Why add a filter before UF? There are usually filters before UF. Such as double filter, activated carbon filter, disc filter, self-cleaning filter, etc.Because the filtration accuracy of UF is 0.001 ~ 0.02 μm, if there are large particles in the raw water, the UF hole eye will be blocked and the trans-membrane pressure difference will be increased. if there are mechanical particles, the UF membrane will be damaged.The general treatment steps in the power plant are: coagulation, clarification and filtration. UF is the last device in the filtration process.The status you said is 'the system is running 2 ~ After 3 days, the surface of the security filter element will form a sticky diaphragm 'which may be caused by poor coagulation effect, or organic pollution and biological material pollution. The specific situation is system operation 2 ~ After 3 days, the surface of the security filter element forms a sticky diaphragm, resulting in an initial filter before entering the UF to intercept some small particles.
Xiao Qiang poured the turbid river into the beaker. First, add alum to mix and dissolve it, calm it for a while, and then filter it. (1) add alum? (1) alum can absorb suspended matter in water,(2) when filtering,(3) the filtered water still contains some water-soluble substances,It is not pure water. Therefore, it is not pure water;