04,24,2026 130 views
Professional and structured guidelines for maintaining tangential flow filtration systems.Tangential flow filtration systemThe core goal of maintenance is to prevent membrane fouling, ensure system integrity, extend membrane life, and ensure process reliability.
1、 After each use (executed immediately after running)
This is the most crucial step, which directly affects the service life of the membrane and its next operational performance.
Immediately flush:
Purpose: To remove soluble substances, particles, and initial pollutants from most of the feed solution, and prevent their deposition and solidification on the membrane surface.
Method: Use purified water (WFI or UPW) or a buffer solution compatible with subsequent cleaning steps to perform a short-term (5-10 minutes) rinse at a higher cross flow rate (usually 1.5-2 times the maximum operating flux). The flushing direction should be consistent with the filtering direction.
Emptying:
Thoroughly drain all liquids from the membrane package and pipeline to prevent residual liquid from concentrating or breeding microorganisms.
2、 Regular deep cleaning (Cleaning in Place, CIP)
When the flux significantly decreases (usually by more than 20-30%) or follows a predetermined cycle (such as every 5-10 runs). The cleaning program should be selected based on the type of pollutants being intercepted.
A. Universal alkaline cleaning (removing proteins, lipids, and polysaccharides)
Cleaning agent: 0.1-1.0 M NaOH (sodium hydroxide) solution.
Temperature: 30 ° C-50 ° C (note: must be below the maximum tolerance temperature of the membrane and membrane packaging materials, usually alkali resistant such as polyethersulfone PES, regenerated cellulose RC, but specifications need to be verified).
Time: Cycle cleaning for 30-60 minutes.
Flow rate: Use standard cross flow velocity.
Function: Saponify oils and fats, dissolve proteins, and destroy biofilms.
B. Acidic cleaning (removing inorganic scale and metal ions)
Cleaning agent: 0.1-1.0 M nitric acid (HNO ∝) or citric acid.
Temperature: from room temperature to 40 ° C.
Time: Cycle cleaning for 20-30 minutes.
Function: Dissolve mineral precipitates (such as calcium carbonate and phosphate), chelate metal ions.
C. Oxidation cleaning (for stubborn organic pollution, disinfection)
Cleaning agent: Sodium hypochlorite (NaOCl), typically with a concentration of 0.1% -1% (200-1000 ppm effective chlorine).
Key limitations:
Only applicable to resistant oxide films (such as certain modified polyether sulfones, polyvinylidene fluoride PVDF). Absolutely prohibited for use in membranes such as polyether sulfone (unmodified), regenerated cellulose, polyacrylonitrile, etc.
The contact time needs to be strictly controlled (usually<1 hour), and the higher the concentration and temperature, the greater the risk of damage.
