Method of deep desalting and recycling of industrial effluent

Abstract

The invention provides a method of deep desalting and recycling of industrial effluent. The method is characterized in that industrial effluent to be treated is treated with a hardness reducing operating unit, an efficient filtering operating unit and an electro-adsorption desalting operating unit to reach a standard of recycling water. The method comprises specific steps of: a. hardness reduction, precipitation and neutralization; b. efficient filtering; and c. electro-adsorption desalting. The provided method of deep desalting and recycling of industrial effluent requires no equipment of electroosmosis or reverse osmosis membrane, or ion exchange resin, keeps stable operation of the system under a condition of water quality conductivity higher than 2500 muS / cm and does not scale; and an outlet water quality satisfies water quality requirements on recycling water replenishment. Discharge secondary industrial effluent with water quality conductivity lower than 4500 muS / cm can be treated to reach water replenishment requirements of an industrial recycling water system. The method is suitable for chemical effluent, printing and dyeing effluent, spinning effluent and oil refining effluent and has wide water quality scope of application, stable technology operation and high desalting efficiency.

Description

technical field [0001] The invention relates to a method for deep desalination and reuse of industrial wastewater. Multi-stage treatment of water, waste water or sewage. Background technique [0002] The worldwide shortage of water resources has given great importance to the sustainable utilization of water resources and water-saving reuse. Sewage reuse can not only save a lot of fresh water, but also greatly reduce the discharge of sewage. Industrial wastewater is highly polluted. In developed countries, industrial wastewater is generally treated briefly at the production site, and then mixed with domestic sewage in a well-equipped urban sewage treatment system for treatment. Separate reuse is rare in industrial developed countries. The desalination and reuse treatment process of industrial wastewater is longer than that of urban sewage treatment, and generally adopts the process of secondary biochemical treatment-filtration-activated carbon adsorption-reverse osmosis-reus...

AI Technical Summary

Problems solved by technology

[0004] 1. Electrodialysis is easy to scale and occupies a large area. At present, it is mainly used for groundwater treatment, and it has not been reported for sewage treatment and reuse.

[0005] 2. The reverse osmosis membrane has extremely strict requirements on the quality of the influent water. Although the desalination is relatively thorough, the membrane is easily polluted and energy consumption is high

[0006] 3. Ion exchange resins are also susceptible to organic pollution in incoming water

[0007] 4. The electro-adsorption method is used to remove salt, only applicable to water quality whose conductivity is less than 2500μS / cm

When the conductivity is greater than 2500μS / cm, the system will have an obvious scaling tendency, resulting in unstable operation of the system and frequent chemical cleaning. At the same time, the water quality of the effluent is difficult to meet the water quality requirements of circulating water.

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