Influence of the flow control (declining rate – constant rate) on the filtration process in drinking water treatment

Abstract

Quick filtration is an important and complex process within the conventional treatments of water purification, since it is the final physical barrier to retain particles and control the microbiological risk. This study evaluated the influence of flow control on the filtration process of the clarified water of the Cauca River on the city of Cali – Colombia (Puerto Mallarino Water Treatment Plant) at pilot scale. Operation´s results of the pilot plant on a declining rate condition were compared with the results of the previous operation at constant rate; the operational control variables of the filters were turbidity of the filtered water and load loss. In general, the declining rate operation allowed a better performance of filters, resulting in a lower turbidity in filtered water during the period of maximum efficiency and a better outcome of the load loss, behavior that is associated with a better distribution of solids on the filter media, which allows to reduce the risk of transfer of particles through the filter.