DISSOLVED AIR FLOTATION IN THE TREATMENT OF INDUSTRIAL WASTEWATERS WITH A SPECIAL EMPHASIS ON FOREST AND FOODSTUFF INDUSTRIES

The suspended solids separation is an essential element in almost any wastewater treatment system. If sedimentation, dissolved air flotation and filtration are compared, flotation has both the largest operation al ranges concerning influent suspended solids concentration and parti cle size, and load bearing capacities. When considering the suitabilit y of flotation as a wastewater treatment process, important factors ar e the effluent and sludge qualities, operation and costs. To get a com prehensive conception of flotation, those factors are presented and di scussed. Flotation is widely used in forest industry wastewater treatm ent, as well as in process water recirculation. It is also proven tech nology in foodstuff industry wastewater treatment. Several cases from both industries are presented.