Download or read book Mercury Adsorption and Desorption Kinetics written by Mark A. Bentley and published by . This book was released on 2012 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mercury emissions in the United States are regulated under the Clean Air Mercury Rule. Multiple mercury removal technologies have been investigated and at this time, activated carbon injection into flue gas has been considered to be an efficient and economically feasible method for the removal of elemental mercury. Also, chemical modifications to activated carbon have shown to increase its mercury sorption capacity and removal efficiency. In this study, adsorption of elemental mercury onto ferric chloride impregnated activated carbon was investigated. The results show that ferric chloride impregnated activated carbon has a higher mercury sorption capacity than raw activated carbon does. A chemisorption mechanism was proposed and confirmed based on the characterization tests of fresh and spent sorbents. A kinetic study for the regeneration of spent sorbents was also conducted. The activation energies of mercury desorption from various substrates were calculated and the corresponding mercury desorption profiles were mathematically modeled.
Download or read book COMBINED THEORETICAL AND EXPERIMENTAL INVESTIGATION OF MECHANISMS AND KINETICS OF VAPOR PHASE MERCURY UPTAKE BY CARBONACEOUS SURFACES written by and published by . This book was released on 2000 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: The overall goal of this research program is to gain fundamental understanding of the important chemistry and physics involved in mercury adsorption on carbonaceous surfaces. This knowledge will then be used to optimize adsorption processes and operating conditions to maximize the uptake of mercury within the required contact time. An additional long-term benefit of this research is the basic understanding of the Hg adsorption process, which may facilitate the design of new adsorbents for more efficient and cost-effective removal of Hg from a variety of effluent streams. Molecular modeling of the adsorption of Hg on carbonaceous surfaces will greatly increase the insight into the physics of the adsorption process and combined with in situ rate measurements of mercury adsorption and desorption (conventional and pulsed laser) on graphite using linear and nonlinear optical probes with real time optical resolution have the potential to provide fundamental insight into the process of mercury uptake by carbonaceous surfaces. Besides accurate assessment of key parameters influencing adsorption equilibrium, fundamental understanding of the kinetics of mercury adsorption, desorption, and diffusion will be developed in this study. These key physical and chemical processes postulated through molecular modeling efforts and verified by in situ measurements will be utilized to select (or develop) promising sorbents for mercury control, which will be tested under dynamic conditions using simulated flue gas.
Download or read book Kinetic Modeling of Mercury Desorption and Adsorption on Fixed bed Sorbents written by Youngkil Lee and published by . This book was released on 1999 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Kinetic Study of Mercury Sorption Desorption Process on Sorbents written by T. C. Ho and published by . This book was released on 1999 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental and Kinetic Study of Mercury Adsorption on Various Activated Carbons in a Fixed Bed Adsorber written by Youngkil Lee and published by . This book was released on 2003 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Adsorption and Coprecipitation Studies of Mercury on Hydrous Iron Oxide written by Peter Avotins and published by . This book was released on 1975 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Carbon Nanomaterial Based Adsorbents for Water Purification written by Suprakas Sinha Ray and published by Elsevier. This book was released on 2020-06-27 with total page 422 pages. Available in PDF, EPUB and Kindle. Book excerpt: The deterioration of water quality and unavailability of drinkable water are pressing challenges worldwide. The removal of toxic organic and inorganic pollutants from water is vital for a clean environment, as a response to water scarcity. Adsorption-based water technologies are among the most widely used because of their high efficiency and low cost, without relying on a complex infrastructure. In recent years, carbon nanomaterials (CNMs), such as graphene and derivatives, carbon nanotubes, carbon nanofibers, nanoporous carbon, fullerenes, graphitic carbon nitride, and nanodiamonds have been extensively exploited as adsorbents due to their extraordinary surface properties, ease of modification, large surface area, controlled structural varieties, high chemical stability, porosity, low density, ease of regeneration, and reusability. This book provides a thorough overview of the state of the art in carbon nanomaterials as they are used for adsorption applications in water purifications, as well as addressing their toxicological challenges. This volume primarily explores the fundamentals of adsorption, its mechanical aspects, synthesis and properties of CNMs, and adsorption performances of CNMs and their nanocomposites with organic and inorganic materials. Structural engineering and activation processes produce materials with enhanced adsorptive properties and separation efficiencies. Furthermore, the formation of CNMs with 2D and 3D macro-and microstructures and high porosities is a potential approach to improve adsorption performances and extend CNM use at the industrial level. The book also addresses important issues regarding these adsorbents that potentially affect future research and industrial applications of carbon-based nanoadsorbents in water security. - Presents advances in multifunctional 3D superstructures of carbon nanomaterials and their composites for adsorption applications - Outlines the fundamentals on synthesis and characterization techniques of carbon-based nanostructures and their composites - Assesses the major toxicological challenges in using nanostructured materials as adsorbents for water purification
Download or read book Mercury Control with Calcium Based Sorbents and Oxidizing Agents written by Thomas K. Gale and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This Final Report contains the test descriptions, results, analysis, correlations, theoretical descriptions, and model derivations produced from many different investigations performed on a project funded by the U.S. Department of Energy, to investigate calcium-based sorbents and injection of oxidizing agents for the removal of mercury. Among the technologies were (a) calcium-based sorbents in general, (b) oxidant-additive sorbents developed originally at the EPA, and (c) optimized calcium/carbon synergism for mercury-removal enhancement. In addition, (d) sodium-tetrasulfide injection was found to effectively capture both forms of mercury across baghouses and ESPs, and has since been demonstrated at a slipstream treating PRB coal. It has been shown that sodium-tetrasulfide had little impact on the foam index of PRB flyash, which may indicate that sodium-tetrasulfide injection could be used at power plants without affecting flyash sales. Another technology, (e) coal blending, was shown to be an effective means of increasing mercury removal, by optimizing the concentration of calcium and carbon in the flyash. In addition to the investigation and validation of multiple mercury-control technologies (a through e above), important fundamental mechanism governing mercury kinetics in flue gas were elucidated. For example, it was shown, for the range of chlorine and unburned-carbon (UBC) concentrations in coal-fired utilities, that chlorine has much less effect on mercury oxidation and removal than UBC in the flyash. Unburned carbon enhances mercury oxidation in the flue gas by reacting with HCl to form chlorinated-carbon sites, which then react with elemental mercury to form mercuric chloride, which subsequently desorbs back into the flue gas. Calcium was found to enhance mercury removal by stabilizing the oxidized mercury formed on carbon surfaces. Finally, a model was developed to describe these mercury adsorption, desorption, oxidation, and removal mechanisms, including the synergistic enhancement of mercury removal by calcium.
Download or read book Mercury written by Sean C. Solomon and published by Cambridge University Press. This book was released on 2018-12-20 with total page 601 pages. Available in PDF, EPUB and Kindle. Book excerpt: Observations from the first spacecraft to orbit the planet Mercury have transformed our understanding of the origin and evolution of rocky planets. This volume is the definitive resource about Mercury for planetary scientists, from students to senior researchers. Topics treated in depth include Mercury's chemical composition; the structure of its crust, lithosphere, mantle, and core; Mercury's modern and ancient magnetic field; Mercury's geology, including the planet's major geological units and their surface chemistry and mineralogy, its spectral reflectance characteristics, its craters and cratering history, its tectonic features and deformational history, its volcanic features and magmatic history, its distinctive hollows, and the frozen ices in its polar deposits; Mercury's exosphere and magnetosphere and the processes that govern their dynamics and their interaction with the solar wind and interplanetary magnetic field; the formation and large-scale evolution of the planet; and current plans and needed capabilities to explore Mercury further in the future.
Download or read book Mercury in the Environment written by Michael S. Bank and published by Univ of California Press. This book was released on 2012-05-31 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Mercury deposition and contamination is widespread and well documented, and it continues to be a public-health concern for certain sectors of the global human population in both developed and developing countries. This edited volume focuses on integrating the diverse sciences involved in the process of mercury cycling in the environment--from the atmosphere, through terrestrial and aquatic food webs, and human populations--to develop a comprehensive perspective on this important environmental pollutant. Using a systems-level approach, this book provides recommendations on mercury remediation, risk communication, education, and monitoring. In response to a growing need for understanding the cycling of this ubiquitous pollutant, the science of mercury has grown rapidly, expanding into several interdisciplinary fields and encompassing such disparate academic and scientific disciplines as biogeochemistry, economics, sociology, public health, decision sciences, physics, global change, and mathematics. Only recently have scientists really begun to establish more holistic approaches to studying mercury pollution, giving rise to investigations that have furthered the integration of a multi-tiered approach, especially by using chemistry, biology, and human health sciences collectively. The study of mercury pollution has produced a variety of contributions to domestic and international policies related to the management of mercury in the environment"-- Provided by publisher.
Download or read book Development of a Novel Activated Carbon Based Adsorbents for Control of Mercury Emissions from Coal Fired Power Plants written by and published by . This book was released on 1997 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: The overall objective of this study is to evaluate pertinent design and operational parameters that would enable successful application of activated carbon adsorption for the reduction of mercury emissions from coal-fired power plants. The study will evaluate the most suitable impregnate such as sulfur, chloride and other chelating agents for its ability to enhance the adsorptive capacity of activated carbon for mercury vapor under various process conditions. The main process variables to be evaluated include temperature, mercury concentration and speciation, relative humidity, oxygen content, and presence of S02 and NO(subscript x) in the flue gas. The optimal amount of impregnate for each of these carbons will be determined based on the exhibited performance. Another important parameter which governs the applicability of adsorption technology for the flue gas clean up is the rate at which vapor phase mercury is being removed from the flue gas by activated carbon. Therefore, the second part of this study will evaluate the adsorption kinetics using the impregnated activated carbons listed above. The rate of mercury uptake will also be evaluated under the process conditions that are representative of coal-fired power plants. Concerned with the ability of the adsorbed mercury to migrate back into the environment once saturated adsorbent is removed from the system, the study will also focus on the mercury desorption rate as a function of the type of impregnate, loading conditions, and the time of contact prior to disposal.
Download or read book Adsorption and Desorption of Mercury from Sorbents in a Hot Air Stream written by Amit Ghai and published by . This book was released on 1996 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Development of Novel Activated Carbon Based Adsorbents for Control of Mercury Emission From Coal Fired Power Plants written by and published by . This book was released on 1997 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The overall objective of this study is to evaluate pertinent design and operational parameters that would enable successful application of activated carbon adsorption for the reduction of mercury emissions from coal-fired power plants. The study will evaluate the most suitable impregnate such as sulfur, chloride and other chelating agents for its ability to enhance the adsorptive capacity of activated carbon for mercury vapor under various process conditions. The main process variables to be evaluated include temperature, mercury concentration and speciation, relative humidity, oxygen content, and presence of SO2 and NOx in the flue gas. The optimal amount of impregnate for each of these carbons will be determined based on the exhibited performance. Another important parameter which governs the applicability of adsorption technology for the flue gas clean up is the rate at which vapor phase mercury is being removed from the flue gas by activated carbon. Therefore, the second part of this study will evaluate the adsorption kinetics using the impregnated activated carbons listed above. The rate of mercury uptake will also be evaluated under the process conditions that are representative of coal-fired power plants. Concerned with the ability of the adsorbed mercury to migrate back into the environment once saturated adsorbent is removed from the system, the study will also focus on the mercury desorption rate as a function of the type of impregnate, loading conditions, and the time of contact prior to disposal.
Download or read book Adsorption and Desorption Reactions of Mercury II and Methylmercury at the Soil solution Interface written by Yujun Yin and published by . This book was released on 1996 with total page 594 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Diffusion in Nanoporous Materials 2 Volumes written by Jörg Kärger and published by John Wiley & Sons. This book was released on 2012-10-29 with total page 932 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atoms and molecules in all states of matter are subject to continuous irregular movement. This process, referred to as diffusion, is among the most general and basic phenomena in nature and determines the performance of many technological processes. This book provides an introduction to the fascinating world of diffusion in microporous solids. Jointly written by three well-known researchers in this field, it presents a coherent treatise, rather than a compilation of separate review articles, covering the theoretical fundamentals, molecular modeling, experimental observation and technical applications. Based on the book Diffusion in Zeolites and other Microporous Solids, originally published in 1992, it illustrates the remarkable speed with which this field has developed since that time. Specific topics include: new families of nanoporous materials, micro-imaging and single-particle tracking, direct monitoring of transient profiles by interference microscopy, single-file diffusion and new approaches to molecular modeling.
Download or read book Modeling of Adsorption and Desorption of Mercury on Sorbents in a Fixed Bed Absorber written by Feng Guo and published by . This book was released on 1997 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt:
