Oil refinery sewage treatment and reusing process system and operation method thereof

Abstract

The invention provides a process system for disposal and recycling of sewage in oil plants and the corresponding operation method, wherein the process system comprises a disposal unit for sewage of superhigh concentration, a disposal unit for sewage of high concentration, a disposal unit for sewage of low concentration and a sewage recycling unit. The invention is characterized in that: after treated by an oxidation tower and a sequencing bioreactor, the sewage of superhigh concentration is effluent and incorporated in the sewage of high concentration; after treated by a separation tank, a floatation tank and a biological aerated filter, one part of the sewage of the high concentration which comes up to the standards is released, another part is used for dilution water of the sequencing bioreactor, and last part is incorporated in the sewage of low concentration; after treated by a separation tank, a floatation tank and a biological aerated filter, one part of the sewage of low concentration is effluent and used for recycling in a reclaimed water system, one part is incorporated in the sewage of high concentration, another part is used for dilution water of the sequencing bioreactor, and last part which comes up to the standards is released. The process system of the invention realizes respective treatment and water recycling of sewage of high and low concentration in oil plants, can ensure that the effluent water quality is stable and qualified and the cost of disposal and recycling of sewage is reduced.

Description

technical field [0001] The invention relates to a sewage treatment device and method, in particular to a process system and an operation method combining sewage treatment and reuse in an oil refinery. Background technique [0002] Oil refinery sewage is a type of industrial sewage produced in the process of crude oil refining, processing and oil washing. Different processes will produce sewage with different water quality and water volume. According to the degree of pollution, it can be roughly divided into two parts: high-concentration sewage and low-concentration sewage. High-concentration sewage includes sewage from the electric desalination section of the oil refinery, sewage from the alkali slag section, and purified water from stripping. The characteristics of high-concentration sewage are poor water quality, high sulfur, phenol, and ammonia nitrogen content, COD and salt content account for 70% and 50% of the total sewage respectively; the water volume is small, acco...

AI Technical Summary

Problems solved by technology

Since the 1960s and 1970s, my country's oil refineries have generally adopted the "old three" treatment process of "oil separation-flotation-biochemical" to mix high-concentration sewage and low-concentration sewage. The impact of the biochemical treatment device has increased the difficulty of biochemical treatment of sewage, resulting in low efficiency of the biochemical treatment device or even failure to operate for a long time, which not only affects the standard discharge, but also creates obstacles for the reuse of refinery wastewater

The disadvantage is that the Fenton reagent is expensive, and the running and operating costs are high

Images