Abstract
In this research work, the removal of chromium(III) ion (Cr
3+
) by raw materials such as zeolite (Z) and chert (CH) was investigated. The batch method was invested, using two concentrations in chromium(III) sulphate at 21.31mg/L and at 22mg/L in nitrate nonahydrate. In order to improve the porous structure, the specific surface area and the adsorbent capacity of these natural materials, a purification technique was undertaken, namely a chemical treatment of the used natural materials (zeolite and cherts) with NaCl was carried out. Thus, the obtained raw and purified materials were characterized through chemical analysis by X-ray fluorescence (XRF), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and liquid nitrogen adsorption-desorption analyses by measuring the specific surface area (BET method). The results demonstrated that zeolite (Z) and chert (CH) are good adsorbents and that the purified materials have a potential adsorbent to reduce the chromium concentration for a maximum adsorbed amount (Qads) of about 2.72mg/g and 2.85mg/g, respectively for purified zeolite and chert (Z-p and CH-p) in chromium(III) nitrate and about 2.83mg/g and 2.48mg/g, respectively for purified zeolite and chert (Z-p and CH-p) in chromium(III) sulphate. These results revealed that natural zeolite and chert hold great potential to remove cationic heavy metal species from industrial wastewater. The kinetics adsorption was also examined using pseudo-first-order and pseudo-second-order kinetics models. The adsorption kinetics was best described by the pseudo-second-order.