A Study On Silting And Prophylactico-therapeutic Measures Of Filtering Bed

Compared with conventionally filter, the technique of percolating water abstraction is a new technics,which is characterized by for good abundant water and low cost.The main disadvantages of the technique appear to be the silting because of the natural water environment.The filtering membrane is a kind of complex biologic mud, which absorbs impurity and feculency, removes microbe, be of strong physics adsorption and biochemistry. It works well on purification but may result in silting. On the basis of former experience, composition of filter film had been analysed fully by adopting physical test, chemical. experiment, stereoscan, energy spectrometer with the practical project in chongqing and hunan.the filtering membrane be provided with complex biologic feature, physics adsorption and biochemistry action, which subjected to hydrodynamic force.To be divided three steps, silting process are made of contaminant penetration, formation and thickening of membrane. This thesis expounds the three key ways of silting, which included local silting on surface of filtering bed, silting in boulder bed and silting around filter. The silting mechanics includes physical mechanics, physical-chemical mechanics, biological mechanics. The factors affected on silting are natural, technology and operation. This thesis presents the conclusion that prophylaxis is the key aspect compared to treatment.