Chemical pretreatment method and device thereof for treating high-salinity wastewater

Abstract

The invention discloses a chemical pretreatment method and a device thereof for treating high-salinity wastewater and belongs to water treatment technologies. The device comprises an adjusting tank, a pipeline mixer, a sedimentation tank, a V-shaped filter tank and ion exchange resin. The method comprises the following steps: adjusting the high-salinity wastewater in the adjusting tank; mixing the wastewater with sodium hydroxide and carbon dioxide in the pipeline mixer, and then putting the mixture into the sedimentation tank; after reacting for a certain period of time, removing solid suspended matters, hard substances and part of COD (chemical oxygen demand) pollutants from water by virtue of high-efficiency flocculation and sedimentation, and leading a supernatant into the V-shaped filter tank; and putting the high-salinity wastewater obtained after filtration in the V-shaped filter tank into an ion exchange resin softening system, and performing further softening treatment on the high-salinity wastewater. According to the technology, the combination of carbon dioxide and sodium hydroxide is adopted to ensure a good hardness removal effect, reduces the surrounding dust pollution to the utmost extent, and greatly reduces the cost of chemicals.

Description

technical field [0001] The invention belongs to the field of water treatment, and relates to a chemical pretreatment method and a device for treating high-salt wastewater. Background technique [0002] At present, several common treatment methods for the removal of hardness in industrial saline wastewater are: lime softening method, lime-soda ash softening method, lime-gypsum treatment method and double alkali method. [0003] Lime softening method is usually used for water with high hardness and high alkalinity; lime-soda ash softening method or double alkali method is used for water with high hardness and low alkalinity; and lime-soda softening method is used for negative hard water with low hardness and high alkalinity. Gypsum treatment. [0004] Lime softening method: In order to avoid dust pollution caused by adding quicklime (CaO), the quicklime is usually made into slaked lime (Ca(OH) 2 , that is, slaked lime) is used, and the slaked lime is put into high-hard water...

AI Technical Summary

Problems solved by technology

[0008] The above methods for removing hardness all have the disadvantages of large consumption of chemicals, difficulty in controlling the dosage, and easy generation of dust pollution to the surrounding environment.

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