The membrane must be cleaned periodically to maintain a certain membrane permeate flux and to extend membrane life. The cleaning method is generally determined by the nature of the membrane and the nature of the treatment liquor. It is usually similar to reverse osmosis, that is, it is first washed with water, and then washed with different chemical detergents according to the situation. For example, ion-containing solubilizers can be used for electrocoating materials, and “bridge” type can be used for water-soluble organic coatings. Solvent. Protein precipitation in the food industry can be carried out using guanidin solvents or phosphate-based, silicate-based alkaline detergents. The precipitate formed on the surface of the membrane by an inorganic salt can be dissolved by a chelating agent such as EDTA or an acid or a base. Different cleaning methods can be used for different membrane modules. For example, the tubular assembly can be mechanically cleaned with a sponge ball, and the hollow fiber assembly can be backwashed. For the food industry, the film needs to be disinfected (using NaOH, H2O2, etc.).
The physical method is to use the force of the device to remove the pollutants on the surface of the membrane without any chemical reaction, so it is relatively simple, convenient and healthy. The following is a brief introduction to several practical ones.
1. For the general membrane pores, the detachable ultrafiltration filter cartridge is not particularly fine. It can be directly disassembled and rinsed with water while wiping with a soft substance.
2. Scrub with a sponge ball. According to the diameter of the membrane tube, select a suitable sponge ball and wipe it with a special tube through a membrane tube. It can be used repeatedly.
3, hot water washing method to heat the water to (30-40 ° C), and then rinse the surface of the membrane, to those sticky or hot soluble impurities work well.