Polyamide forward osmosis membrane for water treatment

Abstract

The invention provides a polyamide forward osmosis membrane for water treatment. The composite polyamide forward osmosis membrane with an asymmetric sandwich structure is designed, i.e., a high-throughput polyamide separating layer and a high-selectivity polyamide separating layer are respectively designed on two sides of a polysulfone supporting layer; then the high-selectivity polyamide separating layer is designed into two thin layers; on one thin layer close to the polysulfone supporting layer, dopamine is added into a water-phase monomer, so that the throughout of the whole membrane is improved; water-phase and oil-phase monomer types of the polyamide separating layers on two sides of the polysulfone supporting layer are selected, so that the best performance of the membrane is ensured.

Description

technical field [0001] The present application relates to a forward osmosis membrane, in particular to a polyamide forward osmosis membrane for water treatment. Background technique [0002] In August 2015, the World Resources Institute released the ranking of national water resource stress in 2040. It is expected that China will change from a country with medium water resource stress to a country with extremely high water resource stress. In order to cope with water resource pressure, countries around the world continue to strengthen the field of water treatment Various water treatment technologies have been developed successively, among which technologies such as reclaimed water reuse and seawater desalination are widely used. [0003] As an important supporting technology in the field of water treatment, membrane water treatment technologies such as microfiltration (MF), ultrafiltration (UF), nanofiltration (NF), and reverse osmosis (RO) have been commercialized after lon...

AI Technical Summary

Problems solved by technology

The internal concentration polarization that occurs inside the support layer will reduce the membrane permeation driving force

In response to this problem, the method of reducing the thickness of the membrane is generally used to reduce the concentration polarization limit to the greatest extent, but the reduction of the thickness of the support layer will lead to the reduction of the strength of the membrane, and the reduction of the thickness of the separation layer will reduce the selectivity.

Some scholars have also proposed a symmetrical sandwich structure with a double skin layer. This method can reduce the degree of concentration polarization in the membrane by blocking the solute in the raw material solution from entering the support body. However, compared with the traditional forward osmosis membrane, it has an additional layer of separation layer so flux is not optimistic