Behavior and mechanism of element dissolution from albite by mannose: experimental and theorical study

In this work, the release behaviors of element from albite by mannose are studied experimentally, and the corresponding decomposition mechanism is explored from a microscopic perspective via density functional theory (DFT) calculations, with the aim of promoting the development of a microbial mineral weathering theory. The sodium, silicon and aluminium in albite are released into a solution under the action of mannose, and the release of these elements makes the surface of albite rough and decreases crystallinity and interplanar spacing of the crystal. The DFT results show that the hydroxyl H atom in mannose forms a hydrogen bond with the O atom on the surface of albite, thus causing the surface atoms to move away from their original positions, destroying the stability of the silica tetrahedron. The results of this study provide insights and deepens the understanding of microbial-mineral interactions at the microscopic level.

The leaching behavior of the elements in albite was evaluated through an ion concentration in a solution. The microscopic mechanism between mannose and albite was calculated based on DFT, via the CASTEP module of Materials Studio software. The GGA-PBE method is used for all the DFT calculations. Analyses of the adsorption configuration and energy, charge density difference, and Mulliken population of the mannose-albite system were carried out.