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Ancient microfossils and stromatolites represent some of our best evidence of early living organisms on Earth. However, due to increasingly critical evaluation of such biomarkers in the last decade, assessing the biogenicity of preserved microbe-like features and stromatolitic structures is far from trivial. Carbonaceous matter associated with bona fide microfossils and stromatolites should contain a general microstructure consistent with that of kerogen, the biogenic organic matter common in oil, gas, and coal source rocks. Although kerogen structure and composition can vary, there are consistent characteristics that may be used to identify ˵kerogen-like″ carbonaceous material. Fischer-Trospch-type (FTT) reactions and other organic synthesis mechanisms may be a significant source of abiotic organic matter on the early Earth. Many minerals associated with hydrothermal activity, which was prevalent on the early Earth, have been shown to catalyze FTT synthesis. However, significant research into the maturation and preservation of FTT-derived carbonaceous matter is necessary before a robust distinction can be made from biogenic kerogen. Controversial microfossils from the 3.458–3.465 Ga Apex Basalt and stromatolites from the 3.350–3.458 Ga Strelley Pool Chert are associated with hydrothermal activity, leading to the suggestion that the carbonaceous matter comprising these features is derived from abiotic FTT synthesis rather than biological processes. Carbon-rich black chert dike samples were obtained from the Apex and Strelley Pool localities for comparison with kerogen from the 1.9 Ga Gunflint Formation and laboratory-derived FTT carbonaceous matter. In situ scanning-transmission X-ray microscopy (STXM) and transmission electron microscopy (TEM) reveal the presence of ∼100 nm carbonaceous films along quartz grain boundaries in the chert samples, which may be separated from the quartz grains in ultramicrotomed sections. Electron energy-loss near-edge structure spectroscopy (ELNES) and X-ray absorption near-edge structure spectroscopy (XANES) indicate Apex and Strelley carbonaceous matter contains a complex microstructure with abundant aromatic domains and oxygenated organic functional groups similar to that observed in Gunflint kerogen. FTT samples were chemically distinct, containing abundant carboxyl functional groups and lacking polyaromatic domains. Although it is possible that FTT material could mature into an abiotic kerogen-like material with similar characteristics, it is more likely that the Apex and Strelley Pool carbonaceous matter formed from biological processes. Biogenic material could be preserved within an ancient hydrothermal system either through gravitational influx of microbial material from the surface or transport of carbonaceous matter from a deeper sediment. [ABSTRACT FROM AUTHOR]

In order to evaluate hydrocarbon inputs to Crater Lake from anthropogenic and natural sources, samples of water, aerosol, surface slick and sediment were collected and analyzed by gas chromatography-mass spectrometry (GC-MS) for determination of their aliphatic and aromatic hydrocarbon concentrations and compositions. Results show that hydrocarbons originate from both natural (terrestrial plant waxes and algae) and anthropogenic (petroleum use) sources and are entering the lake through direct input and atmospheric transport. The concentrations of petroleum hydrocarbons range from low to undetectable. The distributions and abundances of n-alkanes, polycyclic aromatic hydrocarbons (PAH) and unresolved complex mixture (UCM) from petroleum are similar for all surface slick sampling sites. The estimated levels of PAH in surface slicks range from 7-9 ng/m2 which are low. Transport of petroleum-derived hydrocarbons from the lake surface has resulted in their presence in some sediments, particularly near the boat operations mooring (total petroleum HC = 1440 µg/kg, dry wt. compared to naturally derived n-alkanes, 240 µg/kg, dry wt.). The presence of biomarkers such as the tricyclic terpanes, hopanes and steranes in shallow sediments further confirms petroleum input from boat traffic. In the deep lake sediments, petroleum hydrocarbon concentrations were very low (16 µg/kg, dry wt.). Very low concentrations of PAH were detected in shallow sediments (17-40 µg/kg at 5 m depth near the boat operations) and deep sediments (3-15 µg/kg at 580 m depth). The individual PAH concentrations in sediments (µg/kg or ppb range) are at least three orders of magnitude less than reported threshold effects levels (mg/kg or ppm range, test amphipod Hyalella azteca). Therefore, no adverse effects are expected to occur in benthic biota exposed to these sediments. Boating activities are leaving a detectable level of petroleum in surface waters and lake sediments but these concentrations are very low. [ABSTRACT FROM AUTHOR]

The transport of atmospheric particles with associated terrestrial organic matter to the oceans is an important process affecting various global concerns such as climate change and environmental and human health. Aerosol particulate matter over the oceans is derived from autochthonous emissions admixed with varying amounts of continental effluents. It is important to be able to assess the sources and fate (receptors) of aerosols, and both inorganic and organic tracers are of utility. The organic compounds of atmospheric particles from marine and terrestrial regions can be characterized by specific tracers for (1) natural emissions (marine lipids, vegetation waxes, terpenes), (2) fossil fuels utilization (internal combustion engine emissions, coal burning), (3) biomass burning (taxon specific, wildfires), (4) anthropogenic emissions (industry, urban activity), and (5) soil and desert sand resuspension (agriculture, wind erosion). The precursor--product chemistry can then be used to assess the secondary reactions (thermal or atmospheric) and the fate of aerosol organic matter. [ABSTRACT FROM AUTHOR]

In order to study the environmental analysis and impact assessment (EAIA) of contaminants leached from road construction and repair (C&R) materials, the present chapter introduces an advanced technique called "Forensic Analysis and Genetic Source Modeling". This consists of an environmental "molecular marker" approach that is integrated with various statistical/mathematical modeling tools. It generally aims to characterize the organic molecular composition of leachates from road construction materials as well as to confirm their source. Accordingly, the main goals in this chapter are to: (1) review different organic contaminants (such as petroleum hydrocarbons, pesticides, phthalates, phenols, PCBs, organotin compounds, and surfactants) leached from solid wastes used as road construction materials and/or their leachates; (2) evaluate the different analytical techniques used for the determination of these organic compounds; (3) discuss the current instrumental developments and advances for the identification and characterization of these contaminants; and (4) present data for a major research program that investigated the environmental impact of highway construction materials on surface and ground waters. [ABSTRACT FROM AUTHOR]

Improved environmental performance in industry and society is a concept now a quarter-century old. Efforts in this regard have yielded much in the way of environmental improvement. It is easy to demonstrate that most of the activities of today's industrial society are unsustainable. Unfortunately, much of the talk about sustainability lacks a basic understanding of what truly sustainable activity would be. To set sustainability as a target or a goal for our industrial society, it is important to quantify that target or goal. Currently, the transportation industry is under increasing pressure to use alternate or secondary materials because of its high-volume consumption of bulk materials (such as natural fine and coarse aggregates) in road construction. Materials including industrial by-products, concrete aggregates, old asphalt pavement, scrap tires, fly ash, steel slag, and plastics are often used as alternate materials for natural aggregates. As these products are not normal construction materials, there are concerns about their environmental suitability, recyclability and sustainability in concrete and road pavement applications, as well as their environmental impact on surface and ground waters. The present chapter (a) evaluates the general concepts of sustainability, (b) reviews and evaluates the various types of solid wastes that are currently used as road construction and repair (C&R) materials, (c) discusses both the chemical and physical properties of such wastes and their engineering uses, and finally (d) presents the general project approaches of a major research program to investigate the environmental impact of highway C&R materials on surface and ground waters. [ABSTRACT FROM AUTHOR]

Public approval of an environmental analysis and impact assessment project is usually coupled with different conditions that the project is required to meet. Environmental impact assessment (EIA) constitutes an important basis for decisions regarding possible imposition of conditions. The main focus of the present chapter is to clarify the roles that EIAs can have in such decision-making processes. The present chapter discusses and reviews the various types of environmental impacts (natural and man-made); the need for EIA data and its proper handling; the different environmental administrative procedures used in EIA projects; the EIA characteristics (in terms of their goals, impact indicators, impact estimation, applicability); the different EIA methods; and a general conceptual framework that could be applied to any environmental project. [ABSTRACT FROM AUTHOR]

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Copyright of Pollutant-Solid Phase Interactions Mechanisms, Chemistry & Modeling is the property of Springer eBooks and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Pollutant-Solid Phase Interactions Mechanisms, Chemistry & Modeling is the property of Springer eBooks and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Pollutant-Solid Phase Interactions Mechanisms, Chemistry & Modeling is the property of Springer eBooks and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Pollutant-Solid Phase Interactions Mechanisms, Chemistry & Modeling is the property of Springer eBooks and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)