Civil Engineering ETDs

Publication Date

Summer 7-15-2020


The aim of this dissertation was to investigate the biogeochemical processes affecting the mobilization and bioavailability of arsenic (As) from mining-impacted sediments to surface water sources and plants. The Cheyenne River Watershed has been affected by mining legacy for several decades. The biogeochemical cycling of As on tribal land is not well understood, which justified the following research objectives: 1) Investigate the effect of competing anions on the release of As from sediments exposed to oxidizing conditions; 2) Evaluate chemical and microbiological processes affecting the release of soluble As, Fe, and Mn from contaminated sediments under laboratory controlled aerobic and anaerobic conditions; 3) Evaluate As uptake in Schizachyrium scoparium inoculated with endophytic fungi using hydroponic experiments. Field and laboratory approaches used in this work contribute novel information about As speciation and reactivity. Results will be useful to identify potential exposure pathways and enhance risk reduction strategies for nearby communities.


arsenic, biogeochemistry, Native American, mine waste

Document Type




Degree Name

Civil Engineering

Level of Degree


Department Name

Civil Engineering

First Committee Member (Chair)

Jose M. Cerrato

Second Committee Member

Lucia Rodriguez-Freire

Third Committee Member

Abdul-Medhi S. Ali

Fourth Committee Member

Bruce M. Thomson

Fifth Committee Member

Kerry J. Howe