This study examines concentration of pollutants that can contaminate soil, surface water and groundwater in the Bongor Basin. The analysis of thirty soil samples from six oil sites: Koudalwa, Ronier, Ndoubadana, Narenang, Croisement Baobab and Croisement Ridina was carried out using standard laboratory testing methods of chemical elements and pollutants. Results reveal that Nickel has a maximum concentration above the acceptable threshold of INERIS standard of France (2-60 mg/kg). Copper present concentrations above the Cameroonian standard of SONARA site (10 -30 mg/kg), Cadmium has a content above the INERIS standard of France (0.2-0.7 mg/Kg) and Cameroonian standard of SONARA site (1 -2 mg/kg). Phenol was present in all samples with very high concentration values compared to Canadian class A and B standards (0.1-1 mg/kg) and Cameroonian standard of SONARA site (0.2-1 mg/kg).

The objective of this study is to compare various changes of ecological parameters within time period prior petroleum activities and after facilities establishment in Bongor basin. Analysis of landsat 7 images from March 24 to April 5, 2000 and that of landsat 8 from February 13, 2015, before and after oil operations respectively, made it possible to extract four biophysical indices, namely: brightness index of soil, moisture index, greenness index and vegetation index. Maps of land use, hydrology and pedology were established from the analysis of multispectral parameters variations. Significant variations between two study periods were then evaluated to be either increasing, declining or stable over the entire Bongor basin and in the areas of the basin under operations. It appears that, shrub savanna has declined by 15.75% over the entire Bongor basin and by 18.90% in the areas of oil operations in Bongor basin. Floodplain and the water body have also declined by 1.59% and 0.0007% respectively over the whole Bongor basin and loss of paddy field. Agricultural area has increased by 15.15% in Bongor basin and by 14.40% in the operations area of Bongor basin, with industrial area occupying 4.49% and the expansion of urbanized area of 0.01%. Silting up of flood zone over the entire Bongor basin has increased by 0.35%. Areas under oil operations, illustrate impacts of activities on soil, trees and groundwater.

In N'Djaména, the use and marketing of certain hydrocarbons does not comply with any standard in force or with regulations provided for this purpose. Their evaporation and unregulated release into the wild significantly affects the ecosystem. The present work consists in developing a method of extraction from sediments polluted by bio surfactant (rhamnolipid) assisted by microwaves. The goal here is to look for the presence of polycyclic aromatic hydrocarbons in polluted sediments. The rhamnolipid used consists of monorhamnolipids and di-rhamnolipids, its emulsion index is 64.66% and is composed of saturated and unsaturated fatty acids having carbon numbers ranging from 12 to 18. We used the microwave micellar extraction process. It was made by keeping the concentration values fixed at 0.15 g/L and the power at 400 W and more. We observed a positive interaction of the rhamnolipid concentration factors and the power of the microwave to obtain the optimal conditions at the time of 50 S, at the concentration of 0.16 g/L and at the power of 443 W for a rate of optimal extraction of 0.91%. Chromatographic analysis by GC-MS of the optimum extracts allowed us to identify twelve (12) C10 to C43 n-alkanes and eight (8) PAHs. It emerges from this analysis that the rhamnolipid extracts seven (7) Polycyclic Aromatic Hydrocarbons in equivalent proportions while the tween 80 extracts only four (4) Polycyclic Aromatic Hydrocarbons with a high proportion (80.02%) of benzo [a] antracene.