Octyl glucoside derivatives: A tool against metal pollutants

NADÈGE FERLIN; GRASSI, D.; C. OJEDA; M. CASTRO; A, FERNÁNDEZ CIRELLI; J. KAVENSKY; E. GRAND

COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2015 vol. 480 p. 439 - 448

0927-7757

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 cationshave been used as flotation collectors to remove various metallic cations from a water phase. Flota-tion experiments at the laboratory scale were performed on Fe(III), Cu(II), Cr(III), Cd(II), Zn(II), Ni(II) andAs(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 configura-tion was analyzed. Structural variations have an influence on the efficiency and the foaming ability ofthese compounds. The introduction of a chelating functionality preserves the interfacial performancesof these surfactants. Complexes equilibrium constants and species distribution diagrams for Fe(III) andthe best flotation agents 2a and 2b were determined from multi-wavelength spectrophotometric pHtitration. Both compounds showed analogous values for log 1, log 2and log 3. The bidentanted Fe(III)-hydroxamate species (2:1 surfactant-metal ratio) reached a maximum concentration in the pH range of5.5-6.5. At this pH, the best results in the flotation experiments were obtained for both compounds.