Physical, chemical and thermal methods have commonly been employed to clean up the crude oil polluted sites. However, these techniques are relatively expensive and also require site restoration. Therefore, it is an urgent need for promotion of environment friendly techniques for reclamation of crude oil polluted sites. Recent studies have been reported on environment friendly bioremediation. These methods are relatively affordable and do not introduce any additional chemicals to the environment. The uses of biological materials like bacteria, fungi, algae with vermicompost, animal and plant compost, have been reported with good bioremediation potential. Bacteria are one of the best candidates for bioremediation because they have biodiversity, variety of catabolic genes and vast potential for degradation of harmful contamination. The best bioremediation technique is intrinsic bioremediation because it has minimum intervention in the environment. In this paper are presented the effect of bioremediation treatments of a soil polluted with crude oil on soil reaction. Experiments included two groups of experimental variants in which the soil was controlled polluted by 5% and 10% crude oil. For each concentrations of crude oil were created 4 experimental variants, achieved by conditioning the soil with Ecosol in two doses, with or without inoculation with bacteria selected, plus a control variant were the soil polluted was subject to natural attenuation. All data were reported at a variant with unpolluted soil achieved and maintained under the same experimental conditions. Soil reaction in unpolluted soil - control, varies around the average value of 8.11 which defines a weakly alkaline soil. The effect of the application of Ecosol product on soil reaction is to increase values of up to 8.78 or 8.83 to variants with 1% Ecosol. This pH increasing defines soil as a moderated alkali. This could be detrimental to the bioremediation treatments efficiency of soil polluted with crude oil, as microorganisms metabolizing petroleum hydrocarbons have an optimum around a neutral range in the soil reaction. During the three experimental years it can be observed an uniformity of soil reaction. Ecosol product caused a slight alkalizing immediately after application in soil, but with a limited duration, not the activity of bacteria exerted negative influences on the optimal environment for development which is located around neutral.

bioremediation treatments, soil polluted, crude oil, soil reaction

sciences soil

Presentation: poster