The membrane microfiltration method includes three forms: deep filtration, screen filtration and surface filtration.
Deep filtration is a kind of substrate made of woven fiber or compressed materials. It USES passive adsorption or capture to retain particles, such as multi-media filtration or sand filtration.
Deep filtration is an economical way to remove more than 98 percent of suspended solids while protecting downstream purification units from clogging, so it is usually used as pretreatment.
Surface filtration is a multi-layer structure. When the solution passes through the filter membrane, particles larger than the pores inside the filter membrane will be left behind and mainly accumulated on the surface of the filter membrane, such as PP fiber filtration commonly used.
Surface filtration can remove more than 99.9% of suspended solids, so it can also be used as pretreatment or clarification.
The screen filter membrane is basically a consistent structure. Like a sieve, the particles larger than the aperture are left on the surface (the pore measurement of the filter membrane is very accurate).
The microporous filter is usually placed in the final use point of the purification system to remove the residual trace resin sheet, carbon chip, colloid and microorganism.