BIODEGRADATION YIELD OF CRUDE OIL IN SOIL POLLUTED AND TREATED IN DIFFERENT EXPERIMENTAL VARIANTS

Abstract

Soils pollution with crude oil is becoming an ever increasing problem, especially in the light of several breakdowns of oil pipelines and wells reported recently. Due to its toxicity, widespread presence and complex nature, this type of pollution is a serious problem, one reason being that as the modern civilisation, urbanisation and mechanisation develop the use of crude oil products grow. The influence of soil pollution with crude oil depended on the type of soil, crude oil concentration in soil and fertilisation. The study has been undertaken to assay the biodegradation yield of soil polluted with crude oil and treated in different experimental variants. In soil polluted with 5% crude oil, doubling fertiliser dose from 0.25% to 0.5% has exercised the most spectacular effect, causing an increase of yield to 45.7% in absence of bacterial inoculation. Atlow fertiliser dose, inoculation with selected bacteria induced a strong stimulation effect; the bioremediation yield is 24% higher thant hat determined inuninoculated variant. In variants excessively polluted with 10% crude oil, microorganisms with biodegradation capacity of petroleum hydrocarbons have required amore or less period of time to adapt to pollutant presence in excess. Necessary period to adapt to environmental changing, microorganisms was significantly decreased by soil conditioning with Ecosol at 1% concentration.