Date of Award
Spring 5-14-2026
Document Type
Thesis
Degree Name
Master of Science (MS)
Department
Biology
First Advisor
Samuel Mutiti
Second Advisor
Christine Mutiti
Third Advisor
Allison VandeVoort
Abstract
The Earth is dealing with two major environmental challenges: heavy metal pollution and climate change. Many anthropogenic activities contribute to both challenges, as in mining. Many waste materials are left behind from mining, like toxic heavy metals, that contaminate the soil and water. These mining activities also contribute to greenhouse gas (GHG) emissions, which increase climate change.
Heavy metal pollution is an environmental problem, and the contaminants are metals with high relative atomic masses beyond twenty-three, for example copper (Cu) and lead (Pb). To remediate these contaminants, phytoremediation is a sustainable technique used to clean up these areas. The technique uses plants that are known as hyperaccumulators to extract, reduce, or stabilize heavy metal concentrations in the soil.
Climate change affects ecosystem fluxes, such as the carbon cycle. The carbon cycle affects an ecosystem's functions in air, water, vegetation, and soil properties. One part of the carbon cycle is carbon sequestration, which holds carbon in the soil and contributes towards offsetting GHG emissions. Carbon dioxide (CO2) is constantly exchanged between the atmosphere and soil. Vegetation removes carbon from the atmosphere, through photosynthesis, and returns carbon to the atmosphere through respiration and decomposition. Therefore, selecting the right plant species that can accumulate heavy metals and enhance carbon storage is essential in restoring the environment. This study strives to determine which hyperaccumulator species has the best potential for both heavy metal removal and carbon sequestration.
The dual challenge of heavy metal contamination and increasing atmospheric CO2 necessitates identifying plant species capable of both phytoremediation and long-term carbon sequestration (phytosequestration). This dual application requires plants that not only generate high, slow-decomposing biomass (for carbon retention) but also function as excellent phytostabilizers, tolerating high contaminant levels and accumulating metals predominantly in their roots rather than their shoots (high root Bioconcentration Factor, or BCF). This study investigated six plant species, Fountain grass, Lemon grass, Southern Cattail, Lantana, and Tithonia r and Tithonia d, to evaluate their metal uptake, CO2 respiration, dissolved organic carbon (DOC) release, and decomposition rates, aiming to determine the most suitable candidate for this critical dual usage.
The results indicate that Fountain grass showed the greatest overall potential for dual usage in the field data, specifically for Pb phytostabilization and decomposition. It exhibited the highest Pb root-BCF and low shoot uptake, confirming its effectiveness as a phytostabilizer, and demonstrated some of the slowest decomposition rates in litter bag and CO2 release experiments, suggesting superior long-term carbon retention. For Cu contamination, Lemon grass was identified as the best candidate, showing high Cu root-BCF and low shoot uptake, coupled with slower decomposition. While Southern Cattail also displayed high potential for dual usage, its wetland habitat preference limits its versatility. Overall, Lemon grass and Fountain grass are the most promising species for the dual application of phytostabilization and phytosequestration in heavy metal contaminated, non-wetland soils.
Recommended Citation
Morgan*, Tori L., "The Dual Use of Plants for Phytoremediation and Carbon Sequestration" (2026). Biology Theses. 51.
https://kb.gcsu.edu/biology/51