Method and device for treating desulfurization wastewater by wet process

Abstract

The invention discloses a method for treating desulfurization wastewater by a wet process. The method comprises the following implementation steps that 1) the desulfurization wastewater is added to afilter for primary filtration to obtain desulfurization wastewater suspended solids of which are removed; 2) the desulfurization wastewater the suspended solids of which are removed in the first stepis added to an anti-scaling nanofiltration unit for nanofiltration treatment to obtain a divalent ion separation liquid and a monovalent ion separation liquid; 3) the monovalent ion separation liquidis added to an evaporation crystallization unit for evaporation crystallization to obtain monovalent crystallized salt; 4) the divalent ion separation liquid and a condensate liquid are returned to the second step together for repeated nanofiltration treatment until the recovery rate of the monovalent salt in the desulfurization wastewater by the wet process is not less than 85%, nanofiltration treatment is stopped, and a divalent ion separation liquid after multiple times of nanofiltration treatment is obtained; 5) the divalent ion separation liquid after multiple times of nanofiltration treatment is subjected to evaporation crystallization treatment to obtain divalent crystalline salt. By means of the method and a treatment device corresponding to the method, the process is simple and stable, the operation is easy, and the cost is low.

Description

technical field [0001] The invention belongs to the technical field of desulfurization wastewater treatment, and in particular relates to a treatment method and a treatment device for wet desulfurization wastewater. Background technique [0002] The limestone-gypsum wet desulfurization process is the most widely used desulfurization treatment process for coal-fired power plants in the world. This process has the characteristics of high desulfurization efficiency, stable operation, large site occupation, and high water consumption. Strong and high hardness. The impurities contained in the wastewater mainly include suspended solids, supersaturated sulfite, sulfate and heavy metals. Direct discharge will pollute the water body. Desulfurization wastewater must be treated to meet environmental protection requirements. [0003] At present, the commonly used desulfurization wastewater zero discharge process is divided into three process sections: the first process section, the pret...

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Problems solved by technology

[0004] The main purpose of the present invention is to provide a treatment method for wet desulfurization wastewater, which solves the problems of cumbersome treatment process, incomplete treatment and high cost in the prior art; the purpose of the present invention is also to provide a treatment method for wet desulfurization wastewater processing device

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