Green Synthesis of Stable and Reusable Zinc Nanoparticle Adsorbents for the Removal of Carcinogenic Heavy Metals in Aqueous Solution

Abstract

industrial applications led to an alarming rise in their presence, heightening the potential for contamination in various environmental mediums. In order to mitigate the adverse impacts of these heavy metals, it is imperative to reduce their concentrations in environmental samples. Therefore, this study aimed to produce zinc nanoparticles employing Diospyros chloroxylon (Roxb.) to effectively eliminate carcinogenic metals from water. The produced nanoparticles were subjected to comprehensive characterization using FT-IR, XRD, SEM, and EDX techniques. The XRD data indicated the emergence of a hexagonal wurtzite structure. SEM images illustrated the spherical morphology of the synthesized particles, with an average diameter measuring 53 nm and having elemental zinc accounting for 69.4% of the composition. The subsequent heavy metal sorption experiments encompassed a range of variables, remarkably, the nanoparticles displayed exceptional adsorption capabilities, achieving maximum removal rates of 95.81%, 90.13%, and 91.25% within an equilibrium time of 90 minutes for Cr, Pb, and Cd, respectively. The adsorption process adhered to a pseudo-first-order reaction kinetics model, with high correlation coefficients of 0.9561, 0.99058, and 0.98481, along with respective rate constants (K) of 0.483, 0.233, and 0.328 for Cr, Pb, and Cd. The outcomes highlight that the synthesized zinc nanoparticles exhibit biocompatibility, stability, and reusability, making them a promising tool for effectively removing carcinogenic heavy metals from polluted water sources.