Kaolin, Bentonite Modified For Heavy Metal Ion Adsorption Properties Of Study

Kaolin and bentonite are valuable i clay minerals j, which have been applied in many fields. In this paper, the properties and application of kaolin, bentonite, modified kaolin and modified bentonite are described, and the process of preparation of modified kaolin with pillared interlayer clay was studied. Furthermore, the absorption properties of these samples to heavy metals in waste water were also studied.By comparing the ability of absorption of modified kaolin to Pb2+ ion in waste water, the surface modified method proved to be a superior way to prepara kaolin MBT(2-Mercaptobenzothiazole) complex, and the optimum process condition was found by applying orthogonal experiment. The absorption and desorption ability of kaolin MBT complex to heavy metals ion in waste water was investigated, and the results showed that the absorption ability of kaolin MBT complex to Pb2+ ion was higher than that of natural kaolin and that of surface modified kaolin. By investigating the absorption of kaolin MBT complex at different reaction period and different reaction temperature, the optimum process for kaolin to be modified was established.A series of intercalated materials were prepared by using hydroxy-aluminum and hydroxy-zirconium polycations as intercalants, and the absorptive ability of them to Zr~+ ion was investigated. We found that modified bentonite was a good absorbent for heavy metallic ions. The pillared intercalated sample reached optimum absorption with Al:Zr = 2:1 (mole ration). When the condition of 20g/l pillared intercalated clay, 20 min absorption period and pH 4.5 were controlled, the absorption ration was nearly 100%.