Magnetic sodium alginate grafted with waste carbonaceous material for diclofenac sodium removal: optimization of operational parameters and process mechanism

Abstract

As their manufacturing and consumption have increased, pharmaceutical chemicals have increasingly been found in wastewater. It is necessary to look into more effective methods, including adsorption, because current therapies can't completely eliminate these micro contaminants. This investigation aims to assess the diclofenac sodium (DS) adsorption onto an Fe₃O₄@TAC@SA polymer in a static system. Through Box–Behnken design (BBD), system optimization was carried out, and the ideal conditions – adsorbent mass of 0.01 g and agitation speed of 200 rpm – were chosen. The adsorbent was created utilizing X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR), allowing us to gain a comprehensive understanding of its properties. The analysis of the adsorption process revealed that the external mass transference was the primary rate-controlling step, and the Pseudo-Second-Order model demonstrated the best correlation to kinetic experimental results. An endothermic, spontaneous adsorption process took place. The removal capacity was 858 mg g⁻¹, which is a respectable result when compared to other adsorbents that have been utilized in the past to remove DS. Ion exchange, π–π interactions, electrostatic pore filling and hydrogen bonding all play a role in the adsorption of DS on the Fe₃O₄@TAC@SA polymer. After careful examination of the adsorbent towards a true sample, it was determined to be highly efficient after three regenerative cycles.