Removal of toxic metals from wastewater by Brazilian natural scolecite

摘要: Abstract The cation-exchange capacity of Brazilian natural zeolite, identified as scolecite, was studied with the aim evaluating its applications in wastewater control. We investigated process sorption chromium(III), nickel(II), cadmium(II), and manganese(II) synthetic aqueous effluents, including isotherms single-metal solutions at 298, 313, 333 K, by batch experiments, influence pH on process. results have demonstrated that removal metals from specific metal is best described a Freundlich isotherm, which values obtained for K f constants were following order: Cr > Mn > Cd > Ni. A Lagergren pseudo-second-order model mechanism. retention shown to be function pH; maximum binding occurring around 6.0. Thermodynamic data indicate spontaneity endothermic Δ G 0 suggest selectivity series 298 K: Ni > Cr > Cd > Mn. desorption reaches equilibrium during first 60 min binding, suggesting mechanism involves sites located external surface scolecite.