Exploring the adsorption potential of lanthanum (III), samarium (III), and cerium (III) from aqueous solutions utilizing activated carbon derived from date seeds

Abstract

In the present investigation, Lanthanum (III), Samarium (III), and Cerium (III) were subjected to adsorption onto activated carbon derived from date seeds (ACDS), which underwent activation using 40 % sulfuric acid. The activated carbon (ACDS) was characterized through X-ray Diffraction (XRD), Thermogravimetric Analysis-Differential Thermal Analysis (TG-DTA), and Fourier Transform Infrared Spectroscopy (FTIR). Thermodynamic parameters were calculated to assess the sorption process, revealing an endothermic and spontaneous nature, accompanied by an increase in system randomness. The findings showed that when the pH rose to an ideal level of 5.7 and the contact duration was extended to 180 min, the number of cerium (III) and samarium (III) ions absorbed increased. the distribution coefficient (Kd) of La(III) from 22.22 to 1000 mL/g, Ce(III) from 28.07 to 1865.38 mL/g, and Sm(III) from 35.71 to 3971.43 mL/g, with the pH varying from 1.2 to 5.7. The Langmuir model exhibited superior fitting to the experimental data compared to the Freundlich model, suggesting homogeneous adsorption on the ACDS surface. The maximum adsorption capacities (Qmax) for La3+, Ce3+, and Sm3+ onto ACDS were determined as 18.18 mg/g, 24.58 mg/g, and 27.82 mg/g, respectively.