Application of Soil Washing Treatment Method for the Remediation of Petroleum Polluted Soil

Dynamics Of Pollutants In The Soil

Presently, the geosphere is seen as fragile and prone to damages emanating from anthropogenic activities (Raphael et al., 2013). Manahan (2001) defined pollution as an increase in the quantity of a particular element above the levels in which they naturally occur, resulting from external source related to human actions. Xenobiotic behaviour in the soil is of great difficulty to predict, because its composition is completely complex and heterogeneous. Hence, the understanding of the physico-chemical properties of the contaminant compounds and the environment is fundamental to predict its dynamics.

Contaminant spread in the soil in vaporised, residual or absorbed phases, free phase and dissolved phase. The distribution of such phases will depend on their physico-chemical properties and also on the soil type. Hence, the movement of the contaminants and their toxic nature are linked to the soil’s capacity in maintaining them while retained in their solid phase, making them not available to be absorbed by plants, eroded or leached (McBride, 1994). Soil particles (m²/g) have available surface area due to some of the factors that influence binding between the contaminant and the soil. Also, the adsorption of contaminant to the environment is influenced by the electrical charge of the soil particles (Otten et al., 1997).