Confluence of nanotechnology and phytoremediation for lead detoxification using Chrysopogon zizanioides

Heavy metal pollution occurs due to unsustainable waste disposal, rapid industrialization, and urbanization. Phytoremediation is an eco-friendly technology that utilizes plants to remove or stabilize the HMs, and its efficiency can be increased using nanotechnology. The present study compares the potential of both phytoremediation and ZnO nanoparticle-assisted nano-phytoremediation in removing lead using Chrysopogon zizanioides. Batch studies were carried out in a greenhouse with different concentrations of lead (50 µg/mL, 150 µg/mL, 250 µg/mL, 350 µg/mL, and 450 µg/mL) at different time intervals (3, 6, 9, 12, and 15 days), and three concentrations of zinc oxide nanoparticles (ZnO NPs) (10 µg/mL, 50 µg/mL, and 100 µg/mL) that were synthesized from the same plant using a green pathway were deployed in this work. Various biochemical parameters like cellulose, carbohydrates, chlorophyll, phenols, and proline content were studied at different doses and time intervals. During phytoremediation, Vetiver grass absorbed 45.79% of the lead from the contaminated medium. In the nano-phytoremediation treatments, lead absorption increased to 56.57% at 10 µg/mL ZnO concentration, whereas 47.27% and 41.53% lead absorption were observed at 50 µg/mL and 100 µg/mL ZnO concentrations, respectively. These results indicate that the lower ZnO nanoparticle concentration (10 µg/mL) was the most effective in enhancing lead uptake and remediation efficiency, while higher nanoparticle concentrations reduced the remediation performance. The bio-concentration factor and translocation factor less than 1 indicate the phytostabilization mechanism that happens in the Vetiver grass during the remediation process. The statistical analysis using IBM SPSS (version 20.0) software (Armonk, NY) proves that all the data are statistically significant at p < 0.05. Findings of this work immediately advance the field of green remediation technology by providing workable answers for extensive environmental cleanup projects. The results also provide strong support for the advancement of the global sustainable development goals.