High pressure disc tube type nanofiltration membrane salt separation system

Abstract

The invention discloses a high pressure disc tube type nanofiltration membrane salt separation system, and relates to the technical field of environmental protection sewage treatment. The high pressure disc type nanofiltration membrane separation system comprises a sewage storage tank, a pre-filter and modules which are connected in sequence; at least one set of the modules is arranged; each module comprises at least one high pressure disc tube type nanofiltration membrane column, the operating pressure of the high pressure disc tube type nanofiltration membrane column is 30 to 120 bar; and the module is respectively connected with a filtration liquid storage tank and a concentrate liquid storage tank. The high pressure disc tube type nanofiltration membrane salt separation system is especially suitable for treating a high salt concentrate containing sodium sulfate and sodium chloride, by use of the characteristic of high pressure operation, the sodium sulfate is efficiently removed and concentrated, and the sodium chloride is efficiently filtered, so that the sodium sulfate and the sodium chloride are separated, the industrial-grade sodium sulfate and the industrial-grade sodium chloride are efficiently recovered respectively, generation of hazardous waste can be reduced, and the recycling of resources is promoted.

Description

technical field [0001] The invention relates to the technical field of environmental protection sewage treatment, in particular to a high-pressure disc-tube nanofiltration membrane salt separation system. Background technique [0002] In addition to a large amount of toxic and harmful organic pollutants, industrial wastewater also contains a large amount of dissolved total solids mainly composed of inorganic salts. In modern enterprises, in order to save costs and realize the reuse of resources, it is hoped that the inorganic salts in the wastewater can be recovered to obtain industrial-grade products with utilization value. During the treatment process, the sewage is generally pretreated first to remove the organic pollutants, and then concentrated into a high-salt concentrated solution to obtain inorganic salts from the concentrated solution. [0003] To obtain inorganic salts from the concentrated solution, the traditional technology is to adopt the method of fractional ...

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Problems solved by technology

[0003] To obtain inorganic salts from the concentrated solution, the traditional technology is to adopt the method of fractional evaporation and crystallization. This method can crystallize most of the inorganic salts, but the separation effect is poor and the cost is high. Due to the inability to form an effective concentration difference, resulting in The recycling rate of salt is low

[0004] Another way is to use a low-pressure separation membrane, which has low efficiency and a low rejection rate for high-valent salts, resulting in more miscellaneous salts in the obtained monovalent salts, which cannot achieve high-quality industrial inorganic salt products.

At the same time, because of the low operating pressure, it is not practical for the situation of high concentration of high-priced salt

The concentration ratio cannot be increased, so that the concentration difference between high-priced salt and low-priced salt is small, and the amount of crystallized salt of high-priced salt is small, resulting in a large amount of miscellaneous salt hazardous waste, and the recycling rate of salt is low

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