Criterios de diseño de un prefiltro de flujo vertical descendente para el pretratamiento de agua potable

Abstract

Slow sand filters used in the treatment of drinking water in rural areas have operating problems in rainy seasons due to increased turbidity, which causes clogging of the filter medium, making these filters inefficient for turbidity removal. , fecal coliforms and pathogens in general commonly present in water, thus raising the costs of maintenance and cleaning of the filter and causing health problems for users. Due to this, it is necessary to carry out a previous treatment of the water in coarse gravel pre-filters, which are a complement to slow sand filters. The present work exposes the necessary criteria for the design of a gravel prefilter, analyzing the convenience of the flow direction, be it horizontal, vertical, ascending or descending, as well as parameters such as size and height of the gravel and filtration rate. The final result of this work is the design of a downward vertical flow prefilter capable of theoretically removing 98% of the turbidity from a sample of 109 UNT, the design flow is 1 l/s, the prefilter consists of 2 units filtration each with 3 chambers, a gravel filter media 0.5 meters high and sizes from 1 to 4 cm, a filtration speed of 1 m/h in the first chamber and 0.8 m/h.