The influence of petroleum products density on the sorption capacity of thermally treated rice husks and virgin rice husks are shown in Fig. 3. The sorption capacity of samples increased with the increase of petroleum products’ density. Thus the sorption capacity increased three times for TRH700 and four times for the RH, whereby the absolute sorption of TRH700 was much higher than that of RH. This effect may be due to less retention of petroleum products into the pores of RH. As a result, gasoline (AI-80) with the lowest density (ρ=0.734 g/cm3) showed low sorption for the sorbent materials, while the heavy crude petroleum (ρ= 0.937 g/cm3) indicated a high sorption. The influence of the density of petroleum products on the sorption capacity of the adsorbent materials was also investigated with similar result in earlier study [3]. Our results confirm that petroleum sorption depends both on the adsorbent material and the adsorbate type.