Electric field coating process of ultrafiltration membrane

Abstract

The invention relates to an electric field coating process of an ultrafiltration membrane. The electric field coating process of the ultrafiltration membrane belongs to the technical field of water treatment membrane preparation, and comprises the steps of placing coating liquid containing negative charge TiO2 in a coating pond; immersing an ultrafiltration membrane component and a stainless steel plate electrode in the coating liquid; respectively connecting the ultrafiltration membrane component and the stainless steel plate electrode to positive and negative electrodes of a direct-current power supply; carrying out electric field coating under the electric field intensity being 30V/cm to obtain a coating modified ultrafiltration membrane with a TiO2 granular layer on the ultrafiltration membrane surface based on the ultrafiltration membrane component. The prepared modified ultrafiltration membrane can separate a colloidand a macromolecular organic compound, playing a leading role on membrane pollution, from a membrane surface by depending on the functions of adsorption and interception of a precoated layer on a pollutant, so that the membrane pollution is greatly reduced. During backwashing, the pollutant falls off from the membrane surface along with the precoated layer, the backwashing resistance of the membrane is reduced, and a backwashing effect is improved.

Description

technical field [0001] The invention belongs to the technical field of preparation of water treatment membranes. Background technique [0002] The increasingly stringent environmental standards make the advantages of membrane treatment technology applied to high-efficiency water treatment processes particularly prominent. However, membrane fouling is a key factor limiting its wide application. Reducing membrane fouling rate and improving membrane service life has become a research hotspot. The research on reducing membrane fouling at home and abroad mainly focuses on finding membrane materials with strong anti-fouling ability, improving the filterability of feed liquid and designing better filtration flow state, etc. [0003] In recent years, some people in the industry have proposed the concept of membrane pre-coating to prevent direct contact between the membrane and the tiny particles in the feed liquid to reduce membrane fouling. Many studies have shown that ultrafiltr...

AI Technical Summary

Problems solved by technology

[0003] In recent years, some people in the industry have proposed the concept of membrane precoating to prevent direct contact between the membrane and the tiny particles in the feed liquid to reduce membrane fouling. Many studies have shown that ultrafiltration membrane precoating is an effective way to improve membrane filtration flux, It is a technology to reduce the rate of membrane fouling and improve the removal effect of certain pollutants. However, there are many factors that affect the effect of pre-coating. Generally, the powder coating used in the pre-coating process is relatively easy to settle in water, and it will be damaged during the pre-coating process. A large amount of paint is deposited on the bottom of the membrane tank, which increases the sludge production of the membrane tank and affects the quality of the pre-coating. Even if the stirring facilities are added, the degree of bonding between the paint and the membrane is difficult to control

In addition, the ultrafiltration membrane pre-coating process requires that the paint should be easily deposited on the membrane surface to form a pre-coating, and it should also be easy to fall off from the membrane surface during backwashing, making it difficult to screen the paint, and the pre-coating process is complicated and difficult to achieve.

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