Fig. 9 (e) is similar to Fig. 9 (c), but the number of pores in TRH700 is higher than in TRH400 as well as their size are larger. Eventually, the interior structure of TRH700 (Fig. 9 f) shows the converting of backbone-like structures into reticulated structures. High petroleum sorption ability is determined by the porous structure of adsorbents, as well as by the physical and chemical interactions of their functional groups with the crude oil components. One can see in SEM images that thermal treatment allows to obtain a drastically modified structure with higher porosity compared to the virgin husk samples.