Method for treating desulfurization wastewater in power plant

Abstract

The invention provides a method for treating desulfurization wastewater in a power plant. The method comprises the following steps: pretreating the desulfurization wastewater to obtain primary clarified liquor; enabling the primary clarified liquor to enter a filtering device to be filtered; providing a four-compartment electrodialyzer to perform ion recombination on ions in each water flow channel unit through an electric drive effect; further enabling produced water of each water flow channel unit to pass through a nanofiltration system to perform salt separation treatment, concentrating by utilizing an electrodialysis system, and desalinating the wastewater by utilizing a reverse osmosis system. According to the method disclosed by the invention, salts in the wastewater which are easy to scale are subjected to ion recombination so as to form soluble salts which are difficult to scale, so that the problem of scale formation in subsequent electrodialysis equipment or a high-pressure reverse osmosis system is solved. Moreover, according to the nanofiltration system for concentration, the electrodialysis system or the high-pressure reverse osmosis system, the content of total soluble solids in the wastewater is 8-16%, and the recovery rate of 80-90% of the wastewater is realized.

Description

technical field [0001] The invention relates to the technical field of environmental engineering, in particular to a treatment method for desulfurization wastewater of a power plant. Background technique [0002] The limestone-gypsum wet desulfurization process is currently the mainstream flue gas desulfurization process accounting for up to 85%. During the wet desulfurization process, the absorption tower slurry continuously accumulates heavy metal elements, Cl - And some suspended particles, etc., need to regularly discharge a part of the desulfurization wastewater. Although the amount of this part of desulfurization wastewater is small, it is highly toxic and difficult to discharge in a stable manner through conventional treatment. Therefore, desulfurization wastewater from power plants is the most difficult wastewater to treat. [0003] At present, the common treatment method for desulfurization wastewater in China is to use the triple-box process. Although the effluent...

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Problems solved by technology

[0005] In order to solve this technical problem, the present invention provides a treatment method for power plant desulfurization wastewater, which is used to solve the problems of high hardness of desulfurization wastewater, easy fouling of membrane and evaporator, high cost and cumbersome operation in the prior art

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