In this research, the results of bentonite characterization by XRF and SEM/EDS before and after adsorption are presented. The influence of adsorbent mass and initial ion concentration on the capacity and efficiency of adsorption of lead (II) ions using bentonite is determined by adsorption experiments for initial lead (II) concentrations of 200, 300 and 400 mg/L, adsorbent dosage of 0,5, 1 and 2 g, at pH 5, temperature 25 °C, stirring rate of 200 rpm, contact time between adsorbent and lead (II) ions of 2,5 minutes. The obtained results showed that with an increase in the adsorbent mass, the adsorption capacity decreases for all three tested initial concentrations, while the adsorption capacity increases with an increase in the initial concentration of Pb(II) ions for all three investigated masses of adsorbent. On the other hand, the adsorption efficiency increases with increasing adsorbent mass, while the adsorption efficiency decreases with increasing initial ion concentration.
Karić et al. (2025) studied this question.