Efeito da taxa de aplicação superficial na remoção de matéria orgânica em filtros de Areia

Abstract

This research consists of a study of the rate of surface application for sand filter sizing, with septic tank effluents and anaerobic filter. It is a design parameter set by the NBR 13969/1997 as the relation between the flow of sewage and surface area of a treatment unit. We evaluated the effect of rate of application in the removal of organic matter by sand filters as well as the relevance of the anaerobic filter interposed between the septic tank and the sand filter. The research was conducted on two wastewater treatment systems, both mounted in the University Residence of UFPB: (1) Septic Tank + Anaerobic Filter + Sand Filter and (2) Septic Tank + Sand Filter, in order to get the rate of surface application to be adopted in projects for the conditions of the study area (northeastern Brazil), for both options. The rates of application were analyzed in values of 200, 300, 500 and 600 L/m².d. Analyses of BOD5, COD and NO3 were held in Pastel UV equipment. The results of this research show the feasibility of using sand filters in an individual treatment system of sewage, whether for residential units, condominiums or small communities, since the high efficiency values reached on the removal of organic matter. It was obtained a good performance on the nitrification of effluents from the septic tank and the anaerobic filter in the sand filters. Finally, with the analysis of the behavior of the filters results to changes in the applied rates, it reached an "excellent" value of 300 L / m².d, for both systems studied.