Glycolipid Surfactants as Chemical Precipitants for Metal Remediation
Author
McCawley, Ida AnnIssue Date
2022Keywords
Chemical PrecipitationMetal Recovery
Metal Remediation
Rare Earth Elements
Rhamnolipid
Surfactant
Advisor
Hogan, David E.Maier, Raina M.
Metadata
Show full item recordPublisher
The University of Arizona.Rights
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction, presentation (such as public display or performance) of protected items is prohibited except with permission of the author.Abstract
The expansion of low carbon technologies such as solar power, electric vehicles, and wind turbines has increased demand of critical elements such as rare earth elements (REEs). Hardrock mining produces 99% of the REE supply, but mining is environmentally costly; therefore, it is essential to examine nontraditional production methods. Identifying and exploiting cost-effective and green methods of metal recovery from natural and contaminated aqueous systems is widely recognized as necessary to supplement the supply of critical elements, decrease the environmental impacts associated with hardrock mining, and remediate metal-contaminated waters. The objective of this research is to examine a novel approach based on glycolipid-facilitated chemical precipitation of metals and REEs. Three techniques were assessed to remove the glycolipid:metal complex from solution: mixing only, and mixing followed by filtration or centrifugation. Recent advancements in the ability to synthetically produce glycolipid surfactants has allowed for the investigation of a variety of glycolipid structures. Sixteen glycolipids were assessed to determine the effect of structure on the molecule’s ability to chemically precipitate Pb2+, La3+, and Mg2+ from single metal solutions. It was determined that under certain conditionsmetals can be removed by the addition of a glycolipid only, but the addition of an active removal step (filtration or centrifugation) greatly improved the removal of the metals. Results suggest tailoring the glycolipid structure and removal methods may enable selective metal removal to achieve specific outcomes. Future studies in mixed-metal and real-world solutions will be needed to confirm the viability of these techniques in complex systems. Aqueous mining will likely be increasingly important in the mining industry, but additional research and technological innovation are needed to further develop it into an effective tool to meet industrial demands.Type
textElectronic Thesis
Degree Name
M.S.Degree Level
mastersDegree Program
Graduate CollegeSoil, Water & Environmental Science