To optimize and improve the membrane module, change the characteristics of the suspension, reduce the quality concentration of activated sludge mixture into the membrane and membrane pollutants on the shedding of the removal of four aspects.
1, optimize and improve the membrane module
The optimal design of the membrane module should give full consideration to the placement of the membrane module and the relationship between the hydraulic form, the hollow fiber membrane diameter and length of the relationship between the two aspects.
Tests have shown that: there is no aeration when the membrane filament transverse placement is better than axial, with aeration when the axial placement is better. Membrane filament diameter test results show that: in the wrong flow system, whether or not aeration, fine membrane filament is better than coarse membrane filament. Through modeling calculations when the length of the membrane filament is 0.5-3m, the appropriate membrane filament inner diameter of 0.2-0.35mm, the piston flow can effectively improve the membrane flux.
2, change the characteristics of the suspension
Membrane contaminants mainly from the activated sludge mixture, its pretreatment, change its filtration characteristics, can effectively reduce and slow down membrane pollution.
The specific method can be added to the bioreactor in a small amount of flocculant, so that the fine particles flocculation and cohesion, reduce its deposition on the membrane surface.
3, reduce the concentration of activated sludge mixture into the membrane
Specific methods can be added to the bioreactor packing, so that the suspended microorganisms attached to the packing, so that not only to accelerate the decomposition rate of microorganisms on the pollutants, but also effectively reduce the concentration of activated sludge mixture into the membrane, or to control the membrane flux is lower than the critical flux, to slow down the rate of pollutant deposition in the membrane, prolong the membrane life, control membrane pollution. The life of the membrane, control membrane pollution.
4, membrane pollutant removal
Set up aeration device to increase the aeration volume, the membrane surface to produce water shear effect, caused by membrane components near the membrane filament vibration, accelerate the membrane surface deposition of pollutants off. When the membrane contamination reaches a certain level, the membrane components should be cleaned to protect the normal operation of the system, the common cleaning methods are hydraulic cleaning, chemical cleaning, ultrasonic cleaning.