Research
Wild rice stands in St. Louis River Headwater (Skibo landing)
Soil nutrients and microbial ecology in wild rice wetlands
Wild rice (Zizania palustris) is an ecologically and culturally important plant in Minnesota and its state grain. Wild rice was historically abundant in northern Minnesota but its abundance and distribution have been reduced due to environmental contaminants, habitat destruction, physical disturbance, and establishment of competitive or invasive plant species. Recently, our research team received Legislative-Citizen Commission on Minnesota Resources (LCCMR) funding to examine microbial and nutrient associations in self-sustaining wild rice wetlands for 3 years. The information is applied to develop a management strategy to promote restoration success in the St. Louis River estuary and wild rice lakes in Minnesota. We are collaborated with Biology and NRRI at UMD, MNDNR, Fond du Lac Department of Natural Resources, 1854 Treaty Authority, and St. Louis River Alliance.
Sulfate Treatment System
Sulfate is historically and geologically low in Northern Minnesotan freshwater system. Anthropogenic sulfate introduction to these low-sulfate waters can have potential adverse impacts for human and ecosystem health. Our research team has been developing alternative treatment systems to reduce sulfate level to waterbody: bioelectrochemical reactors and sulfide removal by iron-bearing minerals in mining waste streams.
Bioelectrochemical Reactors stimulate biological sulfate reduction
We have developed bioelectrochemical reactors to biologically reduce sulfate and capture it as iron sulfide or elemental sulfur solid. We have constructed lab-scale batch and flow-through bioreactors and examined the efficacy of sulfate removal and microbial communities associated with sulfate removal using industrial wastewaters through experimental and mathematical modeling approaches. The project has been funded from USGS Water Resource Annual Grant Competition and University of Minnesota MnDRIVE Program.
Iron-enhanced sulfide sequestration system coupled with biological sulfate reduction
Biological sulfate removal has the potential to be very cost effective and versatile. Effective dissolved sulfide capture methods remain a challenge that stands in the way of widespread adoption of biological sulfate treatment. One known sink for sulfide is iron. This project has investigated potential to use different iron-rich mining waste rocks in sulfur-capture systems within industrial discharge streams. This project is collaborated with Dr. Nate Johnson in our department and Dr. Lee Penn in the Department of Chemistry at University of Minnesota Twin Cities. The project is funded by Mining Innovation Grant from the State of Minnesota
Antibiotic resistance in upper sewer systems
The continuous release of antibiotics to environment potentially results in an increase in natural resistance background levels which leads the rising numbers of bacterial pathogens becoming resistant against single or multiple antibiotics. Elevated levels of antibiotic resistance genes in wastewater effluents has been reported and it may be best is to reduce the amount of antibiotics and their resistance that reach a treatment plant in the first place. To develop source control strategies, our research group has investigated the levels of antibiotic resistance in residential, hospital, and industrial sewages which enter municipal wastewater treatment plant. We are collaborating with the cities, wastewater treatment plant, industries, hospitals, and pharmacy.
Environmental impacts of conventional and alternative deicing chemicals
Chloride is an emerging contaminant to Lake Superior and other water bodies in Minnesota. We have assessed the pervasiveness and potential sources of chloride contamination and alternative deicing chemicals (e.g. potassium acetate) in streams stormwater drains, and Lake Superior in this region. We also evaluate the effectiveness and feasibility of locally available natural materials including agricultural and iron industry byproducts as alternative effective abrasive materials to sand. The materials include corncob, various types of woodchips, and iron industry byproducts such as taconite tailings, crushed iron ores, and processing byproducts. Potentially, these materials may not only offer traction and skid resistance required on the icy and frozen road during winter, but also hold effectiveness of salt for a longer duration and capture other contaminates on roads. The projects have been funded by MnDOT, NOAA coastal program, and LCCMR.
Left image: Estimated chloride load in model catchment using a Hydrologic Simulation Program-Fortran (MPCA 2018)