Removal of Diclofenac Sodium Using Synthetic Faujasite from Natural Clay

In this study, the removal of Diclofenac sodium (DIC) from water medium was performed using synthetic FAU-X zeolite. The zeolitic material has been synthesized from Illito-Kaolinitic clay. Douiret clay (DC) which was used as raw material for the synthesis of zeolites, for the first time, was supplied from the south-east of Tunisia. The starting material was left to react, for 1 h, with NaOH at 600°C using alkaline fusion process. We have optimised the effect of crystallization time on the generation of zeolitic materials, where FAU-X zeolite was obtained after 4 and 8 h. The mineralogical composition of original material and the synthesized zeolites were identified with X-ray diffraction and Fourier-transform infrared spectrocrcopy techniques. The morphological analysis of FAU-X zeolite was carried out by scanning electron microscopy. It shows a significant uniformity of the zeolite crystal form. The cation exchange capacity of FAU-X zeolite reaches 260 meq/100 g. The adsorption of DIC onto raw material and synthetic zeolite was performed at ambient conditions. We tracked the influence of different parameters such as the adsorbate pH, the adsorbents mass, the effect of contact time and concentration of the DIC solution. Kinetic study proves that the elimination of the pharmaceutical product by both materials reaches its maximum after 30 min. The Langmuir model shows a good affinity with the experimental results of DIC adsorption by DC and FAU-X zeolite where the maximum removal capacity for each one attends more than 95 and 300 mg/g, respectively. The findings of this work highlight the successful preparation of zeolites from local clay and their excellent efficiency as an eco-friendly adsorbent for emerging pollutants from water media.