Zeolite functionalized with metal ions: A dual strategy for water purification − removal of sertraline hydrochloride and pathogenic bacteria

Sertraline hydrochloride (SER) is widely used to treat depression, anxiety, and other disorders, but its presence in global water bodies underscores the need for innovative water treatment solutions. This study introduces a novel adsorbent developed through a sustainable approach, where natural zeolites were functionalized with copper oxide nanoparticles (NZ_NPCuO) to enhance SER removal from contaminated water. Copper oxide nanoparticles were synthesized via a green method using Barbatimão (Stryphnodendron polyphyllum Mart.) stem bark extract. Comprehensive characterization techniques, including scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), X-Ray Diffraction (XRD), X-Ray Fluorescence (XRF), leaching tests, and zeta potential measurements validated the successful formation and chemical stability of the nanoparticles. SER adsorption tests revealed a maximum capacity (q_max) of 25.19 mg/g at 298 K, achieving equilibrium within 960 min. The Elovich and Langmuir models were determined to best describe the kinetic and isothermal data, respectively. Thermodynamic analyses indicated that the adsorption process is exothermic, spontaneous, and reversible. Potential adsorption mechanisms included hydrogen bonding, π-interactions, and electrostatic attraction. We also evaluated the antibacterial properties of NZ_NPCuO using the disk diffusion method against Gram-positive and Gram-negative bacteria, including Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa, resulting in inhibition zones of 26 mm, 7.5 mm, and 14 mm, respectively. Thus, the proposed composite shows great potential for SER removal from wastewater and offers a promising alternative for developing effective antimicrobial agents for different proposals, particularly for microbiological water treatment.