Removal of Non-Steroidal Drug from Waste Water Using Synthetic Zeolites from Illito-Kaolinitic clays

Pure Na-P1 and FAU-X zeolites were successfully synthesised from illito-kaolinitic clays by alkaline fusion process. Starting materials have been provided from Tejra and, unprecedentedly, from Douiret regions located in the south-east of Tunisia. The mineralogical composition of original materials and the synthetic products were identified with XRD and IR techniques. Clays and zeolites were used as eco-friendly adsorbents for diclofenac sodium (DIC), non-steroidal anti-inflammatory drug, from water media. Results showed that Na-P1 and FAU-X zeolites start to appear after 8 h and 4 h of crystallisation at 110 °C, successively. The synthesised zeolite samples showed significant shape uniformity with a cation exchange capacity reaching more than 300 meq/100 g. Batch experiments of DIC removal showed that the kinetic data could be well described by the pseudo-second-order model. The Langmuir model provides the best fit for the adsorption equilibrium data, and the monolayer adsorption capacity up to 308.9 mg/g for FAU-X zeolite. Graphical abstract