This work presents an evaluation of some alternatives of multistage filtration system (MSF), using a pilot plant comprising two dynamic roughing filters, in series, three lines of upflow roughing filters, linked in series and in layers and four slow sand filters with different granular media composition. The performance of the system was evaluated by monitoring some water quality parameters such as: turbidity, suspended solids, total coliforms, fecal coliforms and particle size. The results showed that the MSF system produced effluents with low turbidity, solids and coliforms. The three lines of upflow roughing filters indicated the same efficiency in all tests. The four slow sand filters had similar performance concerning solids reductions and the slow sand filters 3 and 4 reached the greatest reductions in iron, organic matter, turbidity and color, in some experiments.
Multistage filtration system; slow sand filters; dynamic roughing filter; slow sand filtrations
