ABSTRACT
Surface waters contain a variety of suspended, colloidal solids that have aesthetic, economic, or health impacts. Simple sedimentation and direct, unaided filtration are not practical in the case of clays and organic detritus, because the overflow and filtration rates required for their removal lead to facilities that are 100 to 200 times larger than those built today (Fanning, 1887; Fuller, 1898). Consequently, all surface water treatment plants incorporate processes that destabilize and agglomerate colloids into larger, fastsettling particles.
