Removal of naturally occurring compounds by coagulation and sedimentation

Abstract

Naturally occurring compounds are defined as all nonsynthetic materials of constant composition. The emphasis in this review is placed on the removal of humic materials, other organic compounds, trace metals, and certain inorganic ligands. Removal of the alkaline earths is not reviewed. Associations between different compounds, or between compounds of interest and naturally occurring particulates, are important and complex. In this context, the formation and removal of such aggregates is reviewed. As a result, the removal of particles by coagulation and settling is briefly discussed. The removal of certain synthetic compounds is also reviewed, to the extent that removal of such compounds is dependent on the removal of naturally occurring compounds. Both inorganic and organic coagulants are considered.