IRON-MODIFIED CHITOSAN/VERMICULITE COMPOSITE MATERIAL FOR SIMULTANEOUSLY REMOVING ANION AND CATION HEAVY METALS, AND PREPARATION AND APPLICATION THEREOF

摘要

Disclosed are an iron-modified chitosan/vermiculite composite material that simultaneously removes anion and cation heavy metals, and the preparation and application thereof, which relate to the technical field of water treatment. The method is: (1) dissolving chitosan in an acid solution to obtain a chitosan solution, said acid solution being a weakly acidic solution; (2) uniformly mixing a trivalent iron salt, vermiculite and the chitosan solution to obtain a mixture solution; (3) heating and crosslinking a crosslinking agent and the mixture solution to obtain a crosslinked product; (4) adding the crosslinked product dropwise to an alkaline solution, and stirring, aging, and washing to obtain a primary product; (5) in the alkaline solution, performing secondary crosslinking on the primary product and the crosslinking agent, and aging, washing, and drying to obtain an iron-modified chitosan/vermiculite composite material. The composite material has a wide range of sources, a low cost, a high specific surface area, high mechanical stability and good adsorption performance. At the same time, the effect of removing anion and cation heavy metals is excellent, particularly for hexavalent chromium and divalent cadmium.