Search results for "Filtration model"
showing 6 items of 6 documents
Analytical solution of kinematic wave time of concentration for overland flow under green-ampt infiltration
2015
In this paper the well-known kinematic wave equation for computing the time of concentration for impervious surfaces has been extended to the case of pervious hillslopes, accounting for infiltration. An analytical solution for the time of concentration for overland flow on a rectangular plane surface is derived using the kinematic wave equation under the Green-Ampt infiltration. The relative time of concentration is defined as the ratio between the time of concentration of an infiltrating plane and the soil sorptivity time scale, depending on the normalized rainfall intensity and a parameter synthesizing the soil and hillslope characteristics. It is shown that for a more complex case (corre…
Global sensitivity analysis of a filtration model for submerged anaerobic membrane bioreactors (AnMBR)
2014
The results of a global sensitivity analysis of a filtration model for submerged anaerobic MBRs (AnMBRs) are assessed in this paper. This study aimed to (1) identify the less- (or non-) influential factors of the model in order to facilitate model calibration and (2) validate the modelling approach (i.e. to determine the need for each of the proposed factors to be included in the model). The sensitivity analysis was conducted using a revised version of the Morris screening method. The dynamic simulations were conducted using long-term data obtained from an AnMBR plant fitted with industrial-scale hollow-fibre membranes. Of the 14 factors in the model, six were identified as influential, i.e…
Mathematical modelling of filtration in submerged anaerobic MBRs (SAnMBRs): long-term validation
2013
The aim of this study was the long-term validation of a model capable of reproducing the filtration process occurring in a submerged anaerobic membrane bioreactor (SAnMBR) system. The proposed model was validated using data obtained horn a SAnMBR demonstration plant fitted with industrial-scale hollow-fibre membranes. The validation was carried out using both lightly and heavily fouled membranes operating at different bulk concentrations, gas sparging intensities and transmembrane fluxes. Across a broad spectrum of operating conditions, the model correctly forecast the respective experimental data in the long term. The simulation results revealed the importance of controlling irreversible f…
Parameterization of a comprehensive explicit model for single-ring infiltration
2021
International audience; Comprehensive infiltration models can simultaneously describe transient and steady-state infiltration behaviors, and therefore can be applied to a range of experimental conditions. However, satisfactory model accuracy re- quires proper parameterization, including estimating the transition time from transient to steady-state flow conditions (τcrit). This study focused on improving the estimation of two parameters – τcrit and a second constant called a – used in a comprehensive, explicit, two-term model for single ring infiltration (hereafter referred to as the SA model). Different studies have recommended that a should be as low as 0.45 to as high as 0.91. Furthermore…
A filtration model applied to submerged anaerobic MBRs (SAnMBRs)
2013
The aim of this study was to develop a model able to correctly reproduce the filtration process of submerged anaerobic MBRs (SAnMBRs). The proposed model was calibrated and validated in a SAnMBR demonstration plant fitted with industrial-scale hollow-fibre membranes. Three suspended components were contemplated in the model: total solids concentration; dry mass of cake on the membrane surface; and dry mass of irreversible fouling on the membrane surface. The model addressed the following physical processes: the build-up and compression of the cake layer during filtration; cake layer removal using biogas sparging to scour the membrane; cake layer removal during back-flushing; and the consoli…
Alternative analysis of transient infiltration experiment to estimate soil water repellency
2019
The repellency index (RI) defined as the adjusted ratio between soil‐ethanol, Se, and soil‐water, Sw, sorptivities estimated from minidisk infiltrometer experiments has been used instead of the widely used water drop penetration time and molarity of ethanol drop tests to assess soil water repellency. However, sorptivity calculated by the usual early‐time infiltration equation may be overestimated as the effects of gravity and lateral capillary are neglected. With the aim to establish the best applicative procedure to assess RI, different approaches to estimate Se and Sw were compared that make use of both the early‐time infiltration equation (namely, the 1 min, S1, and the short‐time linear…