Treatment system and method for resource utilization of ferrous metallurgy high-salinity wastewater

Abstract

The invention relates to a treatment system and method for resource utilization of ferrous metallurgy high-salinity wastewater. Impurities such as fluorides, silicon scales, heavy metals and suspended solids in the high-salinity wastewater are removed through an adjusting tank, a softening reaction tank, a concentration sedimentation tank and a tubular microfiltration device, and clear water treated by a primary RO device and a secondary RO device is recycled. Concentrated water generated by the primary RO device sequentially passes through an ozone catalytic oxidation device, an activated carbon adsorption device and aresin softening device, so that the hardness and COD in the concentrated water are sequentially reduced; effluent of the resin softening device enters a nanofiltration device, and concentrated water of the nanofiltration device enters a freezing crystallization device and an evaporative crystallization device to separate out sodium sulfate for sale. The water produced by the nanofiltration device respectively enters a high-pressure reverse osmosis device, a defluorination device, an electrodialysis device and a bipolar membrane electrodialysis device to generate diluted hydrochloric acid and diluted alkali lye. The method has the advantages that low-cost treatment is realized, various harmful substances in the high-salinity wastewater are removed step by step, and reasonable resource utilization of the wastewater and wastes is realized.

Description

technical field [0001] The invention belongs to the technical field of industrial wastewater treatment, and in particular relates to a treatment system and method for resource utilization of iron and steel metallurgy high-salt wastewater. Background technique [0002] The water treatment process of iron and steel enterprises will inevitably produce a large amount of high-salt wastewater in the desalination process. The main components of high-salt wastewater are inorganic salts and heavy metals, and also contain a small amount of organic chemicals used in the desalination process. For the treatment of high-salt wastewater, iron and steel enterprises generally use high-salt wastewater to heat and splash slag. However, high-salt wastewater has a large volume of water and extremely high salt content, which is easy to cause corrosion and scaling to slag-splashing equipment, pipelines and nozzles. [0003] In recent years, the state has promulgated a series of regulations, indus...

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Problems solved by technology

Various iron and steel enterprises are also actively carrying out the transformation of concentrated brine treatment, but at present, in the treatment of concentrated brine, they have encountered bottleneck problems such as high water consumption index requirements for users, high treatment costs per ton of high-salt wastewater treatment, and difficult outlets for high-salt wastewater crystalline salt.

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