Adsorption of inorganic pollutants on bauxite residues: An example of methodology to simulate adsorption in complex solids mixtures. (March 2017)

• Record Type: Journal Article
• Authors: Taneez, Mehwish; Hurel, Charlotte; Marmier, Nicolas; Lefèvre, Grégory
• Is Part Of: Applied geochemistry. Volume 78(2017:Mar.)
• Page Start: 272
• Page End: 278
• Publication Date: 2017-03
• Subjects: Surface complexation model -- Red mud -- Iron oxide -- Aluminum oxide; Environmental geochemistry -- Periodicals; Water chemistry -- Periodicals; Geochemistry -- Social aspects -- Periodicals; Geochemistry -- Periodicals; 551.9
• DOI: 10.1016/j.apgeochem.2017.01.007
• Languages: English
• ISSNs: 0883-2927

Abstract

Abstract: Bauxite residue rich in iron and aluminum oxide is good adsorbing material for inorganic pollutants. Composition and physic-chemical parameters of 2 bauxite residues (Bauxaline ® and Bauxsol) were determined. Adsorption of arsenic and cadmium from aqueous solutions on Bauxaline ® and Bauxsol was studied as a function of solid to liquid ratios, pH and initial adsorbate concentrations. Both solids showed optimum removal of As and Cd at near to neutral pH. Adsorption data were modeled using2-pK/Double Layer Model. In the model, the complex composition of bauxite residues was simplified by considering that Bauxaline ® and Bauxsol were made of a binary mixture of iron and aluminum oxides. Considering acid-base and surface complexation (for As and Cd) equilibriums and constants from the literature, the model proposed in this work has shown to be predictive. Adsorption mechanism was found consistent with the formation of a surface complex along with surface precipitation for cadmium. Graphical abstract: Highlights: As(V) and Cd(II) adsorb on bauxite residues. Surface complexation modelling is consistent with sorption results. The reactivity of bauxite residues is governed by iron and aluminium oxides surfaces.