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At least 829 records · Page 46Linked to original sources
PubMed2001

Effects of crude oil spillage on growth and yield of maize (Zea mays L.) in soils of midwestern Nigeria.

The effect of crude oil spillage on growth, productivity and nutrient uptake of maize (Zea mays L.) was assessed in a pot experiment using an Evwreni manifold sample of a petroleum development company, which had a specific gravity of 0.8778. The Suwan 1 variety of maize was used in the experiment. In crude oil polluted soils, germination was delayed and the germination percentage was significantly affected by oil pollution. Growth was poor in polluted soils using parameters such as plant height, stem girth, ear height, leaf area at four weeks after planting, leaf area at maturity and average length of primary roots as growth indicators. Grain yield was significantly reduced at 95% level of probability with yield (when compared with the control) reduced by as much as 98.6%, 96.5% and 58.3% for preplant, five weeks after planting (5 WAP) and seven weeks after planting (7 WAP) treatments, respectively. Leaf analysis of the maize plants grown in soils contaminated with crude oil a week before planting (preplant treatment) revealed mean levels of heavy metals (6.18 ppm Zn2+, 0.62 ppm Cu2+, 26.24 ppm Fe2+, 10.84 ppm Mn2+, 2.96 ppm Pb2+ and 3.88 ppm Co2+) which are higher than the maximum permissible levels (MPL) for maize in tropical soils. Maize plants that were polluted at other time intervals showed no significant (p > 0.05) variation in heavy metal concentrations when compared with the control, and were considered potentially safe for human consumption.

Accidents↗
PubMed2006

Child and maternal household chemical exposure and the risk of acute leukemia in children with Down's syndrome: a report from the Children's Oncology Group.

Compared with the general pediatric population, children with Down's syndrome have a much higher risk of acute leukemia. This case-control study was designed to explore potential risk factors for acute lymphoblastic leukemia and acute myeloid leukemia in children with Down's syndrome living in the United States or Canada. Mothers of 158 children with Down's syndrome and acute leukemia (97 acute lymphoblastic leukemia, 61 acute myeloid leukemia) diagnosed between January 1997 and October 2002 and mothers of 173 children with Down's syndrome but without leukemia were interviewed by telephone. Positive associations were found between acute lymphoblastic leukemia and maternal exposure to professional pest exterminations (odds ratio = 2.25, 95% confidence interval: 1.13, 4.49), to any pesticide (odds ratio = 2.18, 95% confidence interval: 1.08, 4.39), and to any chemical (odds ratio = 2.72, 95% confidence interval: 1.17, 6.35). Most of the associations with acute myeloid leukemia were nonsignificant, and odds ratios were generally near or below 1.0. This exploratory study suggests that household chemical exposure may play a role in the development of acute lymphoblastic leukemia in children with Down's syndrome.

Adult↗
PubMed1990

[Studies on the resolution of racemic gossypol. II. By chiral alpha-methylphenethylamine and alpha-methylbenzylamine].

A simplified and more practical method for the resolution of racemic gossypol was developed by quick chromatographing the condensation products of either (S) or (R)-alpha-methylphenethylamine and alpha-methylbenzylamine with racemic gossypol on a silica column using diethylether/light petroleum as eluent. The optically active gossypol thus obtained showed specific rotation [alpha]D of (+) or (-)370 +/- 10 degrees, with ee% 96.8 and 98.8 respectively and chemical purity greater than 99% by HPLC. Isomerization of the amino condensates of optically active gossypol through the racemization of the binaphthalene moiety of gossypol was observed, though gossypol itself is optically stable in such condition. The rate of racemization varied with the structure of the amine moiety and solvent present and was increased by light and free radical initiator.

Amphetamine↗
PubMed1996

Phenols in hydrothermal petroleums and sediment bitumen from Guaymas Basin, Gulf of California.

The aliphatic, aromatic and polar (NSO) fractions of seabed petroleums and sediment bitumen extracts from the Guaymas Basin hydrothermal system have been analyzed by gas chromatography and gas chromatography-mass spectrometry (free and silylated). The oils were collected from the interiors and exteriors of high temperature hydrothermal vents and represent hydrothermal pyrolyzates that have migrated to the seafloor by hydrothermal fluid circulation. The downcore sediments are representative of both thermally unaltered and thermally altered sediments. The survey has revealed the presence of oxygenated compounds in samples with a high degree of thermal maturity. Phenols are one class of oxygenated compounds found in these samples. A group of methyl-, dimethyl- and trimethyl-isoprenoidyl phenols (C27-C29) is present in all of the seabed NSO fractions, with the methyl- and dimethyl-isoprenoidyl phenols occurring as major components, and a trimethyl-isoprenoidyl phenol as a minor component. A homologous series of n-alkylphenols (C13-C33) has also been found in the seabed petroleums. These phenols are most likely derived from the hydrothermal alteration of sedimentary organic matter. The n-alkylphenols are probably synthesized under hydrothermal conditions, but the isoprenoidyl phenols are probably hydrothermal alteration products of natural product precursors. The suites of phenols do not appear to be useful tracers of high temperature hydrothermal processes.

Chromatography, Gas↗
PubMed2003

Petroleum mineral oil refining and evaluation of cancer hazard.

Petroleum base oils (petroleum mineral oils) are manufactured from crude oils by vacuum distillation to produce several distillates and a residual oil that are then further refined. Aromatics including alkylated polycyclic aromatic compounds (PAC) are undesirable constituents of base oils because they are deleterious to product performance and are potentially carcinogenic. In modern base oil refining, aromatics are reduced by solvent extraction, catalytic hydrotreating, or hydrocracking. Chronic exposure to poorly refined base oils has the potential to cause skin cancer. A chronic mouse dermal bioassay has been the standard test for estimating carcinogenic potential of mineral oils. The level of alkylated 3-7-ring PAC in raw streams from the vacuum tower must be greatly reduced to render the base oil noncarcinogenic. The processes that can reduce PAC levels are known, but the operating conditions for the processing units (e.g., temperature, pressure, catalyst type, residence time in the unit, unit engineering design, etc.) needed to achieve adequate PAC reduction are refinery specific. Chronic dermal bioassays provide information about whether conditions applied can make a noncarcinogenic oil, but cannot be used to monitor current production for quality control or for conducting research or developing new processes since this test takes at least 78 weeks to conduct. Three short-term, non-animal assays all involving extraction of oil with dimethylsulfoxide (DMSO) have been validated for predicting potential carcinogenic activity of petroleum base oils: a modified Ames assay of a DMSO extract, a gravimetric assay (IP 346) for wt. percent of oil extracted into DMSO, and a GC-FID assay measuring 3-7-ring PAC content in a DMSO extract of oil, expressed as percent of the oil. Extraction with DMSO concentrates PAC in a manner that mimics the extraction method used in the solvent refining of noncarcinogenic oils. The three assays are described, data demonstrating the validation of the assays are shown, and test results of currently manufactured base oils are summarized to illustrate the general lack of cancer hazard for the base oils now being manufactured.

Animals↗
PubMedDate not supplied

Correlation of 32P-postlabelling-detection of DNA adducts in mouse skin in vivo with the polycyclic aromatic compound content and mutagenicity in Salmonella typhimurium of a range of oil products.

The in vivo genotoxic activities in mouse skin of the dimethyl sulphoxide (DMSO) extracts of a range of oil products [residual aromatic extract; untreated heavy paraffinic distillate aromatic extract; mildly refined light naphthenic base oil; bitumen (vacuum residue); high viscosity index base oil obtained by catalytic hydrogenation] were evaluated by 32P-postlabelling DNA analysis. The results of quantitative 32P-postlabelling analyses of epidermal DNA from mice treated with the DMSO extracts showed linear relationships with the total polycyclic aromatic compound (PAC) contents, determined by the Institute of Petroleum method IP 346 and also the 3-6 ring PAC contents, measured by on-line liquid-liquid extraction using flow injection analysis. The 32P-postlabelling data also showed a linear relationship with the mutagenicity indices of these oil products determined in S. typhimurium TA98 using the modified Ames Salmonella microsome test. The in vivo genotoxicity of the DMSO extracts from the oil products was low, judged by 32P-postlabelling analysis of DNA adducts measured in epidermal DNA of treated mouse skin, and ranging from 2 to 723 attomole/microg DNA per mg oil product. The in vivo 32P-postlabelling data from this study are consistent with these materials expressing low genotoxicity in mouse skin in vivo. The DMSO extraction procedure coupled with 32P-postlabelling DNA analysis is useful for ranking the relative genotoxic potency in vivo of a wide range of oil products. In general the trend observed is similar to rankings based on physicochemical measurements of total PAC contents or 3 6 ring PAC contents of the oil products.

Animals↗
PubMed2005

Correlation between diverse cyclic lipopeptides production and regulation of growth and substrate utilization by Bacillus subtilis strains in a particular habitat.

The two Bacillus subtilis strains (DM-03 and DM-04) were isolated from two extremely different habitats; one from the traditional fermented food and another one from a petroleum contaminated soil sample. These strains produced quantitatively and qualitatively different cyclic lipopeptides isoforms under laboratory culture conditions. MALDI-TOF mass spectral analysis revealed that lipopeptide profile varied according to the producing B. subtilis strains; iturins and surfactins isoforms were pre-dominant cyclic lipopeptides produced by B. subtilis DM-03 and DM-04 strains, respectively. A comparative study showed that these strains possessed distinct preferences for the carbon and nitrogen substrates, temperature and pH for optimal growth and biosurfactant production. Our study documented that the cyclic lipopeptide isoforms produced by the respective strains played an important role in the utilization of available hydrophobic substrate(s) from their natural habitats and conferred some kind of competitive advantage to the producing B. subtilis strains in their parent ecological niche.

Bacillus subtilis↗
PubMedDate not supplied

NMR imaging of fluid dynamics in reservoir core.

A medical NMR imaging instrument has been modified to image water and oil in reservoir rocks by the construction of a new receiving coil. Both oil and water inside the core produced readily detectable proton NMR signals, while the rock matrix produced no signal. Because of similar T2 NMR relaxation times, the water was doped with a paramagnetic ion, Mn+2, to reduce its T2 relaxation time. This procedure enhanced the separation between the oil and water phases in the resulting images. Sequential measurements, as water imbibed into one end and oil was expelled from the other end of a core plug, produced a series of images which showed the dynamics of the fluids. For water-wet Berea Sandstone a flood front was readily observed, but some of the oil was apparently left behind in small, isolated pockets which were larger than individual pores. After several additional pore volumes of water flowed through the plug the NMR image indicated a homogeneous distribution of oil. The amount of residual oil, as determined from the ratio of NMR intensities, closely approximated the residual oil saturation of fully flooded Berea samples measured by Dean-Stark extraction. A Berea sandstone core treated to make it partially oil-wet, did not show a definitive flood front, but appeared to channel the water around the perimeter of the core plug. The relative ease with which these images were made indicates that NMR imaging can be a useful technique to follow the dynamics of oil and water through a core plug for a variety of production processes.

Equipment Design↗
PubMedDate not supplied

[Bacteriological detection of crude oil contamination in the Bahía Blanca estuary].

In order to evaluate the distribution of occasional oil spills produced by floating system for transferring crude oil, the number of hydrocarbon-degrading bacteria was counted in superficial sediments from Bahía Blanca Estuary, using the Most Probable Number method. Sediment were collected from ten stations located between buoys 21 and 16. Heterotrophic aerobic marine bacteria were counted on Marine Agar 2216. Determination of organic carbon was also carried out. On the base of the number of hydrocarbon-degrading bacteria, statistical analysis differentiated two zones with different degree of pollution, one including the stations of the Principal Channel, with average values, expressed as log10, which ranged from 2.98 to 3.65 bacteria/g of dry sediment, and the other from 4.16 to 4.37, located in small channels on the Southern coast. These results suggest a drift of the oil perpendicular to the Principal Channel, probably caused by the action of predominant winds with direction N, NNW. A linear regression analysis determined highly significant relationship between organic carbon and both bacterial groups. This study shows that the spilled oil is affecting productive zones of the estuary.

Aerobiosis↗
PubMed1999

Catalytic Upgrading of Fermentation-Derived Organic Acids.

The production of organic acids in low-cost, high-efficiency fermentation processes makes available a new route to chemical production from biomass. Because of their multiple functional groups and high reactivity, organic acids can undergo a variety of reactions that are effectively catalyzed by inorganic heterogeneous or homogeneous catalysts. Lactic acid and succinic acid, in particular, are approaching large-scale production via fermentation and show excellent promise as feedstocks for catalytic conversion routes such as hydrogenation, dehydration, or condensation. A number of catalytic conversion pathways of organic acids are potentially competitive with petroleum-based routes in the current economic environment, particularly when integrated into existing biomass/crop processing schemes. This article reviews some of the key reaction pathways available using fermentation-derived organic acids as feedstocks and presents recent results from the authors' lab on succinate hydrogenation to 1,4-butanediol and tetrahydrofuran. By a judicious choice of support properties and reaction conditions, it is possible to achieve yields of either of these two products in excess of 80%.

Journal Article↗
PubMed2001

Factors that contribute to biomarker responses in humans including a study in individuals taking Vitamin C supplementation.

It is possible in many situations to identify humans exposed to potentially toxic materials in the workplace and in the environment. As in most human studies, there tends to be a high degree of interindividual variability in response to chemical insults. Some non-exposed control individuals exhibit as high a level of damage as some exposed individuals and some of these have levels of damage as low as many of the controls. Thus, it is only the mean values of the groups that can substantiate an exposure-related problem; the data on an individual basis are still of limited use. While human lymphocytes remain the most popular cell type for monitoring purposes, sperm, buccal, nasal, epithelial and placental cells are also used. However, for interpretation of responses, the issue of confounding factors must be addressed. There are endogenous confounding factors, such as age, gender, and genetic make-up and exogenous ones, including lifestyle habits (smoking, drinking, etc.) There are biomarkers of exposure, effect/response and susceptibility and the last may be influenced by the genotype and polymorphism genes existing in a population. From our own studies, confounding effects on cytogenetic damage and ras oncoproteins will be considered in relation to workers exposed to vinyl chloride and petroleum emissions and to volunteers taking Vitamin C supplementation. Smoking history, exposure and duration of employment affected the worker studies. For petroleum emissions, so did gender and season of exposure. For the non-smoking volunteer Vitamin C supplementation study, cholesterol levels, plasma Vitamin C levels, lipid peroxidation products and DNA damage in the Comet assay were also measured. Gender affected differences in Vitamin C levels, antioxidant capacity and the number of chromosome aberrations induced by bleomycin challenge in vitro. The results were the same for both high and low cholesterol subjects. The relationship between biomarkers and the various factors which affect them is complex. Sometimes the variables are not completely independent of each other.

Antioxidants↗
PubMed2000

Potential commercial applications of microbial surfactants.

Surfactants are surface-active compounds capable of reducing surface and interfacial tension at the interfaces between liquids, solids and gases, thereby allowing them to mix or disperse readily as emulsions in water or other liquids. The enormous market demand for surfactants is currently met by numerous synthetic, mainly petroleum-based, chemical surfactants. These compounds are usually toxic to the environment and non-biodegradable. They may bio-accumulate and their production, processes and by-products can be environmentally hazardous. Tightening environmental regulations and increasing awareness for the need to protect the ecosystem have effectively resulted in an increasing interest in biosurfactants as possible alternatives to chemical surfactants. Biosurfactants are amphiphilic compounds of microbial origin with considerable potential in commercial applications within various industries. They have advantages over their chemical counterparts in biodegradability and effectiveness at extreme temperature or pH and in having lower toxicity. Biosurfactants are beginning to acquire a status as potential performance-effective molecules in various fields. At present biosurfactants are mainly used in studies on enhanced oil recovery and hydrocarbon bioremediation. The solubilization and emulsification of toxic chemicals by biosurfactants have also been reported. Biosurfactants also have potential applications in agriculture, cosmetics, pharmaceuticals, detergents, personal care products, food processing, textile manufacturing, laundry supplies, metal treatment and processing, pulp and paper processing and paint industries. Their uses and potential commercial applications in these fields are reviewed.

Agriculture↗
PubMed2005

Current status of biodiesel development in Brazil.

In recent years, the concept of producing biodiesel from renewable lipid sources has regained international attention. In Brazil, a national program was launched in 2002 to evaluate the technical, economic, and environmental competitiveness of biodiesel in relation to the commercially available diesel oil. Several research projects were initiated nationwide to investigate and/or optimize biodiesel production from renewable lipid sources and ethanol derived from sugarcane (ethyl esters). Once implemented, this program will not only decrease our dependence on petroleum derivatives but also create new market opportunities for agribusiness, opening new jobs in the countryside, improving the sustainability of our energy matrix, and helping the Brazilian government to support important actions against poverty. This article discusses the efforts to develop the Brazilian biodiesel program in the context of technical specifications as well as potential oilseed sources.

Biotechnology↗
PubMed2004

Incidents/accidents classification and reporting in Statoil.

Based on requirements in the new petroleum regulations from Norwegian Petroleum Directorate (NPD) and the realisation of a need to improve and rationalise the routines for reporting and follow up of incidents, Statoil Exploration & Production Norway (Statoil E&P Norway) has formulated a new strategy and process for handling of incidents/accidents. The following past experiences serve as basis for the changes made to incident reporting in Statoil E&P Norway; too much resources were spent on a comprehensive handling and analysis of a vast amount of incidents with less importance for the safety level, taking the focus away from the more severe and important issues at hand, the assessment of "Risk Factor", i.e. the combination of recurrence frequency and consequence, was difficult to use. The high degree of subjectivity involved in the determination of the "Risk Factor" (in particular the estimation of the recurrence frequency) resulted in poor data quality and lack of consistency in the data material. The new system for categorisation and handling of undesirable incidents was established in January 2002. The intention was to get a higher degree of focus on serious incidents (injuries, damages, loss and near misses), with a thorough handling and follow-up. This is reflected throughout the handling of the serious incidents, all the way from immediate notification of the incident, through investigation and follow-up of corrective and preventive actions. Simultaneously, it was also an objective to rationalise/simplify the handling of less serious incidents. These incidents are, however, subjected to analyses twice a year in order to utilize the learning opportunity that they also provide. A year after the introduction of this new system for categorisation and follow-up of undesirable incidents, Statoil's experiences are predominantly good; the intention to get a higher degree of focus on serious incidents (injuries, damages, loss and near misses), has been met, the data quality for the more serious incidents (5% of the total number of incidents registered) has improved, the improved handling of incidents has contributed to more reliable and accurate HSE indicators at a corporate level, more user friendly codes in place for incident registration (based on MTO methodology), the revised matrix gives distinct criteria with respect to which investigation level to be initiated for a specific incident. All activities related to handling of undesirable incidents have been summarised and illustrated on a two-sided plastic form, incorporating both the categorisation matrix and the activity flowchart (see Figs. 1 and 4).

Accidents, Occupational↗
PubMed2005

Identification of alkyl carbazoles and alkyl benzocarbazoles in Brazilian petroleum derivatives.

Carbozoles are important compounds in crude oils, as they may be used as geochemical tracers, being the major type of nitrogen compounds in petroleum. At the same time, they are regarded as undesirable due to the problems they may cause in the refining process, such as catalyst poisoning, corrosion, gum or color formation in final products. As separation and identification of carbazoles are challenging goals, this work presents a chromatographic method, made of a pre-fractionation on neutral alumina followed by the separation and identification of two classes of carbazoles using FeCl(3)/Chromossorb W and gas chromatograph with mass spectrometer (GC/MS) (SIM-single ion monitoring mode) analysis. For the first time, a series of alkyl carbazoles and alkyl benzocarbazoles were identified in heavy gas oil (HGO) and atmospheric residue of distillation (ARD) obtained from Brazilian petroleum.

Aluminum Oxide↗