Characterization of polystyrene granules as granular media filters

Abstract

The need for water production is increasing in urban populations. In conventional water treatment plants, the filters are backwashed by treated water, which represents high long-term costs. In order to obtain a highly effective production of water with a subsequent reduction in production costs, it was proposed to feature a granular filter element with low density and its potential to provide a down-flow rapid filter, which can represent a reduction in the volume of water used for backwash. The polymer used for this purpose appears to be favorable; in addition, there are possibilities of recycling this material. A velocity of 6.08 m/h for a 50% expansion was demonstrated, which is very low compared to conventional filter elements (i.e. sand and anthracite). So, this element has shown great potential in reducing the volume of water during the backwash process, as observed using mathematical models. The final quality of the filtered water still needs to be analyzed. However, the permeability coefficient was determinate at 1.79 × 10−5 ± 2.87 × 10−6 m/s being satisfactory as filtration. The outlook is that it may become an option for element filtration in down-flow rapid filters for water treatment.