Research Progress of Ultrafiltration Membrane Pollution Control
Causes and mechanism of ultrafiltration membrane fouling
The study of membrane fouling mechanism is the key of ultrafiltration technology
Taking effective control measures for the causes and characteristics of membrane fouling,
Can reduce film pollution.
Concentration polarization and membrane fouling are caused by the ultrafiltration process
The important factor of health.
Membrane fouling is irreversible and concentration polarization
It is often considered reversible and can be recovered by hydraulic cleaning
Reversible pollution is generally not treated as membrane fouling, but many are actually
The membrane fouling is also caused by concentration polarization.
Membrane fouling is caused by low solubility of inorganic salts, colloids and dissolved organic compounds and sludge, biodegradation products of membranes.
When the adsorption of pollutants deposited on the surface of the membrane causes external blockage, from
It increases the flow of water through membrane resistance;
When the pollutant is adsorbed in the film hole
It can cause internal blockage, thus reducing membrane pore diameter and reducing membrane flux.
There is no unified theory about membrane fouling mechanism but in the literature
To be sure, the interaction between the particles and the membrane materials in the original liquid is the shadow
The most important factor of the membrane fouling.
It is generally believed that membrane pollution is mainly concentrated
There are four reasons for differential polarization, formation of filter cake layer and compression, adsorption and hole plugging
The adsorption of the membrane in the ultrafiltration process is considered to be the cause of membrane fouling
The key to dying is the interaction between adsorption and membrane, solvent and solute
Because of the chemical properties and structure of membrane components, it produces suction
The mechanism of attachment is also different, which can be divided into van der Waals force and electrostatic
Use, hydrophobic, hydrogen bonding.
Ultrafiltration membrane pollution is usually a hydrophobic between membrane and solute
Shuji Nakatsuka et al. found hydrophilic acetate fibers
The permeable flux of the membrane was higher than that of the hydrophobic polyether sulfoxide membrane.
Lu xiaofeng et al
It was found that the hydrophilic membrane was small and the membrane was small
The pollution performance is good, and it is suggested that the adsorption of the membrane is acceptable
Film pollution is reduced, but there are conflicting results.
Choo k. H is based on three kinds of cellulose, polysulfone and fluoropolymer
Different membrane materials were used to study the adsorption of pollutants into the surface of the membrane
The change of surface free energy to investigate the degree of pollution, the most hydrophobic
The fluorinated polymer film shows the minimum pollution tendency, which is established
The explanation of the surface tension dispersion phase is based on the surface affinity
The prediction of membrane fouling on the basis of water is the result of the experiment
In the process of using superfiltration surface water to produce drinking water,
Organic matter is the main material that causes membrane fouling
Large, ultraviolet absorption of high humic acid is caused by irreversible pore adsorption and
The main cause of blockage.
Chen Y is based on natural organic matter
Composition and molecular weight of coagulation pretreatment to prevent membrane fouling
And the mechanism is that the hydrophobic compounds with relatively high molecular weight are conductance
The reason for the rapid decrease of ultrafiltration flux.
Bian, like forest, for surface water
The long-term pollution of ultrafiltration membrane was carried out by dissolved organic matter
It is believed that the membrane fouling experienced the early internal adsorption and medium-term table
The process of adhesion of surface adhesion and late adhesion.
In wastewater and secondary discharge ultrafiltration treatment, it is mainly extracellular
An irreversible membrane fouling is formed by adsorption and deposition of membrane surface
G. j. Zhang et al studied some extracellular polymers and no
The adsorption effect of the same type ultrafiltration membrane was evaluated with polysulfone and polypropylene
The ultrafiltration membrane and 6 sludge samples of the three types of nitrile and polyvinylidene fluoride
The direct interaction of the polysulfone ultrafiltration membrane was found to be due to its surface roughness
Large and hydrophobic and highly polluting.
Membrane fouling is not only the membrane material, membrane aperture size and distribution and membrane
It can relate to the properties of the original water.
Membrane surface and solution
The interaction between dissolved substances in liquid is determined by the degree of membrane fouling
It plays an important role in the molecular size, molecular mass and molecular weight of the solution
The shape is closely related to membrane fouling, and membrane fouling and pollutant
The nature of the film will affect the process of membrane fouling.