Hydrophilic/hydrophobic composite membrane for membrane distillation

A composite membrane and membrane distillation technology, which is applied in the field of membrane water treatment, can solve the problems of low strength of single-layer PVDF hydrophobic membrane, increase economic investment, and production impact, and achieve improved anti-pollution performance, wide applicability, and anti-pollution strong effect

Inactive Publication Date: 2013-10-30
HEBEI UNIV OF ENG
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The strength of single-layer PVDF hydrophobic membrane is low, and it is easy to cause membrane rupture during the pressure operation in the actual production process, which will lead to frequent replacement of membrane modules, increase economic investment, and affect production

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0012] 1) Preparation of hydrophobic membrane membrane solution

[0013] The membrane-making liquid system of hydrophobic membrane is DMAC / LiCl / H 2 O / PVDF, wherein the concentration of PVDF is 10wt%, the content of additive LiCl is 5.0wt.%, non-solvent H 2 The content of O is 2.0wt.%, and DMAc is used as a solvent, which is fully dissolved to a colorless and transparent state at about 40° C., and then left to stand for 24 hours for defoaming.

[0014] 2) Preparation of hydrophilic membrane membrane solution

[0015] The membrane-making liquid system of hydrophilic membrane is DMAC / TiO 2 / LiCl / PVP / H 2 O / PVDF, wherein the concentration of PVDF is 10wt%, the content of additive LiCl is 5.0wt.%, non-solvent H 2 O content is 2.0wt.%, polyvinylpyrrolidone (PVP) concentration is 0.2wt%, titanium dioxide (TiO 2 ) concentration is 7wt%, and DMAC is used as a solvent, fully dissolved to a colorless and transparent state at about 40°C, and then left to stand for 24 hours for defoami...

Embodiment 2

[0020] 1) Preparation of hydrophobic membrane membrane solution

[0021] The membrane-making liquid system of hydrophobic membrane is DMAC / LiCl / H 2 O / PVDF, wherein the concentration of PVDF is 12wt%, the content of additive LiCl is 5.0wt.%, non-solvent H 2 The content of O is 2.0wt.%, and DMAc is used as a solvent, which is fully dissolved to a colorless and transparent state at about 40° C., and then left to stand for 24 hours for defoaming.

[0022] 2) Preparation of hydrophilic membrane membrane solution

[0023] The membrane-making liquid system of hydrophilic membrane is DMAC / TiO 2 / LiCl / PVP / H 2 O / PVDF, wherein the concentration of PVDF is 12wt%, the content of additive LiCl is 5.0wt.%, non-solvent H 2 The content of O is 1.0wt.%, the concentration of polyvinylpyrrolidone (PVP) is 0.2wt%, titanium dioxide (TiO 2 ) concentration is 7wt%, and DMAC is used as a solvent, fully dissolved to a colorless and transparent state at about 40°C, and then left to stand for 24 hou...

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PUM

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Abstract

The invention belongs to the technical field of membrane method water treatment and relates to a composite membrane for membrane distillation, which is formed by compounding a hydrophilic layer, a hydrophobic layer and a non-woven fabric supporting layer. The composite membrane is characterized in that a hydrophilic layer membrane casting solution system is DMAC (Dimethylacetamide)/TiO2/LiCl/PVP/H2O/PVDF (Polyvinylidene Fluoride), a hydrophobic layer membrane casting solution system is DMAC/LiCl/H2O/PVDF, and the non-woven fabric supporting layer is made of a polyester material. The preparation method comprises the following steps of: firstly, uniformly striking a hydrophobic layer membrane casting solution on a clean non-woven fabric, standing, carrying out coagulating bath and airing; and then, uniformly striking a hydrophilic layer membrane casting solution on the just made hydrophobic layer, standing, carrying out coagulating bath and airing to obtain the hydrophilic/hydrophobic composite membrane. The hydrophilic/hydrophobic composite membrane for membrane distillation, provided by the invention, has the characteristics of strong antipollution capability, large membrane flux and high mechanical strength, and can be widely applied to different forms of membrane distilled bitter-brackish water desalination, seawater desalination and high salinity wastewater treatment and recycling processes.

Description

technical field [0001] The invention relates to a hydrophilic / hydrophobic composite membrane that can be used for membrane distillation, which is used in different forms of membrane distillation high-salt wastewater treatment and reuse, brackish water desalination and seawater desalination, and belongs to the technical field of membrane water treatment. Background technique [0002] Membrane distillation is a new type of separation technology, which is a membrane separation process that uses the vapor pressure difference on both sides of a hydrophobic microporous membrane as the driving force for mass transfer. The process of membrane distillation is carried out almost under normal pressure, the equipment is simple, and the operation is convenient; the membrane distillation method can handle extremely high concentration of inorganic salt solution, and the desalination rate of desalination through membrane distillation can reach 100% in theory, and the obtained water is very ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B01D69/12B01D61/36
Inventor 李福勤
Owner HEBEI UNIV OF ENG
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