RIASSUNTO
ABSTRACT:
The clean-up of oil spills in the Arctic environment is often limited by severe and cold environmental conditions. Mechanical methods are usually considered to be most favourable for oil spill combatting. However, remote spin sites, long distances, severe environmental conditions and sensitive ecosystems mean that more advanced combatting techniques are also needed to back up conventional recovery and clean-up measures. This paper describes the results of macro-scale tests conducted by VIT Manufacturing Technology to study the effectiveness of biosorbent technology against marine oil spills. The use of biosorbents was studied as a joint research project involving VIT (Finland) and the Murmansk Marine Biological Institute (Russia). Selected biosorbent products of Marine Systems, U.S.A, and the Bios Group, Russia, were used in macro-scale tests conducted in a basin measuring 15.0 II 3.0 m in length and width, respectively. This paper outlines the macro-scale test project, including microbiological and chemical studies, supported by toxicity tests and various analyses to understand better the fate of oil, especially the degree of biodegradation during the test.
1 INTRODUCTION
Hydrocarbon-degrading microbes have been studied extensively, and they have been found in all marine environments. In general, the background-rate of these bacteria increase near the sites of petroleum discharge compared to areas far away from the oil inputs (Bragg, 1992). When spilled into the marine environment, oil is altered not only by biodegradation but also by evaporation, photo-oxidation, dissolution and emulsification. No crude oil is completely biodegradable, even under the most favorable conditions. The proportion of nonvolatile components removable by biodegradation may vary from as little as 11 % to as much as 90 %, depending on the nature and origin of the oil. (Bartha, R. & Atlas, R. M., 1987) Petroleum hydrocarbons generally have a very low water solubility.