Download or read book Elucidation of Retention Processes Governing the Transport of Volatile Organic Compounds in Unsaturated Soils PHD written by Molly Susan Costanza and published by . This book was released on 2001 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Coupling Transport and Biodegradation of Volatile Organic Compounds in Unsaturated Soils written by Yassar Hamad El-Farhan and published by . This book was released on 1997 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Coupled Processes Diffusive Transport and Biodegradation of Volatile Organic Compounds in Unsaturated Porous Media written by and published by . This book was released on 1998 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Diffusive transport of volatile organic compounds (VOCs) and their degradation by bacteria in unsaturated soils are coupled by poorly understood mass transfer kinetics at the gas/water interface. The capability to predict the fate of VOCs in m saturated soil is necessary to evaluate the feasibility of natural attenuation as a VOC remediation strategy. The objective of this study was to develop a mechanistically based mathematical model that considered the interdependence of VOC diffusive transport, mass transfer at the gas/water interface, microbial activity, and sorptive interactions in a moist, unsaturated soil. Because the focus of the model was on description of natural attenuation, the advective VOC transport that is induced in engineered remediation processes such as vapor extraction was not considered. The utility of the model was assessed through its ability to describe experimental observations from well-defined experiments in which toluene was used as a representative VOC and diffused through soil columns that contained a toluene degrading bacterium, Pseudomonasputida. The coefficient for gas-liquid mass-transfer, KLa, was found to be a key parameter controlling the ability of bacteria to degrade VOCs. This finding indicates that soil size and geometry are likely to be dominant parameters in assessing the possible success of natural attenuation of VOCs in contaminated unsaturated soils.
Download or read book Mass Transport of Volatile Organic Compounds Between the Saturated and Vadose Zones written by Monte S. Harner and published by . This book was released on 1996-12-01 with total page 99 pages. Available in PDF, EPUB and Kindle. Book excerpt: Volatile organic compounds (VOCs) dissolved in the saturated zone are transported into the vadose zone primarily by gaseous phase diffusion. If the saturated zone is remediated, VOCs present in the vadose zone may become a secondary source of contamination for the groundwater The amount of VOCs that remain in the vadose zone is dependent on site hydrology, soil properties, and the chemical properties of the contaminants. The purpose of this study was to determine what conditions caused VOC concentrations in the vadose zone to significantly recontaminate the saturated zone. A one-dimensional numerical model was developed to investigate the transport of a VOC, trichioroethylene, between the saturated and vadose zones under a variety of conditions. The model featured steady-state unsaturated water flow and transient contaminant transport Transport mechanisms included aqueous phase advection-dispersion and gaseous phase diffusion. Partitioning between the water, gas, and soil compartments were modeled as equilibrium processes. Sensitivity analyses were performed on several variables including soil type (homogeneous and heterogeneous profiles), water infiltration rate and vadose zone depth. Results indicated that recontamination was most significant rate, and vadose zone depth. Results indicated that recontamination was most significant in the presence of heterogeneous soils, low infiltration rates and deep vadose zones.
Download or read book Transport and Transformations of Volatile Organic Chemicals in Unsaturated Soils written by Yan Jin and published by . This book was released on 1994 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Transport of Dissolved Volatile Organic Compounds in the Unsaturated Zone written by Munjed A. Maraqa and published by . This book was released on 1995 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Numerical Solution to Three dimensional Multiphase Transport of Volatile Organic Compounds in Unsaturated Soils with an Application to the Remedial Method of In situ Volatilization Part I written by and published by . This book was released on 1992 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: Part I of this paper presents the development and application of a numerical model for determining the fate and transport of volatile organic compounds (VOCS) in the unsaturated zone resulting from forced volatilization and gaseous advection-dispersion of organic vapor in a multipartitioned three-dimensional environment. The model allows for single-component transport in the gas and water phases. The hydrocarbon is assumed to be in specific retention and, therefore, immobile. Partitioning of the hydrocarbon between the oil, water, gas, and soil is developed as rate-limited functions that are incorporated into sink/source terms in the transport equations. The code for the model was developed specifically to investigate in-situ volatilization (ISV) remedial strategies, predict the extent of cleanup from information obtained at a limited number of measurement locations, and to help design ISV remedial systems. Application of the model is demonstrated for a hypothetical one-dimensional ISV system. Part II of this paper will present the analysis of an existing ISV system using the full three-dimensional capability of the model.
Download or read book American Doctoral Dissertations written by and published by . This book was released on 2000 with total page 816 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Numerical Solution to Three dimensional Multiphase Transport of Volatile Organic Compounds in Unsaturated Soils with Application to the Remedial Method of In situ Volatilization written by and published by . This book was released on 1992 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Bioavailability of Contaminants in Soils and Sediments written by National Research Council and published by National Academies Press. This book was released on 2003-05-03 with total page 433 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bioavailability refers to the extent to which humans and ecological receptors are exposed to contaminants in soil or sediment. The concept of bioavailability has recently piqued the interest of the hazardous waste industry as an important consideration in deciding how much waste to clean up. The rationale is that if contaminants in soil and sediment are not bioavailable, then more contaminant mass can be left in place without creating additional risk. A new NRC report notes that the potential for the consideration of bioavailability to influence decision-making is greatest where certain chemical, environmental, and regulatory factors align. The current use of bioavailability in risk assessment and hazardous waste cleanup regulations is demystified, and acceptable tools and models for bioavailability assessment are discussed and ranked according to seven criteria. Finally, the intimate link between bioavailability and bioremediation is explored. The report concludes with suggestions for moving bioavailability forward in the regulatory arena for both soil and sediment cleanup.
Download or read book Dissertation Abstracts International written by and published by . This book was released on 2001 with total page 698 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Engineering and Design written by Us Army Corps Of Engineers and published by Military Bookshop. This book was released on 2002-06-01 with total page 434 pages. Available in PDF, EPUB and Kindle. Book excerpt: This manual provides practical guidance for the design and operation of soil vapor extraction (SVE) and bioventing (BV) systems. It is intended for use by engineers, geologists, hydrogeologists, and soil scientists, chemists, project managers, and others who possess a technical education and some design experience but only the broadest familiarity with SVE or BV systems.
Download or read book Contaminants in the Subsurface written by National Research Council and published by National Academies Press. This book was released on 2005-04-23 with total page 371 pages. Available in PDF, EPUB and Kindle. Book excerpt: At hundreds of thousands of commercial, industrial, and military sites across the country, subsurface materials including groundwater are contaminated with chemical waste. The last decade has seen growing interest in using aggressive source remediation technologies to remove contaminants from the subsurface, but there is limited understanding of (1) the effectiveness of these technologies and (2) the overall effect of mass removal on groundwater quality. This report reviews the suite of technologies available for source remediation and their ability to reach a variety of cleanup goals, from meeting regulatory standards for groundwater to reducing costs. The report proposes elements of a protocol for accomplishing source remediation that should enable project managers to decide whether and how to pursue source remediation at their sites.
Download or read book Environmental Risk Assessment of Soil Contamination written by Maria C. Hernandez Soriano and published by BoD – Books on Demand. This book was released on 2014-03-26 with total page 922 pages. Available in PDF, EPUB and Kindle. Book excerpt: Soil is an irreplaceable resource that sustains life on the planet, challenged by food and energy demands of an increasing population. Therefore, soil contamination constitutes a critical issue to be addressed if we are to secure the life quality of present and future generations. Integrated efforts from researchers and policy makers are required to develop sound risk assessment procedures, remediation strategies and sustainable soil management policies. Environmental Risk Assessment of Soil Contamination provides a wide depiction of current research in soil contamination and risk assessment, encompassing reviews and case studies on soil pollution by heavy metals and organic pollutants. The book introduces several innovative approaches for soil remediation and risk assessment, including advances in phytoremediation and implementation of metabolomics in soil sciences.
Download or read book Soil Pollution and Soil Protection written by F. A. M. de Haan and published by Brill Wageningen Academic. This book was released on 1996 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of this book is to provide basic information to aid understanding of the complex problem of soil quality and its evaluation. It should be of use to those who are professionally involved in soil quality and have to deal with problems of soil protection.
Download or read book Volatile Organic Compounds in the Atmosphere written by Ralf Koppmann and published by John Wiley & Sons. This book was released on 2008-04-15 with total page 512 pages. Available in PDF, EPUB and Kindle. Book excerpt: Every day, large quantities of volatile organic compounds (VOCs) are emitted into the atmosphere from both anthropogenic and natural sources. The formation of gaseous and particulate secondary products caused by oxidation of VOCs is one of the largest unknowns in the quantitative prediction of the earth’s climate on a regional and global scale, and on the understanding of local air quality. To be able to model and control their impact, it is essential to understand the sources of VOCs, their distribution in the atmosphere and the chemical transformations which remove these compounds from the atmosphere. In recent years techniques for the analysis of organic compounds in the atmosphere have been developed to increase the spectrum of detectable compounds and their detection limits. New methods have been introduced to increase the time resolution of those measurements and to resolve more complex mixtures of organic compounds. Volatile Organic Compounds in the Atmosphere describes the current state of knowledge of the chemistry of VOCs as well as the methods and techniques to analyse gaseous and particulate organic compounds in the atmosphere. The aim is to provide an authoritative review to address the needs of both graduate students and active researchers in the field of atmospheric chemistry research.
Download or read book Unsaturated Soil Mechanics written by Ning Lu and published by John Wiley & Sons. This book was released on 2004-05-20 with total page 614 pages. Available in PDF, EPUB and Kindle. Book excerpt: Unsaturated Soil Mechanics is the first book to provide a comprehensive introduction to the fundamental principles of unsaturated soil mechanics. * Offers extensive sample problems with an accompanying solutions manual. * Brings together the rapid advances in research in unsaturated soil mechanics in one focused volume. * Covers advances in effective stress and suction and hydraulic conductivity measurement.
