Method for processing high-concentration wastewater containing alkaline mud

Abstract

The invention discloses a method for processing wastewater containing alkaline mud with high COD concentration, high toxicity, low biodegradability and high chroma. In the invention, a micro-electrolysis pretreatment, and flocculating and decoloring process are adopted to reduce the COD concentration and chroma and improve the biodegradability, thus providing precondition for the subsequent acidified hydrolysis and aerobic treatment system to further eliminate alkaline mud contamination load; and the yielding water is deposited by a deposition pool and discharged after disinfection. In the invention, the COD concentration (80,000-300,000mg / L) and the chroma (12,500-50,000 times) of inflowing water are improved to maximum degree, stability for the running of system is considered sufficiently, a large amount of diluted water required in the running process is saved, the yielding water can be directly exhausted to urban sewage pipelines, received by waterbody or combined in other treatment systems for treatment, and can comply with the recycling standard. In the whole treatment process, the secondary pollution is not generated, the total emission amount of COD is reduced, the whole system runs conveniently and quickly, and the investment and running expense is far lower than that of the traditional film treatment system.

Description

technical field [0001] The invention belongs to the field of waste water treatment, and in particular relates to an efficient treatment method for alkali washing waste water (commonly known as oil refinery alkali slag), especially suitable for effluent of alkali slag pretreated by a moderate wet oxidation system. Background technique [0002] The petroleum refining industry takes petroleum as the main raw material and converts it into petroleum products through atmospheric and vacuum distillation, catalytic cracking, hydrocracking, delayed coking and other production processes. Its main products are gasoline, diesel, kerosene, liquid hydrocarbons, Lubricating oil, asphalt, etc. The products of secondary processing of high-sulfur crude oil often contain impurities such as non-hydrocarbon compounds and diolefins with relatively high concentrations, resulting in unstable oil properties and poor quality, which need to be refined. At present, my country's oil refineries generall...

AI Technical Summary

Problems solved by technology

[0009] The following problems exist in the mixed treatment of alkali slag and other wastewater in refineries: (1) The alkali slag has an impact load on the large system, which destroys the stable operation of the large system and leads to deterioration of the effluent water quality; (2) The high chroma of the alkali slag causes the effluent to have an impact (3) The long-term accumulation of persistent organic pollutants in the alkali slag will affect the performance of the biochemical system after a certain period of time;

It needs to dilute the COD of alkali slag wastewater to below 1100mg / L (the dilution factor reaches about 80 times), and it needs to consume a lot of dilution water

[0013] Chinese patent CN 98121082.1 adopts SBR (sequenced batch activated sludge method) to treat alkali residue wastewater. After pretreatment, alkali residue wastewater is diluted with condensed water and enters the SBR system, and the COD load of sludge is controlled through sludge domestication and cultivation. Basically, to realize the COD reduction process, it is also difficult to treat high-concentration alkali slag wastewater. The SBR reactor needs to be set with a high reflux ratio, high power consumption, and the problem of alkali slag toxicity and poor biodegradability is not solved.

Existing technologies are difficult to combat the toxicity and organic matter load of alkali slag wastewater, and the existence of persistent pollutants in the system will affect the long-term and stable operation of the system

[0015] In order to improve the treatment effect of alkali slag wastewater, provide a new sewage solution for oil refineries, especially for the problems of poor biodegradability and poor treatment process feasibility of alkali slag wastewater, and propose feasible, economical and efficient solutions

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