Iron and steel enterprise high-salinity wastewater treatment process

Abstract

The invention discloses an iron and steel enterprise high-salinity wastewater treatment process, and belongs to the technical field of industrial wastewater treatment. According to the technical scheme, the process comprises the steps: treating high-salinity wastewater through an adjusting tank, a chemical softening tank, a multi-medium filter, an ozone catalytic oxidation tower, a membrane bioreactor (MBR), primary ultrafiltration, two-stage low-pressure reverse osmosis, activated carbon adsorption, secondary ultrafiltration, weak acid resin, nanofiltration, high-pressure reverse osmosis, adsorption defluorination, electrodialysis (ED), and treatment with chelating resin and a bipolar membrane in sequence; the quality of recycled water is better than that of industrial new water, the recycled water can be used as desalted water, and the produced by-products hydrochloric acid and sodium hydroxide can be recycled for the process system, other water treatment systems of iron and steel enterprises and the like, so that the outsourcing cost is saved, and resource utilization is realized. The process is low in energy consumption, low in cost, simple in equipment, easy to operate, stablein treatment effect and beneficial to water optimization and sustainable development of iron and steel enterprises.

Description

technical field [0001] The invention belongs to the technical field of industrial wastewater treatment, and in particular relates to a process for treating high-salt wastewater in iron and steel enterprises. Background technique [0002] Iron and steel enterprises mostly use the "ultrafiltration + reverse osmosis" double-membrane process to prepare desalted water to realize the reuse of reclaimed water and reduce the consumption of fresh water. The iron and steel industry has a long technological process, complex production process, large amount of waste water and complex composition of pollutants. During the production process of waste water reuse, most of the pollutants in the waste water are trapped in the reverse osmosis high brine. This leads to high concentration of refractory organic matter in high brine, high salinity, high hardness, and complex inorganic pollution factors. If high brine is not effectively treated and reused as production water, the equipment will be...

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Problems solved by technology

This leads to high concentration of refractory organic matter in high brine, high salinity, high hardness, and complex inorganic pollution factors. If high brine is not effectively treated and reused as production water, the equipment will be scaled and corroded due to excessive salt content, which will affect the heat transfer effect. It even shortens the service life of the equipment; at the same time, toxic and harmful pollutants are enriched in high-salt wastewater. If they are directly discharged into the environmental water, it will seriously threaten the safety of the ecological environment and cause great pressure on the deterioration of the water environment and the shortage of water resources in the area where the enterprise is located. Seriously restrict the sustainable development of the steel industry

[0003] At present, the high brine treatment technology mainly uses various membrane separation technologies to further carry out desalination treatment, thereby improving the utilization rate of water resources, and combining membrane distillation technology to realize salt solidification and obtain solid miscellaneous salts, but only to realize the liquid to solid of pollutants The morphological transformation of salt, the subsequent treatment of miscellaneous salts also has huge environmental and cost pressures

[0004] To sum up, the existing high-brine treatment process of metallurgical enterprises has the disadvantages of poor treatment effect, serious membrane fouling, low water production rate of the system, high process operation cost and inability to completely realize harmlessness

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