Showing papers by "Bruno Lanson published in 2022"
TL;DR: In this paper , the reactivity of cobalt-doped hausmannite with aqueous As(III) and As(V) was studied, and the results provided new insights into the interaction mechanism between TMs and low valence Mn oxides and their effect on the geochemical behaviors of metal pollutants.
Abstract: Hausmannite is a common low valence Mn oxide mineral, with a distorted spinel structure, in surficial sediments. Although natural Mn oxides often contain various impurities of transitional metals (TMs), few studies have addressed the effect and related mechanism of TM doping on the reactivity of hausmannite with metal pollutants. Here, the reactivity of cobalt (Co) doped hausmannite with aqueous As(III) and As(V) was studied. Co doping decreased the point of zero charge of hausmannite and its adsorption capacity for As(V). Despite a reduction of the initial As(III) oxidation rate, Co-doped hausmannite could effectively oxidize As(III) to As(V), followed by the adsorption and fixation of a large amount of As(V) on the mineral surface. Arsenic K-edge EXAFS analysis of the samples after As(V) adsorption and As(III) oxidation revealed that only As(V) was adsorbed on the mineral surface, with an average As-Mn distance of 3.25-3.30 Å, indicating the formation of bidentate binuclear complexes. These results provide new insights into the interaction mechanism between TMs and low valence Mn oxides and their effect on the geochemical behaviors of metal pollutants.
3 citations
TL;DR: In this paper , the authors compared density functional theory (DFT) and molecular dynamics (MD) simulations to experimental X-ray diffraction data for a series of synthetic saponites with layer charge ranging from medium-charge smectite to medium charge vermiculite.
1 citations
TL;DR: In this article , the authors synthesized Mn- or Al-incorporated Ox-GR by oxidation of sulfate-bearing green rust and determined their structure, elemental composition and distribution, and As(III) adsorption.
1 citations
01 Jan 2022
TL;DR: In this article , the effect of foreign metal cations on phyllomanganate transformation is studied under aqueous conditions together with the induced modification of Ni geochemical behavior.