Search results for "Oleum"
showing 10 items of 150 documents
Deformation and fluid flow in the Huab Basin and Etendeka Plateau, NW Namibia
2016
Abstract The Lower Cretaceous Twyfelfontein sandstone formation in the Huab Basin in NW Namibia shows the effects of volcanic activity on a potential reservoir rock. The formation was covered by the Parana-Etendeka Large Igneous Province shortly before or during the onset of South-Atlantic rifting. Deformation bands found in the sandstone trend mostly parallel to the continental passive margin and must have formed during the extrusion of the overlying volcanic rocks, indicating that their formation is related to South-Atlantic rifting. 2D-image porosity analysis of deformation bands reveals significant porosity reduction from host rock to band of up to 70%. Cementation of the sandstone, lin…
Origin of methane and light hydrocarbons in natural fluids emissions: A study from Greece.
2018
Abstract Greece, a country characterised by intense seismic and volcanic activity, has a complex geodynamic and geological setting that favours the occurrence of many gas manifestations. In this study, we address the origin of CH 4 and light hydrocarbons in cold and thermal emissions discharging along the Hellenic territory. Also, we investigate their possible relationship with the main geochemical composition of the gases and the different geological settings of the sampling sites. For this purpose we collected 101 new samples that were analysed for their chemical (O 2 , N 2 , CH 4 , CO 2 , He, Ne, Ar, H 2 , H 2 S and C 2 -C 6 hydrocarbons) and isotopic (R/R A , δ 13 C-CO 2 , δ 13 C-CH 4 a…
Geochemical characterisation of the alkaline and hyperalkaline groundwater in the Othrys Ophiolite Massif, central Greece
2021
The complex geology of Greece includes two important parallel running ophiolitic belts. The Othrys Massif in central Greece belongs to the westernmost of them. In the current study, 33 water samples from cold hyperalkaline and hypothermal (T < 40°C) alkaline springs and 30 gas samples (either dissolved or free) were collected at 17 different sites in and around this wide ophiolite outcrop, aiming to determine the origin of fluids and evidence gas-water-rock interaction processes taking place in the area. Water samples were analysed for their chemical (major ions and trace elements) and isotope (d18O-H2O, d2H-H2O) composition. They can be subdivided into alkaline (pH <11) of both Mg-Ca…
Environmental mitigation hierarchy and biodiversity offsets revisited through habitat connectivity modelling.
2020
International audience; Biodiversity loss is accelerating because of unceasing human activity and land clearing for development projects (urbanisation, transport infrastructure, mining and quarrying …). Environmental policy-makers and managers in different countries worldwide have proposed the mitigation hierarchy to ensure the goal of “no net loss (NNL) of biodiversity” and have included this principle in environmental impact assessment processes. However, spatial configuration is hardly ever taken into account in the mitigation hierarchy even though it would greatly benefit from recent developments in habitat connectivity modelling incorporating landscape graphs. Meanwhile, national, Euro…
Numerical investigation on water exchange of shale samples
2020
Interest in the hydraulic and mechanical characterization of shales has grown in recent years, because of their application in the context of energy geotechnics. In the frame of nuclear waste disposal shales are considered as host formations for the placements of nuclear waste at high depths. In the frame of hydrocarbon production they are considered as unconventional reservoirs, from which extracting natural gas. Understanding how fluids flow through shales is then a key aspect for both fields of application. This paper focuses on the analysis of the transport of water vapour through laboratory samples. After reviewing the balance and flow laws that govern the transport of fluid in unsatur…
Phase-selective low molecular weight organogelators derived from allylated D-mannose
2022
In the last decades, synthesis and design of low molecular weight organogelators has gained increasing attention due to their versatile use in, for example, cosmetics, biomedicine and oil spill remediation. In this work, three potential gelators have been prepared from allylated d-mannose. Both the gelators and the corresponding gels formed were thoroughly characterized by crystallography, FTIR spectroscopy, SEM, rheometry and NMR spectroscopy, in solution and in solid state. The results showed that two of the compounds phase-selectively form gels with hydrocarbon solvents. The most promising gelator compound is alkene terminated, with the unsaturated end functionality not critical for gel …
Model of hydrocarbons transport through the porous ground media
2014
Dispersion model of hydrocarbons transport in porous media has been presented. Mathematical description of this process allows to estimate whether the menace of ground waters can occur as a result of hydrocarbons transport through the soil. The convection term in the mass transport equation is taken into account due to the higher velocity of propagation in vertical direction. Additionally, introduction to the balance equation the biosorption link allows to take into account microorganisms influence on impurities concentration, especially on heavy oils derived compounds. To verify the theoretical model series of the experiment in the soil filter has been carried out.
Influence of bioremediation stimulators in soil on development of oat seedlings (Avena sativa) and their aminopeptidase activity
2015
Dobór technik bioremediacji jest bardzo ważny w oczyszczaniu gleby skażonej substancjami ropopochodnymi, która ma być wykorzystywanej rolniczo. Prezentowane wyniki wskazują, że na rozwój siewek owsa większy wpływ ma stosowana metoda bioremediacji niż poziom zanieczyszczenia węglowodorami. Z zastosowanych technik najbardziej przyjazne dla wegetacji owsa były te, w których wykorzystywano szczepionkę drożdżową.
Wpływ sposobu dawkowania preparatu enzymatycznego na zmiany mikrobiologiczne i przemiany węglowodorów alifatycznych w glebie skażonej węglowodorami
2016
Usuwanie produktów ropopochodnych ze skażonej gleby jest trudnym procesem, wymagającym uwagi oraz stałej kontroli. W pracy podjęto próbę określenia wpływu techniki dawkowania preparatu enzymatycznego na zmiany mikrobiologiczne i przemiany węglowodorów alifatycznych w glebie naturalnie skażonej węglowodorami. Materiał do badań stanowiła gleba naturalnie skażona substancjami ropopochodnymi, w której całkowite stężenie węglowodorów alifatycznych o długości łańcuchów C8-C40 wynosiło 420,1 mg/kg suchej masy. Przeprowadzono doświadczenia wazonowe, dawkując preparat enzymatyczny w odstępach tygodniowych. Kontrolę stanowiła skażona gleba bez dodatku preparatu enzymatycznego. Doniczki inkubowano w t…
THE USE OF MBR SYSTEMS FOR THE TREATMENT OF REAL SHIPBOARD SLOPS: ANALYSIS OF BIOLOGICAL PERFORMANCE AND BIOMASS BIOKINETIC ACTIVITY
2016
In order to prevent hydrocarbon discharge at sea from ships, the International Maritime Organization (IMO) enacted the MARPOL 73/78 convention in which any oil and oil residue discharged in wastewater streams must contain less than 5 ppm hydrocarbons. Effective treatment of this petroleum-contaminated water is essential prior to its release into the environment, in order to prevent pollution problem for marine ecosystems as well as for human health. The present paper reports the first results of a field gathering campaign aimed at gaining insight about the treatment of real shipboard slops with a MBR pilot plant, in terms of pilot performance and biomass biokinetic activity. The achieved re…