Desulfurization waste water sludge separation and salt separation zero-emission pretreatment system and process

Abstract

The invention discloses a desulfurization waste water sludge separation and salt separation zero-emission pretreatment system and process. The system comprises a raw water pond, a primary reaction clarification system, a secondary reaction clarification system, a tertiary reaction clarification system and a clean water tank, all of which are sequentially connected. The reaction clarification systems each comprise a reaction tank and a clarifier. According to the pretreatment process, desulfurization waste water enters the raw water pond, an aeration fan introduces compressed air into the raw water pond, then the desulfurization waste water is lifted to primary reaction clarification through a raw water pump, through three levels of softening, the clarified desulfurization waste water enters the clean water pond, one part of the water in the clean water pond is supplied to a membrane treatment process system, and the other part of the water in the clean water pond is supplied to an agent adding system. The three-level clarification process is adopted, impurity sludge and industrial grade magnesium hydrate and calcium carbonate are output, sediment is classified, the disposal amount of hazardous waste is reduced, the operating cost of the system is reduced, part of the sediment has additional value, resource comprehensive utilization and waste recycling are achieved, and obvious environmental benefits are achieved.

Description

technical field [0001] The invention relates to a water treatment process, in particular to a zero-discharge pretreatment system and process for desulfurization wastewater by separating sludge and separating salt. Background technique [0002] The desulfurization wastewater produced by the limestone-gypsum process in thermal power plants contains high concentrations of Cl - , SO 4 2- 、Na + , Ca 2+ , Mg 2+ , is a typical high-salt, high-hardness wastewater. At present, most domestic and foreign coal-fired power plant desulfurization wastewater zero discharge projects adopt the "softening + evaporation crystallization" process route. In order to reduce evaporation, some projects use membrane concentration after pretreatment to reduce evaporation load. When the above zero-emission projects are in operation, a large amount of sludge and mixed salt will be produced. These by-products have complex components and low utilization value, so they can only be disposed of as solid...

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Problems solved by technology

[0006] Purpose of the invention: The purpose of the invention is to solve the deficiencies in the prior art, to provide a zero-discharge process for desulfurization waste water sludge separation and salt separation, to separate the by-products produced in the system according to different components, and to achieve industrial High-grade purity, to solve the problem of resource utilization of by-products in the zero-emission system, not only can reduce the cost of sludge and mixed salt disposal, but also can reduce project operating costs through the revenue of by-products craft

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