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Sulfate Treatment System
Sulfate Treatment System
Sulfate, the most abundant form of dissolved sulfur on Earth, is often scarce in many freshwater environments. However, its concentration has globally increased largely due to human activities as well accelerated mineral oxidation by hydrological alteration and climate change. This may increase the extent and effect of sulfate on biogeochemical cycles of other elements and lead to ecotoxicological consequences. Additionally, sulfate-laden wastewater posed a challenge for many industries and municipalities. my research group has developed a range of technologies for treating sulfate in various types of wastewaters, tailored to different sulfate concentrations through collaboration and partnerships. Our multi-pronged approach includes biological treatment coupled with sulfide immobilization for high sulfate levels; an in situ electrode-integrated biofiltration system as a semi-passive treatment option, short-rotation tree-based phytoremediation, and barite precipitation method for low sulfate levels. Each technology was developed through a stepwise process, from lab scale proof-of-concept to pilot-scale testing.
Electrode-integrated biofiltration
Electrode-integrated biofiltration
We have developed bioelectrochemical reactors to microbiologically reduce sulfate, capturing it as solid phase iron sulfide or elemental sulfur. We have examined the efficacy of sulfate removal and microbial communities associated with sulfate removal using industrial wastewaters through experimental and mathematical modeling approaches. This project is progressing with a pilot-scale feasibility study and field demonstration in collaboration with industrial partners and agencies. Funding: USGS Water Resource Annual Grant Competition , USDA Forest Service, and Minnesota Pollution Control Agency.
Biological sulfate treatment with sulfide immobilization
Biological sulfate treatment with sulfide immobilization
Biological sulfate removal has the potential to be very cost effective and versatile in application. Our collaborative team has demonstrated the feasibility of biological sulfate treatment coupled with sulfide immobilization as a reliable option in removing sulfate from both industrial sources, such as coal power plant wet flue gas desulfurization water and municipal wastewater, through successful field operation of a pilot-scale system. The project is funded by Mining Innovation Grant from the State of Minnesota and MnDRIVE program. Here is our research story of the pilot-scale demonstration.
Phytoremediation for sulfur pollution
Phytoremediation for sulfur pollution
We have assessed the feasibility of phytoremediation for removing sulfate from contaminated water and soil in collaboration with Dr. Ron Zalesny Jr. of the Northern Research Station, US Forest Service. Specifically, we identified hybrid poplar varieties with superior growth under sulfur pollution and studied the fate and transport of sulfur within the soil-poplar-water continuum using Phyto-Recurrent Selection and controlled mass balance experiments. In partnership with the City of Aurora, we plan to conduct a field demonstration between 2025 and 2029. Funding is provided by the USDA Forest Service.
Environmental DNA
Environmental DNA
Environmental DNA (eDNA) has been applied to evaluate community composition, identify rare and invasive species, and understand interactions of biota within aquatic ecosystems in relation to contaminants. Recently, our collaborative team has examined impacts of various field and lab methods on detection of multiple aquatic invasive species to provide guidance for widespread eDNA monitoring including volunteer surveillance. Collaborative PIs: Josh Dumke, Gretchen Hansen, and Eric Larson.
Built on the previous study, we are currently developing a framework to detect multiple aquatic invasive species and other aquatic organisms more quickly, reliably, and affordably using a portable eDNA sequencing method. This project represents a step toward creating a tool that resource managers could widely adopt for routine, passive surveillance and early detection. A new technology, nanopore sequencing, offers potential for on-site, rapid, and cost-effective detection of multiple AIS through whole-community analysis, thanks to its portability and quick turnaround time. However, applying nanopore sequencing to eDNA surveillance is still in the experimental stages and requires the development of an appropriate workflow for practical use.
Sampling locations in the Great Lakes
The U.S. Environmental Protection Agency announced significant federal investments in Great Lakes research. The funds include $3 million to the Natural Resources Research Institute for collecting and analyzing legacy and emerging chemical contaminants in lake sediments. This Great Lakes Sediment Surveillance Program will entail collecting sediment samples throughout the entire Great Lakes system, including Canadian waters. Not only is it a massive project by size, there are hundreds of contaminants to analyze – some introduced decades ago and some emerging more recently. Scientists are keen to understand more about the interactions of these contaminants with the environment. The findings of this five-year (2020-2025) project will lead to improved management strategies that more effectively target potentially harmful contaminants and protect ecosystem health. Collaborative PIs: Chris Filstrup (PI), Bridget Ulrich, and Euan Reavie, Kathryn Schreiner,
Environmental impacts of conventional and alternative deicing chemicals
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)
Wild rice stands in St. Louis River Headwater (Skibo landing)
Soil nutrients and microbial ecology in wild rice wetlands
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.
Antibiotic resistance in upper sewer systems
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.
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