Master of Science, The Ohio State University, 2024, Food, Agricultural and Biological Engineering

Waste coal in abandoned mine lands poses significant environmental challenges, affecting nearby communities, rivers, and streams. Effective management of these piles is essential due to concerns such as acid mine drainage, soil and water contamination, coal fires, and methane emissions. Various strategies have been proposed for managing waste coal, including potential utilization for rare earth element recovery, soil amendment, construction aggregates, and energy generation. However, the implementation of these strategies remains uncertain due to the lack of precise location and volume data on waste coal piles. Traditional methods for gathering these data rely on field visits and Global Navigation Satellite System surveying, which are costly and labor-intensive. Advances in satellite technologies and the availability of digital elevation models (DEMs) offer an opportunity to estimate waste coal volume on a regional scale in a timely and cost-effective manner. Thus, the objective of this thesis was to develop a robust data analytical framework to locate and estimate the volume of waste coal piles on a regional scale, using the Muskingum River Basin (MRB) in Ohio as the study area. Initially, a prototype was developed to determine the most effective machine learning (ML) model to map waste coal piles in a historical coal mine site within the MRB. While all four ML models effectively identified dominant classes such as Grassland and Forest, the Random Forest (RF) model demonstrated superior performance in classifying the more complex waste coal class, with a precision of 86.15% and recall of 76.71%. Subsequently, the greatest disturbance and reclamation mapping of these waste coal piles were conducted using the LandTrendr algorithm to distinguish waste coal piles in abandoned mine lands from those in active mining areas. Moreover, this study utilized publicly available elevation models to estimate waste coal volume in the MRB. However, since historical terrain mo (open full item for complete abstract)

Committee: Ajay Shah (Advisor); Sami Khanal (Advisor); Tarunjit Singh Butalia (Committee Member) Subjects: Artificial Intelligence; Engineering; Geographic Information Science; Remote Sensing; Sustainability

Master of Science (MS), Ohio University, 2019, Mechanical Engineering (Engineering and Technology)

The goal of this study was to upgrade fuel properties of two different coal wastes (CW) namely, Middle Bottom (CW1) and 4Top (CW2) as well as reduce their ash, sulfur, and chloride content through co-hydrothermal carbonization (co-HTC) with food waste (FW). CW and FW were mixed in 1:1 (dry wt. basis) ratio and co-HTC experiments were performed at three different temperatures of 180, 230, and 280 °C for a reaction temperature of 30 min. Mass yield, proximate and ultimate analyses, energy content as well as combustion indices were evaluated to determine the fuel properties. Results showed that co-HTC at 230 °C produced hydrochar with maximum fixed carbon, elemental carbon, and HHV as well as minimum sulfur and ash for both CW samples. Combustion indices also indicated that CW2FW-H230 hydrochar had combustion indices similar to bituminous coal. Later a techno-economic analysis (TEA) was performed for a scaled-up hydrochar production through the co-HTC process. A process flow diagram was drawn to produce 49192 kg hr-1 hydrochar. Two cases were considered for the TEA analysis. The case I considered hydrochar production at a coal mine site while case II assumed hydrochar production at a power plant. In both cases, FW will be collected within 50 mile radius of the co-HTC plant and will be transported to the plant site. The break-even selling prices of hydrochar was $72.83 and $77.13/ton for the case I and case II, respectively. A sensitivity analysis was performed to evaluate the effect of process parameters on the break-even cost. The analysis revealed that utilizing raw materials collected from the vicinity of the production site and increasing the production of hydrochar would lower the break-even cost of hydrochar production.

Committee: Dr. M. Toufiq Reza (Advisor) Subjects: Mechanical Engineering

BS, Kent State University, 2018, College of Arts and Sciences / Department of Earth Sciences

Abandoned coal mines are common throughout the Appalachian region of the United States as surface and underground mines. The exposed mine waste from mining operations has led to the contamination of multiple streams throughout the region with acid mine drainage (AMD). The AMD at these sites is caused by the oxidation of the iron sulfides (pyrite, mracasite, etc.) within the coal mine waste. Associated with the AMD, heavy metals and metalloids such as As, Se, Co, Cd, Ni, Mn, Mg, Pb, and Zn are released into these streams. These can lead to associated water quality issues for drinking water and local environments near abandoned coal mine sites.The research conducted here seeks to better define the nature of the iron sulfides in coal mine waste and to demonstrate a method to observe and analyze the mineralogical transformations of iron oxides from ferrihydrite to hematite that occur in AMD settings at abandoned coal mines in the Huff Run Watershed. We use a combination of x-ray diffraction (XRD) and scanning electron microscopy (SEM) to determine the mineralogical differences between the coal shale parent material and the soils developing on the coal mine waste, the crystal form of the iron sulfides within the coal shale parent material, and the mineralogical transformations of the subsequent iron oxides as a result of dry heating. We determine that pyrite is not a primary constituent of the bulk mineralogical phases picked up by XRD in the the soils developed on the coal mine spoil although present as a bulk mineral phase in the coal shale parent material, and the method of dry heating iron oxides to simulate the mineralogical transformations over time is hindered by a persistence of ferrihydrite at high temperature ranges. From this, implications on the rate of oxidation of pyrite in these soils and the release of heavy metals and metalloids can be further inferred.

Committee: David Singer Dr. (Advisor); Alison Smith Dr. (Committee Member); Christopher Fenk Dr. (Committee Member); Elizabeth Herndon Dr. (Committee Member) Subjects: Environmental Geology; Environmental Science; Geology