Since the water diffusion coefficient of hollow fiber ultrafiltration membrane is relatively large, the concentration value of the intercepted residue on the membrane surface rapidly expands, resulting in polarization of the concentration value. What's more serious is that some very fine particles will enter the pore size of hollow fiber uf membrane and block the safe passage of water. In addition, the microorganisms and basal metabolites in the water are converted into viscous chemicals and adhere to the surface of the membrane. All these factors will cause the permeability coefficient of hollow fiber ultrafiltration membrane to decrease and its separation function to change. At the same time, the water supply temperature, PH value and concentration value of uf membrane module also have certain regulations. Therefore, the water supply of hollow fiber ultrafiltration membrane must be properly pretreated and adjusted to meet the water supply standard, so as to extend the service life and reduce the cost of water treatment.

1. Eliminate microorganisms

When the water contains microorganisms, after being added to the pre-treatment system, some of the intercepted microorganisms are likely to adhere to the pre-treatment system, such as the material surface of a multi-substance filter device. It grows and multiplies when adsorbed on the surface of hollow fiber ultrafiltration membrane, the microporous plate is completely clogged, and the inner wall of the hollow chemical fiber is highly likely to be completely clogged. To remove bacteria, algae and other microorganisms in raw water, great attention must be paid. In water treatment, oxides such as NaClO and O3 are generally added, and the concentration value is generally 1~5mg/l. In addition, ultraviolet sterilization can also be applied. The laboratory performs disinfection treatment on uf membrane module. Hydrogen peroxide (H2O2) or potassium permanganate solution can be used to circulate the treatment for 30-60 minutes. The elimination of microorganisms can only eliminate microorganisms, but cannot remove microorganisms from the water, and can only avoid the reproduction of microorganisms.

2. Reduce water seepage and turbidity

If the water contains suspended solids, colloidal solutions, microorganisms and other impurities, it will cause the water to produce a certain degree of turbidity. This turbidity will affect the effect of the light source, the electron optical effect and the number, size and appearance of the debris related. Considering that the turbidity of water is generally expressed by the degree of etching, the turbidity caused by 1mg/l SiO2 is 1 degree. The greater the myopia, the greater the impurity content. . Since the turbidity detection is to accurately measure the visibility, hue, and opacity of the particles reflected from the water through the source water, the size, total number and shape of the particles are harmful to the measurement, and the relationship between turbidity and suspended solids varies with From here. Turbidity cannot be reflected on particles below multiple μm.

In the biological fiber mask solution, high-precision film optics, intercepting molecular structure and even positive ion particles use turbidity to indicate that the water is significantly inaccurate. In order to better predict and analyze the trend of raw water pollution, the SDI value experiment was developed.