ABSTRACT
Filtration is a “polishing” process employed to meet stringent effluent quality standards or as a pre treatment to protect more sensitive adsorption, ultrafiltration, or ion-exchange equipment. It is used to remove limited quantities of suspended solid, but it is not an alternative to sedimentation or flotation, which can more effectively treat heavy solid loadings. Waste filtration design is based on water treatment operating experience, expressed as standard design criteria, refined to include pilot data, and adopted to specific waste conditions. Waste solids characteristics such as concentration, size, and size distribution impact filtration efficiency. In simple terms, separation is a result of waste flow transporting solids through the bed; the waste suspended particles contact the media grains, are removed, and are stored in the void space. Filtration operating efficiency is determined by filtration time, which is maximized; and the backwash volume, which is minimized.
