Simulation and Lab-Scale Experiment of a Particle Filtration Solution for Rural Potable Water Supply

Abstract

Lamella clarifiers are becoming increasingly popular for solid–liquid separation due to their low system footprint, low cost, and high separation efficiency at superior settling times when compared to settling tanks. Despite this, limited research has considered their feasibility as a compact potable water treatment solution. In this paper, a small-scale lamella clarifier, designed to maximize suspended solid separation efficiency within a hand pump driven supply system, has been studied using a combination of computational fluid dynamics (CFD) and experimental analyses. The CFD simulations have relied on a one-way coupled Lagrangian tracking scheme. The separation efficiency has been studied in terms of its sensitivity to the lamella geometry, the influent concentrations, and the particle diameters. Results show good agreement between CFD predictions and experimental measurements. The clarifier is found to achieve suspended solids removal efficiencies as high as 99.8%. This represents a potential improvement by 20% when compared with a conventional settling tank. The flow visualizations highlight the importance of the front baffle that disperses the incoming jet and the role played by the lamellae plates in spreading the flow within the settling chamber.