Water adsorption and antibacterial activity studies for characterization of Ca-LTA zeolite/diatomite adsorbents

In this study, Ca-LTA Zeolite-diatomite-based adsorbents with purified diatomite loading rates of 15, 20 and 25 wt% are investigated by physicochemical, thermal and antibacterial characterizations. X-ray diffraction and FTIR spectroscopy analyses show that the purified diatomite is homogeneously dispersed into the Ca-LTA zeolite and that the zeolite crystalline structure is preserved. All analyses indicate that porous volumes, specific surface areas and initial water adsorption rates are affected by the mesoporosity nature of diatomite. Based on the water TPD profiles, the variation of the activation energy (E-a) and enthalpy (Delta H-#) calculated via the Kissinger and Ozawa models, highlights the complexity of adsorption processes on the zeolite-diatomite pores. The lowest Ea and Delta H-# values (475 and 410 J/g, respectively) are obtained for the sample containing 15 wt% of diatomite. Furthermore, zeolite-diatomite adsorbents have significant antibacterial activity against Escherichia coli and Methicillin-resistant Staphylococcus aureus and could be promising adsorbents for hemostatic applications.