Salt crystallization separation device and process capable of realizing zero emission

Abstract

The invention relates to a salt crystallization separation device and process capable of realizing zero emission and discloses a zero-emission treatment method and device for high-salt wastewater. Wastewater is subjected to intensified softening treatment with a tubular microfiltration membrane and then enters a special separation membrane for separation of monovalent ions and divalent ions. Further concentration is performed with a high-pressure reverse osmosis or selective permeable electric ionic membrane according to the properties of materials on a fresh water side and a concentrated water side, and the evaporation system treatment scale and scaling tendency are reduced to the maximum extent. Crystalline salt is obtained by use of a low-temperature normal-pressure crystallizer at an evaporative crystallization section, wastewater and crystalline salt are finally recycled, the investment is saved, the wastewater operation cost is significantly reduced, and zero emission of wastewater can be really realized.

Description

technical field [0001] The invention relates to a zero-discharge crystallization and salt separation treatment device and process for high-salt wastewater, and belongs to the technical field of industrial wastewater recovery and treatment. Background technique [0002] The shortage of water resources and the pollution of waste water have become worldwide problems. The requirements of my country's wastewater discharge standards are becoming increasingly stringent, especially the newly promulgated "Water Ten Measures", which raises water environmental protection to the national strategic level. With the progress of industrialization, a large amount of industrial wastewater is discharged correspondingly, which puts a lot of pressure on the environment. At the same time, it also promotes the exploration and development of zero-discharge technology for industrial wastewater by domestic environmental protection manufacturers. At present, the research and development of domestic...

AI Technical Summary

Problems solved by technology

The single use of crystallization evaporation technology in zero discharge is not suitable for treating wastewater with high hardness, corrosiveness and volatile substances, and a strict pretreatment process is required before treatment; fluctuations in the salinity of wastewater cause fluctuations in boiling point, which leads to changes in system energy consumption; high temperature evaporation Or boiling and evaporation under negative pressure increases the fouling tendency, the cleaning intensity of the heat exchanger surface is high, and the process is complicated

Moreover, the current treatment technology generally has the problem of high process investment and operation cost, and the problem of secondary pollution caused by crystalline miscellaneous salt as solid waste, which limits the application in actual engineering.

Images