University of Iowa
Reid Simmer is a PhD student in Environmental Engineering at the University of Iowa. His research focuses on bioaugmenting to poplar microbiome to accelerate phytoremediation of 1,4-dioxane-contaminated groundwater. He also holds a Master's in Geography from the University of Iowa, where his thesis focused on predictive modeling of recreational water quality. Previously, he also worked for the Iowa Department of Natural Resources studying Iowa water quality and harmful algal blooms.
Utilizing the Plant Microbiome and Bioaugmentation to Degrade 1,4-Dioxane And Co-Contaminants
"1,4-Dioxane (dioxane) is a probable carcinogen and persistent groundwater pollutant that often forms large and dilute plumes. Because of this, remediation of dioxane-contaminated groundwater has proven to be particularly difficult and costly. A promising, low-cost solution is to pump contaminated groundwater onto plantations of poplar trees and to bioaugment the poplar rhizosphere with dioxane-degrading bacteria to speed degradation. In this research, we conducted bench-scale simulated aquifer experiments to evaluate whether phytoremediation and bioaugmentation can treat dilute dioxane-contaminated groundwater to health advisory levels (<1 µg/L). We also compared the performance of several metabolic dioxane-degrading strains, including Pseudonocardia sp. CB1190 and Mycobacterium sp. PH-06. In our findings, we report that phytoremediation alone can treat dioxane to <1 µg/L. In addition, bioaugmentation significantly increased the rate of removal by hybrid poplar. Overall, this research demonstrates that combining phytoremediation and bioaugmentation is an attractive strategy to treat dioxane-contaminated groundwater to low risk-based concentrations. "