Abstract: A process and apparatus for separating suspended solid material from a fluid, comprising the steps of adding in a chamber buoyant media as glass spheres with 30-250 micron diameter (106) to the fluid to form a first mixture of fluid influent and buoyant media, adding a flocculant (108) to the said first mixture to form a second mixture of influent, buoyant media and flocculant, transferring said second mixture to a flotation chamber (200), introducing a pressurised fluid (203) to the second mixture in said flotation chamber, removing separated floating sludge from said flotation chamber, and removing separated clarified effluent from said flotation chamber Optionally, a coagulant may be added after the flocculant.