Keywords: dissolved-air flotation, DAF, anaerobic effluent flotation, physicochemical treatment, phosphorus removal, anaerobic reactors, sewage treatment, waste treatment, wastewater treatment, effluent coagulation, water pollution, environmental pollution
Dissolved-air flotation associated with an anaerobic reactor, as applied to sewage treatment
This paper presents the results of a study performed with a pilot sewage treatment plant consisting of an aerobic reactor followed by a flotation unit. To coagulate the anaerobic effluent, different ferric chloride dosages were applied by adopting two approaches: applying constant dosages during the essay and varying the dosages according to the anaerobic effluent turbidity. To obtain more than 95% TSS, 90% COD and 70% phosphorous removals a critical chemical ratio ranging 0.012-0.013 (in terms of Fe/Turbidity ratio) was required. When aiming higher phosphorous removal (above 95%) the required Fe/Turbidity ratio range rose to 0.016?0.018.