Theses and Dissertations at Montana State University (MSU)

Permanent URI for this collectionhttps://scholarworks.montana.edu/handle/1/733

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Abandoned coal waste reclamation in Montana
(Montana State University - Bozeman, College of Agriculture, 1987) Gitt, M. J.
Development of wildlife habitat on mined lands
(Montana State University - Bozeman, College of Agriculture, 1982) Carlson, Robert Steven; Chairperson, Graduate Committee: Frank Munshower.
Effect of slope gradient and plant cover on soil loss on reconstructed high altitude slopes
(Montana State University - Bozeman, College of Agriculture, 1999) Kapolka, Nicole Michelle
Effect of two dolomitic industrial by-products on pH control, leachate chemistry and plant response in acidic-metalliferous mine waste
(Montana State University - Bozeman, College of Agriculture, 1997) Kelly, Laureen Susan
Factors affecting the native species invasion of a reclaimed subalpine minesite near Grande Cache, Alberta
(Montana State University - Bozeman, College of Agriculture, 1987) Van Zalingen, Sylvia Frances
Interactive effects between lime, organic matter, and bacteria in the establishment of Leymus cinereus in mine tailings
(Montana State University - Bozeman, College of Agriculture, 2015) Sanchez Espinoza, Deicy Noemi; Chairperson, Graduate Committee: Anthony Hartshorn
The landscape legacy of historical metal-mining activity can persist for decades. The most frequent strategies used for the remediation of contaminated soils include: the use of synthetic membranes to isolate contaminants (>$0.5 million/acre), direct revegetation (less expensive but difficult to sustain), or lime amendments ($5000/acre). Looking for more cost-effective bioremediation approaches, we performed a set of greenhouse studies to determine what combinations of soil amendments would lead to the best vegetative response, and potentially associated reductions in soil arsenic (As) levels, in "slickens" collected from the Lampert Ranch along the upper Clark Fork near Warm Springs, MT. In our first greenhouse experiment, we planted Leymus cinereus (basin wildrye) and compared (after 12 weeks) plant growth and foliar metal concentrations across treatments. Amendments included single or factorial additions of 5% lime, organic matter (+OM), and an arsenic-oxidizing (+oxbact) strain of Agrobacterium tumefaciens (Agtu). Surprisingly, the OM+oxbact treatment revealed among the best plant growth and arsenic uptake response. We then performed a second greenhouse experiment with two levels of OM (1.5% and 5%) and an additional treatment: a mutant (reducing strain) of Agtu. Basin wildrye grown in soils amended with 5% OM generally did better than those grown in soils amended with 1.5% OM. At the same time, foliar As uptake (biomass multiplied by As concentration) was unexpectedly high (0.020 mg pot-1) for plants grown in soils amended with 5% OM + oxbact, 3 times greater than foliar arsenic uptake in plants grown in soils amended with 5% OM+ lime and 4 times greater than foliar uptake by plants grown in soils amended with 5% OM and the reducing strain of Agtu. These results suggest the combination of OM and Agtu oxbact strain could provide a potentially cost- effective approach to remediating As-contaminated soils. Finally, our study results imply that soil restoration approaches could be improved through a greater consideration of microbial communities supported by these re-establishing vegetation communities, which could lead to more sustainable ecosystem successional trajectories.
Nonlinear optical studies of gypsum dissolution mechanisms, surfactant adsorption on gypsum surface and analysis of environmentally related ions
(Montana State University - Bozeman, College of Letters & Science, 2023) Yiyen, Galip; Chairperson, Graduate Committee: Robert Walker; This is a manuscript style paper that includes co-authored chapters.
Southeastern Montana hosts one of the largest open-air coal mine sites in the world. Federal regulations after finalization of the open-air coal mining activities require reclamation, which creates buried spoils that may serve as aquifers at former mining sites. Once hosting an inland sea, the region's saline sedimentary rocks and soils contribute to the groundwater salinity, though at lower levels prior to mining. However, the creation of spoils through mining pulverizes soils, sediment, and rocks formerly overlying coal deposits, mixing them and increasing their surface area. In infiltrating waters from snow melt and heavy rain, minerals dissolve more readily due to this enhanced surface area in spoils, increasing the salinity in groundwater. A primary water quality concern in regional groundwater is high sulfate concentrations. Sulfate in water originates from weathering and dissolution of soluble secondary salts, such as calcium sulfate (dihydrate, hemihydrate and anhydrite), sodium sulfate and magnesium sulfate. Gypsum (CaSO 4 x 2H 2O) is thought to be a primary source of dissolved sulfate in the ground and surface waters in Southeastern Montana and 'gypsum dissolution' is at the focus of this dissertation. Vibrational sum frequency generation spectroscopy was used to understand the molecular level interactions at the gypsum surface upon interaction with bulk water. Additionally, surfactant adsorption on gypsum surface and its impacts of gypsum dissolution were investigated. Besides optical spectroscopy studies, an efficient and quick water analysis technique was adapted to determine the sulfate concentrations in environmental samples. Two different types of orientations of structural water molecules at the gypsum surface were observed. Results also showed that these water molecules are tightly bound to the surface. Surfactant adsorption was found to be only limited to the surfactants with sulfate headgroups and resulted in suppressed gypsum dissolution. A titration technique is found to be effective and accurate for sulfate analysis of environmental water samples.
Reclamation effectiveness at three reclaimed abandoned mine sites in Jefferson County, Montana
(Montana State University - Bozeman, College of Agriculture, 2006) Tafi, Tara Christine; Chairperson, Graduate Committee: Dennis Neuman.
Montana has an estimated 6000 abandoned mine sites, many with associated waste rock and tailings materials contributing to the release of high levels of acidity, heavy metals, and other contaminants, creating a risk to human health and the environment. Many abandoned mine sites in Montana have been reclaimed, however, little post-reclamation monitoring has been performed, and the effectiveness of reclamation has not been quantified. The goal of this project was to quantify the effectiveness of reclamation at three sites in Jefferson County, Montana based on soil suitability for sustaining plant growth. Vegetation and soil studies were executed using a stratified random sampling design. Vegetation measurements included canopy cover using Daubenmire cover classes, above ground biomass, and species richness/diversity. Co-located soil samples were excavated in increments to a depth of 60 cm, and determinations of pH, electrical conductivity, nutrients, soluble, and total metal levels were made. Canopy cover estimates ranged from 0-120% and biomass production estimates ranged from 0-4583 kg ha-1.