Method and system for treating desulfurization wastewater with heterogeneous nucleation crystallization process

Abstract

The invention provides a method and a system for treating desulfurization wastewater with a heterogeneous nucleation crystallization process. The method comprises the following steps: 1) the desulfurization wastewater is fed into a two-stage recirculation concentration device, reduced concentration of 75% of the desulfurization wastewater is realized with a heating medium and desulfurization wastewater reverse flow manner; 2) the reduced concentrated water is fed into a microcrystalline box, and dissolved salt in the concentrated water is promoted through the magnetic field effect released by a permanent magnet in the box to form a large number of active suspended microcrystals; 3) the suspended microcrystals enter a final crystallization reactor with water and are induced by seed crystal to form crystal nuclei, and crystalline salt is formed rapidly; 4) solid salt is separated by an automatic plate scraper centrifuge. According to the process, a heterogeneous nucleation crystallization principle is used, the crystallization process of the dissolved salt in the desulfurization wastewater is accelerated, no wastewater remains in the system finally, the separated salt is discharged into a cement building material curing system, accordingly, zero discharge of the desulfurization wastewater is realized to the greatest extent, recycling of comprehensive resources is improved, and a positive effect on promoting green development is realized.

Description

technical field [0001] The invention relates to the field of power plant wet desulfurization wastewater treatment, in particular to a method and system for treating desulfurization wastewater by heterogeneous nucleation and crystallization. Background technique [0002] Under the strict environmental protection requirements of ultra-low emissions, wet desulfurization systems are commonly used in domestic power plants to ensure stable and efficient removal of sulfur oxides in flue gas from coal-fired boilers. The wet desulfurization system produces a small amount of desulfurization wastewater during continuous operation. Desulfurization wastewater mainly has the following characteristics: desulfurization wastewater is acidic, generally at 5-6.5; the content of heavy metal ions in desulfurization wastewater is not high, but there are many types of ions (Pb, Hg, Ni, Fe, Al, As, Cd, Se, Cr, Cu, etc.); desulfurization wastewater contains a large amount of Cl - (concentration ex...

AI Technical Summary

Problems solved by technology

At present, the treatment of desulfurization wastewater mainly includes three-box technology, MVR technology, osmotic membrane method, flue evaporation technology, etc., but there are defects such as cumbersome process equipment, large floor area, inability to completely achieve zero discharge or low treatment effect.

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