Radium Accumulation is Sediment Associated with Coal Drainage: Dependence on Environmental Conditions and Sequestration Mechanisms
Open Access
- Author:
- Reese, Garrett
- Area of Honors:
- Environmental Engineering
- Degree:
- Bachelor of Architectural Engineering
- Document Type:
- Thesis
- Thesis Supervisors:
- Nathaniel Richard Warner, Thesis Supervisor
Andrew Zydney, Thesis Honors Advisor - Keywords:
- AMD
Anthracite
Bituminous
Radium
Passive
Active
Sequestration - Abstract:
- The objective of this thesis was to explore and document the levels of radium activity present at several different coal mining discharge sites in both western and eastern Pennsylvania. More specifically, the scope of this thesis was to observe how the environmental conditions of Pennsylvania’s coal regions, which consisted of either anthracite or bituminous coal mining, affect the sequestration mechanism of radium. Due to a rich past of coal mining in these areas, thousands of miles of streams were left polluted with acid mine drainage (AMD), which contains high levels of sulfate, manganese, and iron oxides. In these regions, radium would likely be adsorbed by manganese and iron oxides as opposed to the common mechanism of co-precipitation with barium and sulfate as radiobarite. If radium is adsorbed and not co-precipitated as radiobarite, radium could be mobilized downstream of discharges. Thus, by sampling regions rich in sulfate, manganese and iron oxide minerals, such as those affected by AMD, this hypothesis was tested. Anthracite samples that were subjected to a four-step sequential leaching process had only two samples that maintained all radium after the first three steps that target soluble salts, exchangeable cations, and carbonates. These samples, Tracy Wetland and Silvercreek Out, had concentrations of 0.90 and 1.69 ppm for manganese and 2.99 and 0.15 ppm for iron respectively. Their corresponding barium concentrations were 0.046 and 0.038 ppm respectively. Given these values, it is assumed that both samples would have a majority of the radium removed after the final leaching step that targets iron and manganese oxides. All bituminous samples (Sterrett 1, Sterrett 2, Sterrett 3, and Sterrett Flush) maintained most of the initial radium through the first three steps of the sequential leaching process and collectively had higher concentrations of manganese and iron when compared to barium. Iron concentrations were approximately 0.17 ppm while the manganese concentrations were quite higher at 1.1 ppm. However, the concentrations of barium in bituminous samples were exceptionally low at 0.013 ppm. Overall, it is likely that both anthracite and bituminous sample sets would lose most of their adsorbed radium after the fourth and final leaching step. If this were true, then it would prove that radium would adsorb to iron and manganese oxides in coal regions of Pennsylvania instead of the typical route of co-precipitating with barium and sulfate as radiobarite. Once this final leaching step is completed in the near future, these speculations can be verified.