Filtro de fluxo ascendente com taxa declinante.

Abstract

The upflow stations with declining rate of filtration allow the clarification of natural surface waters that are not polluted. This type of station has been used for small communities of 3000 to 5000 inhabitants as it meets the requirements of national water quality standards. The present work deals with the development of a research carried out on this subject in a Pilot Station set up in the Laboratory of the Water Treatment Station of the Companhia de Agua e Esgotas de Paraíba (CAGEPA) in Alto Branco, Campina Grande - Pb, from July to November of 1988. The research was conducted in order to verify the performance of the Pilot Station considering initial rates of filtration 32 of 150 to 400 m / m / day. The crude water used in the experiments presented artificial turbidity ranging from 85 to 150 UJ. Therefore, it was possible to observe the following parameters: (i) affluent turbidity and effluent; (i i) loss of charge and (i i) rate of filtration at the end of the filtration stroke. It is important to point out that the last mentioned item constitutes the basic objective of the research. The final experimental results showed that the effluent turbidity reduction was higher than 90% considering an initial filtration cycle of 170 m3 / m2 / day. In this work, the efficiency of upflow filters with declining rates was verified as a valid alternative in the clarification of natural waters, with low contamination index.