High-salt-content industrial wastewater electrodialysis-high pressure nanofiltration combined salt separation system

Abstract

The invention relates to a high-salt-content industrial wastewater electrodialysis-high pressure nanofiltration combined salt separation system and technique, belonging to a water treatment technique. The technique comprises the following steps: high-salt-content wastewater treated by a front end pretreatment system is supplied to an electrodialysis system and concentrated by the electrodialysis system to obtain high-salt-content concentrated water; the high-salt-content concentrated water is directly sent into a high pressure nanofiltration system by a charging pump, and separated by a high pressure nanofiltration membrane assembly in the high-pressure nanofiltration system into sodium chloride concentrated water and sodium sulfate concentrated water; the sodium chloride concentrated water directly enters a subsequent evaporative crystallizing system I, thereby finally obtaining industrial-grade sodium chloride; and the sodium sulfate concentrated water directly enters a subsequent evaporative crystallizing system II, thereby finally obtaining the industrial-grade sodium sulfate. The system and technique are simple to operate, and have the characteristics of stable operation, high salt separation efficiency and the like. Compared with the existing salt separation technique, the technique provided by the invention implements salt separation on ultrahigh-salt-content water, can achieve the effect of high-efficiency salt separation, and greatly lowers the energy consumption and operating cost.

Description

technical field [0001] The invention relates to an electrodialysis-high-pressure nanofiltration combined salt separation system for treating high-salt industrial wastewater, in particular to the treatment of high-salt industrial wastewater produced in the production process of coal chemical enterprises, and belongs to the technical field of water treatment. Background technique [0002] At present, the rapid development of social economy has driven enterprises into a period of rapid development. However, the ensuing environmental problems, such as chemical wastewater and chemical waste gas, have become bottlenecks restricting economic development. At the same time, the country's increasing attention to environmental protection and the people's higher and higher requirements for quality of life have forced green, environmentally friendly, and sustainable production and management to become the only way to go. Chemical wastewater, especially the wastewater produced by coal ch...

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Problems solved by technology

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art, to provide an electrodialysis-high pressure nanofiltration combined salt separation system and process for high-salt industrial wastewater, and to solve the "zero discharge" of high-salt industrial wastewater in a targeted manner. "The mixed salt produced in the process cannot be used, has no economic value, and will also cause problems such as accumulation of hazardous waste and secondary pollution; the present invention mainly uses the selective permeability of high-pressure nanofiltration membranes to different ions to convert The concentrated high-salt industrial wastewater is divided into monovalent sodium chloride concentrated water and divalent sodium sulfate concentrated water, and then crystallized to finally obtain industrial-grade standard sodium chloride and sodium sulfate; the process has the advantages of simple operation, stable operation, Compared with the existing salt separation technology, it has the characteristics of high salt separation efficiency, realizes ultra-high concentration of saline water salt, and can achieve the effect of high-efficiency salt separation, while greatly reducing energy consumption and operating costs

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