A modified model for the prediction of bioclogging in saturated porous media

Abstract

Bioclogging or the process that biofilm is conditioned for the development in porous media, leading the biomass accumulation in pore spaces and reducing the permeability of porous media that impedes fluid flow. Numerous research has focused on the study of bioclogging, but the process is very complicated and still poorly understood. This results in various permeability models that are only capable of predicting under certain conditions. In the study, we aim to mathematically develop a macroscopic model to predict permeability reduction in the saturated biofilter. The model adopts the concept that permeability reduction results from two mechanisms: pore radius reduction and pore plugging by mass accumulation. In the former, porosity, grain sizes, tortuosity and bulk factor determine the magnitude of permeability reduction. The pore plugging, in the other hand, interprets recent experimental findings of straining process in deep bed filtration that clogging in pore throat can be induced by deposited particles with the diameter many times smaller than that of pore throat. The model proves its capacity by obtaining a good match to a wide range of experimental data in predicting: permeability of clean porous media and magnitude of bioclogging in the biofilter.