric desalination wastewater, due to the special properties of wastewater and the mutual constraints between different units, Processing effect is still very limited