Investigating the Interaction between Hydroxyapatite and Uranium in Groundwater to Facilitate Remediation

Authors

Olivia H. Bustillo, Florida International UniversityFollow

Document Type

Thesis

Degree

Master of Science (MS)

Major/Program

Environmental Engineering

First Advisor's Name

Leonel Lagos

First Advisor's Committee Title

Co-Committee chair

Second Advisor's Name

Ravi Gudavalli

Second Advisor's Committee Title

Co-Committee Chair

Third Advisor's Name

Berrin Tansel

Third Advisor's Committee Title

Committee Member

Fourth Advisor's Name

Anna Bernardo-Bricker

Fourth Advisor's Committee Title

Committee Member

Keywords

uranium, remediation, permeable reactive barrier, sequestration, department of energy

Date of Defense

6-26-2023

Abstract

Due to persisting uranium groundwater contamination at Department of Energy Office of Legacy Management’s (DOE-LM) Old Rifle, CO site, DOE began investigating the use of an in-situ hydroxyapatite (HA) permeable reactive barrier (PRB) for remediation. It was observed that hydroxyapatite PRB maintains uranium groundwater concentrations below Uranium Mill Tailings Radiation Control Act (UMTRCA) limits of 44 ppb, but a better understanding of the environmental factors that influence the uranium-hydroxyapatite interaction is required. Batch experiments were conducted with hydroxyapatite at varying Ca:P ratios under diverse environmental conditions (pH, temperature, ORP) with 250 ppb uranium. Results found that pH and ORP had a significant effect on uranium removal, with less uranium removed at pH 4 and in anoxic conditions. In oxic conditions, uranium removal reached 88% and above. These studies support hydroxyapatite use for uranium remediation in groundwater and provide information on which site conditions would result in more effective uranium removal.

Identifier

FIDC011222

Recommended Citation

Bustillo, Olivia H., "Investigating the Interaction between Hydroxyapatite and Uranium in Groundwater to Facilitate Remediation" (2023). FIU Electronic Theses and Dissertations. 5343.
https://digitalcommons.fiu.edu/etd/5343