Highly efficient TiO₂-functionalized nylon-6 nanofibrous membranes for rapid adsorptive removal of atrazine from...

Increasing concentrations of the atrazine pesticide in water pose a significant risk to human health and aquatic life. In this study, TiO₂-functionalized electrospun nylon-6 nanofibrous membranes are developed for the adsorptive removal of atrazine under batch conditions. The as-synthesized nanofibrous composite membrane was characterized using a scanning electron microscope (SEM), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), Fourier-transform infrared spectroscopy (FTIR), etc. The SEM studies revealed the average fiber diameter to be in the range of 110-130 nm. A BET analysis of the surface area of nylon-6/TiO₂ (24.5 m² g^-1) was obtained with surface area and porosity. The XRD pattern confirms the crystallinity of materials and membranes. Further, the incorporation of TiO₂ nanoparticles (NPs) also enhanced the tensile strength (1.2 MPa) of the composite membrane and its adsorption capacity. Then, liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to evaluate the removal efficiency of atrazine. Furthermore, the key adsorption parameters, such as pH, initial concentration of atrazine, contact time, nanofiber dosage, etc., were also optimized. The as-prepared nylon-6/TiO₂ nanofibrous membrane exhibited a good adsorption removal efficiency of 67.12 mg g^-1 (as determined by the Langmuir isotherm model). This study suggests monolayer chemisorption behavior. The adsorption kinetics followed a pseudo-second-order (PSO) model, with equilibrium reached within approximately 30 minutes of contact time. In addition, the removal efficiency of the nylon-6/TiO₂ composite membrane was also compared with both the pristine TiO₂ and nylon membranes, and it showed significantly higher efficiency. We believe such a cost-effective, and energy-efficient nanofibrous membrane system can be an alternative solution for rapid wastewater treatment applications.