Arsenic in hydrothermal apatite: Oxidation state, mechanism of uptake, and comparison between experiments and nature
文摘
As(III) and As(V) both can be incorporated in hydroxylapatite during dynamic coupled dissolution/reprecipitation reactions. As(III) moieties replace phosphate groups with a high local strain compared to As(V). Upon recrystallization, As(V) replaces the As(III) in the hydroxylapatite structure. Most studied natural hydrothermal apatites retain mainly As(V), even though they formed from solutions that mainly contained As(III). Reaction pathway and kinetics exert a major controls on As(III) uptake in hydrothermal apatite.