The objective of this research was to evaluate the effect of varying the shape and dimensions of the diffuser plate fitted in a commercial sand filter on its head loss when subjected to filtration flow direction, under the conditions of an empty filter and filled with sand. It was compared the hydraulic behavior of the filter original plate diffuser with a designed flat diffuser with edge. The experiments were performed in experimental module assembled at the Hydraulic and Irrigation Laboratory of FEAGRI/UNICAMP, using four different dimensions of proposed diffuser, for filtration rate values of 40, 60, 80 e 100 m³ h-1 m-2. The results showed that the proposed diffusers did not change statistically the head loss values in the recommended sand filter operation range (up to 60 m³ h-1 m-2). However, they caused smaller sand surface layer deformations, fact that contributes to the reduction of preferential paths of water, improving the equipment removal efficiency. The research showed the occurrence of interaction between the diffuser model used in sand filters and the sand surface layer drift.
localized irrigation; water treatment; emitters clogging
