To optimize the backwashing effect of activated carbon filters, we need to focus on three aspects: parameter control, operating procedures, and maintenance management.
I. Backwashing Parameter Control
air washing stage
strength:
10-15 L/(m²·s) Take 3-5 minutes to loosen the filter media and remove impurities.
Avoid using strong airflow for backwashing to prevent activated carbon loss.
Water washing stage
strength:
15-20 L/(m²·s) This allows the filter bed expansion rate to reach 50%-80% (suitable for activated carbon with a particle size of 1-2mm).
Time: 5-10 minutes, until the turbidity of the drain water is ≤1-2 NTU
II. Backwashing Operation Procedure
Triggering conditions
Backwashing should be initiated when the pressure difference between the inlet and outlet reaches 0.05-0.1 MPa, or when the effluent water quality slightly exceeds the standard.
Highly polluted water requires a shorter backwashing cycle (e.g., once a day).
Operating steps
Air washing → water washing → forward washing, ensuring the drain is clear and free of impurities.
Backwash water should have low turbidity (≤1 NTU) to avoid secondary pollution.
III. Maintenance and Management
Filter media inspection and replenishment
After backwashing, check the filter bed height, replenish any lost filter media, and ensure the thickness meets the standard (1.0-1.5m).
Regularly test the activated carbon adsorption performance; replace the filter media when the adsorption rate drops below 50% of the initial value.
Equipment maintenance
Check the water distributor and valve sealing, and replace any damaged parts promptly.
When restarting after a long period of inactivity, rinse for 5 minutes until the water runs clear.
Water pretreatment
When there is high turbidity or organic pollution, enhanced pretreatment (such as sedimentation tanks and precision filters) is required.
Before backwashing, soak the product in clean water or dilute acid/alkali for 1-2 hours to improve the removal of impurities.
IV. Optimization for Special Scenarios
Low-temperature environment : When the water temperature is low in winter, increase the backwash intensity appropriately to avoid freezing.
High hardness water source : Add a citric acid cleaning step after backwashing to remove calcium scale.
Microbial contamination : Regularly soak in a 0.1% sodium hypochlorite solution for sterilization to prevent biofilm growth.
The above measures can effectively improve the backwashing effect of activated carbon filters, extend the service life of filter media, and ensure that the quality of effluent meets standards.
