How do ultrafiltration membranes achieve efficient water purification?

Ultrafiltration membrane technology is a water treatment technology based on the principle of physical filtration, the core of which is through the ultrafiltration membrane precision pore size structure selective retention of impurities and pollutants in the water, has achieved the effect of water purification.
I.Structure and working principle of ultrafiltration membrane

Ultrafiltration membranes are porous membranes made of polymer materials with a dense distribution of micropores on the surface and inside, with a pore size range usually in the range of 0.01~0.1 microns (equivalent to one ten-thousandth of a hair strand).This size is much smaller than bacteria (0.5~5 microns) and most suspended particles, but allows water molecules and some small molecules (such as mineral ions) to pass through.

When water flows through the surface of the ultrafiltration membrane under pressure-driven flow, contaminants larger than the pore size (such as bacteria, colloids, macromolecules and organics) are retained on the membrane surface or outside the membrane pores, thus achieving water purification.However, this purification principle, a long time purification will lead to membrane surface clogging, reduce the purification effect, so some water purifiers set up a backwash function to reduce the accumulation of pollutants clogging, improve the purification efficiency and service life of the cartridge.

AW-UF-03

II.Types of pollutants that can be purified by ultrafiltration membranes
Microorganisms: complete interception of bacteria (e.g. E. coli, salmonella), but less effective in virus interception.
Suspended matter and colloids: removes sediment, rust, algae, colloidal particles, etc. and significantly improves water turbidity.
Macromolecular organic matter: such as grease, protein, humic acid, etc.
III.Substances that cannot be removed by ultrafiltration membranes
Dissolved substances: dissolved salts, heavy metal ions, dissolved organic matter.
Small molecule substances: e.g. chlorine gas, some pesticide molecules.
IV.Advantages of ultrafiltration water purifier for water purification
Safety: Pure physical aperture sieve filtration, safe and no secondary pollution.
Health: retaining some minerals, such as allowing calcium, magnesium, potassium and other beneficial minerals to pass through, maintaining the natural taste and nutrition of water.
Environmental protection and energy saving: no electricity is needed, no thick water discharge, only relying on tap water pressure to achieve filtration and purification, energy saving and applicable to a wide range of scenarios.
High efficiency and long lifespan: high throughput, and can be periodically flushed to restore performance, normal service life of up to 2~3 years.

Based on the purification principle and performance of ultrafiltration membrane, ultrafiltration water purifier can efficiently intercept large particles of pollutants and microorganisms in the water, both safety and economy, is one of the commonly used household water purification programme.However, ultrafiltration water purifier can not remove calcium and magnesium ions to reduce water hardness, and can not be dissolved in water dissolved pollutants (such as nitrite, fluoride) screening purification.Therefore, ultrafiltration water purifier is more suitable for the better quality of raw water for in-depth purification, the complex water quality of raw water purification, the use of reverse osmosis purification is more effective.