**Author details**

organic material with hydrogen peroxide showed low ethanol sorption. The aromatic com‐

Evaluating the transportation of gasoline compounds by soil with application of 50 kPa of pressure, indicates low retention and greater mobility, because mostly they are hydrophobic compounds that do not bind the soil particles. Another aspect of this experiment is that has not been evaluated by diffusion flux, which occurs at speeds equal to or less than 10-10 cm/s. The test of sorption to organic matter proved to be important in the retention process of ethanol. In view of the low adsorption of gasoline compounds by soil suggests considering projects of liners gradients below 75 and pressures less than 50 kPa ensuring a hydraulic conductivity greater than 10-8 cm/s and use clayey material rich in organic matter to promote greater

Since the lateritic soil studied possesses a high aggregation capacity, even when compacted at normal Proctor energy, micropores remain which, in high hydraulic gradient situations, are interconnected, forming flow channels. However, even under higher hydraulic gradients in the gasoline percolation tests, this soil presents good material of liners. This is due to the stabilizing of the flow channels formed, favoring also the stabilizing hydraulic conductivity.

The measure that gasoline occupies the pores in the process of saturation the concentration of ethanol increases. This is due to the polarity of the ethanol. The aromatic compounds maintain a **C/Co** ration close to 1, as the volume of pores increases, indicating that these are tracers due to their low dielectric constant and polarity. Due to their low solubility in water, the olephines and saturates are more present in the LNAPL phase. These hydrocarbons may form emulsions,

Regarding the retarding potential of the lateritic soil, evaluated by the sorption parameter, it is not directly correlated with the mineralogy, because the aromatic compounds are not absorbed when the organic material is extracted. Actually, this sorption may be correlated with a certain type of humic substance, which may be interacting with the poly-amorphs of the oxyhydroxides of Fe and Al in the soil, favoring interaction with the aromatic compounds.

Finally, a low hydraulic gradient context (< 75), hydraulic conductivity < 10-8 and organic

The authors are gratefully to the Conselho Nacional de Desenvolvimento Científico e Tecno‐ lógico – CNPq, CAPES and ANP for the fellowships and financial support granted to the

pounds, which are hydrophobic, were not absorbed.

652 Environmental Risk Assessment of Soil Contamination

**6. Conclusion**

**Acknowledgements**

accomplishment of this research.

retention of ethanol and avoid or reduce the effect of co-solvency.

favoring transportation through the soil in the aqueous phase.

matter, in lateritic soil can improve the performance of liner.

Wisley Moreira Farias1 , Geraldo Resende Boaventura1 , Éder de Souza Martins2 , Fabrício Bueno da Fonseca Cardoso3 , José Camapum de Carvalho1 and Edi Mendes Guimarães1

1 Universidade de Brasília, Brasília-DF, Brazil

2 Embrapa/ Cerrados, Planaltina –DF, Brazil

3 ANA-Agência Nacional de Águas –Brasília-DF, Brazil
