o:458 Lead removal from aqueous solutions using bean shells - equilibrium, kinetics and thermodynamic studiese en Abstract: Lead ions removal from aqueous solutions onto bean shells is presented in this paper. The experiments were conducted in a batch system. The bean shells samples were rinsed with distilled water before the adsorption experiments. The analysis of the rinsed water showed that a significant amount of alkali and alkaline-earth metal ions are transferred from the adsorbent structure into the rinsed solution during the rinsing process. The COD analysis showed that these waters should be treated before being discharged into the surrounding watercourses. The influence of different process parameters (the pH value of the solution, the initial metal ions concentration, and the initial mass of the adsorbent) on the adsorption capacity was investigated. The adsorption capacity was higher at higher pH values of the solution. The adsorption capacity showed a decrease with the increase in the mass of the adsorbent. The increase in the initial metal ions concentration was shown to lead to an increase in the adsorption capacity until 0.8 g dm-3 , after which a slight decrease was noted. Characterization of the adsorbent was performed by SEM-EDX, DTA-TGA, and FTIR analysis. The SEM-EDX analysis indicates a change in the morphology of the sample after the adsorption, as well as that K and Mg are possibly exchanged with lead ions during the adsorption process. The results obtained by the DTA-TGA analysis showed a weight loss of 77.8 % in the temperature range from 20oC to 900oC. The FTIR analysis indicated that the amide group is involved in the adsorption process. The pseudo-second order kinetic model was shown to be the best fit for the analyzed data, which led to the conclusion that chemisorption was a possible way of binding lead ions onto the surface of the bean shells. The Hill isotherm model was the best model for the analyzed adsorption equilibrium data. Obtained thermodynamic data indicated that the adsorption process was spontaneous, endothermic, and disordered, in which lead ions are bound to the surface of the bean shells by chemisorption. The maximum achieved adsorption capacity was 46.36 mg g-1 Keywords: adsorption, bean shells, equilibrium, kinetics, lead ions 91552100 66313481 1552099 10.37358/RC.21.4.8462 2022-06-22T10:25:33.533Z 44 yes 46 Miljan Marković Univerzitet u Beogradu, Tehnički fakultet u Boru ; University of Belgrade, Technical faculity in Bor Milan Gorgievski Univerzitet u Beogradu, Tehnički fakultet u Boru ; University of Belgrade, Technical faculity in Bor person 0000-0002-9899-719X Dragana Božić Institut za rudarstvo i metalurgiju Bor ; Mining and metallurgy Institute Bor person 0000-0003-1055-8449 Velizar Stanković Univerzitet u Beogradu, Tehnički fakultet u Boru ; University of Belgrade, Technical faculity in Bor person 0000-0002-1399-3481 Milorad Cakić Univerzitet u Nišu, Tehnološki fakultet u Leskovcu ; University of Niš, Faculty of Technology in Leskovac person Vesna Grekulović Univerzitet u Beogradu, Tehnički fakultet u Boru ; University of Belgrade, Technical faculity in Bor person Kristina Božinović Univerzitet u Beogradu, Tehnički fakultet u Boru ; University of Belgrade, Technical faculity in Bor person 0000-0002-9834-448X application/pdf 906842 https://unilib.phaidrabg.rs/o:458 no yes 16 70 92000001 71A03 Revista de chimie [Elektronski izvor]. - ISSN 0034-7752 72 4 118 137 2021