NUMERICAL INVESTIGATION OF BACKWASHING HYDRODYNAMICS IN SLOW SAND FILTERS

Slow sand filtration is a reliable and low-cost technology for water treatment, particularly in decentralized systems, but its application is often limited by challenges associated with filter cleaning. In this context, backwashing has emerged as an alternative approach, relying on fluidization of the granular bed to remove accumulated particles. This work investigates the backwashing process using CFD simulations, focusing on flow uniformity across gravel layers and fluidized bed expansion. Results show that the gravel layers improve flow distribution, reducing non-uniformities, while the fluidized bed reaches an expansion of approximately 42%, indicating effective operating conditions.