High salinity wastewater treatment method and treatment system

Abstract

The invention relates to the field of water treatment, and discloses a high salinity wastewater treatment method and treatment system. The method includes the following steps: (1) mixing high salinitywastewater and at least a part of concentrated water after membrane concentration treatment, and carrying out normal temperature crystallization treatment on the mixed intake water to obtain sparingly soluble salts and normal temperature crystallization exit water; (2) carrying out filtering treatment on at least a part of the normal temperature crystallization exit water to obtain filtered exitwater; and (3) carrying out membrane condensation treatment on the filtered exit water which is taken as membrane condensation intake water to obtain concentrated water and product water, and returning at least a part of the concentrated water to the normal temperature crystallization treatment. The method can fully reduce water quality requirement for an upstream high salinity wastewater pretreatment unit. The changes of the upstream high salinity wastewater pretreatment unit have wider applicability, and can effectively prevent fouling of a membrane separation element and greatly reduce thefixed assets investment of a whole process system.

Description

technical field [0001] The invention relates to the field of water treatment, in particular to a treatment method and system for high-salt wastewater. Background technique [0002] Most power plants and coal chemical plants in my country use limestone wet desulfurization technology to remove SO from flue gas. 2 , the desulfurization wastewater generated during operation has become one of the most difficult wastewater to treat in coal-fired power plants due to its complex composition and many types of pollutants. At present, the chemical precipitation method (commonly known as triple box precipitation) is mainly used in China to treat desulfurization wastewater. The treated water has a high salt content, and it is easy to cause secondary pollution after direct discharge. At the same time, due to the small amount of desulfurization wastewater and high salt content, the process system for further treatment of desulfurization wastewater in power plants and coal chemical plants ...

AI Technical Summary

Problems solved by technology

However, if this method is used to treat high-salt wastewater from power plants and coal chemical industries, slightly soluble inorganic salts (such as calcium sulfate, magnesium hydroxide, calcium carbonate, magnesium sulfate, etc.) will block the micropore channels of the membrane separation element, reducing the membrane flux of the separation membrane element. , and even make the membrane separation element scrapped and have to be replaced with a new separation membrane, thus increasing the operation and maintenance cost of the process system

[0008] There is no better method and system for treating high-salt wastewater from power plants and coal chemical industry in the prior art methods. Therefore, a low-cost, high-resource reuse and high-salt wastewater treatment that can prevent fouling of membrane separation elements is developed. The method and processing system have important practical significance and market application value

Images