| Sumario: | Abstract: Aiming to solve the difficulties inherent in the separation of adsorbents in powder form loaded with contaminant ions from treated solutions, this study presents the Linde Type A (LTA) zeolite immobilized in agarose (AG) as a new alternative outstanding adsorbent material (AG-LTA) for cation removal from mine-impacted water (MIW). Synthetic MIW containing Al, Fe, and Mn ions was tested in adsorption processes with different LTA percentages (2.34, 4.00, 8.00, 12.00, and 13.66%) immobilized in agarose. The central composite rotational design carried out indicated the optimal values of LTA dosage (8.57 g L) and agitation rate (107 rpm), with removals of 99.49, 95.55, and 95.29% for Al, Mn, and Fe, respectively, in acidic conditions. Scanning electron microscopy and spectroscopic and thermogravimetric techniques allowed the characterization of the AG-LTA material, of the ion-saturated adsorbent, and identify the ion exchange of the adsorbates Al, Fe, and Mn with the alkaline ions of LTA zeolite. Precipitation of the metal ions as hydroxides was not involved in the removal process. Experimental maximum sorption capacities of AG-LTA were 15.78, 3.02, and 19.23 mg g for Al, Mn, and Fe, respectively. The high removal efficiency of the new AG-LTA adsorbent under acidic conditions may allow its use in the remediation of real MIW, complying with the stringency of environmental regulations. It is to note that AG-LTA is remarkably easy of separating from the aqueous medium after use Graphical Abstract: [Figure not available: see fulltext.]
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