Integrating Zeolitic Imidazolate Framework-8 with DES-Treated Loofah Sponge for Enhanced Toluene Adsorption

Abstract

The pervasive presence of toluene in aquatic environments, primarily due to oil spills and industrial effluents, necessitates the development of effective and sustainable remediation strategies. This study introduces ZIF-8@DES-treated loofah sponge (ZIF-8@DLS), a novel adsorbent composite material, synthesized via an in situ process that integrates the high surface area of ZIF-8 with the natural loofah sponge. The composite was characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR), confirming the successful loading of ZIF-8 onto the loofah substrate. The adsorption capacity of ZIF-8@DLS for toluene was evaluated, achieving a maximum of 145.3 mg/g with an efficiency of 72% under standard conditions. Kinetic studies revealed that the adsorption process predominantly followed a pseudo-second-order model, indicative of chemisorption. The adsorption isotherm data were found to align more closely with the Freundlich model, suggesting a multilayer adsorption mechanism on the composite’s heterogeneous surface. The ZIF-8@DLS composite demonstrates a promising synergy of high adsorption performance, cost-effectiveness, facile synthesis, and environmental benignity, positioning it as a candidate for practical applications in wastewater treatment and adsorptive separation processes.