Emily Anderson (Minnesota) and Sean O'Donnell, Ph.D. (Maryland) will each present a technical session at the 92nd Annual Meeting of the Minnesota Section of the Society for Mining, Metallurgy & Exploration (SME) in Duluth, Minnesota on April 16, 2019.
Emily is a Staff Scientist based in Minnesota focused on bioremediation, environmental microbiology, and bioinformatics/data analysis. A remediation and water treatment practitioner, she is a key contributor to projects in industries including mining, agribusiness, manufacturing and refining. Her prior experience includes work at New Zealand Petroleum and Minerals, and the Ministry of Social Development.
Sean O'Donnell is a Staff Geotechnical Engineer based in Maryland focused on geotechnical design, analysis, and monitoring of waste containment structures. His Ph.D. dissertation focused on the use of denitrifying microorganisms for the mitigation of earthquake-induced soil liquefaction as a two-stage process through desaturation and microbially induced carbonate precipitation. His experience involves the study of biologically-mediated ground improvement techniques through both laboratory-based studies and the development and analysis of computer simulations.
The 2019 SME MN Conference examines how global events and economies affect careers. Professionals will share how careers in the mining industry will not only survive but thrive in this modern world.
The Society for Mining, Metallurgy & Exploration Inc. (SME) is a professional society (nonprofit 501(c)(3) corporation) whose more than 15,000 membership represents all professionals serving the mining, minerals and underground construction industries in more than 100 countries. SME members include engineers, geologists, metallurgists, educators, students and researchers. SME advances the worldwide minerals community through information exchange and professional development.
Title: Algae Bioreactor for Removal of Manganese from Mine - Affected Waters
Time: 3:30 p.m.
Presenter: Emily Anderson
Abstract: Manganese is a common element in Minnesota's geologic materials and can occur in mine-affected waters in its soluble reduced form. Manganese has a secondary drinking water standard of 50 ug/L and was nominated to the USEPA's fourth contaminant candidate list (CCL4) by the Minnesota Department of Health. Manganese oxidation/precipitation occurs slowly under abiotic conditions, but the reaction rate can be several orders of magnitude faster when catalyzed microbially. The mechanism of microbial manganese oxidation remains unclear, however. This study characterized manganese-oxidizing microorganisms and tested manganese removal using a novel algae bioreactor in which algae provide fixed carbon to manganese-oxidizing microorganisms. Biofilm samples composed of algae and manganese-oxidizing microorganisms were collected from a manganese-oxidizing waterfall in Hokkaido, Japan. Using a culture-dependent approach, 68 manganese-oxidizing bacteria and fungi were isolated from the biofilm samples, including some not previously known to oxidize manganese such as Aeromonas, Skermanella, Ensifer and Aspergillus. A culture-independent approach was also used to characterize the total microbial community and determine how abundant the isolated manganese-oxidizing bacteria were in a manganese-oxidizing environmental sample. Biofilm samples were also used to develop a manganese-removing algae bioreactor. By adjusting operating parameters, the bioreactor was optimized to remove dissolved manganese to below detectable concentrations. This algae bioreactor could be scaled up for treatment of mine-effected water. Additionally, the bioreactor was designed to be coupled with sulfate reduction, which, when applied to mine wastewater could facilitate the removal of sulfate, along with iron or other metals of concern in mine-impacted waters.
Title: Bio - Mediated Carbonate Precipitation for Dust Control at Mine Tailings Facilities
Time: 4:00 p.m.
Presenter: Sean O'Donnell
Abstract: Wind tunnel tests and benchtop experiments conducted on taconite tailings samples show that enzyme induced carbonate precipitation (EICP) and microbially induced carbonate precipitation (MICP) hold promise for mitigating windblown dust at mine tailings storage facilities (TSFs). Wind erosion of tailings is a significant challenge at many mine sites and must be controlled to comply with fugitive dust emissions requirements. Conventional methods for mitigating windblown dust at tailings facilities, including application of polymer or straw, or management of tailings basin water level may be prohibitively expensive, variably effective, or limiting to tailings basin operation. MICP and EICP present a cost-effective alternative method to control fugitive dust emissions at TSFs. MICP and EICP rely on the hydrolysis of urea (ureolysis) to induce precipitation of calcium carbonate (CaCO3), a cementing agent, on the tailings surface. Precipitation of CaCO3 results in an erosion resistant crust that may significantly reduce the risk of windblown dust from tailings facilities. Preliminary results of wind tunnel testing show that EICP-treated tailings are significantly less erosive than untreated tailings. Additionally, benchtop stimulation experiments show that in-situ stimulation of native ureolytic microbes for MICP may be possible at some TSFs, depending on site-specific conditions. Together, these results suggest that EICP and MICP hold promise for mitigation of windblown dust from TSFs.
About the event: http://www.smemnconference.com/index.cfm/conference/agenda/technical-sessions/
About The Society for Mining, Metallurgy & Exploration Inc. (SME): https://www.smenet.org
Learn more about Emily at: https://www.linkedin.com/in/emily-anderson-59303085/