Method for physicochemical and biochemical combined treatment of coking wastewater

Abstract

The invention discloses a method for physicochemical and biochemical combined treatment of coking wastewater. The method comprises the following steps: adding a calcium source and sodium metaaluminateinto coking wastewater and stirring, removing precipitates, carrying out micro-nano ozone catalytic oxidation reaction on the coking wastewater subjected to preliminary dechlorination, carrying out A2O biochemical reaction on coking wastewater obtained after the pretreatment is completed to obtain biochemical effluent, carrying out coagulating sedimentation, carrying out primary reverse osmosis treatment to obtain clear liquid, namely wastewater meeting the discharge standard, carrying out adsorption treatment on the generated membrane treatment concentrated liquid by utilizing fly ash, and returning to the step (1) to carry out physicochemical and biochemical combined treatment of the next cycle. The method is good in coking wastewater treatment effect and high in treatment efficiency, the effluent index can completely meet the national current discharge standard, and the requirement of national standard discharge can be stably met for a long time.

Description

technical field [0001] The invention belongs to the technical field of waste water treatment, and in particular relates to a method for combined physical, chemical and biochemical treatment of coking waste water. Background technique [0002] Coking wastewater mainly refers to the wastewater generated from coal pyrolysis, gas purification and benzene refining processes. Due to the influence of various factors such as the nature of raw coal and complex processing procedures, there are hundreds of organic pollutants in the coking wastewater, which is a typical high-concentration organic wastewater that is toxic, harmful and difficult to degrade. There are not only a large amount of suspended solids and Water-soluble inorganic compounds, including phenolic compounds, benzene and its derivatives, pyridine, etc. There are hundreds of organic compounds. Most of the pollutants have high concentrations, are harmful to the human body, can cause cancer, teratogenicity and mutagenesis...

AI Technical Summary

Problems solved by technology

Most of the pollutants have high concentrations, are harmful to the human body, can cause cancer, teratogenicity and mutagenesis, and have long-term impacts on environmental ecological security.

At present, the existing coking wastewater treatment processes at home and abroad can hardly meet the national standard discharge requirements stably

For example, a coking plant in Henan has high salt content, and the concentration of chloride ions is as high as 1.8g / L, which will cause corrosion to the metal pipes of the test device, which will further cause the pipe diameter to become smaller and the system pressure to increase

At the same time, high concentrations of chloride ions will also inhibit the microbial activity in the subsequent biochemical system and reduce the efficiency of biochemical treatment

As a result, the current market treatment process cannot stably meet the national standard emission requirements

[0003] The country raised the standard, and the original widely used "degreasing-A 2 O-coagulation and sedimentation" coking wastewater treatment process is difficult to meet the new discharge standards stably, and the existing process has serious fouling and corrosion, forcing many coking enterprises to close for rectification

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