Simultaneous adsorption of sulfamethoxazole and neodymium from wastewater by a MXene-, α-aminophosphonate-, and sulfated fucan-based ternary composite based on anion-synergistic interactions

Abstract

The simultaneous removal of antibiotics and heavy metal ions is of utmost importance because of their hazardous effects on the environment and humans. For the adsorption of sulfamethoxazole (SMX) and neodymium (Nd³⁺) in mono- and binary contaminant systems (SMX–Nd³⁺ and Nd³⁺–SMX), a novel composite was designed using sulfated fucan (FuS), MXenes, and α-aminophosphonates (AMPs) in this study. As far as we know, the concurrent adsorption of SMX and Nd³⁺ employing materials made of MXenes, FuS, and AMPs with this specific structure has not yet been reported. At 318 K, the FuS@MXene@AMP adsorbent demonstrated excellent adsorption capacities of 448.91 and 255.78 mg g⁻¹ for SMX and Nd³⁺, respectively. The pseudo-first-order (PSO) kinetic model was the most appropriate for depicting the adsorption of SMX and Nd³⁺ among all the tested kinetic models. The adsorption of SMX and Nd³⁺ is better described by the Langmuir isotherm model with a higher value of adsorption capacity and R². The simultaneous presence of Nd³⁺ and SMX promoted mutual sorption between the antibiotic and metal ions in the binary systems. The results of FTIR and XPS studies indicated that the removal mechanisms were primarily due to hydrogen bonding, complexation, electrostatic interaction, and π–π interaction.