Process for treating high-concentration oil refining wastewater

Abstract

The invention discloses a process for treating high-concentration oil refining wastewater, which mainly comprises the following steps: the oil refining wastewater is subjected to physicochemical pretreatment such as oil removal, air flotation and the like; the pretreated wastewater is delivered to a three-section biochemical treatment system; according to the water quality condition of the wastewater, the biochemical treatment unit of the first section can be switched into a facultative reaction tank or an aerobic reaction tank to correspondingly complete front denitrification reaction or aerobic reaction to remove sulfides; a phosphate is quantitatively added into the biochemical treatment unit of the second section, and organic pollutants such as volatile phenol and the like are mainly removed; the biochemical treatment unit of the third section mainly completes nitration reaction, a mixed solution of sodium hydroxide and sodium carbonate is accurately added, and the alkalinity and the pH value are regulated to create an optimal nitration environment; the biochemical tank of each section is operated in a plug flow manner, and the interior of each tank is of internal-circulation complete mixing manner; and the biochemically treated wastewater is delivered to an oblique tube sedimentation tank, and the bottom sludge of the sedimentation tank is lifted by an air lift device. The system adopting the process discharges clear water and runs stably, and the process is flexible and can adapt to the oil refining wastewater of various concentration.

Description

technical field [0001] The present invention relates to high-concentration refinery wastewater technology, especially in small and medium-sized old refinery enterprises where the wastewater concentration is high, the original sewage treatment facilities are outdated, and cannot meet the discharge requirements, and need to meet relatively low investment, basically no increase in floor area, and less Refinery wastewater treatment process under the requirements of operating costs and adapting to water quality fluctuations. Background technique [0002] Oil refinery wastewater is a kind of industrial wastewater with a large amount of water. Oil refinery wastewater has the characteristics of many types of pollutants, complex components, high toxicity and serious hazards. Due to historical reasons, there are still a large number of local oil refineries with a capacity of less than one million tons in operation in China. Due to various reasons such as production processes, the con...

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Problems solved by technology

[0005] The present invention solves the problem that the treatment of high-concentration wastewater in local small and medium oil refineries is difficult to meet the standard, solves the problem of poor adaptability and high energy consumption of traditional refinery wastewater treatment process routes, and solves the upgrading and transformation of wastewater treatment stations in local small and medium oil refineries Due to limited land use and insufficient financial resources, it can only be upgraded on the basis of the original treatment facilities. In order to solve the problem of the traditional process route for the treatment of oil refining wastewater to meet the first-level A discharge standard in the "Comprehensive Wastewater Discharge Standard" (GB8978-1996), the process flow is long , Large floor area, high investment, high operating cost, many fault points, and unstable operation, the invention provides a high-concentration refinery wastewater treatment process

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