Fabrication of iron nanoparticles from tea waste as an efficient adsorbent towards the removal of profenofos pesticide from aquatic environment

Abstract

ABSTRACT Pesticide contamination has led to serious environmental issues that pose a significant threat to living organisms throughout the world. Therefore, the significant removal of pesticides from aquatic environments has attracted the attention of environmental scientists and academicians in recent decades. Hence, in the present investigation, the iron nanoparticles (INPs) from tea waste were fabricated as an efficient adsorbent towards the removal of profenofos (PF) from aqueous solution. The as-synthesised INPs were systematically characterised by various analytical techniques such as Ultra Violet-visible (UV-vis) spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), powder X-ray diffraction (PXRD) and dynamic light scattering (DLS). Various influencing factors such as contact time, adsorbent dosage, solution pH and initial concentration of pesticide were systematically optimised for the maximum adsorption efficiency of PF by the prepared INPs. Based on the obtained results, the INPs showed greater adsorption efficiency towards the removal of PF. The kinetic data were analysed using various adsorption kinetic models such as pseudo-first-order, pseudo-second-order and intra-particle diffusion. Further, the interaction between prepared INPs and PF was evaluated using various adsorption isotherm models such as Langmuir, Freundlich, Temkin and Dubinin-Radushkevich (D-R) models. The monolayer Langmuir adsorption capacity of 43.67 mg g−1 was obtained with a minimum contact time of 15 min. According to the kinetic and isotherm data, the pseudo-second-order kinetic and Langmuir isotherm models were found to be well fitted for PF adsorption using the prepared INPs. The obtained findings of this study clearly demonstrated that the fabricated INPs are an efficient material towards the removal of pesticide molecules from aquatic environments.