Utilização de filtro intermitente de areia como pós-tratamento de esgoto doméstico – estudo da taxa de aplicação superficial

Abstract

This research is the study of surface application rate for intermittent sand filter sizing, with emphasis to its constructive aspect. It is a design parameter set by the NBR 13969/1997 like the relation between the flow of sewage and surface area of a treatment unit. We examined the main research projects that studied the use of sand filter as post-treatment sewage, highlighting the superficial application rates used in these studies, comparing them with the recommendations of the Brazilian standard that deal with it. The results show that the NBR 13969/97 recommends a lower value to those obtained by Brazilian and foreigner researchers, and regarding Brazilian research, the value of the standard (100 L / m².dia) is always below the rates evaluated. Thus, we highlight the need to update the NBR 13969/97, for that would meet the actual demand for building sand filters, reactor treating of low cost of construction and maintenance, and good removal efficiency of organic matter and nitrification . The environmental benefits are indisputabl and the improvement of the quality of the effluent decreases the impact on water bodies and soil.

Keywords

• sewage treatment. sand filter. rate of surface application.