Download or read book Calcite dissolution kinetics and lake neutralization written by Harald Ulrik Sverdrup and published by . This book was released on 1985 with total page 169 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Calcite Dissolution Kinetics at the Sediment water Interface in an Acidifying Ocean written by Olivier Sulpis and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "Carbon dioxide (CO2), produced and released to the atmosphere by human activities, has been accumulating in the oceans for approximately two centuries and will continue to do so well beyond the end of this century if emissions are not curbed. One direct consequence of CO2 build-up in the atmosphere and its transfer to the ocean is the acidification of seawater. Calcite, a mineral secreted by many organisms living in the surface ocean to produce their shells and skeletons, covers a large part of the seafloor and acts as a natural anti-acid, neutralizing CO2. Thus, a precise knowledge of the kinetics of this dissolution reaction is necessary to predict the ocean recovery time towards its pre-acidification state once anthropogenic CO2 emissions are curbed. This thesis combines laboratory experiments, oceanographic measurements and model outputs to explore and unravel the mechanisms that control calcite dissolution at the sediment-water interface (SWI) on the seafloor in the context of current anthropogenic ocean acidification. Using a newly developed temperature-controlled rotating-disk reactor, as well as a stirred reactor, we were able to measure the rate of dissolution of simulated and natural sediment disks of variable calcite content under environmental and hydrodynamic conditions representative of deep-sea benthic environments. These experiments revealed that, in contrast to the reigning paradigm that calcite dissolution kinetics in seawater is surface reaction-controlled and of high order, calcite dissolution at the SWI and under deep-sea conditions is linearly dependent on the undersaturation state of the overlying seawater with respect to calcite and controlled by the presence of a diffusive-boundary layer (DBL) above the sediment bed. Therefore, irrespective of the mineralogy and sediment properties, the dissolution rate is simply a function of the saturation state of the overlying seawater with respect to calcite, the calcite content of the sediment, and hydrodynamics at the seafloor. From these observations, using a compilation of seawater chemical variables in the global ocean, corresponding sediment calcite content and rain rates, as well as recently modeled bottom current velocities, we have been able to identify the loci of current anthropogenic calcite dissolution and its rate. We found that significant anthropogenic dissolution of calcite at the seafloor currently occurs in the western North Atlantic, where the bottom waters are youngest, and at various hot spots in the southern Atlantic, Indian and Pacific Oceans. Using model projections for the 21st century, under a “business as usual” scenario, we found that while seawater will become more corrosive to this mineral, calcite dissolution at the seafloor will decrease in intensity because bottom currents will slow down and the amount of calcite particles delivered to the seafloor will diminish. These results indicate that the neutralization of human-made CO2 by calcite dissolution at the seafloor may take longer than previously thought. These findings are of critical interest to the scientific community and the public, as these results have far reaching implications for ocean acidification mitigation, to the fate of benthic communities living under increasing environmental stress, and to geologists contemplating both present and past records of ocean acidification"--
Download or read book Public Roads of Tennessee written by and published by . This book was released on 1906 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book APMP Guidance Manual written by James E. Fraser and published by . This book was released on 1985 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Lake and Reservoir Management written by North American Lake Management Society. Conference and published by . This book was released on 1984 with total page 628 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Liming of Acidified Surface Waters written by Lennart Henrikson and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 471 pages. Available in PDF, EPUB and Kindle. Book excerpt: Acidification is one of the most serious environmental problems - especially in Sweden, which suffers most from the consequences of acid rain. Besides international negotiations to reduce sulphur emissions - 85% of the acid load on Sweden can be traced to emissions from outside the country itself - the Swedish Government has employed large-scale, operative liming activities to counteract acidification of surface waters. The scientific results show that - although acidification cannot be solved by liming alone - the measures taken resulted in substantial improvements to around 8,000 Swedish lakes and watercourses. The idea is that other countries affected by acidification may also profit from this experience.
Download or read book Kinetics and Mechanism of Calcite Dissolution in Aqueous Solutions at Low Temperatures written by E. Lennart Sjöberg and published by . This book was released on 1978 with total page 482 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy Research Abstracts written by and published by . This book was released on 1989 with total page 760 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Acid Precipitation written by and published by . This book was released on 1986 with total page 570 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Acidic Precipitation written by H.C. Martin and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 2096 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the beginning of the 1980's, research has continued to clarify and improve our understanding of the problern of the ecological impact of acidic precipitation. From September 15-20, 1985, Canada convened the the Muskoka Symposium on Acidic Precipitation to review progress and help chart the direction of future studies. The Conference was held in central Ontario, Canada, a region of heavy sulphate deposition where aquatic effects are evident. Approximately 700 people attended, over 500 of whom were research scientists. Over 400 papers were presented. Nearly 200 of the papers are included in these proceedings, which tagether give the present state of the art of acid rain research. The Conference focused on atmospheric science and aquatic and terrestrial effects. I have made some general observations on progress in clarifying issues and linkages between these areas of research. Out standing issues which require a great deal more work are identified. These are my views, influenced by personal bias and limited by my expertise. Atmospheric Seiences Three aspects were covered: measurement techniques, the actual measure ments, and source-receptor relationships.
Download or read book Proceedings of the 5th International Symposium Honoring Professor Ian M Ritchie written by Courtney Young and published by John Wiley & Sons. This book was released on 2013-09-19 with total page 1061 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sponsored by The Extraction and Processing Division (EPD) of TMS, The Mineral and Metallurgical Processing Division (MPD) of SME, Metallurgical Society (MetSoc) of CIM 2003 TMS/EPD Fall Meeting held in conjunction with 33rd Annual Hydrometallurgy Meeting and 2003 Conference of Metallurgists Vancouver BC Canada August 24-27,2003.
Download or read book Restoration of Aquatic and Terrestrial Systems written by R.W. Brocksen and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 499 pages. Available in PDF, EPUB and Kindle. Book excerpt: The proceedings of a special technical session dealing with the addition of Ca based materials to waters and soils for the purpose of restoring or enhancing fisheries in acidified waters are contained in this volume. The session was part of the North American Fisheries Society's annual meeting sponsored by the Water Quality Section of the Society. While the concept of liming is not new, the extent of the recent research, demonstrations and applications reported at the conference is enlightening. Six countries are represented by government, state and private sector participants. The scope of activities reported in the following 23 papers range from the simple to the very complex addition of liming materials to ponds, lakes, streams and watersheds. This volume of presentations is broad and impressive as are the methods used in the actual application of the neutralizing materials. Those programs that are demonstration application oriented are deploying techniques that are either new or modifications of existing technology.
Download or read book Calcite Dissolution Kinetics and Solubility in Na Ca Mg Cl Brines of Geologically Relevant Composition at 0 1 to 1 Bar PCO2 and 25 to 80 C written by Dwight Kuehl Gledhill and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Sedimentary basins can contain close to 20% by volume pore fluids that are commonly classified as brines. These fluids can become undersaturated with respect to calcite as a result of processes such as migration, dispersive mixing, or anthropogenic injection of CO2. This study measured calcite solubility and dissolution rates in geologically relevant Na-Ca-Mg-Cl synthetic brines (35 to 200 g L−1 TDS). In brines 50 g L−1 TDS, the EQPITZER calculated calcium carbonate ion activity product (IAP) at steady-state was in reasonable agreement ("10%) with the thermodynamic solubility constant for calcite (K[subscript]c). However, the IAP systematically exceeded K[subscript]c in more concentrated brines. The deviation was strongly correlated with calcium concentration and also was observed in magnesium-free solutions. This is interpreted as an uncertainty in the carbonate ion activity coefficient, and minor adjustment in stoichiometric association constants (K*[subscript]M2+CO0[over]3) for the CaCO0[over]3 or MgCo0[over]3 ion pairs would correct for the error. The dissolution rate dependency on brine composition, pCO2 (0.1 to 1 bar), and temperature (25.0 to 82.5 °C) was modeled using the empirical rate equation R = k(1-[omega]0 [superscript]n where R is the rate, k and n are empirical fitting terms, and [omega] the degree of disequilibrium with respect to calcite. When [omega] was defined relative to an apparent kinetic solubility, n could be assumed first-order over the range of [omega] investigated ([omega] = 0.2 to 1.0). Rates increased with increasing pCO2 as did the sensitivity to brine concentration. At 0.1 bar, rates were nearly independent of concentration (k = 13.0 "2.0 x 10−3 moles m−1 hr−1). However, at higher CO2 partial pressures rates became composition dependent and the rate constant, k, was shown to be a function of temperature, pCO2, ionic strength, and calcium and magnesium activity. The rate constant (k) can be estimated from a multiple regression (MR) model of the form [unable to replicate formula]. A relatively high activation energy (E[subscript]a = 20 kJ mol−1) was measured, along with a stirring rate independence suggesting the dissolution is dominated by surface controlled processes at saturation states [omega] 0.2 in these calcium-rich brines. These findings offer important implications to reaction-transport models in carbonate-bearing saline reservoirs.
Download or read book Proceedings of the 12th International Symposium Continuous Surface Mining Aachen 2014 written by Christian Niemann-Delius and published by Springer. This book was released on 2014-09-20 with total page 639 pages. Available in PDF, EPUB and Kindle. Book excerpt: This edited volume contains research results presented at the 12th International Symposium Continuous Surface Mining, ISCSM Aachen 2014. The target audience primarily comprises researchers in the lignite mining industry and practitioners in this field but the book may also be beneficial for graduate students.
Download or read book Canadian Journal of Fisheries and Aquatic Sciences written by and published by . This book was released on 1989 with total page 772 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Restoring Acid Waters Loch Fleet 1984 1990 written by G. Howells and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt: Detailed and comprehensive accounts of pre-liming conditions, liming techniques employed, post-liming changes in water quality and fish restoration.
Download or read book The Lakes Handbook written by Patrick O'Sullivan and published by John Wiley & Sons. This book was released on 2008-04-15 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt: Continuing concern about water supply and quality, ecosystem sustainability and restoration demands that the modern approach to the management of lakes and reservoirs should be based on a sound understanding of the application of the scientific and ecological principles that underlie freshwater processes. The Lakes Handbook provides an up-to-date overview of the application of ecologically sound approaches, methods and tools using experience gained around the world for an understanding of lakes and their management. Volume one of the Handbook addresses the physical and biological aspects of lakes pertinent to lake management, emphasising those aspects particularly relevant to large, still bodies of water. Volume two then considers lake management, with particular emphasis on sustainability, restoration and rehabilitation. This handbook will be invaluable to ecologists, environmental scientists, physical geographers and hydrologists involved in limnological research, as well as advanced undergraduate and graduate students looking for authoritative reviews of the key areas of limnological study.
