Preparation method of nanofiltration membrane for dye concentration and desalination

A nanofiltration membrane and membrane-forming technology, applied in the field of membrane separation, can solve the problems of poor product quality consistency, low product purity, and product quality restrictions.

Inactive Publication Date: 2012-05-16
INST OF URBAN ENVIRONMENT CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

At present, the domestic traditional dye production process mainly adopts salting out or acid precipitation to separate dye components, the product purity is not high, and the quality consistency of different batches of products is poor, which greatly limits the product quality

Method used

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  • Preparation method of nanofiltration membrane for dye concentration and desalination
  • Preparation method of nanofiltration membrane for dye concentration and desalination
  • Preparation method of nanofiltration membrane for dye concentration and desalination

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0015] Example 1, dissolve 7g of lithium chloride and 1g of polyvinylpyrrolidone in 74g of N,N-dimethylacetamide, then add 18g of aromatic polyamide, dissolve the mixture at a constant temperature of 90°C, and vacuum defoam , to prepare the casting solution. Put a certain amount of the prepared film casting liquid into the trough, use the polyester non-woven fabric as the support layer, and control the film thickness to 0.2 mm by a feeler gauge. After the casting solution is applied to the non-woven fabric, it stays in an oven at 90°C for 0.3 minutes to evaporate part of the solvent, and then enters the gel bath to solidify to form a film. The prepared membrane was placed in pure water for more than 24 hours to completely remove excess organic solvent. Under the pressure of 0.6MPa, the pure water flux of the membrane is 150.8L / m 2 h. Use 2000mg / L of Na 2 S0 4 The solution was tested with a flux of 183.1L / m 2 h, the rejection rate is 6.7%. Under the operating pressure of ...

Embodiment 2

[0016] Example 2, dissolve 5g of lithium chloride and 3g of polyvinylpyrrolidone in 74g of N,N-dimethylacetamide, then add 18g of aromatic polyamide, dissolve the mixture at a constant temperature of 90°C, and vacuum defoam . Put a certain amount of casting solution into the trough, use polyester non-woven fabric as the support layer, and control the film thickness to 0.2 mm with a feeler gauge. After the casting solution is applied to the non-woven fabric, it stays in an oven at 90°C for 0.3 minutes to evaporate part of the solvent, and then enters the gel bath to solidify to form a film. The prepared membrane was placed in pure water for more than 24 hours to completely remove excess organic solvent. Under the pressure of 0.6MPa, the pure water flux of the membrane is 112.1L / m 2 h. With 2000mg / L Na 2 SO 4 The solution was tested with a flux of 108.2L / m 2 h, the rejection rate is 7.9%. Under the operating pressure of 0.6MPa, the flux of the membrane to 1g / L chrome blac...

Embodiment 3

[0017] Example 3, dissolving 6g of lithium chloride and 2g of polyvinylpyrrolidone in 74g of N,N-dimethylacetamide, then adding 18g of aromatic polyamide, dissolving the mixture at a constant temperature of 90°C, and vacuum defoaming . Put a certain amount of casting solution into the trough, use polyester non-woven fabric as the support layer, and control the film thickness to 0.2 mm with a feeler gauge. After coating the casting solution on the non-woven fabric, stay in an oven at 90°C for 0.4min to evaporate part of the solvent, and then enter the gel bath to solidify to form a film. The prepared membrane was placed in pure water for more than 24 hours to completely remove excess organic solvent. Under the pressure of 0.6MPa, the pure water flux of the membrane is 97.2L / m 2 h. With 2000mg / L Na 2 SO 4 The solution was tested with a flux of 99.9L / m 2 h, the rejection rate is 7.6%. Under the operating pressure of 0.6MPa, the flux of the membrane to 1g / L chrome black T d...

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Abstract

The invention discloses a preparation method of an aromatic polyamide nanofiltration membrane. The method is mainly characterized by comprising the following steps of: on the basis of utilizing aromatic polyamide as a major polymer membrane preparation material, completely defoaming a membrane casting liquid containing aromatic polyamide, organic solvent and additives; then flatly paving the product on a non-woven fabric by use of a membrane casting machine; evaporating in an oven for certain time; and curing in a gel tank to obtain the membrane. By adopting the preparation method, the nanofiltration membrane has relatively high rejection rate against small-molecular organisms, especially the dye with molecular weight of about 400, and has a penetration rate of greater than 80% for sodium sulfate and sodium chloride, thus being suitable for the concentration and desalination of dye.

Description

technical field [0001] The invention relates to a preparation method of a nanofiltration membrane used for dye concentration and desalination, and belongs to the technical field of membrane separation. Background technique [0002] In recent years, the competition in the dye industry has become increasingly fierce, and the requirements for dyes have also become higher and higher. Environmentally friendly dyes and salt-free liquid dyes with bright colors and high dye uptake are very popular. In the traditional production process of direct dyes, the process of salting out, filtration and concentration is generally carried out; the purpose is to desalt, remove unreacted raw materials, intermediates and secondary dyes, and remove water to obtain dyes with the required concentration and purity. It is then spray-dried to make powdered dyes or directly into liquid fuels. Practice has proved that the impurities and salt brought by the synthesis and salting out process have brought ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B01D71/56B01D69/12B01D67/00C09B67/54
Inventor 张凯松黄健
Owner INST OF URBAN ENVIRONMENT CHINESE ACAD OF SCI
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