Download or read book Photochemically Induced Changes in the Optical Properties of Chromophoric Dissolved Organic Matter CDOM in Rainwater electronic Resource written by Mary Beth Adams and published by . This book was released on 2010 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Direct and Indirect Photoreactions of Chromophoric Dissolved Organic Matter written by Jared Verrill Goldstone and published by . This book was released on 2002 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt: Photochemical transformations of chromophoric dissolved organic matter (CDOM) are one of the principal processes controlling its fate in coastal waters. The photochemical decomposition of CDOM leads to the formation of a variety of biologically available carbon substrates. Photomineralization of CDOM to dissolved inorganic carbon may constitute a significant flux in the global carbon cycle. Photoreactions ultimately lead to the destruction of the chromophores and hence to the loss of absorption and fluorescence (bleaching), thus acting as a sink for CDOM. Photodecomposition may proceed both via direct photochemical reactions, following absorption of photons by CDOM, or via indirect processes, involving DOM reactions with photochemically generated intermediates such as reactive oxygen species (ROS). The reactions of CDOM with two important ROS, superoxide (02- ) and hydroxyl radical (OH), have different consequences. Superoxide reactions with CDOM did not appear to degrade the CDOM. Instead, CDOM catalysed the dismutation of 02- to 02 and HOOH. This reactivity has the effect of limiting the steady-state concentration of 02- in most coastal waters. In contrast, reactions of CDOM with radiolytically produced OH formed CO2 and several low molecular weight carboxylic acids, as well as bleached both the absorption and fluorescence at slow rates. These reactions did not increase the bioavailability of this material to a microbial consortium. Both direct and indirect photochemical processes are expected to be accelerated by the presence of iron.
Download or read book Chromophoric Dissolved Organic Matter in Coastal Rainwater written by Seth Neil Reid and published by . This book was released on 2003 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Chromophoric Dissolved Organic Matter in Coastal Rainwater written by Kelly Jo Gordon and published by . This book was released on 2007 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Biogeochemical and Photochemical Dynamics of Oceanic Chromophoric Dissolved Organic Matter written by Chantal Melanie Swan and published by . This book was released on 2009 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt: Absorption by open-ocean chromophoric dissolved organic matter (CDOM), the optically-active fraction of the marine DOM pool (
Download or read book Optical absorption and fluorescence properties of chromophoric dissolved organic matter in natural waters written by S.A. GREEN and published by . This book was released on 1994 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Characterization of Chromophoric Dissolved Organic Matter with Iron Chelates in Rain Water written by Lorri Resetar and published by . This book was released on 2005 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Transport and Transformation of Chromophoric Dissolved Organic Matter CDOM from Land to Ocean written by Wei Huang and published by . This book was released on 2010 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Chromophoric Dissolved Organic Matter CDOM in Natural Waters written by Rossana Del Vecchio and published by . This book was released on 2002 with total page 482 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Characterization and Optical Properties of Colored Dissolved Organic Matter During the Coastal Mixing Optics Experiment Using in Situ and Discrete Sampling Methods written by Robyn Nicole Conmy and published by . This book was released on 1999 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Photochemistry of Dissolved Organic Matter written by Stephen Andrew Timko and published by . This book was released on 2014 with total page 145 pages. Available in PDF, EPUB and Kindle. Book excerpt: Constructed wetlands have the potential to provide low-energy treatment of pharmaceuticals and other micropollutants via photolysis. Natural dissolved organic matter (DOM) reacts with sunlight to produce reactive species such as singlet oxygen and excited triplet states of DOM that react quickly and efficiently with contaminants. To study the photo-chemistry of DOM, a unique solar-simulation system was developed, allowing for semi-continuous monitoring of absorbance and fluorescence spectra throughout the irradiation. This system was utilized to investigate the effect of solution pH on the fluorescence properties and degradation of DOM. For the first time, parallel factor (PARAFAC) analysis was utilized to deconvolute photo-labile, photo-stable, and pH- dependent fluorescent components during irradiation. Fluorescence is highly pH dependent, and as pH increases, the total amount of fluorescence loss, and the rate at which it is lost, increases significantly. This has important implications in treatment systems, as the photo-reactivity of DOM will change when pH gradients or fluctuations are observed. The photo-degradation of organic matter collected from a depth profile (0-4,500 m) the Sargasso Sea showed increased reactivity with increasing depth. Ultra-high resolution mass spectrometry (FT-MS) was used to characterize the samples, and correlation analyses between the fluorescence data and mass spectra revealed that high molecular weight, aromatic, and possibly polyphenolic compounds are contributing the most to the fluorescence properties that show the most reactivity in marine samples.Production of singlet oxygen, hydroxyl radical, and triplet excited states of DOM along two riverine transects in the Everglades were measured. The abundance of fluorescence PARAFAC components was compared to the reactive species production, and suggested that terrestrial organic matter may be more efficient producers of reactive species than microbial- or seagrass- derived organic matter.Finally, the relationship between optical properties of DOM samples collected around the world and their reactivity were investigated. Photo-irradiations and pH titrations were performed on all samples, and mass spectra collected via FT-MS. Humification indices, the biological index (BIX), and spectral slope from 275-295 nm were found to be most closely tied to changes in the mass spectra of the samples, and showed strong relationship to DOM source.
Download or read book Remote Sensing of Chromophoric Dissolved Organic Matter by Ocean Color Radiometers Calibrated by Laser induced Fluorescence written by Luca Fiorani and published by . This book was released on 2005 with total page 25 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Subsea Optics and Imaging written by John Watson and published by Elsevier. This book was released on 2013-10-31 with total page 615 pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of optical methodology, instrumentation and photonics devices for imaging, vision and optical sensing is of increasing importance in understanding our marine environment. Subsea optics can make an important contribution to the protection and sustainable management of ocean resources and contribute to monitoring the response of marine systems to climate change. This important book provides an authoritative review of key principles, technologies and their applications. The book is divided into three parts. The first part provides a general introduction to the key concepts in subsea optics and imaging, imaging technologies and the development of ocean optics and colour analysis. Part two reviews the use of subsea optics in environmental analysis. An introduction to the concepts of underwater light fields is followed by an overview of coloured dissolved organic matter (CDOM) and an assessment of nutrients in the water column. This section concludes with discussions of the properties of subsea bioluminescence, harmful algal blooms and their impact and finally an outline of optical techniques for studying suspended sediments, turbulence and mixing in the marine environment. Part three reviews subsea optical systems technologies. A general overview of imaging and visualisation using conventional photography and video leads onto advanced techniques like digital holography, laser line-scanning and range-gated imaging as well as their use in controlled observation platforms or global observation networks. This section also outlines techniques like Raman spectroscopy, hyperspectral sensing and imaging, laser Doppler anemometry (LDA) and particle image velocimetry (PIV), optical fibre sensing and LIDAR systems. Finally, a chapter on fluorescence methodologies brings the volume to a close. With its distinguished editor and international team of contributors, Subsea optics and imaging is a standard reference for those researching, developing and using subsea optical technologies as well as environmental scientists and agencies concerned with monitoring the marine environment. Provides an authoritative review of key principles, technologies and their applications Outlines the key concepts in subsea optics and imaging, imaging technologies and the development of ocean optics and colour analysis Reviews the properties of subsea bioluminescence, harmful algal blooms and their impact
Download or read book Acid Rain Deposition to Recovery written by Peter Brimblecombe and published by Springer Science & Business Media. This book was released on 2007-12-11 with total page 405 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book looks at the sources and composition of the atmosphere and rainfall, with particular attention on acidifying components and those that affect ecosystems. It further widens the subject to look at trace metals. It includes papers on the impact of deposition on soils and forests and the recovery of the natural environment. Work on critical loads makes a contribution to understanding the degree to which deposition must be reduced to limit its impact.
Download or read book UV Effects in Aquatic Organisms and Ecosystems written by E Walter Helbling and published by Royal Society of Chemistry. This book was released on 2007-10-31 with total page 600 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book offers extensive coverage of the most important aspects of UVR effects on all aquatic (not just freshwater and marine) ecosystems, encompassing UV physics, chemistry, biology and ecology. Comprehensive and up-to-date, UV Effects in Aquatic Organisms and Ecosystems aims to bridge the gap between environmental studies of UVR effects and the broader, traditional fields of ecology, oceanography and limnology. Adopting a synthetic approach, the different sections cover: the physical factors controlling UVR intensity in the atmosphere; the penetration and distribution of solar radiation in natural waters; the main photochemical process affecting natural and anthropogenic substances; and direct and indirect effects on organisms (from viruses, bacteria and algae to invertebrate and vertebrate consumers). Researchers and professionals in environmental chemistry, photochemistry, photobiology and cell and molecular biology will value this book, as will those looking at ozone depletion and global change.
Download or read book Advanced Oxidation Processes for Water Treatment written by Mihaela I. Stefan and published by IWA Publishing. This book was released on 2017-09-15 with total page 712 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advanced Oxidation Processes (AOPs) rely on the efficient generation of reactive radical species and are increasingly attractive options for water remediation from a wide variety of organic micropollutants of human health and/or environmental concern. Advanced Oxidation Processes for Water Treatment covers the key advanced oxidation processes developed for chemical contaminant destruction in polluted water sources, some of which have been implemented successfully at water treatment plants around the world. The book is structured in two sections; the first part is dedicated to the most relevant AOPs, whereas the topics covered in the second section include the photochemistry of chemical contaminants in the aquatic environment, advanced water treatment for water reuse, implementation of advanced treatment processes for drinking water production at a state-of-the art water treatment plant in Europe, advanced treatment of municipal and industrial wastewater, and green technologies for water remediation. The advanced oxidation processes discussed in the book cover the following aspects: - Process principles including the most recent scientific findings and interpretation. - Classes of compounds suitable to AOP treatment and examples of reaction mechanisms. - Chemical and photochemical degradation kinetics and modelling. - Water quality impact on process performance and practical considerations on process parameter selection criteria. - Process limitations and byproduct formation and strategies to mitigate any potential adverse effects on the treated water quality. - AOP equipment design and economics considerations. - Research studies and outcomes. - Case studies relevant to process implementation to water treatment. - Commercial applications. - Future research needs. Advanced Oxidation Processes for Water Treatment presents the most recent scientific and technological achievements in process understanding and implementation, and addresses to anyone interested in water remediation, including water industry professionals, consulting engineers, regulators, academics, students. Editor: Mihaela I. Stefan - Trojan Technologies - Canada
Download or read book Ecological Stoichiometry written by Robert W. Sterner and published by Princeton University Press. This book was released on 2017-02-15 with total page 465 pages. Available in PDF, EPUB and Kindle. Book excerpt: All life is chemical. That fact underpins the developing field of ecological stoichiometry, the study of the balance of chemical elements in ecological interactions. This long-awaited book brings this field into its own as a unifying force in ecology and evolution. Synthesizing a wide range of knowledge, Robert Sterner and Jim Elser show how an understanding of the biochemical deployment of elements in organisms from microbes to metazoa provides the key to making sense of both aquatic and terrestrial ecosystems. After summarizing the chemistry of elements and their relative abundance in Earth's environment, the authors proceed along a line of increasing complexity and scale from molecules to cells, individuals, populations, communities, and ecosystems. The book examines fundamental chemical constraints on ecological phenomena such as competition, herbivory, symbiosis, energy flow in food webs, and organic matter sequestration. In accessible prose and with clear mathematical models, the authors show how ecological stoichiometry can illuminate diverse fields of study, from metabolism to global change. Set to be a classic in the field, Ecological Stoichiometry is an indispensable resource for researchers, instructors, and students of ecology, evolution, physiology, and biogeochemistry. From the foreword by Peter Vitousek: ? "[T]his book represents a significant milestone in the history of ecology. . . . Love it or argue with it--and I do both--most ecologists will be influenced by the framework developed in this book. . . . There are points to question here, and many more to test . . . And if we are both lucky and good, this questioning and testing will advance our field beyond the level achieved in this book. I can't wait to get on with it."
