Download or read book Influence of Porous Media Heterogeneity on Nonaqueous Phase Liquid Dissolution Fingering and Upscaled Mass Transfer written by Matthew W. Farthing and published by . This book was released on 2012 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Upscaling Mass Transfer for NAPL Dissolution Fingering written by Mir Ahmad Seyedabbasi and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Laboratory experiments and numerical simulations in homogeneous porous media were used to investigate the influence of porous medium wettability on the formation and growth of preferential dissolution pathways, dissolution fingers, during nonaqueous-phase liquid (NAPL) dissolution. As the porous medium became increasingly NAPL-wet, dissolution fingers grew wider and slower. This result was observed in physical experiments with 0 and 100% NAPL-wet conditions and confirmed with numerical simulations at these and intermediate wettabilities. A previously derived expression for an upscaled mass transfer rate coefficient that accounts for the growth of dissolution fingers was used to quantify the effect of fingering on overall NAPL removal rates. For the test cases evaluated, NAPL dissolution fingering controlled the overall rate of NAPL dissolution after the dissolution front moved 9 cm in 0% NAPL-wet conditions and 34 cm in 100% NAPL-wet conditions. Thus, even in completely NAPL-wet media dissolution fingering may control the overall rate of NAPL dissolution after relatively short travel distances. The influence of aqueous-phase boundary conditions on dissolution fingering was also investigated. For the range of conditions studied here, constant head and constant flux boundary conditions resulted in similar finger growth and morphology of the interface between clean and NAPL-contaminated regions: the interface roughness and the growth of this roughness with pore volumes flushed were independent of boundary condition type. Laboratory studies were conducted to evaluate the influence of heterogeneity on NAPL dissolution fingering. During a spill event heterogeneous porous media favor the formation of nonuniform NAPL saturation fields, including NAPL residual and NAPL pools, that may affect the fingering mechanism. A light transmission technique was used to measure trichloroethylene saturation fields at a 0.05-cm resolution that resulted from spills in two heterogeneous packings of a laboratory test cell. The correlation length of the permeability field transverse to the mean water flow direction was selected to be similar to (1.0 cm) or significantly greater than (6.0 cm) the expected wavelength of dissolution fingers. As the entrapped NAPL dissolved into water, preferential NAPL dissolution patterns occurred in both experiments, with patterns strongly affected by the heterogeneities. Experimental results were used to validate the utility of a numerical simulator for capturing the growth of centimeter-scale preferential NAPL dissolution patterns. Using data from these experiments, four different methods for upscaling the mass transfer rate coefficient for NAPL dissolution were examined [Basu et al., 2008; Christ et al., 2006; Imhoff et al., 2003a; Saenton and Illangasekare, 2007]. These models were developed to account for the influence of dissolution fingering or NAPL architecture on the long-term flux of contaminants from NAPL source zones. In the packing where the correlation scale of permeability perpendicular to the mean water flow direction was 6.0 cm, greater than the scale of the dissolution fingers, all upscaling approaches predicted effluent concentrations reasonably well. When the correlation scale of the heterogeneities was smaller (1.0 cm), the models performed much more poorly. These results and their implications on the applicability of the upscaling models will be discussed. Among the four different upscaling approaches tested in Chapter 4 the stream-tube approach developed by Basu et al. [2008] seemed very promising in predicting the upscale mass transfer and effluent concentrations in the two physical experiments we conducted with different degrees of heterogeneities in permeability and NAPL saturation distribution. A simple stream-tube approach was developed to predict the dissolution front dynamics and effluent concentration profiles. This simple model worked poorly when used for the large correlation length system where the permeability heterogeneity was close to homogeneous, where the dissolution rate is controlled by dissolution fingering. However, when the correlation scale of heterogeneity decreased for the small correlation length system, the dissolution rate was controlled solely by the heterogeneities in permeability and NAPL saturation fields and not by the dissolution fingering mechanism. In this case the stream-tube model was able to predict the effluent concentration profile and capture the tailing in that very accurately. This model needs to be combined with the dissolution fingering model and be tested for wider range of heterogeneous systems. This is outlined as a recommendation for the future work.

Download or read book Mass Transfer in Non aqueous Phase Liquid Contaminated Heterogeneous Porous Media written by Panagiotis Nikolopoulos and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Dissolution of Nonaqueous Phase Liquids in Porous Media written by Thomas Scott Soerens and published by . This book was released on 1995 with total page 584 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Physical and Chemical Dissolution Front Instability in Porous Media written by Chongbin Zhao and published by Springer. This book was released on 2014-07-18 with total page 363 pages. Available in PDF, EPUB and Kindle. Book excerpt: This monograph provides state-of-the-art theoretical and computational findings from investigations on physical and chemical dissolution front instability problems in porous media, based on the author’s own work. Although numerical results are provided to complement theoretical ones, the focus of this monograph is on the theoretical aspects of the topic and those presented in this book are applicable to a wide range of scientific and engineering problems involving the instability of nonlinear dynamic systems. To appeal to a wider readership, common mathematical notations are used to derive the theoretical solutions. The book can be used either as a useful textbook for postgraduate students or as a valuable reference book for computational scientists, mathematicians, engineers and geoscientists.

Download or read book Dissolution of Non aqueous Phase Organic Liquids in Porous Media written by Jil Talkovsky Geller and published by . This book was released on 1990 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Mass Transfer To from Distributed Sinks Sources in Porous Media written by Weishu Zhao and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Handbook of Chemical Mass Transport in the Environment written by Louis J. Thibodeaux and published by CRC Press. This book was released on 2010-10-21 with total page 636 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive account of the state of the science of environmental mass transport Edited by Louis J. Thibodeaux and Donald Mackay, renowned experts in this field, the Handbook of Chemical Mass Transport in the Environment covers those processes which are critically important for assessing chemical fate, exposure, and risk. In a comprehensive and authoritative format, this unique handbook provides environmental chemists, geoscientists, engineers, and modelers with the essential capabilities to understand and quantify transport. In addition, it offers a one-stop resource on environmental mass transfer and mass transport coefficient estimation methods for all genres. The book begins by discussing mass transport fundamentals from an environmental perspective. It introduces the concept of mobility — key to environmental fate, since transport must occur prior to any reaction or partitioning within the natural multimedia compartments. The fugacity approach to environmental mass transfer and the conventional approach are examined. This is followed by a description of the individual mass transport processes and the appropriate flux equations required for a quantitative expression. The editors have identified 41 individual processes believed to be the most environmentally significant, which form the basis for the remainder of the book Using a consistent format for easy reference, each chapter: Introduces the specific processes Provides a detailed qualitative description Presents key theoretical mathematical formulations Describes field or laboratory measurements of transport parameters Gives data tables and algorithms for numerical estimates Offers a guide for users familiar with the process who are seeking a direct pathway to obtain the numerical coefficients Presents computed example problems, case studies and/or exercises with worked-through solutions and answers The final chapter presents the editors’ insight into future needs and emerging priorities. Accessible and relevant to a broad range of science and engineering users, this volume captures the state of the transport science and practice in this critical area.

Download or read book Determination of Mass Transfer Coefficients for a Dissolving Nonaqueous Phase Liquid Pool in Porous Media written by Pin-yi Hsuan and published by . This book was released on 2000 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Characterization of Non aqueous Phase Liquid Dissolution in Porous Media Using Nuclear Magnetic Resonance Imaging written by Alicia Renee Aragon and published by . This book was released on 2000 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Dissolution of a Nonaqueous Phase Liquid in Saturated Porous Media written by Paul T. Imhoff and published by . This book was released on 1992 with total page 688 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Spreading and Evaporation of Non aqueous Phase Liquid in Water wet Porous Media written by Han-Chih Angela Liang and published by . This book was released on 1999 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Dissolution Mass Transfer of Trapped Phase in Porous Media written by Anindityo Patmonoaji and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dissolution mass transfer of trapped phase (TP) to flowing phase (FP) in porous media plays significant roles in hydrogeology, e.g., groundwater contamination by non-aqueous phase liquids, groundwater in-situ bioremediation, and geological carbon sequestration. In this chapter, this phenomenon is described. First, the physical and mathematical models are given. Afterwards, various conditions affecting this process, i.e., porous media characteristics, capillary trapping characteristics, flow bypassing, TP characteristics, and FP velocity, are discussed. These various conditions are described based on three parameters affecting the dissolution mass transfer: TP interfacial area (A), TP dissolution ratio (ξ), and mass transfer coefficient (k). Eventually, models to predict the mass transfer are formulated based on non-dimensional model. All of the data in this chapter are based on the experiments obtained by using micro-tomography and a series of image processing techniques from our latest works.

Download or read book Study of Transport and Dissolution of a Nonaqueous Phase Liquid in Porous Media written by Mirrya Mosier Fontenot and published by . This book was released on 2001 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt: The transport and dissolution of residual non-aqueous phase liquids (NAPLS) trapped in water saturated porous media is a problem pertinent to both environmental and petrochemical industries. In this work we have quantitatively examined the complete dissolution of residual entrapped NAPL at the pore-scale in three dimensions using refractive index matching techniques along with planar laser induced fluorescence. The results yielded pore-scale information regarding ganglia volume, surface area, and position over time at various Capillary numbers. We found that with increasing Capillary numbers, the time for total dissolution decreased. In addition, it appears that large ganglia exhibit fractal area to volume scaling. We were also able to examine the distributions of the ganglia in the direction of flow over time. The use of low-frequency flow pulsations as a removal technique was also examined. A two dimensional micro model was used for these studies. We found that for this system, lower frequencies and higher amplitudes were more effective in NAPL removal due to breakup and mobilization. We also examined the effect of increasing amplitude and continuous versus pulsed stimulation. In addition, mass transport in the presence of a surfactant was also enhanced due to flow pulsation with lower frequencies and higher amplitudes again being most effective.

Download or read book Theoretical Analyses of Nonaqueous Phase Liquid Dissolution induced Instability in Two dimensional Fluid saturated Porous Media written by Chongbin Zhao and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Multiple Experimental Realizations of Dense Nonaqueous Phase Liquid Spreading in Water saturated Heterogeneous Porous Media written by Ronald Compos and published by . This book was released on 1998 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Anneaux de Gorenstein et torsion en alg bre commutative written by and published by . This book was released on 1970 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: