Particle capture models: Comparison with experimental data

Abstract

Sand filtration is a becoming a widely used technique for the treatment of urban run off water, particularly for the capture of particulate metal pollutants. Currently the design rules for such systems are focussed on the civil engineering and hydrological aspects, whilst metal removals are typical quoted as broad percentages. The present study is the first step in developing a new design method for such systems, by comparing an established particle capture model consisting of two partial differential equations, one for particle capture and one for loading. The particle capture model was fitted to the outlet concentrations of several metal species, assuming that all particles of a particular metal are identical and have the same probability of capture. Particle loading through the column was then used as a check on the model. Whilst the particle loading results near the surface of the sand

A Deep Bed Filtration Model of Two-Component Suspension in Dual-Zone Porous Medium

“…In empirical (phenomenological) models [7,[16][17][18][19], the process of filtering a suspension in a porous medium is described using equations of continuum mechanics, which are supplemented by empirical relations. In classical deep bed filtration models system of partial differential equations describing the process consists of mass balance equation end kinetic equation of deposition [16,17].…”

“…In reversible deposition [18][19][20][21][22][23][24][25][26], both attachment and detachment of suspended particles may occur in parallel and kinetic equation has the form…”

“…In the literature, we can find various types of kinetic equations, because there are many factors affecting the process of suspended particles transportation and deposition in porous medium such as particle size distribution [24,[27][28][29], grain size distribution [28][29][30], hydrodynamic forces [30,31], temperature [32,33] and others. In [7,19], a multistage deposition kinetics is used, with ripening, transient and breakthrough stages. Studies of the flow in deep bed filters revealed the existence of two components: the jet stream and stagnant zones in the areas of grain contact [34].…”