Technical-economic evaluation of double filtration technology

ABSTRACT

This study evaluates the double filtration technology for the definition of its selection criteria. According to the literature, double filtration requires the development of a draft of two types of installations (one with a gravel upflow filter - GUF and another with a sand upflow filter - SUF) and then a study for the definition of the best alternative to be employed. As in Brazil the literature lacks studies on such technology selection, this paper propose guidelines for the double filtration selection in an attempt to support the work of design engineers. The costs of 50 systems of double filtration were studied. The results show that the management of sludge, excavation and energy consumption in double filtration with SUF can increase the costs up to 33% in comparison to double filtration with GUF; the results are valid for systems with flows between 10 and 100L.s^-1. Design engineers must justify the use of double filtration with SUF, therefore the costs involved must be evaluated and compared with the microbiological risk of supply source.

Keywords:
costs; drinking water treatment; double filtration; technology selection.