In recent years, ultrafiltration has been widely used in the treatment of oily sewage in industrial production, the preparation of ultra-pure water systems in smart water purification plants, and cell biotechnology. It can reasonably separate, purify and purify some small water-soluble solutes and polymerizations in domestic water.

1. The basic characteristics of ro uf membrane.

According to the division of ro uf membrane structure, it can be divided into symmetric membrane and asymmetric membrane. At present, most commonly used ro uf membrane are asymmetric encryption membranes. Located between the nanofiltration membrane and the microfiltration membrane, in the small diameter area, it overlaps with the RO reverse osmosis, and in the large diameter area, it overlaps with the microfiltration membrane. The diameter of the separated components is between 5nm~10μm, and the relative molecular mass of the biomacromolecule or colloidal solution can be intercepted between 5~50,000. In operation and application, it is found that the uf membrane module has a high water production rate during the entire process of drinking water treatment, is convenient to use, and the actual operating pressure is low. Therefore, in the water treatment market prospects, the application range is extremely wide.

2. The basic characteristic types of ro uf membrane

The basic characteristics of the entire process of ro uf membrane are generally concentration polarization, convective heat transfer index, and micropore model.
(1) Concentration polarization: ultrafiltration membrane has selective permeability. When a large amount of polymer material solutes and colloidal solutions are intercepted by the membrane, the polymer material solutes will accumulate on the surface of the membrane. When it exceeds a certain level, under the action of the concentration gradient, the solute on the membrane surface will slowly fall off and enter the raw material liquid again, so that the cycle will reciprocate and finally reach equilibrium. The surface of the ultrafiltration membrane will produce an additional surface layer that blocks small water solutes, which is called concentration polarization. Concentration polarization is very harmful to the selective permeability of the membrane. The larger the concentration polarization displacement coefficient is, the more solutes will accumulate on the surface, which is harmful to the interception effect of the membrane.
(2) Mass transfer coefficient: Increasing the convective heat transfer index can increase the interception rate of the uf membrane module. In other words, the greater the convective heat conductivity index, the less the concentration polarization.

(3) Microporous model: Generally, the microporous solid model is used to evaluate the permeation principle of ultrafiltration. Generally speaking, the physical model of the membrane micropores is expressed by the micropore half length, liquid viscosity and membrane length. The changes in the main parameters of the microporous solid model are harmful to the membrane properties.