Dynamic separation technology, based on a swirling motion to remove settleable particles, has been used in North America and Europe for treatment of combined storm water and sewer overflow systems. However, treatment is limited to the removal of large settleable particles. In wastewater, a substantial portion of the pollutants can be either in the form of a colloidal suspension or in solution. Investigations were carried out to observe the removal of colloidal particles and dissolved pollutants using a coagulation process in conjunction with a dynamic separator. The effects of flowrate and coagulant dose on the flee size and their subsequent removal efficiency in the separator was studied. The combined process had an efficiency of 95-99% (mass percentage) in the removal of suspended solids, for a range of flowrates between 8 to 101/min. Lower efficiencies were observed for flowrates lower than 81/min and higher than 101/min. The particle size distribution of the overflow and inlet flow of the separator was monitored to investigate the effects of flowrate on the particle size classification in the separator.