Mathematical modeling of depth filtration : investigation of initial removal through three-dimensional trajectory analysis

Depth filtration is used in virtually every drinking water plant and is rapidly becoming a standard unit process in wastewater treatment. Currently, the only truly predictive approach to modeling depth filtration is trajectory analysis. In trajectory analysis, the structure and flow field of the packed bed is modeled mathematically, and particle trajectories in the mathematical representation of the packed bed are determined through resolution of forces and torques. Sphere-in-cell and constricted tube media models have been used extensively in trajectory analysis and account for the presence of neighboring filter grains in a spatially averaged sense. In this research, a face centered cubic packing of spheres was used to represent the packed bed, allowing explicit consideration of grain contact points and a more realistic flow field. Results were compared to experimental data and existing trajectory models