Method for treatment of electric adsorption concentrated water of circulation water and blow-down water in steel industry

Abstract

The invention discloses a method for treatment of electric adsorption concentrated water of circulation water and blow-down water in the steel industry. According to the method, an electric adsorptiontechnique is adopted for desalting treatment on concentrated water generated from clean circulation water and blow-down water at procedures of a steel plant, treatment of softening pretreatment, Fenton oxidation and flocculation and sedimentation is implemented, treated concentrated water can be used as electric adsorption fed water for continuous desalting, generated water is recycled to clean circulation systems of different procedures, and can be also directly used as production water for slag flashing and ore mixing with low requirements, and thus zero liquid emission of the circulation water and the blow-down water of the steel industry can be achieved. The method is reasonable in procedure configuration, is capable of efficiently removing salt ions in concentrated water and reducingthe content of CODs (Chemical Oxygen Demands), and is short in process course, simple in equipment structure, convenient to maintain and repair, controllable in operation cost, wide in application range and easy in industrial application.

Description

technical field [0001] The invention belongs to the field of industrial waste water treatment, and in particular relates to a method for treating circulating water discharge sewage in the iron and steel industry by electric adsorption concentrated water. Background technique [0002] More than 70% of industrial water consumption is industrial circulating cooling water. The reuse of circulating cooling water can not only relieve the tension of urban water supply and reduce the cost of water for enterprises, but also reduce the burden on drainage facilities and reduce environmental pollution. The impact on soil, surface water and groundwater Therefore, it is imperative to improve the reuse rate of circulating water and strive to achieve "zero discharge". For improving the utilization rate of circulating water, its salt content is one of the main limiting indicators, and soluble inorganic salts in circulating water will cause serious environmental pollution. Therefore, wastewat...

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Problems solved by technology

The use of electro-adsorption technology to desalinate circulating water and sewage is a very common technology. The electro-adsorption process generally produces about 70-75% of produced water, which can be reused in the production process, but also produces about 30% of concentrated water. The conductivity, hardness and COD increase accordingly, and the pollutants are 2-3 times higher than the system influent

It is difficult to control the corrosion and scaling faults in the application, and the long-term accumulated concentrated water will have certain safety hazards and must be treated

[0004] The outlet of the concentrated water is an important factor affecting the electro-adsorption technology. Some enterprises use the evaporation crystallization process to concentrate and crystallize the concentrated brine, and the salts are precipitated in the form of solids. Linhai Steel Enterprises directly discharge the treated concentrated brine into the deep sea , but this does not fundamentally solve the problem of concentrated water, and may cause secondary pollution

First of all, the crystallized salt produced by evaporation, concentration and crystallization is a big problem. If it is mixed salt, it must be strictly controlled according to hazardous waste. Further separation of mixed salt to produce sub-salt is also a problem.

Secondly, the direct discharge mode of concentrated brine will lead to higher and higher seawater concentration, which will seriously affect the marine ecosystem.

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