Abstract: Sedimentation studies have the possibility of providing profile curves and other vital parameters useful for modeling two-phase flow operations and dimensioning of clarification tanks in water purification plants. In continuation of the study on sedimentation of alkaline-earth metal phosphates, the effects of temperature and ion concentration variables on sedimentation rate profiles, order and rate constant of trimagnesium phosphate (TMP) and tribarium phosphate (TBP) precipitates were evaluated at different temperatures using the Modified Isolation (Initial Rate) method.