A visual study of particle deposition and reentrainment during depth filtration of hydrosols with a polyelectrolyte

摘要: Abstract A new experimental apparatus was developed to observe and photographically record the process of particle deposition pore-clogging during deep bed filtration sols in a model porous medium. Runs were made for twelve different sets conditions, using three pH values four concentrations commercial cationic polyelectrolyte. All other conditions kept constant. In most cases practical interest, it observed that main mechanism through which deposited particles alter geometry flow channels is throat-clogging. case weakly unstable hydrosols, clogging occurs either by gradual constriction throat or sudden blocking caused reentrained cluster. agglomerated throat-clogging growing pillar-like deposits blocking. Throat-clogging causes profound changes local pattern, turn result an increase capture efficiency decrease rate. leads systematically formation resembling “pendants”, “pouches” cascades pendants pouches. hydrosols with reversed charge (due polymer overdosing) checkerboard pattern develops. These observations explain initial following monotonic decrease. They also drastic permeability only small amounts matter.