3, microfiltration and ultrafiltration membrane technology
3.1 basic principles of ultrafiltration (UF) and microfiltration (MF)
Ultrafiltration and microfiltration are in the static pressure difference under the action of the liquid phase separation process, from the principle that there is no essential difference, with the sieve separation process. Under the action of a certain pressure, when the mixed solution containing the solute of the polymer and the low molecular solute flows through the membrane surface, the solvent and the low molecular solute (such as an inorganic salt) smaller than the membrane pore are permeated through the membrane, Membrane pore polymer solute (such as organic colloid) is retained as a concentrate and retained as a concentrate. Can be cut off the molecular weight of more than 500, 106 the following molecular membrane separation process known as ultrafiltration; can only be retained more molecules (usually referred to as dispersed particles) membrane separation process known as microfiltration.
3.2 ultrafiltration and microfiltration membrane applications
Ultrafiltration, microfiltration technology can effectively remove particulate matter, including microorganisms such as latent insects, Giardia, bacteria and viruses. The disinfection by-products can also be reduced by reducing the concentration of the detoxification byproduct precursor to a certain extent and limiting the oxidant requirement during the sterilization process. But the removal rate of organic matter in water is very low, only 20% or less. Ultrafiltration and microfiltration use a wide range, can be applied to deal with different water quality.