Effects Of Hydrocarbon Pollution Research Articles

Effect of Hydrocarbon Pollution on the Fungal Communities of the White and Barents Sea Littoral Sediments

The effect of hydrocarbon pollution on the fungal communities of littoral sediments of the cold-water White and Barents seas was investigated. The samples were collected at locations with different levels of pollution with oil products, from ports to relatively undisturbed areas. Using the diesel fuel-containing medium resulted in detection of hydrocarbon-degrading fungi in almost all studied samples, although in all cases they were less diverse than sugar-degrading fungi. In this relatively small group, Penicillium chrysogenum and Penicillium brevicompactum were the most common organisms. Fungal communities isolated on a sugar-containing medium exhibited higher diversity and abundance, with being the most common sugar degraders. The major factors affecting the structure of the fungal communities were the percentage of hydrocarbons in the total mass of organic carbon in the samples in the case of hydrocarbon-degrading fungi and location, for sugar degraders. In the experiment, the highest hydrocarbon-degrading activity was shown for Penicillium chrysogenum (the loss of residual hydrocarbons was 77.4%), Cadophora fastigiata (72%), and Tolypocladium inflatum (67.2%).

Effect of Hydrocarbon Pollution on the Fungal Communities of the Littoral Sediments of the White and Barents Seas

Effect of Hydrocarbon Pollution on the Fungal Communities of the Littoral Sediments of the White and Barents Seas

A Critical Review on Expansive Soils Including the Influence of Hydrocarbon Pollution and the Use of Electrical Resistivity to Evaluate their Properties

This paper reviews the studies on expansive soil with a main focus on failure mechanism, financial losses, mineralogy, determination of swelling parameters and others. Effect of hydrocarbon pollution on geotechnical properties of expansive soil was presented. The paper discussed the assessment of electrical response of contaminated swelling soils. Wide extend of expansive grounds around the world and the serious impact created on infrastructures requires to identify its influential aspects and the appropriate treatments. Also, it was found that petroleum product affect significantly on the basic properties of swelling soils such as gradation, consistency, compaction, swelling and others, and electrical resistivity can be employed to reveal the electrical characteristics of polluted expansive soil.

Process optimization of silica encapsulation technique as a unique remediation technology for the treatment of crude oil contaminated soil

The effect of hydrocarbon pollution on soil quality is globally challenging. Addressing the menace of pollution on soil necessitates research into the development of viable remediation technique that is fast, effective, efficient and environmentally friendly; with cutting edge advantages over conventional remediation techniques. The technique was designed using a formulated silica encapsulating product and applied on soil contaminated by simulation with 10% crude oil. Soil was characterized for its physicochemical properties using standard methods, while its TPH content determined by molecular spectroscopy. Properties such as conductivity, pH and phosphorus levels were severely impacted by the hydrocarbon effect. Silica encapsulating product was formulated from sodium silicate and sodium dodecyl sulphate using proper optimization procedures. The encapsulating product (sodium silicate and SDS) were used in a ratio of 1:2. Optimum concentrations of 60,000 ppm sodium silicate solution, 120,000 ppm SDS, applied at optimum pH and temperature of 5 and 25 °C respectively were established from the process optimization of the experimental technique. The technique shows rapid response towards TPH removal, as 86.79% TPH reduction is achieved after seven days of treatment. The encapsulation process follows pseudo first order kinetics. Significant reduction in metals; Ni (0.61–0.036 mg/kg), V (0.82–0.11 mg/kg) and Cd (0.05–0.016 mg/kg) shows the efficacy of the technique, thereby providing a dual alternative for the remediation of hydrocarbons and heavy metals. The technique seems to be effective in restoring some lost soil properties as seen in pH, conductivity and total nitrogen after treatment. The environmental friendliness, cost effectiveness and merits associated with this technique gives it a unique advantage over other conventional methods; as such presents promising alternative route for remediation experts in addressing the challenges associated with hydrocarbon and metals pollution on soil. Silica encapsulation technique is therefore suitable for outright applications in real field challenges.

The effect of hydrocarbon pollution on polysulfone-based membranes in aqueous separations

This work investigates the influence of hydrocarbon pollution on the performance of desalination membranes with a polysulfone support. Toluene was chosen as the model hydrocarbon compound and permeation measurements were performed on two commercial membranes with a polysulfone support in water saturated with toluene. Over time, the TriSep TS80 membrane under analysis broke down and the delamination of the separation layer was observed. The influence of the polysulfone layer on the membrane deterioration was studied in detail by the use of a model system of a thin polysulfone film on top of a silicon wafer. In situ spectroscopic ellipsometry, and in situ optical microscopy revealed that the non-ideality of the hydrocarbon in water system initiates a dewetting of the polysulfone layer which is the root cause of the membrane failure.

Effects of hydrocarbon pollution in the structure of macrobenthic assemblages from two large estuaries in Brazil

Changes in the structure of benthic macrofauna and its relationship with hydrocarbon contamination were determined at different spatial scales in sublittoral sediments of two large estuaries in Brazil. Guanabara Bay (GB) is a heavily polluted estuary due to the presence of a large industrial complex and high demographic density. Laranjeiras Bay (LB) lies in an Environmental Protection Area and can still be considered as preserved from human activities. Despite some spatial differences within each bay, the PAHs concentrations were significantly and consistently higher in GB, with values generally above the threshold effect levels. No signs of hydrocarbon contamination were observed in LB. Macrofauna abundance, diversity and overall assemblage structure were largely different between bays. Canonical analysis of principal coordinates (CAP), used to model the relationship between macrofauna and PAHs levels, indicated that this class of hydrocarbons is the main structuring factor of soft-bottom assemblages in both bays.

Effect of hydrocarbon pollution on the microbial properties of a sandy and a clay soil

The aim of this work was to ascertain the effects of different types of hydrocarbon pollution on soil microbial properties and the influence of a soil’s characteristics on these effects. For this, toxicity bioassays and microbiological and biochemical parameters were studied in two soils (one sandy and one clayey) contaminated at a loading rate of 5% and 10% with three types of hydrocarbon (diesel oil, gasoline and crude petroleum) differing in their volatilisation potential and toxic substance content. Soils were maintained under controlled conditions (50–70% water holding capacity, and room temperature) for six months and several microbiological and toxicity parameters were monitored 1, 60, 120 and 180 days after contamination. The toxic effects of hydrocarbon contamination were greater in the sandy soil. Hydrocarbons inhibited microbial biomass, the greatest negative effect being observed in the gasoline-polluted sandy soil. In both soils crude petroleum and diesel oil contamination increased microbial respiration, while gasoline had little effect on this parameter, especially in the sandy soil. In general, gasoline had the highest inhibitory effect on the hydrolase activities involved in N, P or C cycles in both soils. All contaminants inhibited hydrolase activities in the sandy soil, while in the clayey soil diesel oil stimulated enzyme activity, particularly at the higher concentration. In both soils, a phytotoxic effect on barley and ryegrass seed germination was observed in the contaminated soils, particularly in those contaminated with diesel or petroleum.

The effects of hydrocarbon pollution from a two‐stroke outboard engine on the feeding behaviour of Lythrypnus dalli (Perciformes: Gobidae)

Feeding behaviour (time of attack on flake fish food) in Lythrypnus dalli was measured under pollution concentrations of 2.1 and 4.01mgl−1 total extractable material produced by a two‐stroke outboard engine. The variance of the times increased in pollution versus control treatments for both concentrations. No significant difference was found between the mean times of the control and 2.1 mgl−1 pollution treatments. A significant difference was found between the mean times of the control and pollution treatments for two different tests at 4.01 mgl−1. The combination of the increase in mean time of food attack and the increase of variance indicates that pollution concentrations lower than LD50 levels change feeding behaviour, and thus may indirectly effect the survival of the organism.

Nitrification and autotrophic nitrifying bacteria in a hydrocarbon-polluted soil.

In vitro ammonia-oxidizing bacteria are capable of oxidizing hydrocarbons incompletely. This transformation is accompanied by competitive inhibition of ammonia monooxygenase, the first key enzyme in nitrification. The effect of hydrocarbon pollution on soil nitrification was examined in situ. In a microcosm study, adding diesel fuel hydrocarbon to an uncontaminated soil (agricultural unfertilized soil) treated with ammonium sulfate dramatically reduced the amount of KCl-extractable nitrate but stimulated ammonium consumption. In a soil with long history of pollution that was treated with ammonium sulfate, 90% of the ammonium was transformed into nitrate after 3 weeks of incubation. Nitrate production was twofold higher in the contaminated soil than in the agricultural soil to which hydrocarbon was not added. To assess if ammonia-oxidizing bacteria acquired resistance to inhibition by hydrocarbon, the contaminated soil was reexposed to diesel fuel. Ammonium consumption was not affected, but nitrate production was 30% lower than nitrate production in the absence of hydrocarbon. The apparent reduction in nitrification resulted from immobilization of ammonium by hydrocarbon-stimulated microbial activity. These results indicated that the hydrocarbon inhibited nitrification in the noncontaminated soil (agricultural soil) and that ammonia-oxidizing bacteria in the polluted soil acquired resistance to inhibition by the hydrocarbon, possibly by increasing the affinity of nitrifying bacteria for ammonium in the soil.

Influence sur l'aerosol marin d'une pollution accidentelle de la mer

Abstract In order to study the effect of hydrocarbon pollution on the particles size distributions of a marine aerosol in the atmosphere, impactor and Nuclepore filters were used. Comparisons between marine aerosol and hydrocarbon polluted aerosol are carried out, showing important modifications.