Octyl glucoside derivatives: A tool against metal pollutants

• Published in: Colloids and surfaces. A, Physicochemical and engineering aspects Vol. 480; pp. 439 - 448
• Main Authors: Ferlin, Nadège, Grassi, Diego, Ojeda, Carlos, Castro, Mariano J.L., Cirelli, Alicia Fernández, Kovensky, José, Grand, Eric
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 05-09-2015
• Subjects: Flotation; Interfacial properties; Ion extraction, Iron(III) complexes; Sugar-based surfactants; Ion extraction, Iron(III) complexes; Flotation; Sugar-based surfactants; Interfacial properties
• ISSN: 0927-7757; 1873-4359
• DOI: 10.1016/j.colsurfa.2014.09.041

•Sugar based chelating surfactants are used for metal recovery from water phases.•Relations between surfactant structures and interfacial properties are studied.•Flotation concerns Fe(III), Cu(II), Cr(III), Cd(II), Zn(II), Ni(II) and As(III) ions.•Different parameters are modulated for flotation experiments with Fe(III).•Species distribution diagrams for surfactant-Fe(III) are studied.
Derivatives of octyl glucoside modified by the introduction of a chemical function (carboxylic acid, hydroxamic acid) able to enhance the complexing properties of the surfactants toward metallic cations have been used as flotation collectors to remove various metallic cations from a water phase. Flotation experiments at the laboratory scale were performed on Fe(III), Cu(II), Cr(III), Cd(II), Zn(II), Ni(II) and As(III) aqueous solutions. The most interesting results were obtained in the extraction of Fe(III) and Cu(II). Interfacial properties were studied, and the effect of the polar head structure and anomeric configuration was analyzed. Structural variations have an influence on the efficiency and the foaming ability of these compounds. The introduction of a chelating functionality preserves the interfacial performances of these surfactants. Complexes equilibrium constants and species distribution diagrams for Fe(III) and the best flotation agents 2a and 2b were determined from multi-wavelength spectrophotometric pH titration. Both compounds showed analogous values for log β1, log β2 and log β3. The bidentanted Fe(III)-hydroxamate species (2:1 surfactant-metal ratio) reached a maximum concentration in the pH range of 5.5-6.5. At this pH, the best results in the flotation experiments were obtained for both compounds.