Oil and Petrochemical Pollution最新文献

Cultures of the marine diatom Skeletonema costatum (Grev.) Cleve exposed to sea water extracts of various oil- and water-based muds and cuttings showed reduced photosynthetic capacity within a few minutes; mortality was generally low on the first day. Growth rate was the most sensitive indicator of toxicity, falling to zero even for cultures which appeared normal and physiologically intact. Exposure to aqueous solutions of 100–1000 ppm of diesel-based muds reduced growth rate significantly, while water-based muds exerted a similar effect only at 100 000 ppm. Various alternative (low aromatic) oil-based muds gave intermediate effects, not only dependent on the base oil, but also on the mud composition and on changes occurring during drilling. The toxicity of the muds and the derived cuttings was clearly correlated, even in 9 months old sediment layers of cuttings. Programme.

To be effective, risk control requires scientific, engineering, technological, and managerial expertise. The latter discipline is frequently overlooked. This is ironic because it is the managerial factor that truly establishes a result-oriented program. A new concept has recently been developed and successfully carried out that stresses management of risk control function. This concept steps ahead of traditional methods and answers two important questions: What is the necessary level of control for your organization? How can that level of control be economically attained?

It is important to have an understanding of an organization's error exposures and existing control over these exposures before any effective program can be carried out. Only when the exposure/control relationship is known can potential incident causes be identified in time to take corrective action. The combination of these three principles is the basis for this program.

Effective management of the risk control function requires recognition of the control/exposure relationship,subsequent prediction of future incident trends and appropriate action based on these predictions. The numerous forces exerting an influence on the control/exposure relationship are summarized in four factors: resistance, operational, motivational, and historical.

Quantification of these factors leads to the determination of the risk control performance index for the operation. Comparison of this index to past incident trends will permit prediction of future incident and loss trends. With this understanding, an action plan containing sound, well-directed risk control procedures and practices can be developed and carried out, greatly assisting in the prevention of future oil spills.

Oil-related industrial developments in Milford Haven began in 1960. Over the next 13 years four refineries, one terminal and one power station were opened. With the onset of tanker movement came the inevitable oil spills. Ecological studies of the rocky shores began in 1958 and continued until 1982. This paper deals with the most recent studies, carried out in 1982. Results show that biological changes have occurred on some rocky shores, mainly in limpet, barnacle, gastropod and seaweed populations. Changes tend to be shore-specific and are either interpreted as natural or tentatively linked to oil industry activity.

Apart from localised changes, Milford Haven continues to support apparently healthy rocky shore communities. There are several factors which have helped to prevent the deterioration of the shores, such as tidal flushing, active port management and strict water authority effluent quality standards. In addition, the rocky shores are comparatively resilient, and Milford Haven has never been subjected to an extremely severe oil spill.

Sublittoral benthic studies revealed that the communities in certain areas may have been subjected to mild pollution stress. To date, damage in Milford Haven has been very limited, but strict controls must be maintained in the future to ensure that conditions do not deteriorate further.

At the request of the Commission of the European Communities, the Advisory Committee on Pollution of the Sea undertook a study to develop a centralized oil pollution survey for member states. A feasibility study identified the operational needs of the survey, which sought to standardize the level and range of data collected between countries. In two pilot surveys, completed during 1982 and 1983, questionnaires were distributed to a representative sample of reporting organizations. Although fewer than expected returns were received, and some states were unable to provide the required information within the time period allocated, useful statistics were generated particularly for the southern North Sea area.

Furthermore, validation procedures suggested that the magnitude of reporting errors was less than 5% overall and the questionnaire developed did fulfil the objectives of the study. Future surveys of a similar type are likely to be more successful, in terms of the volume of data collected, if arranged on a systematic basis thereby overcoming the constraints of the ‘one-off’ retrospective approach.

The effects on freshwater wildlife of chronic exposure to oil field discharges are not well known. Collections of wastewater, aquatic invertebrates, fish, salamanders, and small mammals were made in several streams in the oil fields of western Pennsylvania during 1980-81. Estimates of the petroleum content of two wastewater discharges were high (21.9 and 8.4 ppm) and one was low (0.3 ppm). Water conductivity was inversely related to aquatic invertebrate biomass. Hydrocarbons, accumulated in significantly greater amounts in crayfish, fish, and small mammals from collection sites with oil extraction activity than from sites without oil extraction activity. Estimates of total petroleum in invertebrates, trout, and suckers averaged between 200 and 280 ppm for oil extraction sites and between 8 and 80 ppm for sites without oil extraction activity. Oil extraction activity did not affect metal accumulation by fish. Oil and wastewater discharges in oil fields disrupt community composition and can cause an overall reduction in stream productivity.

In South Australia, the newest Australian liquid hydrocarbon marine export terminal has been completed in record time. The terminal services domestic and export trade in crude oil, condensate and liquefied petroleum gases while operating within a gulf which supports a major shellfish and scalefish industry and a small, but growing, recreation market. The Terminal Operator has undertaken an integrated, rational and cost-effective environmental protection strategy based on planning studies designed to ensure Government and community approval for the facility. This paper outlines those planning studies, which include: oil slick trajectory forecasting, ballast water diffuser outfall performance, prawn taint testing, coastal habitat sensitivity rating and mapping, oil spill response equipment selection and deployment strategies, equipment field trials and industry-government consultative groups.

The practical value of the mechanical oil recovery system was proved during various oil control operations and further improvements were made to the system. The experience thus gained resulted in the final design of the type-8 ‘sweeping arm’ and more recently in a new mechanical recovery system for highly viscous oils — the ‘oil crab’.

The sweeping arm system consists of a fixed sweeping boom with a built-in weir-type skimmer and pumping equipment. The oil crab is also based on a weir-type skimmer system towards which the oil is concentrated by a V-shaped arrangement. The main difference between the two systems is that the oil crab has an integrated storage and oil-water separation facility, while with the sweeping arm system these facilities should be on board the towing vessel.

The advantages of the sweeping arm system are that the whole system is very flexible and can therefore be adapted to changing circumstances, it is mobile, easily transported and can be used from any vessel or barge. The system is, however, limited by its inability to handle very high viscosity oils and debris and the safety requirements of the towing vessel in the case of lighter oils.

To overcome these problems and to have an alternative system the oil crab has been developed. The efficiency of the oil crab is unaffected by the viscosity of the oil and the presence of debris. The whole process is non-mechanical and takes place without the aid of pumps or other moving parts.

The performance of both systems can be improved by using booms to concentrate the oil.

The Civil Liability Convention of 1969 and the Fund Convention of 1971 were amended at an International Conference on Liability and Compensation for Damage in Connection with the Carriage of Certain Substances by Sea held in London from 30 April to 25 May 1984.

The changes in the Conventions, their implication and the arguments leading to the alterations are discussed. An assessment is made of the importance of the decisions taken at the Diplomatic Conference and the consequences for persons claiming for pollution damage.