As we all know, acidic and alkaline cleaning agents are commonly used cleaning drugs, and the appropriate cleaning scheme is selected according to the type of contamination.
①. Acid cleaning method of hollow fiber uf membrane
When the Fe or Mn content in the influent exceeds the design specification, or the suspended solids in the influent of the Dow reverse osmosis membrane module are particularly high, it will cause environmental pollution of inorganic compounds on the permeate side of the membrane. Clean the ultrafiltration unit with an acidic solution.
②. Alkaline cleaning method of hollow fiber uf membrane
When the content of organic compounds in the feed water is high, the filter paper is likely to be contaminated by the organic compound environment. In addition, some bacteria and algae also proliferate in uf membrane module when the conditions are favorable for the survival of the organism, leading to biological invasion. Ultrafiltration filter is washed with a saturated solution of alkali oxide.
2. Precautions for chemical cleaning of hollow fiber uf membrane
1) All cleaning agents must enter hollow fiber uf membrane from the water inlet side to prevent impurities in the cleaning agent from entering the interior of the membrane wall from the back of the dense filtration skin.
2) Before the organic chemical cleaning, it is necessary to carry out multiple gas cleaning and complete the softener.
3) The whole process of organic chemical cleaning takes about 2 to 4 hours; if the sewage is seriously blocked, it must be soaked for more than 12 hours.
4) If it is closed for more than three days after cleaning, it must be maintained according to the standard of long-term shutdown.
5) The cleaning solution must be prepared with ultrafiltration water or higher quality water.
6) The cleaning agent must remove possible contaminants before the circulating system enters uf membrane module.
7) The temperature of the cleaning solution can generally be adjusted between 10°C and 40°C. Increasing the temperature of the cleaning solution can improve the cleaning efficiency.
8) A variety of cleaning agents can be used for cleaning if necessary, but the cleaning agents and pesticides and fungicides will not damage the raw materials of the membrane and parts. After each cleaning, the cleaning agent should be drained, the system should be rinsed with ultrafiltration or reverse osmosis permeate water, and then cleaned with another cleaning agent.