Removal of Lead and Nickel Ions Using Zeolite Tuff

Factors affecting adsorption characteristics of Zn2+ on two natural zeolites

“…In the literature, only limited data exists regarding the effect of slurry concentration on heavy metal removal by the zeolites [25,36]. Thus, we attempted to determine the effect of slurry concentration on uptake of Zn 2+ on zeolite; initial metal ion concentrations were taken as 20 mg/l for zeolites and other situations, such as pH, grain size and temperature were kept constant.…”

“…The finding of this study is not unique, there are studies reporting that decrease in grain size leads to an increase in adsorption capacity [25], whereas Leyva-Ramos et al [26] reports that decreasing the grain size does not increase the adsorption capacity. It appears that the effect of decrease in grain size on adsorption capacity hinges on an increase of the internal surface area.…”

Kinetic and equilibrium studies in removing lead ions from aqueous solutions by natural sepiolite

“…These values compare favourably with some of those reported in the literature. The maximum sorption capacities of other minerals for lead ions removal were given in range of 60-35 mg/g [28,29]. Table 3 A comparison of first order reversible, pseudo-first order and pseudo-second order kinetic models rate constants obtained at different experimental conditions…”

Comparison of isotherms for the ion exchange of Pb(II) from aqueous solution onto homoionic clinoptilolite

“…In several works it has recently been reported that the ion exchange equilibrium on natural zeolites can be represented by the Langmuir isotherm [10][11][12]17,18]. In this isotherm model it is assumed that the cations can be exchanged on specific sites, which are the cationic sites of the zeolite; these sites are formed by the unbalanced charges of the aluminum atoms present in the zeolite framework.…”

“…The procedure for fitting this isotherm to the experimental data is rather tedious and requires additional thermodynamic information to account for the nonideal behavior of the ions in solution and exchanged on the zeolite. Recently, the ion exchange equilibrium on natural zeolites has been represented by the Langmuir isotherm [10][11][12]. It has been found that this isotherm fits the experimental data very satisfactorily.…”