Download or read book The Influence of Dissolved Organic Matter Composition on Its Reactivity in Natural and Engineered Systems written by Reid Milstead and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dissolved organic matter (DOM) is a complex heterogeneous mixture of organic compounds that is found in all water systems. DOM is derived from both terrestrial and microbial sources. The composition of DOM can vary greatly depending on a number of variables, including time of year, surrounding groundcover type, and water column depth. The characterization of DOM composition is increasingly performed using high-resolution mass spectrometry, although different instrumentation and techniques may yield different results. Importantly, DOM plays a key role in a number of chemical processes in both natural and engineered systems, such as the generation of carbon dioxide (CO2) from surface waters, the degradation of aquatic contaminants, and the formation of disinfection byproducts (DBPs) during drinking water treatment. The composition of DOM determines its reactivity in all of these processes. Using both bulk and high-resolution analytical techniques, the photooxidation of DOM can be explored. DOM compounds that are more oxidized and aromatic tend to be associated with the consumption of oxygen and the production of CO2. Bulk scale measurements show that DOM becomes less aromatic and lower in molecular weight as a result of partial photooxidation. High-resolution mass spectrometry also provides evidence of oxygen addition and the loss of CO2 from DOM during irradiation experiments. However, the chemical formulas that are most photolabile vary depending on the initial composition of DOM. Using light exposure experiments the kinetics of degradation of four contaminants were quantified for a large set of diverse waters. Using this information, we evaluated the relationships between indirect photolysis rate constants and the formation of photochemically produced reactive intermediates (PPRI) using linear regression analysis. Additionally, quencher experiments were performed to identify the PPRI associated with the degradation of each contaminant in all waters. Triplet state DOM (3DOM) and singlet oxygen (1O2) were identified as critical for atorvastatin, carbamazepine, and sulfadiazine, while hydroxyl radical (•OH) is important for benzotriazole. Our results suggest that quenching experiments should be used with caution due to the non-targeted nature of quenching compounds and the interconnection of PPRI. All of these factors result in probe compounds possibly overstating the importance of PPRI in the indirect photolysis of common contaminants. The characterization of DOM in drinking waters reveals a high degree of variability in DOM composition and reactivity with chlorine, particularly in groundwater samples. Despite the variability in DOM composition, novel DBPs with up to three halogen substituents are compositionally similar among all waters. These novel DBPs are positively correlated with trihalomethane and, to a lesser extent, the formation of haloacetonitriles. This suggests that some low molecular weight DBPs and novel DBPs detected via high-resolution mass spectrometry share similar aromatic precursors, providing evidence that low molecular weight DBPs are useful proxies for the formation of unknown, unidentified high molecular weight DBPs. Compared to Fourier transform-ion cyclotron resonance mass spectrometry (FT-ICR MS), Orbitrap MS yields significantly fewer formula matches and appears to have a bias towards sulfur-containing formulas and against nitrogen-containing formulas. Additionally, the choice of calibration method is particularly important for the less powerful Orbitrap MS. The matched formulas yielded from Orbitrap MS tend to be more oxidized and less highly saturated than those yielded by FT-ICR MS. Despite these differences, the formulas produced by both instruments tend to yield similar relative differences between samples, suggesting that Orbitrap MS is an acceptable replacement for FT-ICR MS in some cases.
Download or read book The Influence of Dissolved Organic Matter Composition on Its Reactivity in Natural and Engineered Systems written by Reid Milstead and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dissolved organic matter (DOM) is a complex heterogeneous mixture of organic compounds that is found in all water systems. DOM is derived from both terrestrial and microbial sources. The composition of DOM can vary greatly depending on a number of variables, including time of year, surrounding groundcover type, and water column depth. The characterization of DOM composition is increasingly performed using high-resolution mass spectrometry, although different instrumentation and techniques may yield different results. Importantly, DOM plays a key role in a number of chemical processes in both natural and engineered systems, such as the generation of carbon dioxide (CO2) from surface waters, the degradation of aquatic contaminants, and the formation of disinfection byproducts (DBPs) during drinking water treatment. The composition of DOM determines its reactivity in all of these processes. Using both bulk and high-resolution analytical techniques, the photooxidation of DOM can be explored. DOM compounds that are more oxidized and aromatic tend to be associated with the consumption of oxygen and the production of CO2. Bulk scale measurements show that DOM becomes less aromatic and lower in molecular weight as a result of partial photooxidation. High-resolution mass spectrometry also provides evidence of oxygen addition and the loss of CO2 from DOM during irradiation experiments. However, the chemical formulas that are most photolabile vary depending on the initial composition of DOM. Using light exposure experiments the kinetics of degradation of four contaminants were quantified for a large set of diverse waters. Using this information, we evaluated the relationships between indirect photolysis rate constants and the formation of photochemically produced reactive intermediates (PPRI) using linear regression analysis. Additionally, quencher experiments were performed to identify the PPRI associated with the degradation of each contaminant in all waters. Triplet state DOM (3DOM) and singlet oxygen (1O2) were identified as critical for atorvastatin, carbamazepine, and sulfadiazine, while hydroxyl radical (•OH) is important for benzotriazole. Our results suggest that quenching experiments should be used with caution due to the non-targeted nature of quenching compounds and the interconnection of PPRI. All of these factors result in probe compounds possibly overstating the importance of PPRI in the indirect photolysis of common contaminants. The characterization of DOM in drinking waters reveals a high degree of variability in DOM composition and reactivity with chlorine, particularly in groundwater samples. Despite the variability in DOM composition, novel DBPs with up to three halogen substituents are compositionally similar among all waters. These novel DBPs are positively correlated with trihalomethane and, to a lesser extent, the formation of haloacetonitriles. This suggests that some low molecular weight DBPs and novel DBPs detected via high-resolution mass spectrometry share similar aromatic precursors, providing evidence that low molecular weight DBPs are useful proxies for the formation of unknown, unidentified high molecular weight DBPs. Compared to Fourier transform-ion cyclotron resonance mass spectrometry (FT-ICR MS), Orbitrap MS yields significantly fewer formula matches and appears to have a bias towards sulfur-containing formulas and against nitrogen-containing formulas. Additionally, the choice of calibration method is particularly important for the less powerful Orbitrap MS. The matched formulas yielded from Orbitrap MS tend to be more oxidized and less highly saturated than those yielded by FT-ICR MS. Despite these differences, the formulas produced by both instruments tend to yield similar relative differences between samples, suggesting that Orbitrap MS is an acceptable replacement for FT-ICR MS in some cases.
Download or read book Advances in the Physicochemical Characterization of Dissolved Organic Matter written by Fernando Rosario-Ortiz and published by ACS Symposium. This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The study of dissolved organic matter (DOM) has fascinated scientists and engineers for at least 60 years - from the initial efforts focused on measuring the concentrations of carbon in marine and aquatic systems, to the discovery of the role of DOM in the formation of disinfection byproducts, all the way to the new emphasis on the detailed understanding of the different functional groups and basic structural features which are the basis for the physicochemical properties of the material. After 50 years of work in the area, there are still many questions regarding DOM. The study of dissolved organic matter (DOM) has fascinated researchers in different fields of science and engineering for many decades. The impact that DOM has on a wide array of environmental processes has resulted in the development of a multidisciplinary community of researchers all focusing on using different analytical techniques and experimental design to better understand DOM. This book offers select case studies focusing on the advanced characterization of DOM in different environments and with respect to different processes. It results from the conclusion of a symposium that E. M. Thurman and I had organized for the 245th meeting of the American Chemical Society, which was held on April 7-11, 2013 in New Orleans, Louisiana.
Download or read book Biophysico Chemical Processes Involving Natural Nonliving Organic Matter in Environmental Systems written by Nicola Senesi and published by John Wiley & Sons. This book was released on 2009-07-23 with total page 905 pages. Available in PDF, EPUB and Kindle. Book excerpt: An up-to-date resource on natural nonliving organic matter Bringing together world-renowned researchers to explore natural nonliving organic matter (NOM) and its chemical, biological, and ecological importance, Biophysico-Chemical Processes Involving Natural Nonliving Organic Matter in Environmental Systems offers an integrated view of the dynamics and processes of NOM. This multidisciplinary approach allows for a comprehensive treatment encompassing all the formation processes, properties, reactions, environments, and analytical techniques associated with the latest research on NOM. After briefly outlining the historical background, current ideas, and future prospects of the study of NOM, the coverage examines: The formation mechanisms of humic substances Organo-clay complexes The effects of organic matter amendment Black carbon in the environment Carbon sequestration and dynamics in soil Biological activities of humic substances Dissolved organic matter Humic substances in the rhizosphere Marine organic matter Organic matter in atmospheric particles In addition to the above topics, the coverage includes such relevant analytical techniques as separation technology; analytical pyrolysis and soft-ionization mass spectrometry; nuclear magnetic resonance; EPR, FTIR, Raman, UV-visible adsorption, fluorescence, and X-ray spectroscopies; and thermal analysis. Hundreds of illustrations and photographs further illuminate the various chapters. An essential resource for both students and professionals in environmental science, environmental engineering, water science, soil science, geology, and environmental chemistry, Biophysico-Chemical Processes Involving Natural Nonliving Organic Matter in Environmental Systems provides a unique combination of the latest discoveries, developments, and future prospects in this field.
Download or read book Advances in Understanding the Molecular Composition of Dissolved Organic Matter and Its Reactivity in the Environment written by Rajaa Mesfioui and published by . This book was released on 2014 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Linking Optical and Chemical Properties of Dissolved Organic Matter in Natural Waters written by Christopher L. Osburn and published by Frontiers Media SA. This book was released on 2017-01-17 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt: A substantial increase in the number of studies using the optical properties (absorbance and fluorescence) of dissolved organic matter (DOM) as a proxy for its chemical properties in estuaries and the coastal and open ocean has occurred during the last decade. We are making progress on finding the actual chemical compounds or phenomena responsible for DOM’s optical properties. Ultrahigh resolution mass spectrometry, in particular, has made important progress in making the key connections between optics and chemistry. But serious questions remain and the last major special issue on DOM optics and chemistry occurred nearly 10 years ago. Controversies remain from the non-specific optical properties of DOM that are not linked to discrete sources, and sometimes provide conflicting information. The use of optics, which is relatively easier to employ in synoptic and high resolution sampling to determine chemistry, is a critical connection to make and can lead to major advances in our understanding of organic matter cycling in all aquatic ecosystems. The contentions and controversies raised by our poor understanding of the linkages between optics and chemistry of DOM are bottlenecks that need to be addressed and overcome.
Download or read book Reactive Transport in Natural and Engineered Systems written by Jennifer Druhan and published by Walter de Gruyter GmbH & Co KG. This book was released on 2020-03-04 with total page 514 pages. Available in PDF, EPUB and Kindle. Book excerpt: Open system behavior is predicated on a fundamental relationship between the timescale over which mass is transported and the timescale over which it is chemically transformed. This relationship describes the basis for the multidisciplinary field of reactive transport (RT). In the 20 years since publication of Review in Mineralogy and Geochemistry volume 34: Reactive Transport in Porous Media, RT principles have expanded beyond early applications largely based in contaminant hydrology to become broadly utilized throughout the Earth Sciences. RT is now employed to address a wide variety of natural and engineered systems across diverse spatial and temporal scales, in tandem with advances in computational capability, quantitative imaging and reactive interface characterization techniques. The present volume reviews the diversity of reactive transport applications developed over the past 20 years, ranging from the understanding of basic processes at the nano- to micrometer scale to the prediction of Earth global cycling processes at the watershed scale. Key areas of RT development are highlighted to continue advancing our capabilities to predict mass and energy transfer in natural and engineered systems.
Download or read book Relating Dissolved Organic Matter Composition and Photochemistry with High Resolution Mass Spectrometry written by Andrew Chapin Maizel and published by . This book was released on 2017 with total page 301 pages. Available in PDF, EPUB and Kindle. Book excerpt: The irradiation of dissolved organic matter (DOM) produces reactive intermediates, such as excited triplet states of dissolved organic matter (3DOM), which contribute to the degradation of environmental contaminants. An understanding of how DOM composition determines the production of reactive intermediates is useful for predictions of contaminant fate and for relating the environmental processing of DOM to its photochemistry. To compare the reactivity of common 3DOM probe compounds, the photoreactivity of diverse, environmentally relevant waters was quantified with trans,trans-hexadienoic acid, 2,4,6-trimethylphenol, and furfuryl alcohol under ambient and standardized conditions. Measurements with each probe, including apparent quantum yields and pseudo-steady state concentrations, were found to exhibit unique sensitivities to variation in solution conditions. Comparisons of apparent quantum yields under standardized conditions suggest that the probe compounds each react with different 3DOM populations. 3DOM photoreactivity varies with molecular weight, but the underlying mechanisms are unclear. Therefore, the photochemistry and composition of ultrafiltration-fractionated fulvic acid isolates were compared with reactive intermediate probes compounds and Fourier transform-ion cyclotron resonance mass spectrometry (FT-ICR MS). Terrestrially derived DOM was increasingly aromatic with molecular weight, while microbially derived DOM was invariant. 3DOM pseudo-steady state concentrations decreased with molecular weight due to increased 3DOM quenching, rather than variation in 3DOM formation rates. In order to relate DOM processing in natural systems to altered composition and photoreactivity, DOM from related lakes of different trophic status was evaluated with FT-ICR MS and reactive intermediate probe compounds. The presence of highly aromatic formulas, similar to lignin and tannin, correlated with 3DOM formation and light absorbance. Conversely, aliphatic formulas correlated with enhanced 3DOM quantum yields and environmental persistence. To investigate the unique composition and photochemistry of DOM from aquatic microbial sources, DOM from a wastewater treatment plant was evaluated by FT-ICR MS and UV-visible spectroscopy. Wastewater DOM contained molecular formulas that were compositionally similar to lipids, proteins, carbohydrates, and lignin, and were enriched in heteroatoms such as N, S, P, and Cl. Secondary treatment increased highly aromatic formulas and increased the number of identified heteroatom containing formulas, while other treatment stages produced smaller changes in DOM composition.
Download or read book The Ethiopian Church written by and published by . This book was released on 197? with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Aquatic Organic Matter Fluorescence written by Paula G. Coble and published by Cambridge University Press. This book was released on 2014-07-14 with total page 407 pages. Available in PDF, EPUB and Kindle. Book excerpt: A core text on principles, laboratory/field methodologies, and data interpretation for fluorescence applications in aquatic science, for advanced students and researchers.
Download or read book Aquatic Redox Chemistry written by Paul Tratnyek and published by OUP USA. This book was released on 2012-06-14 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume provides a comprehensive overview of aquatic redox chemistry through chapters contributed by many of the leading investigators in the field.
Download or read book Spatiotemporal Variability in Dissolved Organic Matter Composition and Its Relationship to Photochemical Reactivity written by Stephanie Berg (Ph.D.) and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dissolved organic matter (DOM) is a ubiquitous group of biologically derived organic molecules found in all natural waters. DOM makes up a substantial amount of the carbon stored in surface waters, and its original sources include allochthonous, or terrestrial, inputs as well as autochthonous, or aquatic, inputs. It is primarily made of up small (i.e.,
Download or read book Adsorption of Dissolved Organic Matter in Aquatic Ecosystems written by and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Water Chemistry written by Patrick L. Brezonik and published by Oxford University Press. This book was released on 2022-06-15 with total page 977 pages. Available in PDF, EPUB and Kindle. Book excerpt: Water Chemistry provides students with the tools needed to understand the processes that control the chemical species present in waters of both natural and engineered systems. After providing basic information about water and its chemical composition in environmental systems, the text covers theoretical concepts key to solving water chemistry problems. Water Chemistry emphasizes that both equilibrium and kinetic processes are important in aquatic systems. The content focuses not only on inorganic constituents but also on natural and anthropogenic organic chemicals in water. This new edition of Water Chemistry also features updated discussions of photochemistry, chlorine and disinfectants, geochemical controls on chemical composition, trace metals, nutrients, and oxygen. Quantitative equilibrium and kinetic problems related to acid-base chemistry, complexation, solubility, oxidation/reduction reactions, sorption, and the fate and reactions of organic chemicals are solved using mathematical, graphical, and computational tools. Examples show the application of theory and demonstrate how to solve problems using algebraic, graphical, and up-to-date computer-based techniques. Additional web material provides advanced content.
Download or read book Soil and Water Pollution Monitoring Protection and Remediation written by Irena Twardowska and published by Springer Science & Business Media. This book was released on 2007-04-30 with total page 638 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book details the state-of-the art in early warning monitoring of anthropogenic pollution of soil and water. It is unique with regard to its complex, multidisciplinary, mechanistic approach. Top scientists establish links and strengthen weak connections between specific fields in biology, microbiology, chemistry, biochemistry, toxicology, sensoristics, soil science and hydrogeology.
Download or read book Towards an Understanding of Dissolved Organic Matter Molecular Composition and Reactivity in the Environment written by Barbara Cottrell and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Water Chemistry written by Patrick L. Brezonik and published by Oxford University Press. This book was released on 2022 with total page 977 pages. Available in PDF, EPUB and Kindle. Book excerpt: Water Chemistry provides students with the tools needed to understand the processes that control the chemical species present in waters of both natural and engineered systems. After providing basic information about water and its chemical composition in environmental systems, the text coverstheoretical concepts key to solving water chemistry problems.Water Chemistry emphasizes that both equilibrium and kinetic processes are important in aquatic systems. The content focuses not only on inorganic constituents but also on natural and anthropogenic organic chemicals in water. This new edition of Water Chemistry also features updated discussions ofphotochemistry, chlorine and disinfectants, geochemical controls on chemical composition, trace metals, nutrients, and oxygen.Quantitative equilibrium and kinetic problems related to acid-base chemistry, complexation, solubility, oxidation/reduction reactions, sorption, and the fate and reactions of organic chemicals are solved using mathematical, graphical, and computational tools. Examples show the application of theoryand demonstrate how to solve problems using algebraic, graphical, and up-to-date computer-based techniques. Additional web material provides advanced content.
