ordinary municipal water treatment equipment more difficult, especially if a high level of decontamination is expected at nominal costs.Because coagulation operates through many mechanisms (adsorption, coprecipitation, precipitation, entrainment, occlusion, and isomorphous-replacement ion exchange), the applicability of a coagulation technique to decontamination was investigated. A coagulant that could combine several of these mechanisms in a highly ionic medium would be desirable. The present study was undertaken to evaluate the decontamination efficiencies in sea water of various materials, particularly the silicates, for a single-stage coagulation and sedimentation method.The study consisted of two parts: [1] a preliminary selection from among the possible coagulating agents of those that were the most promising decontaminants; and [2] a detailed evaluation of the decontaminating capacity of the selected agents.