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Showing papers in "Organic Geochemistry in 1999"


Journal ArticleDOI
TL;DR: In this paper, the authors review the design considerations faced by the developers of fast pyrolysis, upgrading and utilisation processes in order to successfully implement the technologies and provide a case study of the application of the technology to waste wood and how this approach gives very good control of contaminants.

1,664 citations


Journal ArticleDOI
TL;DR: Isotopic compositions of carbon-bound hydrogen in individual compounds from eight diAerent organisms were measured using isotope-ratio-monitoring gas chromatography-mass spectrometry.

545 citations


Journal ArticleDOI
TL;DR: These results add to the growing list of microalgae that contain a high proportion of 24-ethylcholesterol, which is more typically associated with higher plants, and confirm that the same class of compounds occurs in freshwater eustigmatophytes.

317 citations


Journal ArticleDOI
TL;DR: In this paper, a set of crude oils, which differ mainly in their level of maturity, were compared with mixtures obtained after heating methylated naphthalenes with clay, leading to the proposal of three new parameters, one for each class of naphthenes.

276 citations


Journal ArticleDOI
TL;DR: The authors showed that the degree of gas hydrate alteration appears to be related to duration of exposure at the sea floor and that bacterial oxidation of a mixed pool of hydrocarbons yields a net production of CO2 depleted in 13C.

248 citations


Journal ArticleDOI
TL;DR: The location of the algaenan in the algal cells and the resistance of these materials to chemical and bacterial attack are discussed with respect to their role as a potential sink of organic carbon in aquatic environments.

205 citations


Journal ArticleDOI
TL;DR: In this paper, the carbon isotope systematics of benzene, toluene, ethylbenzene, and xylene monoaromatic hydrocarbons (BTEX) with regard to an improved understanding of the behavior of these compounds in the subsurface, particularly during remediation processes were investigated.

192 citations


Journal ArticleDOI
TL;DR: Stable carbon isotopes have the potential to be a useful indicator for identification and monitoring of intrinsic bioremediation of chlorinated hydrocarbons such as TCE and more conservative isotopic values may instead be more applicable as a means of source differentiation at sites with a history of multiple spills.

177 citations


Journal ArticleDOI
TL;DR: In this paper, the phytotoxicity of various contaminated soils was assessed by plant inventories on ancient industrial fields and by phytoxoxicity tests, and the results showed that contaminated samples can be classified into two categories: a recently excavated soil/liquid tar that was foul-smelling and phytotropic and second, an ‘aged’, surface soil that was weathered and non-phytotoxic.

169 citations


Journal ArticleDOI
TL;DR: The applicability of sulphur aromatic parameters, based on ratios of dibenzothiophene (DBT) and its alkylated homologues, as indicators of oil maturity has been investigated in 27 oils from the Damintun and Zhuanhua Depressions, Bohai Bay Basin this article.

158 citations


Journal ArticleDOI
TL;DR: In this paper, a step procedure to characterise soil ecotoxicity is proposed which allows one to study the pollutant mobility, toxicity and genotoxicity, which can be used to identify the hazard, to classify soil hazards and thus map contaminated sites, to assess the success of treatment and finally to monitor rehabilitated sites.

Journal ArticleDOI
TL;DR: In this article, two pure solvents (trichloroethene and dichloromethane) were evaporated at room temperature (24±1°C) and the carbon and chlorine isotopic compositions were measured as a function of the fraction remaining.

Journal ArticleDOI
TL;DR: In this article, the authors used a case study to test the simulation of generation, migration and cracking of petroleum fluids by a 2D compositional basin simulator using kinetic models based on chemical classes of compounds.

Journal ArticleDOI
TL;DR: The mechanism by which heated tetramethylammonium hydroxide (TMAH) degrades the lignin biopolymer was investigated and substantiate the base-catalyzed reactions previously postulated by Gierer (1970) to explain alkali wood pulping and explain the facile formation and distribution of lignIn derivatives obtained in the TMAH thermochemolysis of natural samples.

Journal ArticleDOI
TL;DR: Shewanella putrefaciens (Strain MR-4), a gram negative facultative marine bacterium, was grown to stationary phase under both aerobic and anaerobic conditions using lactate as the sole carbon source, causing detection of isotopically depleted fatty acids in sediments to be falsely attributed to a terrestrial origin.

Journal ArticleDOI
TL;DR: In this article, a thermal and chemical degradation approach was followed to determine the precursors of pristane (Pr) and phytane (Ph) in samples from the Gessoso-solfifera, Ghareb and Green River Formations.

Journal ArticleDOI
TL;DR: In this article, the authors describe a method for the preparation of wax-free asphaltene fractions and provide a quantitative subdivision of the wax fraction into pentane soluble and insoluble waxes which, when correlated with physical properties of crude oil such as viscosity, pour point, cloud point, etc, may help explain causes of wax deposition during production, transportation and storage of petroleum.

Journal ArticleDOI
TL;DR: In this article, a purge-and-trap unit was used to extract chlorinated solvents for isotope analyses, and the results showed that the purification unit produces both accurate and reproducible results for dissolved chlorinated solvent δ 13 C and δ 37 Cl analyses.

Journal ArticleDOI
TL;DR: In this article, two taxa of Neoproterozoic acritarchs of unknown affinity, Multifronsphaeridium pelorium and Species A, were analysed by electron microscopic (SEM, TEM) and chemical (micro-FTIR, pyrolysis GC-MS, thermal desorption-MS) methods.

Journal ArticleDOI
TL;DR: In this paper, the sources and inputs of terrigenous organic matter (OM) to the upper St Lawrence system have been influenced by increased discharges of industrial solid organic wastes from the pulp and paper industry following its expansion in the 1920-1940's.

Journal ArticleDOI
TL;DR: Microbial culture experiments were performed to investigate isotopic fractionation of carbon (C) and chlorine (Cl) during aerobic degradation of dichloromethane (DCM) by MC8b, a gram-negative methylotrophic organism closely related to the genera Methylobacterium or Ochrobactrum.

Journal ArticleDOI
TL;DR: Total carbohydrate yields, mole percentages of glucose and percent deoxy sugars in highly degraded herbaceous tissues were similar to those measured in particulate organic matter fractions of major world rivers, and provide diagenetic parameters which link relatively fresh plant tissues to their degraded counterparts in aquatic environments.

Journal ArticleDOI
TL;DR: In this paper, a first-order examination of NOM and contaminant interactions is presented, which highlights a number of essential features that should be included in future molecular models of natural organic matter (NOM)-and contaminant-sorption.

Journal ArticleDOI
TL;DR: Chung et al. as discussed by the authors found that most of the migrated gases are actually generated in the Colorado Group shales, and not the Mannville sands in which the wells were completed.

Journal ArticleDOI
TL;DR: The lipid assemblages of the “living fossil” stromatoporoid Astrosclera willeyana and the demosponge Agelas oroides were investigated and found to contain abundant linear, long-chain C24–C26 dienoic “demospongic” acids.

Journal ArticleDOI
TL;DR: In this paper, geochemical analysis of whole rock samples of organic-rich and organic-lean laminated mudrocks of the Devonian-Carboniferous Exshaw Formation, Alberta, highlight the importance of primary production in governing the quantity and quality of organic matter.

Journal ArticleDOI
TL;DR: In this paper, fixed-bed hydropyrolysis tests have been conducted on cellulose, sugar cane bagasse and eucalyptus wood using hydrogen pressures up to 10 MPa, with heating rates of 5 and 300°C min −1.

Journal ArticleDOI
TL;DR: In this article, the carbon isotope fractionation of chlorinated ethenes during reductive dehalogenation by metallic iron was investigated and large isotopic shifts were observed during the reaction duration for each of the solvents.

Journal ArticleDOI
TL;DR: The effects of thermal maturation upon the abundance and composition of tricyclic terpanes have been investigated within a single sedimentary horizon within the Dun Caan Shale Member (Isle of Skye, Scotland) intruded by a 0.9 m thick Tertiary dolerite dyke as discussed by the authors.

Journal ArticleDOI
TL;DR: In this article, the stable carbon isotopic ratio of individual hydrocarbons in the gasoline-range fraction (C 5 −C 8 ) of these oils was compared using continuous flow-isotope ratio mass spectrometer (CF-IRMS).