Sophie with her poster at the Undergraduate Research Symposium
Author: Sophie Sward | Major: Environmental, Soil, and Water Science | Semester: Spring 2024
My name is Sophie Sward and I am an Environmental, Soil, and Water Science major in the Bumpers College of Agricultural, Food, and Life Sciences. My mentor for my undergraduate thesis is Dr. Kristofor Brye in the Crop, Soil, and Environmental Sciences department. I am in the spring semester of my research and plan to wrap up my thesis by the end of the upcoming fall semester.
In the fall of my sophomore year, I took the class Plants and Environmental Restoration with Dr. Chuck West. In this class, we explored techniques in environmental restoration and remediation with a focus on ecosystem sustainability and resiliency by using plants in restoration projects. This sparked my interest in phytoremediation, which is the use of plants to remove contaminants from the soil, air, and water. For my undergraduate thesis, I have been investigating industrial hemp’s (Cannabis sativa L.) capacity alongside biochar treatments to remediate heavy-metal-contaminated soils from the Tar Creek Superfund Site in Picher, OK.
Contamination of soils and water with heavy metals can have deleterious effects on both human and environmental health. Traditional engineering-based methods of remediation are expensive and resource-consuming, oftentimes creating byproducts that require further processing. Phytoremediation has been proposed as a sustainable and cost-effective alternative as contaminants are sequestered in plant tissues or degraded.
I chose my topic and found my mentor by reaching out to Dr. Kristofor Brye in the spring of my sophomore year. I saw that Dr. Brye had research interests in soil health, groundwater contamination, and prairie restoration and so I reached out to him and told him my interests were in environmental restoration and phytoremediation of contaminants in soil and water. As luck would have it, he and Dr. David Miller had an ongoing project with a Master’s student, Dietrich von Thurston, investigating phytoremediation of heavy-metal-contaminated soils.
Beginning in the summer of 2023, I have been working with Dr. Brye, Dr. Miller, and Dietrich von Thurston in Dr. Miller’s soil chemistry lab to investigate industrial hemp’s capacity to remediate heavy-metal-contaminated soils as well as the effect of biochar on heavy metal concentration and uptake in plant tissues. I performed a modified EPA 3050b procedure on plant root tissues which had grown in contaminated soils amended with biochar, then processed the digested samples through inductively coupled plasma optical emission spectrometry (ICP-OES) to determine concentrations of lead (Pb), cadmium (Cd), and zinc (Zn) in the belowground plant tissue. These root tissue concentrations from the current study plus root dry matter data from Thurston were used to calculate heavy metal uptake in the root tissue. The generated root tissue uptake data was added to aboveground tissue Pb, Zn, and Cd uptakes from Thurston to determine and report whole-plant heavy metal uptake. The ratio of above- to belowground heavy metal uptakes were calculated and analyzed as the translocation factor to determine if hemp is a hyperaccumulator plant. Dr. Brye and I ran data analyses in SAS using the PROC GLIMMIX procedure to evaluate the effects of soil-contamination level, hemp cultivar, biochar rate, and their interactions on root Cd, Pb, and Zn tissue concentrations and uptakes, whole-plant Cd, Pb, and Zn uptakes, and Cd, Pb, and Zn translocation factors. I then generated tables and graphs and began the results and discussion portion of my thesis, and my next steps are finishing up writing!