SANTOS, J. C. S.; http://lattes.cnpq.br/1651779375025677; SANTOS, José Claúdio Silveira dos.
Abstract:
Phosphorus is one of the most important macro nutrients responsible for eutrophication of
surface waters. A concentration of 0,03 mg/L indicates an eutrophic condition in a lake. To
avoid problems with eutrophication, there is a need to remove phosphorus from effluents
produced in sewage treatment plants that are to be discharged into surface waters. In
practice, phosphorus can be removed by biological means in aerobic treatment plants if the
P/COD ratio is high enough, or by physical chemical treatment, using the fact that several
phosphates are poorly soluble. In anaerobic- aerobic plants, the only alternative to produce
an effluent with a low P concentration is the application of physical chemical treatment. A
bench scale experimental investigation was carried on with the objective to establish the
feasibility of physical chemical phosphorus removal in anaerobic-aerobic sewage treatment
plants, using both ferric chloride (FeCh) and aluminium sulfate (A^CSO^). The results
indicated that the partial removal is feasible, but for a low effluent P concentration a high
dosage of either coagulant is required. The results also indicated that ferric chloride is more
recommendable because of its low price per mass unit and a less problematic final disposal
of the produced sludge.
