Oil and crease contg. wastes - treated by two=stage acidic flotation and final neutralisation

摘要

Industrial alkaline wastes with an oil and/or grease content are treated with demulsifiers and acids (pH-value of 4-5). The oil and/or grease is removed in a first flotation stage as froth. In the second flotation stage, surfactants and detergents are turned into floats and are recycled to the first stage. The water outflow from the second stage is finally neutralised by adding an alkaline soln. This system produces oil and grease with little moisture content so that they can be processed immediately in refineries or burned in combustion chambers. The expenditure for chemicals as well as for power is low.