The metabolism of toluene by natural populations of marine bacteria, stored to enhance their activity, gave hyperbolic kinetics with saturation at only K, = 0.6 to 3.4 pg liter-‘. Similarly Kl in fresh seawater was 0.26 pg toluene liter-‘. Freshly collected populations could be moderately active toward toluene, affinity azA = 1.1-37.5 liters g-cells-l h-l. These moderate affinities taken togeth...

The nature of layers of a series of poly(ethy1ene glycol) monoalkyl ethers (C,,Em) adsorbed on silica surfaces has been systematically investigated by means of null ellipsometry. The results show that adsorption remains low until a well-defined concentration ((=0.6-0.9)cmc) is exceeded. Then, as surfactants in the interfacial region start to self-absemble, it increases abruptly and plateau adso...

The bacterial diversity of a chronically oil-polluted retention basin sediment located in the Berre lagoon (Etang-de-Berre, France) was investigated. This study combines chemical and molecular approaches in order to define how the in situ petroleum hydrocarbon contamination level affects the bacterial community structure of a subsurface sediment. Hydrocarbon content analysis clearly revealed a ...

The stimulation of the microbial population by a more bioavailable supplementary carbon source and by a surfactant pretreatment was studied in petroleum hydrocarbon-polluted soils bioremediation. Two types of soils were used, Soil A which had been recently polluted and the aged Soil B. They contained 52.4 and 50.4 g of total petroleum hydrocarbons per kg of dry soil, respectively. The effect of...

BACKGROUND Microorganisms have devised ways by which they increase the bioavailability of many water immiscible substrates whose degradation rates are limited by their low water solubility. Hexadecane is one such water immiscible hydrocarbon substrate which forms an important constituent of oil. One major mechanism employed by hydrocarbon degrading organisms to utilize such substrates is the pr...

Aliphatic and polycyclic aromatic hydrocarbon and stable and radiocarbon isotope distributions are compared for dated cores from the 1970s and 2000 for a 25-year retrospective in Lake Washington, Seattle, WA (USA). Contamination of Lake Washington sediments by petrogenic aliphatic hydrocarbons and pyrolytic polycyclic aromatic hydrocarbons via atmospheric deposition and stormwater runoff peaked...

Traditionally, hydrocarbon-impacted soils at E&P sites have been managed based on their total petroleum hydrocarbon (TPH) content. Oil and gas industry guidance on TPH clean-up concentrations at E&P sites was not based upon risk to human health; rather, it was based on the protection of plants and water resources [API, 1993; Currier and Peoples, 1954; Udo, et al., 1975; Baker, 1970; deOng, et a...

Isoprene is a volatile and climate-altering hydrocarbon with an atmospheric concentration similar to that of methane. It is well established that marine algae produce isoprene; however, until now there was no specific information about marine isoprene sinks. Here we demonstrate isoprene consumption in samples from temperate and tropical marine and coastal environments, and furthermore show that...

The diacylglycerol-carrying lipoprotein (DGLP) was purified from hemolymph of the locust, Locusta migratoria, by a rapid method which included a specific precipitation at low ionic concentration and DEAE-cellulose column chromatography. The final preparation was highly homogeneous as judged by gel electrophoresis, electron microscopy, and immunodiffusion. The locust DGLP molecule was almost sph...

in this paper, a modeling tool for risk assessment analysis of the movement of hydrocarbon contaminants in the vadose zone and mass flux of contamination release into the groundwater table was developed. also, advection-diffusion-reaction equations in combination with a three-phase equilibrium state between trapped air, soil humidity, and solid particles of unsaturated soil matrix were numerica...