Abstract
Crude oil and refined petroleum products are mixtures of a large numbers of components, each with its own chemical and physical properties.
Once oil is spilled, it immediately begins to undergo many natural physical, chemical and biological changes.
Oil and oily wastes can sometimes be broken down using biological process. Biodegradation of oil by microorganisms can only take at oil–water interface, so that on land the oil must be mixed with a moist substrate.
The rate of degradation depends upon temperature and availability of oxygen and appropriate nutrients containing nitrogen phosphorous.
There are a number of products on the market which contain oil degrading bacteria and other micro-organisms. And addition of oil soluble nutrients to accelerate the process of natural degradation these nutrients are more likely remain at the oil water interface rather than become dissolved in the sea. Although degradation rates can often be increased by regular aeration of the soil and by the addition of fertilizers, such as urea and ammonium phosphate. The method is only likely to be applicable to relatively small spills because of the amount of land required.
The contaminated material should not contain more than 20% oil, the oily debris is the spread over the surface to a depth of no more than 0.2 meters, the maximum application rate being about 400 tones of oil per hectare of land the oil should be left to weather until it is no longer sticky before being thoroughly mixed in with the soil using a plough or rotavator mixing should repeated at intervals of 4–6 weeks for the first six months but less frequently thereafter the biodegradation is suitable to applicable on artificial island at Belayim.
