Study of the Pt(IV) sorption on the Aspergillus niger O-5 biomass for remediation and/or analytical purposes

The use of Pt (IV) salts in different processes generates, even at low concentrations, toxic residuals that contaminate natural waters. For this reason, the improvement of limit of detection in Pt(IV) quantification for control and monitoring purposes, as well as, the development of methodologies for remediation is convenient. This study was aimed at the assessment of the dead Aspergillus niger O-5 biomass without treatment and chemically treated as sorbents for Pt(IV) concentration. The influence of pH and volume of dissolution, sorbent mass and contact time on the Pt(IV) sorption capacity of materials was studied. At optimized experimental conditions, a maximum sorption capacity of 79.63 +/- 0.03 mg center dot g(-1) was achieved using cetyltrimethylammonium bromide (CTAB)- treated biomass. A good fitting of the pseudo-second-order model of Ho to the experimental kinetic data suggested that chemisorption or chemical reactivity processes are involved in the biosorption. Those processes could be explained via the substitution of the hydrogen present in N-H bonds of amide groups on the biomass surface for Pt(IV) species in dissolution. This hypothesis was supported by the XPS analysis results. The best Pt(IV) desorption equal to 99% was achieved, when 15% (m/v) thiourea dissolution was used as eluent.