Influence of biofilm accumulation on porous media hydrodynamics

Abstract

Laboratory-scale porous media biofilm reactors were used to evaluate the effect of biofilm accumulation, measured as the average thickness along a 50-mm flow path, on media porosity, permeability, and friction factor. Media tested consisted of 1-mm glass spheres, 0.70-mm sand, 0.54-mm sand, and 0.12-mm glass and sand. Pseudomonas aeruginosa was used as inoculum and 25 mg L_1 glucose substrate was continuously supplied to the reactor. Reactors were operated under constant piezometric head conditions resulting in a flow rate decrease as biofilm developed. The progression of biofilm thickness followed a sigmoidal-shaped curve reaching a maximum thickness after ~5 days. Media porosity decreased between 50 and 96% with increased biofilm accumulation while permeability decreased between 92 and 98%. Porous media friction factor increased substantially for all media tested. Observations of permeability in the biofilm-media matrix indicate that a minimum permeability [(3-7) X 10~8 cm2] persisted after biofilm thickness has reached a maximum value. Such results indicate substantial interaction between mass transport, hydrodynamics, and biofilm accumulation at the fluid-biofilm interface in porous media. Improved understanding of these interactions will lead to industrial and environmental applications in biohydrometallurgy, enhanced oil recovery, and bioremediation of contaminated groundwater and soil.

Simulations of two‐dimensional modeling of biomass aggregate growth in network models

“…This phenomenon has been observed in laboratory experiments [Cunningham et al, 1991;McCarty, 1999, 2000;Baveye, 1992a, 1992b] and in field studies [Vecchioli et al, 1980]. Clogging closer to the injection well could lead to permeability reduction that may be underestimated if the high heterogeneity of clogging is not properly taken into account (Table 4).…”

“…When As noted by Cunningham et al [1991], who assumed a continuous biofilm, growth is initially exponential and identical in all the pores regardless of size. Growth eventually levels off when substrate becomes limiting, and this occurs at different times depending on the size of the channels.…”

Mineral Transformation and Biomass Accumulation Associated With Uranium Bioremediation at Rifle, Colorado

“…For example, the initial bioavailable Fe(III) content was changed from 5.0 mol/g in the column experiments to 2.5 mol/g in the field. This is likely due to the fact that the column experiment used the <4 mm fraction of the sediment, which Multiple studies have shown that it is easier to clog a porous medium with fine-grained materials (29)(30)(31). The current estimate is based on the assumption that the system is a homogeneous system with uniform distributions of aquifer properties.…”

Biodecolorization and Bioremediation of Denim Industrial Wastewater by Adapted Bacterial Consortium Immobilized on Inert Polyurethane Foam (PUF) Matrix: A First Approach with Biobarrier Model

“…The first dual-species biobarrier model (1.7) with standard Monod kinetics (1.9) has been validated in with the porous media experiments done by Cunningham et al (1991) for a 1 × 1 cm long PU foam cube with 0.70 mm, in diameter. In our first simulation, we consider initial and boundary conditions for S C that correspond to a high nutrient concentration experiment, i.e.…”