How ultrafiltration works

What is Ultrafiltration?  How Does Ultrafiltration Work?

Ultrafiltration membrane is a polymer semi-permeable membrane that can block polymer colloids or suspended particles between about 0.002 and 0.1 μm and separate them from the solution. However, small molecules, soluble solids, inorganic salts, etc. can pass through the ultrafiltration membrane pores.

The earliest ultrafiltration membranes used were thin membranes of animal organs, which had a small application range and slow development. It was not until the 1970s that ultrafiltration technology entered a rapid development stage with the development of science and technology.

Due to the characteristics of ultrafiltration such as simple equipment, small footprint, low filtration pressure, and easy availability of materials, its application range has rapidly extended to electronics, medicine, beverages, food, chemicals, medical treatment, wastewater treatment and recycling, and product demand has also grown rapidly.

Ultrafiltration membrane is a microporous filtration membrane with consistent pore size specifications and a rated pore size range of 0.001-0.02 microns. The membrane filtration method using pressure difference as the driving force is called ultrafiltration membrane filtration.

When the rated pore size range of the membrane is used as the distinction standard, membrane filtration with pressure difference as the driving force can be divided into:

The rated pore size range of microporous membrane (MF) is 0.02~10um;
Ultrafiltration membrane (UF) is 0.001~0.02 um;
Reverse osmosis membrane (RO) is 0.0001~0.001 um.

The pore size of an ultrafiltration membrane is only a few nanometers to tens of nanometers, which means that by applying appropriate pressure on one side of the membrane, solute molecules larger than the pore size can be screened out to separate particles with a molecular weight greater than 500 Daltons and a particle size greater than 2~20 nanometers. The macromolecular substances and particles in the wastewater are removed by using the mechanical screening effect of the membrane surface pore size, the blocking and retardation effect of the membrane pores, and the adsorption of impurities by the membrane surface and membrane pores. It is generally believed that it is mainly screening.

Under the action of external force, the separated solution flows along the surface of the ultrafiltration membrane at a certain flow rate. The solvent low-molecular substances and inorganic ions in the solution pass through the ultrafiltration membrane from the high-pressure side into the low-pressure side and are discharged as filtrate. In contrast, the ultrafiltration membrane retains the macromolecular substances, colloidal particles and microorganisms in the solution, and the solution is concentrated and discharged in the form of concentrated liquid.

1. Ultrafiltration membrane has high chemical stability and is resistant to high temperature, acid and alkali, so it does not require high water quality and has strong versatility.

2. The principle of ultrafiltration membrane technology is simple, easy to realize automatic operation, save labor, and easy to operate, easy to maintain, safe and stable operation.

3. Ultrafiltration membrane technology is a physical method. No chemical agents are required during the water treatment process, so it can effectively prevent secondary pollution of the water body.

4. Ultrafiltration membrane technology has high efficiency and large water treatment volume, especially for the treatment of urban drinking water with less pollution, showing high work efficiency.

The performance of ultrafiltration membrane technology is constantly improving, and its application advantages in various fields are prominent. When using ultrafiltration membrane, you must pay attention to the daily maintenance of membrane elements, effectively extend the service life of membrane elements, and create higher profits for users.