The determination of moisture (M), volatile matter (VM), and ash content was conducted according to a modified ASTM
method D1762-84 [30]. The changes in the surface morphology of adsorbent samples were determined by analyzing their
respective SEM images, which were obtained using a scanning electron microscope (SEM) model JEOL JSM-6390LV (Japan).
The surface chemistry of the adsorbent surfaces was analyzed by an FTIR (PerkinElmer Model 2000, USA). The FTIR spectra
measurements were carried out over 4000-400 cm-1 using the KBr method. The surface areas of samples were determined by
using nitrogen adsorption/desorption method measured at 77K using a surface analyzer (NOVA-2000e; Quantachrome Corp.,
Boyton Beach, FL, USA). The CP or char was degassed for about 9 hours under vacuum at 393 K prior to conducting adsorption
measurements. The surface area was calculated using the BET methods, and the pore volumes were taken at P/Po = 0.99.