凹凸棒石吸附重金属的研究进展

The complexity and diversity of the chemical composition and crystal structure of attapulgite were increased due to polymorphism, mixture of dioctahedrons and trioctahedrons, and cation isomorphism replacement of octahedrons. Fibrous attapulgite has high porosity, large specific surface area, active sites and cationic exchangeability on the surface, which enable it to effectively absorb heavy metal pollutants. In recent years, it has been widely used in the treatment of heavy metal pollution in the environment. The effect of raw attapulgite on the heavy metals adsorption is not ideal, so raw attapulgite is often modified to dissociate the crystal beam, increase the surface area and porosity, and introduce the adsorption active groups to greatly improving its adsorption activity. Conventional modification methods include calcining at high temperature, acidizing modification, alkalizing modification, organic or macromolecule grafting modification and inorganic compound modification. Compared with the conventional modified adsorbents, the modification of magnetic material composite, electric adsorption, millimeter porous microsphere and three-dimensional mesh filtration membrane can improve the recovery rate of adsorbents, which is the research direction of attapulgite modification in the future.