Download or read book Biogeochemical Controls on Methylmercury Production in a Northern Wisconsin Wetland written by Joel Creswell and published by . This book was released on 2011 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effects of Salinity on Biogeochemical Processes and Methylmercury Production in Freshwater Wetland Sediments written by and published by . This book was released on 2008 with total page 61 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Control of Mercury Methylation in Wetlands Through Iron Addition written by David L. Sedlak and published by . This book was released on 2009 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sediment Methylmercury Concentrations and Production Rates in Coastal Wetlands of Chequamegon Bay WI Lake Superior written by Jacob Ogorek and published by . This book was released on 2009 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mercury in Lake Superior is understudied, and (1) geochemical factors in sediments that influence sedimentary methylmercury concentrations and (2) key habitats for methylmercury production are unclear. The primary methylmercury source in aquatic systems is typically inorganic mercury methylation by sulfate reducing bacteria (SRB). Mercury methylation is generally greatest in wetland sediments, and is mediated by inorganic mercury bioavailability and SRB activity, both of which are strongly influenced by sulfidic compounds and organic matter. We hypothesize that Lake Superior coastal wetlands are important sites for methylmercury production, and sediment methylmercury correlates with sedimentary geochemical factors such as inorganic mercury, sulfide/sulfate, organic matter, and mercury methylation potential. We measured sediment methyl and total mercury concentrations, mercury methylation potential (via isotopic mercury additions), organic matter, sulfide, and sulfate in three coastal wetlands (two of which are located at the mouth of a tributary) and one open-water site in Chequamegon Bay (Lake Superior). Sediment mercury levels were relatively low, with the highest concentrations measured in coastal wetlands, particularly when associated with a tributary. We found methylmercury levels were correlated with multiple geochemical parameters, and it appears that sediment organic matter is the primary driving force of SRB activities leading to methylmercury production.
Download or read book Hydrological and Biogeochemical Controls on Mercury Fate and Transport in a Southern Ontario Forested Wetland written by Maggie Young and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This study assessed linkages between wetland hydrology, total mercury (HgT) and methylmercury (MeHg) fate and transport in Beverly Swamp, a forested swamp in southern Ontario, Canada. The hydrologically distinct wetland reaches exhibited differences in wetland-stream connectivity. Confined reaches showed little interaction with the wetland during low water levels, but there was hydrological and biogeochemical evidence of increased interaction at high flow. The unconfined reach showed disconnected, effluent flow during periods of high flow, and an influent regime during low flow. HgT flux in both reaches was highest during connected flow. Increased flux of McHg in the confined reaches was found during high flow, high water table connected periods due to decreasing redox and soil flushing. The unconfined reach showed no relationship between McHg and discharge due to periods of flow cessation and localized McHg production in-stream. Overall, the wetland is a sink for HgT and a source for McHg.
Download or read book Methylmercury in Managed Wetlands written by Rachel Jean Strickman and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Methylmercury (MeHg), a bioaccumulative neurotoxin, is microbially produced in anoxic wetland environments. The direct or indirect management of wetlands is pervasive, but many questions remain regarding the impact of wetland management on MeHg biogeochemistry. To address this, I investigated the extent, drivers, and consequences of MeHg production in important types of managed wetlands, as well as the response of MeHg to specific management interventions. In a field study which simulated industrial increases and legislated decreases in sulfate deposition to peatlands, I found evidence that MeHg production in peatlands is quantitatively related to sulfate-mediated changes in the community structure of the Deltaproteobacteria, rather than simple metabolic stimulation of sulfate-reducing bacteria (SRB), one in the best studied groups of mercury methylators. Furthermore, the structure of the bacterial community, as well as MeHg accumulation, was resilient to the end of sulfate amendments, demonstrating the value of this management intervention. In a series of observational biogeochemical field studies in artificial wetlands, I found similar evidence that the wetland microflora was resilient to the disturbance of wetland dredging, which only temporarily reduced MeHg production and concentrations. Methylmercury production in stormwater wetlands was carried out by SRB, with their activity modulated by availability of inorganic mercury, labile and total organic carbon, and competition with nitrate reducers. MeHg production in stormwater wetlands was overall dampened in comparison to those managed for habitat provision. Finally, I used a controlled greenhouse experiment to study the source of MeHg and IHg to paddy grown rice, a staple food recently shown to be a significant dietary source of MeHg to some populations. I confirmed the soil origin of MeHg to rice grains, and identified a window of elevated MeHg uptake during vegetated growth. Inorganic mercury, by contrast, appears to derive from the atmosphere alone, presenting challenges in controlling its concentrations in rice.
Download or read book Proceedings and Summary Report written by and published by . This book was released on 2002 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Biogeochemistry of Wetlands written by K. Ramesh Reddy and published by CRC Press. This book was released on 2022-09-10 with total page 926 pages. Available in PDF, EPUB and Kindle. Book excerpt: The globally important nature of wetland ecosystems has led to their increased protection and restoration as well as their use in engineered systems. Underpinning the beneficial functions of wetlands are a unique suite of physical, chemical, and biological processes that regulate elemental cycling in soils and the water column. This book provides an in-depth coverage of these wetland biogeochemical processes related to the cycling of macroelements including carbon, nitrogen, phosphorus, and sulfur, secondary and trace elements, and toxic organic compounds. In this synthesis, the authors combine more than 100 years of experience studying wetlands and biogeochemistry to look inside the black box of elemental transformations in wetland ecosystems. This new edition is updated throughout to include more topics and provide an integrated view of the coupled nature of biogeochemical cycles in wetland systems. The influence of the elemental cycles is discussed at a range of scales in the context of environmental change including climate, sea level rise, and water quality. Frequent examples of key methods and major case studies are also included to help the reader extend the basic theories for application in their own system. Some of the major topics discussed are: Flooded soil and sediment characteristics Aerobic-anaerobic interfaces Redox chemistry in flooded soil and sediment systems Anaerobic microbial metabolism Plant adaptations to reducing conditions Regulators of organic matter decomposition and accretion Major nutrient sources and sinks Greenhouse gas production and emission Elemental flux processes Remediation of contaminated soils and sediments Coupled C-N-P-S processes Consequences of environmental change in wetlands# The book provides the foundation for a basic understanding of key biogeochemical processes and its applications to solve real world problems. It is detailed, but also assists the reader with box inserts, artfully designed diagrams, and summary tables all supported by numerous current references. This book is an excellent resource for senior undergraduates and graduate students studying ecosystem biogeochemistry with a focus in wetlands and aquatic systems.
Download or read book Environmental chemistry of mercury Sources pathways transformations and impact written by Ashu Dastoor and published by Frontiers Media SA. This book was released on 2024-01-29 with total page 149 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 361 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mercury pollution and contamination are widespread, well documented, and continue to pose a public health concern in both developed and developing countries. In response to a growing need for understanding the cycling of this ubiquitous pollutant, the science of mercury has grown rapidly to include the fields of biogeochemistry, economics, sociology, public health, decision sciences, physics, global change, and mathematics. Only recently have scientists begun to establish a holistic approach to studying mercury pollution that integrates chemistry, biology, and human health sciences. Mercury in the Environment follows the process of mercury cycling through the atmosphere, through terrestrial and aquatic food webs, and through human populations to develop a comprehensive perspective on this important environmental problem. This timely reference also provides recommendations on mercury remediation, risk communication, education, and monitoring.
Download or read book Early Diagenesis written by Robert A. Berner and published by Princeton University Press. This book was released on 1980-08-21 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses mainly on the chemical composition of interstitial waters of sediments. Chapter 2 presents the basic theory used throughout the rest of the book in terms of a general diagenetic equation. Chapters 3,4,and 5 provides detailed discussion of each of the terms in general diagenetic equation as well as presentations of data. Chapters 6,7 and 8 gives examples of diagenetic calculation using the theory developed earlier.
Download or read book Mercury as a Global Pollutant written by Donald B. Porcella and published by Springer. This book was released on 2014-08-23 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: ACKNOWLEDGEMENTS xiv PART I MERCURY AND HUMAN HEALTH B. WHEATLEY and S. PARADIS I Exposure of Canadian Aboriginal Peoples to Methylmercury 3-11 M. GIRARD and C. DUMONT I Exposure of James Bay Cree to Methylmercury during Pregnancy for the Years 1983-91 13-19 M. RICHARDSON, M. MITCHELL, S. COAD and R. RAPHAEL I Exposure to Mercury in Canada: A Multimedia Analysis 21-30 M. RICHARDSON, M. EGYED and D. J. CURRIE I Human Exposure to Mercury may Decrease as Acidic Deposition Increases 31-39 L. E. FLEMING, S. WATKINS, R. KADERMAN, B. LEVIN, D. R. AVYAR, M. BIZZIO, D. STEPHENS and J. A. BEAN I Mercury Exposure in Humans through Food Consumption from the Everglades of Florida 41-48 J. M. GEARHART, H. J. CLEWELL III, K. S. CRUMP, A. M. SHIPP and A. SILVERS I Pharmacokinetic Dose Estimates of Mercury in Children and Dose-Response Curves of Performance Tests in a Large Epidemiological Study 49-58 I. SKARE I Mass Balance and Systemic Uptake of Mercury Released from Dental Amalgam Fillings 59-67 J. DELLINGER, N. KMIECIK, S. GERSTENBERGER and H. NGU I Mercury Contamina tion of Fish in the Ojibwa Diet: I. Walleye Fillets and Skin-On versus Skin-Off Sampling 69-76 J. DELLINGER, L. MALEK and M. BEATTIE I Mercury Contamination of Fish in the Ojibwa Diet: II. Sensory Evoked Responses in Rats Fed Walleye 77-83 H. AKAGI, O. MALM, F. J. P. BRANCHES, Y. KINJO, Y. KASHIMA, J. R. D. GUIMARAES, R. B. OLIVEIRA, K. HARAGUCHI, W. C. PFEIFFER, Y.
Download or read book Forest and Rangeland Soils of the United States Under Changing Conditions written by Richard V. Pouyat and published by Springer Nature. This book was released on 2020-09-02 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt: This open access book synthesizes leading-edge science and management information about forest and rangeland soils of the United States. It offers ways to better understand changing conditions and their impacts on soils, and explores directions that positively affect the future of forest and rangeland soil health. This book outlines soil processes and identifies the research needed to manage forest and rangeland soils in the United States. Chapters give an overview of the state of forest and rangeland soils research in the Nation, including multi-decadal programs (chapter 1), then summarizes various human-caused and natural impacts and their effects on soil carbon, hydrology, biogeochemistry, and biological diversity (chapters 2–5). Other chapters look at the effects of changing conditions on forest soils in wetland and urban settings (chapters 6–7). Impacts include: climate change, severe wildfires, invasive species, pests and diseases, pollution, and land use change. Chapter 8 considers approaches to maintaining or regaining forest and rangeland soil health in the face of these varied impacts. Mapping, monitoring, and data sharing are discussed in chapter 9 as ways to leverage scientific and human resources to address soil health at scales from the landscape to the individual parcel (monitoring networks, data sharing Web sites, and educational soils-centered programs are tabulated in appendix B). Chapter 10 highlights opportunities for deepening our understanding of soils and for sustaining long-term ecosystem health and appendix C summarizes research needs. Nine regional summaries (appendix A) offer a more detailed look at forest and rangeland soils in the United States and its Affiliates.
Download or read book Biogeochemistry of Environmentally Important Trace Elements written by Yong Cai and published by . This book was released on 2003 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt: Biogeochemistry of Environmentally Important Trace Elements discusses fate, transport, and transformation in soils, waters, and plants in biogeochemistry of environmentally important trace elements, with a focus on arsenic, mercury, and selenium.
Download or read book Nonpoint Source News notes written by and published by . This book was released on 2004 with total page 538 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Successes Limitations and Frontiers in Ecosystem Science written by Michael L. Pace and published by Springer Science & Business Media. This book was released on 2013-12-01 with total page 515 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ecosystem research has emerged in recent decades as a vital, successful, and sometimes controversial approach to environmental science. This book emphasizes the idea that much of the progress in ecosystem research has been driven by the emergence of new environmental problems that could not be addressed by existing approaches. By focusing on successes and limitations of ecosystems studies, the book explores avenues for future ecosystem-level research.
Download or read book Spring Meeting written by American Geophysical Union. Meeting and published by . This book was released on 1998 with total page 476 pages. Available in PDF, EPUB and Kindle. Book excerpt:
