Excellence in Research: Phytoremediation Using Vetiver Grass to address Heavy Metals and PFAS in Contaminated Soil and Wastewater

Jackson State University, Jackson MS

Investigators

Abstract

Per- and polyfluoroalkyl substances (PFAS) and heavy metals are persistent contaminants that pose serious risks to environmental and public health, especially in landfill and wastewater treatment systems where conventional treatment methods often fail to remove them effectively. Heavy metals such as cadmium (Cd), mercury (Hg), chromium (Cr), nickel (Ni), lead (Pb), zinc (Zn), and arsenic (As) are often found in landfill leachate. These metals can cause severe environmental harm and create public health issues when they pollute surface or groundwater bodies. This project explores an innovative, nature-based solution using Vetiver grass (Chrysopogon zizanioides), a fast-growing plant with a demonstrated ability to absorb harmful contaminants from soil and water. Vetiver grass offers a low-cost, energy-efficient, and resilient approach to treating contaminated wastewater and landfill leachate while addressing critical environmental concerns related to PFAS and heavy metals. The project will address several unknowns to evaluate the performance of Vetiver grass, including Vetiver’s adaptability in highly toxic environment, adjusting its root and molecular structure to accumulate heavy metals and contaminants in it. A robust, data-driven framework that evaluates both the efficacy and sustainability of Vetiver-based phytoremediation systems will be developed. The integration of mechanistic and machine learning models will enable predictive capabilities, offering insights into site-specific applications and long-term management strategies. The scientific understanding of Vetiver’s phytoremediation capabilities and experimental results from this project will contribute to sustainable nature-based remediation practices that create alternative to chemical-based treatments. This research aims to evaluate and optimize the performance of Vetiver grass in phytoremediation applications to remove PFAS and heavy metals from wastewater, leachate, and contaminated soils. The project addresses three fundamental scientific questions: (1) What is the absorption rate and storage capacity of Vetiver grass for heavy metals and PFAS in various environmental conditions? (2) How are these contaminants distributed between Vetiver’s roots and shoots post-uptake? (3) How do contaminant concentrations and climatic factors influence Vetiver’s phytoremediation efficiency? (4) What is the long-term fate of the contaminants uptake by Vetiver grass? Experiments will be conducted using hydroponic systems and soil media. The contaminant uptakes will be quantified through advanced analytical techniques, including Gas Chromatography-Mass Spectrometry (GC-MS), Liquid Chromatography–Mass Spectrometry (LCMS/MS), and Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). The research will examine the influences of microbial interactions and soil type on Vetiver’s remediation capacity alongside the evapotranspiration studies for landfill applications. The project will synthesize data across varied conditions to develop predictive models for optimizing Vetiver-based phytoremediation systems. It is expected that this study will establish Vetiver grass as a viable, sustainable, and cost-effective means for PFAS and heavy metal remediation in different environmental contexts. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.