Waste to health: Green synthesis of Zn loaded LTA zeolite prepared from waste glass and aluminum scrap with high antioxidant and antimicrobial activities

Abstract

The aim of this study is to evaluate the in vitro antibacterial and the antioxidant activities of low cost ZnO@Zn-ZF2 zeolite. The carrier was Na-LTA type zeolite prepared from waste glass and aluminum scraps by alkaline fusion at 550 °C using NaOH as mineralizer followed by hydrothermal crystallization at 60 °C for 6 days. Three samples of ZnO@Zn-ZF2 were prepared with different amount of zinc (2, 4 and 6 wt%). The antioxidant activities of ZnO@Zn-ZF2 zeolite were evaluated by different methods, including 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical method, reducing power and β-carotene bleaching assay. All particles showed interesting antioxidant activities. Further, the prepared samples exhibited considerable antibacterial activity against Gram- and Gram + bacteria. The obtained results showed that 6ZnO@Zn-ZF2 zeolite had the highest antioxidant and antibacterial activities against Klebsiella pneumoniae and Micrococcus luteus, which can be attributed to the good dispersion of ZnO particles on the zeolite surface.