With the continuous accumulation of the pollutants intercepted by uf membrane module on the inner surface of the membrane and in the membrane pores,utrafiltration membrane flux and the separation capacity gradually decrease. According to the reverse cleaning,utrafiltration membrane flux can be partially restored, but the reverse cleaning cannot achieve 100% of the actual recovery effect. Therefore, when the water flux is reduced by more than 30%, drug cleaning must be carried out, and the contaminants attached to the membrane wall and membrane pores must be cleaned immediately to avoid irreversible blockage.
1. Drug cleaning of uf membrane module
①. Configure the pH value of pure water or ultra-filtered water to 2 with detergent, enter from the inlet valve through the booster pump, circulate back from the discharge valve, adjust the discharge valve to stabilize the working pressure at 0.25Mpa, and cycle for cleaning for 30 minutes Then close the water inlet valve, discharge valve and regulating valve, soak for 2 hours and clean with ultra-filtered water.
②. Use detergent to configure the pH value of purified water or ultra-filtered water to 12, enter through the booster pump, the inlet valve, and circulate back from the discharge valve, adjust the discharge valve to stabilize the working pressure at 0.25Mpa, and cycle cleaning for 30 Close the water inlet valve, drain valve and regulating valve after minutes, and rinse with ultra-filtered water after soaking for 2 hours.
③. Add 0.5% pesticide fungicide to clean ro uf membrane, and then carry out cyclic drug cleaning or soaking.
2. Cleaning and storage of uf membrane module
When uf membrane module is not in use, it is generally put into a maintenance solution for sealed storage to avoid shrinking the wet membrane after drying, reducing the membrane pores, destroying the membrane structure engineering, and reducing the water flux.
①. Short-term storage: When suspending use (less than 10 days), the ultrafiltration membrane should be sterilized and backwashed once, add 15ppm (ml/L) HY-240 fungicide to the backwash water, and then close the inlet valve, outlet valve and The regulating valve keeps the sealing and sterilization effect.
②. Long-term storage: If it is not used for a long time (more than 10 days),uf membrane module should be sterilized and backwashed first, and then the maintenance solution should be introduced for sealed storage (RO water is best).