Comparison of Two Different Biosorbents for Heavy Metal Removal

Pistachia lentiscus (LPw) and date palm leaves (PDw) are two biosorbents that are mainly used for the removal of chromium and cobalt from an aqueous solution. These biosorbents were characterized by physicochemical procedures, including Fourier transform infrared spectroscopy, zero charge point, Boehm method, and Brunauer-Emmett-Teller (BET) method. Various parameters, such as contact time, biosorbent quantities, diameter of the biosorbent particles, ionic strength, initial pH, and initial concentration of solutions, were optimized. The reactions of PDw+Co, LP+Co, and LPw+Cr exhibited similar isotherm profiles of type L, but indicated isotherm type C in the reaction PDw+Cr profile, according to the BET classification. All reactions mentioned above were described by the Freundlich and Temkin adsorption isotherm models, with R-2 greater than 0.97. The kinetics most likely followed the pseudo-second-order model which was confirmed by error calculation.