Download or read book Studies on the Interactions Between Organic Matter Trace Metals and Sulfur in Recent and Ancient Sediments written by Erdem Fahri Idiz and published by . This book was released on 1987 with total page 602 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Geochemical Investigations in Earth and Space Sciences written by R.J. Hill and published by Elsevier. This book was released on 2004-06-16 with total page 481 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume is the product of a technical session organized for the 2002 Geological Society of America Annual Meeting in recognition of Isaac Kaplan's many contributions to various fields of geochemistry. As Kaplan enters his sixth decade of scientific investigation, it is fair to say that his work has touched or influenced innumerable scientists either directly or indirectly. Readers of this volume are presented with a collection of 29 papers written by former students, post-doctoral researchers, friends and colleagues from countries all over the world (including Sweden, Japan, Taiwan, New Zealand, Australia, Israel and the United States) from the fields of stable isotope, forensic, environmental and petroleum geochemistry, atmospheric chemistry and cosmochemistry.The stable isotope section includes papers investigating climate change, diagenesis, recent sediment and petroleum geochemistry and cosmochemistry problems. The forensic and environmental geochemistry section includes a variety of papers ranging from trace metals in soils to atmospheric CO2 projections. The petroleum geochemistry section includes both basic research and applied geochemistry papers. The ancient and recent sediments section contains papers ranging from carbon flux in modern sediments to Precambrian microfossils. All of the articles together cover a broad range of geochemical studies and represent the diverse and distinguished career of Isaac Kaplan.
Download or read book Geochemical Interactions of Heavy Metals in Southeastern Salt Marsh Environments written by Herbert L. Windom and published by . This book was released on 1976 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Petroleum Abstracts written by and published by . This book was released on 1997 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Monterey Formation written by Caroline M. Isaacs and published by Columbia University Press. This book was released on 2001 with total page 592 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides an extraordinary case study of a classic marine petroleum system in the prolific oil basins of California. Based on results from the Cooperative Monterey Organic Chemistry Study, the volume examines paleoenvironmental conditions, organic-matter deposition, source-rock characteristics, thermal maturation, and oil generation in the Monterey Formation.
Download or read book Petroleum Abstracts Literature and Patents written by and published by . This book was released on 1990 with total page 1416 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Microbial Connections Between the Subsurface Sulfur Cycle and Other Elemental Cycles written by Alexandra V. Turchyn and published by Frontiers Media SA. This book was released on 2018-11-16 with total page 213 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sulfur has many redox states and is a major metabolite in suboxic and anaerobic environments including, but not restricted to, marine and marginal marine sediments, the water column of oxygen minimum zones, salt marshes and oil wells. Microbially mediated redox cycling of sulfur typically comprises dissimilatory sulfate reduction (MSR), sulfide reoxidation, disproportionation and the oxidation and reduction of sulfur redox intermediates. These processes contribute to the degradation of organic matter, link the cycles of sulfur and carbon, control the production and consumption of methane and are critical for the long term budget of O2 in the atmosphere. Microbial and abiotic processes at redox interfaces also connect the sulfur cycle to the redox cycles of nitrogen, iron and other elements, producing distinctive geochemical and molecular signatures. Studies that couple microbiology with stable isotope geochemistry have informed interpretations of microbial sulfur cycling in modern and past environments. Laboratory-based studies and models of MSR have sought to understand the physiological and environmental controls of the magnitude of sulfur isotope fractionation. The fractionations of stable sulfur and oxygen isotopes during MSR are also used to track enzymatic activity during MSR and processes that oxidize sulfide in the presence of environmental oxidants. Outstanding questions in the field concern the importance of oxidative processes within the natural environment, the delivery of oxidants and carbon sources to the zones of sulfate reduction and the ability to detect or reconstruct oxidative processes from the chemical, isotopic, metagenomic, transcriptomic, proteomic and metabolomics profiles in the environment. Recent studies have emphasized the complex connections between sulfur and methane, iron, nitrogen and other elements. These links may involve the redox cycling of species that occur at concentrations difficult to detect by standard geochemical techniques or that are cycled at very rapid rates (cryptic cycles). Of particular interest is the use of isotope geochemistry to quantify links among various electron acceptors, including sulfate, ferric iron, and nitrate, during the anaerobic methane oxidation. For example, recent geochemical measurements have hinted that microbial sulfate reduction coupled to organic matter oxidation is mechanistically different to when sulfate reduction is coupled to methane oxidation. Recent studies have also suggested a possible contribution of a number of previously uncultured microbial groups in sulfur cycling in sulfidic environments, inspiring further studies of these organisms and their partnerships in anaerobic environments. This Research Topic highlights studies of microbial interactions, processes and communities that couple the sulfur cycle to the cycles of other elements in aphotic environments.
Download or read book Dissertation Abstracts International written by and published by . This book was released on 1999 with total page 700 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Treatise on Geochemistry written by and published by Newnes. This book was released on 2013-10-19 with total page 14787 pages. Available in PDF, EPUB and Kindle. Book excerpt: This extensively updated new edition of the widely acclaimed Treatise on Geochemistry has increased its coverage beyond the wide range of geochemical subject areas in the first edition, with five new volumes which include: the history of the atmosphere, geochemistry of mineral deposits, archaeology and anthropology, organic geochemistry and analytical geochemistry. In addition, the original Volume 1 on "Meteorites, Comets, and Planets" was expanded into two separate volumes dealing with meteorites and planets, respectively. These additions increased the number of volumes in the Treatise from 9 to 15 with the index/appendices volume remaining as the last volume (Volume 16). Each of the original volumes was scrutinized by the appropriate volume editors, with respect to necessary revisions as well as additions and deletions. As a result, 27% were republished without major changes, 66% were revised and 126 new chapters were added. In a many-faceted field such as Geochemistry, explaining and understanding how one sub-field relates to another is key. Instructors will find the complete overviews with extensive cross-referencing useful additions to their course packs and students will benefit from the contextual organization of the subject matter Six new volumes added and 66% updated from 1st edition. The Editors of this work have taken every measure to include the many suggestions received from readers and ensure comprehensiveness of coverage and added value in this 2nd edition The esteemed Board of Volume Editors and Editors-in-Chief worked cohesively to ensure a uniform and consistent approach to the content, which is an amazing accomplishment for a 15-volume work (16 volumes including index volume)!
Download or read book The Impact of Small Organic Acids on Iron and Manganese Mineral Transformations and the Fate of Trace Metals written by Elaine Denise Flynn and published by . This book was released on 2018 with total page 143 pages. Available in PDF, EPUB and Kindle. Book excerpt: Iron and manganese oxides are ubiquitous in soils and sediments and play a critical role in the geochemical distribution of trace elements and heavy metals through adsorption and coprecipitation. At redox interfaces, biogeochemical processes generate conditions with coexisting dissolved Fe(II) and solid-phase Fe(III). In such systems, Fe(II) induces the recrystallization of iron oxides through coupled mineral growth and dissolution due to electron transfer as oxidative adsorption of Fe(II) and reductive dissolution of Fe(III) occur. Aqueous Mn(II) adsorption onto Mn(III/IV) oxides also likely involves oxidation although likely through different mechanisms than that of the Fe system because of the potential for Mn(II)-Mn(IV) comproportionation reactions. During reactions between reduced and oxidized forms of Fe and Mn, trace metals may be redistributed among the mineral bulk, mineral surface, and aqueous solution. Many metals, including Ni and Zn, are important micronutrients but are also toxic at higher concentrations. It is important to identify the processes controlling the fate and availability of trace metals in the environment and this requires understanding the behavior and stability of Fe and Mn oxides. Small organic acids, produced as root exudates or by decomposition of organic matter in aerated soils, may potentially alter reactions involving Fe and Mn oxide minerals and trace metals through a series of cooperative or competitive processes: solution complexation, ternary surface complexation, surface site competition, ligand-promoted dissolution, and reductive dissolution. The effects of organic acids on trace metal fate in such systems is unclear because these processes may involve both trace metals and Fe or Mn oxides, and multiple processes may co-occur. The main objective of this dissertation is to determine how organic acids interacting with Fe and Mn oxides affect structural transformations of these minerals, including dissolution and recrystallization, and the resulting impact on trace metals micronutrient and contaminant fate. Three main research projects were conducted to meet this objective. First, the cooperative and competitive interactions between oxalate and Ni during adsorption to Fe oxide minerals were identified. Next, the effects of oxalate on Ni incorporation into and release from Fe oxides at pH 4 and 7 was investigated during Fe(II)-promoted recrystallization of these minerals. Finally, reductive transformations of layered Mn oxides by oxalate, citrate, and 4-hydroxybenzoate at pH 4, 5.5, and 7 were characterized as well as the associated changes in Ni and Zn adsorption extent and mechanisms. The addition of oxalate in macroscopic adsorption studies suppresses Ni uptake by goethite and hematite at pH 7. Aqueous speciation modelling indicates that this is dominantly the result of oxalate complexing and solubilizing Ni. Comparison of the Ni surface coverage to the concentration of free (uncomplexed) Ni2+ in solution suggests that oxalate also alters Ni adsorption affinity. Extended X-ray absorption fine structure and attenuated total reflectance Fourier transform infrared spectroscopies indicate that these changes in binding affinity are due to the formation of Ni-oxalate ternary surface complexes. When Ni is initially structurally-incorporated into hematite and goethite, oxalate and dissolved Fe(II) each promote the release of Ni to aqueous solution at pH 4 and 7. With the co-addition of both species, the effects on Ni release are synergistic at pH 7 but inhibitory at pH 4. This suggests that cooperative and competitive interactions vary with pH. In contrast, oxalate suppresses Ni incorporation into goethite and hematite during Fe(II)-induced recrystallization. Mn oxides may undergo redox and structural changes which can weaken trace metal binding and promote metal mobility. The conditions studied to date involve Mn(II) and are most similar to those found at redox interfaces which are limited in spatial extent in nature. Aging e-MnO2 and hexagonal birnessite in the presence of small organic acids was investigated using powder X-ray diffraction and X-ray absorption fine structure spectroscopic measurements. Organic acids caused partial Mn reduction but did not substantially alter the phyllomanganates sheet structure nor result in transformations to Mn(III) oxyhydroxides or mixed-valent minerals. All organic acids were fully consumed, producing solid-phase Mn(II) and Mn(III) as well as dissolved Mn(II), the latter favored under acidic pH conditions. Citrate caused the greatest reduction, with its oxidation products continuing to react and near-complete mineralization observed at pH 4. These redox reactions improved stacking of the phyllomanganate sheets for e-MnO2 at pH 7 and enhanced capping of vacancy sites by cations occurred for both minerals under all conditions studied. As a result of this mineral alteration, Ni and Zn adsorption behaviors were also modified. Net metal uptake did not change substantially at pH 7 where nearly all of the Ni and Zn in the system were adsorbed to the mineral surface. However, at pH 4, adsorption of Ni and Zn decreased in the presence of the organic acids. Ni adsorption mechanisms transitioned from binding above vacancy sites to at sheet edges in the presence of citrate and 4-hydroxybenzoate, while oxalate increased binding above and in vacancy sites; citrate inhibited Ni incorporation into vacancies. Zn adsorption also transitioned to binding at weaker sites on the particle edges. The adsorption behaviors of Ni and Zn suggest that during reaction with organic acids, phyllomanganate mineral reactivities towards metals are altered by organic acids via a decrease in the vacancy content of Mn oxides. This work improves our understanding of the effect of Fe and Mn oxides in soils and aquatic systems on micronutrient availability and heavy metals sequestration. Oxalate largely enhances trace metal mobility through multiple processes occurring in solution and on Fe oxide surfaces. Similarly, phyllomanganates structural changes in the presence of oxalic, citric, and 4-hydroxybenzoate alter the reactivity of Mn oxides through Mn reduction and subtle structural changes. Overall, this dissertation demonstrates that complex interactions at Fe and Mn oxide surfaces with organic acids must be considered when evaluating micronutrient availability and contaminant sequestration in the environment.
Download or read book California Geology written by and published by . This book was released on 1990 with total page 596 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sulfur Biogeochemistry written by Jan P. Amend and published by Geological Society of America. This book was released on 2004 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Index to American Doctoral Dissertations written by and published by . This book was released on 1986 with total page 606 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Geochemical Transformations of Sedimentary Sulfur written by Murthy A. Vairavamurthy and published by . This book was released on 1995 with total page 596 pages. Available in PDF, EPUB and Kindle. Book excerpt: Offers a comprehensive discussion of the geochemistry of sedimentary sulfur, including low temperature transformation in early diagenesis, thermal reactions occurring during later diagenesis and catagenesis. Provides a detailed examination of sulfur-organic matter interactions. Presents an interdisciplinary overview of recent research in the complex process of sedimentary sulfur transformations. Includes contributions from internationally recognized experts in the field.
Download or read book Index to Graduate Theses and Dissertations on California Geology 1973 1989 written by and published by . This book was released on 1978 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Oxidation of Sulfur IV in Natural Waters written by Philip James Kijak and published by . This book was released on 1987 with total page 372 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Preliminary Index to Graduate Theses and Dissertations on California Geology 1982 1988 written by and published by . This book was released on 1989 with total page 310 pages. Available in PDF, EPUB and Kindle. Book excerpt:
