Oil biodegradation is a natural but slow process, limited mainly by the scarcity of nitrogen and phosphorus. To enhance hydrocarbon breakdown by indigenous microbial communities, a fertilizer formulation that would keep nutrients in contact with oil was sought. A research project established for this purpose 12 years ago has resulted in the development of an oleophilic fertilizer known as Inipol EAP22. The product is an oil-soluble fertilizer formulated as an oleophilic microemulsion. It contains not only nitrogen and phosphorus, but also an easily biodegradable carbon source. Numerous experiments, in both laboratory and field, have shown that, even in cold climates, application of this fertilizer increases the number of hydrocarbon-degrading organisms and the extent and rate of biodegradation. Kinetic studies show that the amount of nitrogen and phosphorus in the fertilizer is sufficient to allow the indigenous bacteria to consume all of the carbon source contained in Inipol EAP22. Once this carbon is consumed and the number of hydrocarbon degrading bacteria has increased, oil biodegradation can begin. In addition, adding fertilizer has a marked effect on the oil's consistency and increases its bioavailability. The recent large bioremediation project in Alaska has shown that it is possible to enhance the biodegradation of oil on shorelines through the application of such a fertilizer. Enhanced oil biodegradation can be considered today as a new tool in oil spill cleanup, to be used in conjunction with other treatments.

Oil exploration in arctic regions will require special oil spill cleanup methods for shorelines. The application of fertilizers to speed biodegradation of oil may hold promise. INIPOL EAP22, an oil-soluble fertilizer that is nontoxic and biodegradable, was tested in a series of experiments on Spitsbergen, Norway, to determine its effectiveness under various conditions. The fertilizer was applied to floating oil and to oil on shoreline sediments. Effectiveness of the treatments varied. The oil-on-water experiments showed virtually no signs of biodegradation, perhaps because photo-oxidation products and low-boiling-point hydrocarbons interfered. Experiments with oil in sediments showed mixed results: oil in finer sediments showed little or no biodegradation, but oil in coarser sediments was significantly biodegraded. Uptake and exchange of nutrients depends on the complex growth kinetics of the bacteria involved, and requires detailed study.

Hexadecane biodegradation by a marine bacterium has been investigated in the presence of an oleophilic nutriment (INIPOL EAP 22). Hydrocarbon attack was only observed after metabolism of the fatty acids present in the fertilizer.The bacterium used up 95 % fatty acids in the first 24 hours. Hexadecane biodegradation took place after 50 h incubation and reached 40 % after 360 h.

The oil spill simulation model GULFSLIK III is applied to simulate an oil spill in the Mar jan oil field, an important offshore field in the Arabian Gulf. The model incorporates several new changes over previous versions, including a surface spreading formula developed from measurements of experimental spills in the gulf. Other features are a variable release rate for the spilled oil, a two-component evaporation model, and dispersion in the vertical and horizontal directions. The currents in the region are simulated using a multilayer hydrodynamical model, in which the driving forces include wind stress and density gradients produced by evaporation, fresh water inflow, and radiative heat transfer.The three-dimensional transport and dispersion of the oil from the Mar jan simulated spill are mapped to examine their impact on the surrounding marine environment. Changes in the oil as it weathers are recorded. Results show that Bahrain is the area most threatened by surface oil and Qatar waters by subsurface oil. Evaporation removes a significant amount of the spilled oil.

Ten years ago, Elf Aquitaine began developing the technologies for the acceleration of hydrocarbon biodegradation. The continuation of this work has involved the study of new additives to complement the oleophilic nutrient, INIPOL EAP 22. In particular, it has been shown in both laboratory and in situ tests that hydrocarbon degradation can be accelerated by animal meals, which are natural products. Preliminary laboratory studies carried out under batch conditions, have shown that the use of these products has resulted in considerable growth of the bacteria, coupled with a notable increase in the biological degradation kinetics of the hydrocarbons. These results are comparable with the performance of the nutrient INIPOL EAP 22. In situ experiments undertaken on soils polluted by hydrocarbons have shown that by using animal meals, 50 percent biodegradation was obtained after six weeks and this increased to 80 percent when mechanical aeration was also employed. Under nutrient-free control conditions, 25 percent biodegradation was obtained with no aeration and 35 percent with mechanical aeration. In trials using coastal sandy sediments, the use of these nutrients has resulted in an increase of both the number of hydrocarbon specific bacteria and the hydrocarbon degradation. It can be concluded from these pilot experiments that in the development of bioremediation as an operational tool in the response to accidental oil spills, these nutrients of natural origin represent an interesting advance.