Preprints

Filtering by Subject: Environmental Chemistry

Sedimentary structures discriminations with hyperspectral imaging on sediment cores

Kévin Jacq, Rapuc William, Benoit Alexandre, Coquin Didier, Fanget Bernard, Yves Perrette, Pierre Sabatier, Wilhelm Bruno, Debret Maxime, Fabien Arnaud

Published: 2020-07-17
Subjects: Analytical Chemistry, Chemistry, Earth Sciences, Environmental Chemistry, Environmental Monitoring, Environmental Sciences, Multivariate Analysis, Optics, Physical Sciences and Mathematics, Physics, Sedimentology, Statistical Models, Statistics and Probability

Hyperspectral imaging (HSI) is a non-destructive high-resolution sensor, which is currently under significant development to analyze geological areas with remote devices or natural samples in a laboratory. In both cases, the hyperspectral image provides several sedimentary structures that need to be separated to temporally and spatially describe the sample. Sediment sequences are composed of [...]

Forecasting the localized bilateral effects of ocean acidification on the counter carbonate pump using recurrent neural networks

Eshan Ramesh

Published: 2020-07-08
Subjects: Artificial Intelligence and Robotics, Chemistry, Computer Sciences, Environmental Chemistry, Numerical Analysis and Scientific Computing, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics

The counter carbonate pump(CCP) is responsible for carbon dioxide sequestration and cycling forms of carbon in the ocean. It is primarily driven by calcifying plankton, such as foraminifera, coccolithophores, and pteropods. These organisms are particularly vulnerable to ocean acidification, which can have disastrous effects on their skeletons and productivity, upsetting the marine carbon cycle in [...]

Toward stable, general machine-learned models of the atmospheric chemical system

Makoto Kelp, Daniel J. Jacob, J. Nathan Kutz, Julian D. Marshall, Christopher W. Tessum

Published: 2020-03-23
Subjects: Artificial Intelligence and Robotics, Chemistry, Computer Sciences, Earth Sciences, Environmental Chemistry, Environmental Sciences, Physical Sciences and Mathematics

Atmospheric chemistry models—used as components in models that simulate air pollution and climate change—are computationally expensive. Previous studies have shown that machine-learned atmospheric chemical solvers can be orders of magnitude faster than traditional integration methods but tend to suffer from numerical instability. Here, we present a modeling framework that reduces error [...]

On the difficulties of being rigorous in environmental geochemistry studies: some recommendations for designing an impactful paper

Olivier Pourret, BOLLINGER Jean-Claude, Eric D. van Hullebusch

Published: 2019-10-25
Subjects: Biogeochemistry, Chemistry, Earth Sciences, Environmental Chemistry, Environmental Sciences, Geochemistry, Other Environmental Sciences, Physical Sciences and Mathematics

There have been numerous environmental geochemistry studies using chemical, geological, ecological and toxicological methods but each of these fields requires more subject specialist rigour than has generally been applied so far. Field-specific terminology has been misused and the resulting interpretations rendered inaccurate. In this paper, we propose a series of suggestions, based on our [...]

Probing the chemical transformation of seawater-soluble crude oil components during microbial oxidation

Yina Liu, Helen White, Rachel Simister, David Waite, Shelby Lyons, Elizabeth Kujawinski

Published: 2019-06-18
Subjects: Biogeochemistry, Chemistry, Earth Sciences, Environmental Chemistry, Environmental Sciences, Life Sciences, Microbiology, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Oil, Gas, and Energy, Physical Sciences and Mathematics

Studies assessing the environmental impacts of oil spills focus primarily on the non-water-soluble components, leaving the fate of the water-soluble fraction (WSF) largely unexplored. We employed untargeted chemical analysis along with biological information to probe the transformation of crude oil WSF in seawater, in the absence of light, in a laboratory experiment. Over a 14-day incubation, [...]

High-resolution prediction of organic matter concentration with hyperspectral imaging on a sediment core

Kévin Jacq, Yves Perrette, Fanget Bernard, Pierre Sabatier, Coquin Didier, Martinez-Lamas Ruth, Debret Maxime, Arnaud Fabien

Published: 2019-02-21
Subjects: Analytical Chemistry, Chemistry, Earth Sciences, Environmental Chemistry, Environmental Monitoring, Environmental Sciences, Optics, Physical Sciences and Mathematics, Physics, Sedimentology, Statistical Models, Statistics and Probability

In the case of environmental samples, the use of a chemometrics-based prediction model is highly challenging because of the difficulty in experimentally creating a well-ranged reference sample set. In this study, we present a methodology using short wave infrared hyperspectral imaging to create a partial least squares regression model on a cored sediment sample. It was applied to a sediment core [...]

Insights into agricultural influences and weathering processes from major ion patters

Robert van Geldern, Peter Schulte, Michael Mader, Alfons Baier, Tobias Juhlke, Johannes Barth, Kern Lee

Published: 2018-06-04
Subjects: Chemistry, Earth Sciences, Environmental Chemistry, Environmental Sciences, Geochemistry, Hydrology, Physical Sciences and Mathematics, Water Resource Management

Karst areas and their catchments pose a great challenge for protection because fast conduit flow results in low natural attenuation of anthropogenic contaminants. Studies of the hydrochemistry of karst sources and river solutes are an important tool for securing and managing water resources. A study of the geochemical downriver evolution of the Wiesent River and its tributaries, located in a [...]

What caused Earths largest mass extinction event? New evidence from the Permian-Triassic boundary in northeastern Utah

Benjamin Burger

Published: 2018-02-26
Subjects: Biogeochemistry, Biology, Chemistry, Earth Sciences, Environmental Chemistry, Environmental Indicators and Impact Assessment, Environmental Sciences, Geology, Life Sciences, Paleobiology, Paleontology, Physical Sciences and Mathematics, Sedimentology

The discovery of a Permian-Triassic boundary section in northeastern Utah reveals a detailed record of events that led to one of the greatest mass extinctions on the planet. From 83% to 97% of the species living on the planet went extinct during this relatively short interval of geological time, which defines the major geological boundary between the Paleozoic and Mesozoic Eras. The cause and [...]

Lake sediment records of persistent organic pollutants and polycyclic aromatic hydrocarbons in Southern Siberia mirror the changing fortunes of the Russian economy over the past 70 years

Jennifer K Adams, César C. Martins, Neil L. Rose, Alexander A. Shchetnikov, Anson W. Mackay

Published: 2017-12-18
Subjects: Chemistry, Ecology and Evolutionary Biology, Environmental Chemistry, Environmental Sciences, Life Sciences, Physical Sciences and Mathematics, Terrestrial and Aquatic Ecology

Persistent organic pollutants (POPs) and polycyclic aromatic hydrocarbons (PAHs) have previously been detected in the surface sediments, water, and endemic organisms of Lake Baikal, a UNESCO World Heritage Site. The Selenga River is the primary source of freshwater to Lake Baikal, and transports pollutants accumulating in the Selenga River basin to the lake. Sources of POPs and PAHs in the [...]

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