Environmental Properties of Minerals and Contaminants Purified by the Mineralogical Method

Abstract

Abstract The investigation of the environmental properties of minerals, i.e., environmental mineralogy, is a branch of science dealing with interactions between natural minerals and spheres of the Earth surface as well as a reflection of global change, prevention of ecological destruction, participation in biomineralogy, and remediation of environmental pollution. Pollutant treatment by natural minerals is based on the natural law and reflects natural self‐purification functions in the inorganic world, similar to that of the organic world — a biological treatment. A series of case studies related to natural self‐purification, which were mostly completed by our group, are discussed in this paper. In natural cryptomelane there is a larger pseudotetragonal tunnel than that formed by [MnO6] octahedral double chains, with an aperture of 0.462–0.466 nm2, filled with K cations. Cryptomelane might be a real naturally‐occurring mineral of the active octahedral molecular sieve (OMS‐2). CrVI‐bearing wastewater can be treated by natural pyrrhotite, which is used as a reductant to reduce CrVI and as a precipitant to precipitate CrIII simultaneously. Batch experiments were conducted using the CTMAB‐Montmorillonite as an adsorbent for aromatic contaminants (phenol, aniline, benzene, toluene and xylenes), which are detected frequently in the leaching water from municipal waste deposits around China. The CTMAB modification has proved very effective to enhance the adsorption capacity of the sorbent. Expansion of vermiculite develops loose interior structures, such as pores or cracks, inside briquettes, and thus brings enough oxygen for combustion and the sulfation reaction. Effective combustion of the original carbon reduces the amount of dust in the fly ash.