Ion exchange capacity of zeolite A with zinc nitrate and its antimicrobial activity

Abstract

Abstract Various type of zeolites has been produced based on kaolinite and this study likewise utilized kaolin clay as raw material to synthesis zeolite A. Kaolin was in inactive state, therefore it was transformed to metakaolin through dehydroxylation at 800 °C for 4 h. The metakaolin as a source of silica and alumina was then utilized in the synthesis of zeolite A. After hydrothermal synthesis, the zeolite A was exchanged with different concentration of zinc nitrate solution. Zinc content in ion-exchanged zeolite A, ZnA was determined through AAS to calculate the ion exchange capacity. Higher concentration of zinc nitrate had higher zinc content and higher ion exchange capacity. Zeolite A and zinc-exchanged zeolite A were characterized under SEM, XRD and FTIR. Finally, zeolite A and zinc-exchanged zeolite A was used to investigate the antimicrobial properties against gram-negative bacteria, Escherichia coli and gram-positive bacteria Staphylococcus aureus. There was no antimicrobial activity for zeolite A yet zinc-ion–exchanged zeolite A showed inhibition zones around the samples for both the microorganisms.