Process device and method for realizing zero discharge of desulfurization waste liquid based on electric drive ion membrane

Abstract

The invention discloses a process device and method for realizing zero discharge of desulfurization waste liquor based on an electrically-driven ion film, and belongs to the field of wastewater treatment. The device comprises a desulfurization waste liquor clarification tank, sedimentation-filtration equipment, a dilution tank, multivalent ion separation electrically-driven ion film equipment, homogeneous-phase concentration electrically-driven ion film equipment and bipolar-film electrically-driven ion film equipment. The process method comprises the following steps: removing solid impurities of the desulfurization waste liquor; entering the dilution tank to perform dilution; performing ion separation through the multivalent ion separation electrically-driven ion film equipment, and concentrating obtained sodium chloride in the homogeneous-phase concentration electrically-driven ion film equipment; and introducing concentrated sodium chloride into the bipolar-film electrically-driven ion film equipment to perform electrolysis, thereby obtaining sodium hydroxide and hydrochloric acid. The method is used for treating the desulfurization waste liquor based on an electrically-driven ion film technology, has the effect of zero emission, and has the advantages of low cost, simple process flow, capability of recycling most of treated materials, no secondary pollution, low energy consumption and good economic benefit.

Description

technical field [0001] The invention relates to the field of wastewater treatment, and more specifically relates to a process device and method for realizing zero discharge of desulfurization waste liquid based on electric drive ion membrane. Background technique [0002] The desulfurization waste liquid mainly comes from the absorption waste liquid discharged from the process of boiler flue gas wet desulfurization (lime method / double alkali method), which contains a large amount of suspended solids, salt, trace heavy metals, fluorine and other pollutants. The typical water quality is shown in the following table Show. [0003] Table 1 Typical water quality of desulfurization wastewater [0004] [0005] The traditional zero-discharge process of desulfurization wastewater generally adopts the method of direct treatment of desulfurization waste liquid, that is, firstly, the wastewater is pre-softened and filtered; The water is evaporated after being concentrated by the c...

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Problems solved by technology

[0013] (4) The traditional zero-discharge process route of desulfurization waste liquid is based on the simple terminal treatment idea, and the water quantity and quality of the desulfurization waste liquid are analyzed and proposed. Since the desulfurization waste liquid contains high concentrations of calcium and magnesium, sulfate, and salinity, Therefore, the softening-ultrafiltration-reverse osmosis-evaporation process is adopted to convert all the ions in the desulfurization waste liquid into solid waste, and the water is recycled. The process is complicated, and a large amount of chemicals needs to be added. Secondary pollution, and lead to extremely high investment and treatment costs for waste liquid treatment, poor economic and social benefits, unable to meet the needs of enterprises and society

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