Effective storage techniques and taboos for ultrafiltration membranes
1. Storage of new ultrafiltration membranes components
Ensure that the original packaging of the ultrafiltration membranes components is intact and stored in a dark and cool place (temperature range of 0 to 40°C), avoiding direct sunlight and humid environment.
2. Storage of ultrafiltration membranes components after use
(1) In case of short-term shutdown
If the shutdown is within 3 days, please stop the water supply and ensure that the membrane components are always filled with water and the temperature is between 0 and 40°C.
If the shutdown is between 4 and 7 days, fill the ultrafiltration membranes components with the solution of concentration shown in Table 1. At least use qualified filtered water to prepare the solution and ensure that the temperature is between 0 and 40°C.
Table 1 Storage conditions for short-term shutdown of membrane modules (within 7 days)
Maximum storage period
Chemical agent
Concentration of solution
7 days
Sodium hypochlorite
20 mg/L (as Clz)
(2) In case of long-term shutdown
First, perform chemical cleaning with sodium hypochlorite solution, and then fill the membrane module with chemicals of the concentration shown in Table 2. Use at least membrane filtered water and store the ultrafiltration membranes module according to the guidelines shown in Table 2.
Table 2 Conditions required for long-term storage of membrane modules for more than 7 days
Storage period
Type of drug to be stored
Drug concentration
7 days
Sodium bisulfite
1,000 mg/L
Seal the ultrafiltration membranes assembly with the aqueous solution shown in Table 1 or Table 2. If the ultrafiltration membranes assembly is removed from the device and stored offline, be sure to seal the membrane assembly, avoid direct sunlight during storage, and ensure that the temperature is between 0 and 40°C.
Note: After chemical cleaning with sodium hypochlorite solution, the solution in the membrane assembly must be thoroughly rinsed with clean water, and then sodium bisulfite preservation solution is injected. If not rinsed, the mixture of sodium hypochlorite solution and sodium bisulfite will produce toxic chlorine gas.
3. Replace chemical protection solution
If the preservation solution is sodium bisulfite, regularly check whether the pH value of the sodium bisulfite protection solution is between 3 and 6. Usually, sodium bisulfite reacts with oxygen to produce sulfuric acid, and the pH value will decrease. If the pH value is lower than 3, the preservation solution should be replaced.