Oil and Chemical Pollution最新文献

The use of airborne sensing techniques to detect discharges of oil from offshore installations has been investigated. It is shown that side-looking airborne radar can provide initial detection of oil-like targets from a range of 15 km; the presence of oil can then be confirmed by investigation at close range with a combined infrared/ultraviolet line scanner. During 154 h of flying, 21 oil slicks were detected near offshore installations; however, most of these slicks contained less than 100 litres of oil.

A numerical model has been developed to simulate the time-space evolution of oil spills in marine environments of arbitrary and complex geometry. The model is applicable to gravity-viscosity regimes, i.e. up to 1 week for large spills, and takes into account dispersion caused by wind, tides and currents, spreading and evaporation, as well as accumulation and dispersion along the shorelines.

The computer model is tested against data reportedfrom the Amoco Cadiz accident, with satisfactory agreement on the extent and location of the slick. The model is also used to simulate and estimate the consequences of a hypothetical accidental spill occurring in the vicinity of the Tarragona harbour during transportation or unloading operations of crude oil. This is of importance because the Mediterranean coast of Tarragona, and in particular the Costa Daurada region, is one of the leading European tourist resorts.

The concentration of polycyclic aromatic hydrocarbons (phenanthrene, anthracene, fluoranthene, pyrene, benz(a)anthracene/chrysene, benzo(a)pyrene, benzo(e)pyrene/perylene, benzo(k)fluoranthene and benzo(ghi)perylene) and n-alkanes ranging from n-hexadecane (C-16) to n-dotriacontane (C-32) in sixty sediment and water samples from the southern Baltic Sea were determined. Since hydrocarbon concentration itself cannot be used for estimation of marine environment pollution, multivariate classification and comparison using principal component analysis (PCA) has been made on the data matrices. The connection of the principal component score values with the geography of the sampling area was investigated. Some suggestions on the usefullness of the aforementioned parameters for the estimation of marine environment contamination are given.

Recent increased human pressures on the environment have led to biological consequences in Lagos' coastal waters, notably in the Lagos lagoon and its drainage channel to sea. Two broad surveys were conducted in February and June 1985 and repeated in 1986 to obtain information on the distribution, habitats and communities in the Lagos lagoon in relation to environmental factors. The samples were used for biological, sediment particle size, organic matter, heavy metal and hydrocarbon analyses.

A wide variety of sediments occurred throughout the study area. These ranged from fine, medium and coarse sands to admixtures of silt and clay which provided a wide selection of habitats. The western industrialized areas contained high levels of selected heavy metals. Petroleum hydrocarbon contamination was present in most samples. The percentage of total organic matter was closely associated with the sediment types and the influence of waste inputs. The distribution of several species was influenced by the salinity regime and nature of bottom deposits. Benthic macro-infauna was dominated by molluscs, which were most common in the shallow shoal sands of the northeastern portions of the study area. Species characteristic of stressed environments, notably Capitella capitata, Nereis sp. and Polydora sp., were more abundant in the polluted western industrialized portions. Several species showed seasonal population fluctuations. Diversity indices indicated that the communities exhibited high dominance with a small number of species.

Offshore oil exploration activity usually requires the discharge of drilling muds and formation cuttings into adjacent waters or on ice above these waters. Although dispersal of these muds is well documented in marine environments of moderate to high energy, the fate of drilling muds in shallow, low-energy Arctic environments has received little attention. This study focused on three drilling effluent disposal sites around Stefansson Sound in the Alaskan Beaufort Sea. All sites were in shallow (less than 5 m), low-energy marine environments. Sediment concentrations of six metals often present in drilling effluents (aluminum, arsenic, barium, chromium, lead and zinc) were examined. Metal concentrations obtained from replicate grab samples along 100 m transects were compared with those taken at four shallow-water offshore island control sites, and with data from other studies.

The results indicate persistence of barium, chromium, lead and zinc at certain stations at all three discharge sites, and elevated concentrations of aluminum at one of the three sites when sampled 2–4 years after the discharges. Metal concentrations, when elevated, were typically highest near the discharge points, continued in the direction of wind-induced longshore transport, and generally diminished with distance from the discharge site. However, distributions displayed some patchiness indicative of in place melting of ice-rafted muds or reworking of sediments by currents or icegouging.

Further work will be needed to evaluate the biological impacts of drilling effluents. However, the slow dispersal of these materials suggests there is a need for closer evaluation of drilling effluent persistence problems at shallow, lowenergy locations in the Beaufort Sea.

Five lorries shipped on board the ferry Herald of Free Enterprise that sank off the Belgian coast in 1987 contained together over 100 different chemicals. During the intricate salvage operation that followed the tragedy, the environmental protection activities met with technical, scientific, legal and organizational difficulties. An assessment of the exact nature, harmfulness, and situation of the cargo had to be done while access to the casualty was limited, and information insufficient. The risks for the personnel and for the marine environment were evaluated using both simplified scenarios and sophisticated computer simulations. Environmental contamination was monitored and protective counterpollution measures were implemented under supervision of the authorities. Although more than half the dangerous cargo was lost, environmental damage was kept to a minimum.

The application of flexible polyurethane (PU) foam for the removal and recovery of priority pollutant phenols, such as phenol, anisole, guaiacol, 2,3-dimethyl, 2,4-dimethyl, 2,5-dimethyl, 2,6-dimethyl, 3,4-dimethyl, 3,5-dimethyl phenols, 1,2-dihydroxy benzene (Catechol), 1,3-dihydroxy benzene (Resorcinol), 1,2,3-trihydroxy benzene (Pyrocatechol) and 1,3,5-trihydroxy benzene (Phloroglucinol) and their mixtures, from dilute aqueous solutions was investigated. The effect of various parameters on the absorption of phenols by PUfoam was examined. Maximum absorption can be achieved at a flow rate of I ml/min in the range pH 3–9, which is marginally increased as the temperature of the effluent variesfrom 30 to 60°C. As phenol concentration is increased, though the total quantity of phenol absorbed increases, the percentage absorption decreases. It is also observed that at low concentrations of some phenols, satisfactory extraction can be achieved even with increasing volumes of aqueous phase. Based on the extraction data, an extraction mechanism was proposed. Model schemes for the removal and recovery of phenols from industrial effluents (10–100 kl), both by dynamic and static methods, are proposed.

Levels of aliphatic hydrocarbons within the boiling range of alkanes n-C₁₄ to n-C₃₄ were determined in samples of surface sediments and in two bivalve species, Unio tigridis and Pseudodontopsis euphraticus (Unionidae), from seven locations in the lower reaches of the rivers Tigris and Euphrates, and the upper Shatt Al-Arab. These levels, and data derived from them, indicate only slight pollution, mostly by degraded hydrocarbons arising from anthropogenic sources. The Shatt Al-Arab samples were most contaminated and those from the river Tigris the least contaminated.