This research focuses on the use of Fe(III) salt to make quantitative studies of the rate at which flocculation processes occur, the factors on which these rates depend, and the mechanisms involved. Fe(III) salts are receiving attention as alternative coagulants to alum for several important reasons: concerns about residual aluminum concentration in treated waters and post-precipitation of aluminum in distribution systems; possible cost savings comparing to other alternative coagulants; and better coagulation efficiency at low water temperature and more efficient removal of color-causing organic materials than alum. The overall objectives of this research are: to investigate the kinetics of flocculating kaolin clay in water suspension using ferric nitrate as a coagulant under a number of treatment conditions; to investigate the role of sulfate in flocculation kinetics; and to assess the effects of temperature on flocculation kinetics, spanning the full range of coagulation domains including the A/D and sweep floc mechanisms of coagulation.