A REVIEW OF BIOLOGICAL METHODS TO REMEDIATE CRUDE OIL POLLUTED SOIL

Abstract

Environmental pollution by crude oil can occur naturally through seepage or from anthropogenic sources via spillage, accidents or improper disposal of crude oil and related products. The main characteristic of pollution from refinery and petrochemical plants consists in that the pollution source is active, most often for a short period of time, but has an important intensity, polluting agent consisting generally of petroleum fractions. Also, in most cases of accidental spills of petroleum products, surface soil affected is much smaller than the first surface polluted aquifer pollution front met. Recent research has shown that biological methods to remediate crude oil polluted soil are a superior effective and much cheaper method compared with physicochemical methods. Biological methods are based on the activity of microorganisms to use crude oil as a source of carbon and energy. These methods are considered to be the most effective because it does not have irreversible effects on soil characteristics. Microorganisms such as bacteria, cyanobacteria, yeasts and fungi break down these dangerous chemicals into less toxic or non-toxic compounds.