Treatment method of desulfurization wastewater

Abstract

The invention provides a desulfurization wastewater treatment method. The desulfurization wastewater treatment method comprises the following steps: pretreating desulfurization wastewater to obtain primarily clarified liquor, enabling the primarily clarified liquor to enter a softening reactor A, and regulating pH value to be 10-11; enabling producing water of the softening reactor A to enter a softening reactor B, and then treating by virtue of a microfiltration membrane system; regulating pH value of producing water of a microfiltration system to 6-7, enabling microfiltration producing water to enter a nanofiltration membrane system A, and separating to obtain nanofiltration A fresh water and nanofiltration A concentrated water; enabling the nanofiltration A fresh water and the nanofiltration A concentrated water to respectively enter four water passageway units of a four-compartment electrodialyzer, and carrying out ion recombination on ions in each water passageway unit by virtue of electric drive. The desulfurization wastewater treatment method provided by the invention has the advantages that salts easy to scale in the wastewater are recombined to form soluble salts difficult to scale, so that the difficulty of scaling of follow-up electrodialysis equipment or a high pressure reverse osmosis system is solved; and then the content of total dissolved solids in the wastewater is controlled to be 8-16% by virtue of concentration of the nanofiltration membrane system, an electrodialysis system or the high pressure reverse osmosis system, 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. 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 slurry in the absorption tower continuously accumulates heavy metal elements, Cl- and some suspended particles, etc., and a part of the desulfurization needs to be discharged regularly. waste water. Although the amount of this part of desulfurization wastewater is small, it is highly toxic, and conventional treatment methods are difficult to discharge in a stable manner. [0003] The current environmental protection policy has begun to require zero-discharge treatment of desulfurization wastewater, but desulfurization wastewater has the following characteristics: 1. High calcium and magnesium content, cal...

AI Technical Summary

Problems solved by technology

[0004] In order to solve this technical problem, the present invention provides a treatment method for desulfurization wastewater, which is used to solve the problems of serious equipment fouling in the prior art, large dosage of softener, large sludge output, and difficult regulation

Images