[PDF] Analysis Of Groundwater Contaminant Transport With Three Dimensional Scaled Models eBook

Author : Tariq O. Hashim
Publisher :
Page : 124 pages
File Size : 38,82 MB
Release : 1998-12-01
Category : Finite element method
ISBN : 9781423555179

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Macroscale rate-limited sorption modeling was tested using a production transport code, the GMS/FEMWATER ground-water modeling package. The code (Version 1.1 of FEMWATER. dated 1 August 1995) was applied to a 3D conceptual model developed from a field site at Dover AFB, DE. A simulation was performed of a 200 hour contaminant injection pulse followed by clean water flushing. A moment analysis performed on the resulting breakthrough curve validated code self-consistency. Another injection pulse simulation showed that retardation temporally delays the breakthrough peak. Transport simulations of pulsed clean water pumping of the test cell with a prescribed initial contaminant distribution demonstrated both tailing and rebound without any additional microscale modeling. In comparison with both previous numerical solutions and the actual field data from the Dover AFB test site, FEMWATER has demonstrated high numerical dispersivity. For an initial contaminant distribution corresponding to the field data, the FEMWATER breakthrough curve was much flatter than the experimental result, failing to capture the plug-like elution of the field site.

Author : Mark Goltz
Publisher : John Wiley & Sons
Page : 272 pages
File Size : 36,79 MB
Release : 2017-02-28
Category : Science
ISBN : 0470242345

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Teaches, using simple analytical models how physical, chemical, and biological processes in the subsurface affect contaminant transport Uses simple analytical models to demonstrate the impact of subsurface processes on the fate and transport of groundwater contaminants Includes downloadable modeling tool that provides easily understood graphical output for over thirty models Modeling tool and book are integrated to facilitate reader understanding Collects analytical solutions from many sources into a single volume and, for the interested reader, shows how these solutions are derived from the governing model equations

Author : Karl Bandilla
Publisher :
Page : 114 pages
File Size : 48,81 MB
Release : 2009
Category :
ISBN :

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This work introduces a combination of the vertically integrated Analytic Element and deterministic Streamline methods for watershed-scale groundwater flow and contaminant transport modeling. This new method combines the Analytic Element Method's ability of modeling large spatial domains while preserving stream-scale details, with the conceptional elegance of the Streamline method. Both methods allow for parallel processing in order to reduce model run-times. The intended use of this new method is the study of non-point source contaminant transport on the watershed scale (e.g., nutrient loading to surface water from agricultural fields). A new iterative Analytic Element Method algorithm is devised for solving 2D steady-state groundwater flow models containing large numbers of head-specified elements (e.g. rivers and lakes).^The new algorithm improves convergence of models containing head-specified elements by explicitly computing fluxes of all such features at the start of each iteration. The new algorithm alsoenables the use of efficient parallel processing on distributed-memory super-computers. The combination of parallel processing and reduced number of iterations significantly extends the size and complexity of problems that can be modeled using the Analytic Element Method. The vertically integrated Analytic Element Method flow solution is used to construct three-dimensional particle tracks that define the geometry of the Streamline Method by approximating vertical flow. The inherently parallel nature of the algorithm supports the development of reactive transport models for spatial domains much larger than current grid-based methods.^The applicability of the new approach is verified for cases with negligible transverse dispersion through comparisons to analytic solutions and existing numerical solutions, and parallel performance is demonstrated through a realistic test problem based on the regional-scale transport of agricultural contaminants from spatially distributed sources.

Author : Chunmiao Zheng
Publisher : Wiley
Page : 0 pages
File Size : 31,46 MB
Release : 1995-08-07
Category : Technology & Engineering
ISBN : 9780471285366

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Applied Contaminant Transport Modeling Theory and Practice Chunmiao Zheng and Gordon D. Bennett The design of remedial systems for groundwater contamination requires a thorough understanding of how various interacting processes — advection, dispersion, and chemical reactions — influence the movement and fate of contaminants. Solute transport simulation provides an ideal vehicle to synthesize these controlling processes, evaluate their interactions, and test the effectiveness of remedial measures. Applied Contaminant Transport Modeling is the first complete resource designed to provide clear coverage of the basic principles of solute transport simulation — including the theory behind the most common numerical techniques for solving transport equations, and step-by-step guidance on the development and use of field-scale models. Written by two experts with extensive practical experience in the field, Applied Contaminant Transport Modeling clearly explains: Factors controlling the transport and fate of solutes in the subsurface —g including advective and dispersive transport and chemical reaction — and the equations governing these processes Development of mathematical models of solute transport regimes and representative analytical solutions to the transport equation Particle tracking as a practical tool for solving many types of field problems Development of Eulerian-Lagrangian methods for solving advection-dispersion-reaction equations Step-by-step development and application of solute transport models — emphasizing problem formulation, model setup, parameter selection, calibration, and sensitivity analysis Sources of uncertainty in transport simulation, and methods of evaluating and managing uncertainty Applied Contaminant Transport Modeling presents detailed case histories illustrating how hydrologists, geologists, chemists, and environmental engineers apply transport models in real-life situations, including landfills, hazardous waste sites, and contaminated aquifers. An optional diskette designed to accompany the text provides software to help the reader explore the concepts and techniques presented in the text and gain hands-on experience in transport simulation. Driven by growing concern over groundwater quality and the rapid dissemination of computer technology, solute transport simulation has become an essential means of evaluating and solving groundwater contamination and remediation problems. Applied Contaminant Transport Modeling provides you with the tools to master this significant field of study.