Abstract
A series of adsorbents were prepared from palm shell powder (PSP) at different thermochemical conditions. APSP was prepared by treating PSP with H2SO4, PAPSP by further modification of APSP with K2S2O8 at 150 °C and 9AAC by thermal activation of APSP at 900 °C. Fourier transform infrared spectroscopy analysis revealed similarity of functional groups in PSP, APSP and PAPSP, suggesting that functional groups are retained during chemical or physical treatment of PSP at 150 °C. A wide pH range (3–8) was found suitable for cadmium and zinc adsorption. The adsorption of Cd2+ and Zn2+ was found to be feasible, spontaneous, exothermic, and could be described by the pseudo-second-order kinetic model as well as by Langmuir and Freundlich isotherm models. The maximum adsorption capacity was found to be 363.636 and 238.095 mg/g for Cd2+ and Zn2+, respectively, using PAPSP. Desorption was achieved using HCl and EDTA for Cd2+ and Zn2+, respectively.
