ABSTRACT
Generally, about 5% of the suspended solids and other impurities remain after sedimentation. This small percentage of remaining nonsettleable žoc particulate matter causes noticeable turbidity, and may shield microorganisms from disinfection. Filtration is a polishing process, and it involves passing the water through a layer (or bed) of porous granular material. This removes suspended particles by trapping them in the pore spaces of the ›lter media as the water žows through the ›lter bed (see Figure 7.2).
