Thesis
Biogeochemical cycling of toxic metals in Lake Coeur d'Alene sediments
Washington State University
Master of Science (MS), Washington State University
2006
Handle:
https://hdl.handle.net/2376/536
Abstract
Historic mining in the Coeur d'Alene area of Idaho has contaminated sediments, soils, and waters with heavy metals including, but not limited to, lead, copper, and zinc. Metal contamination continues to be introduced into Lake Coeur d'Alene and its tributaries by a variety of factors including seasonal changes, flooding, acid mine drainage, and air borne dust and this poses a significant health hazard to humans and biota. Bacteria residing in Lake Coeur d'Alene are capable of detoxifying metals using largely unknown processes. However, heavy metals exert toxic effects on the indigenous bacteria and these toxic effects highly depend on metal speciation, chemical properties, and geochemical factors. Therefore to develop an effective understanding of the metal toxicity in this environment and its effects on indigenous microorganisms, metal concentration, speciation, associated mineral phase, microbial toxicity, and microbial biogeochemical contributions to metal cycling must be studied. This work is broken up into five chapters. The first deals with the historic contamination, toxic metal transport, and microbial interactions with toxic metals, focused mainly on lead, copper, and zinc. Chapter two launches a more in depth look at the geochemistry of the Coeur d'Alene River Delta, both aqueous and sediment, using synchrotron based X-ray analyses to characterize the sediments. Chapter two also proposes some theoretical interactions between these identified mineral phases and microbes. The third chapter focuses on bacterial enrichments, isolation, and identification from the sediments using a novel flow reactor and batch culturing. The fourth chapter examines the toxic effects of zinc on Arthrobacter sp., an isolate from the novel reactor. This chapter includes a dual-Monod kinetic model to represent zinc inhibition of this organism. The model represents the experimental data very well at low metal concentrations and deviates at higher metal concentrations and this could be due to lag-components not included in the model or a variety of other reasons. Chapter five discusses some future work in biogeochemical metal cycling as it pertains to Coeur d'Alene.
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Details
- Title
- Biogeochemical cycling of toxic metals in Lake Coeur d'Alene sediments
- Creators
- James Gill Moberly
- Contributors
- Rajesh K. Sani (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Chemical Engineering and Bioengineering, School of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; Pullman, Wash. :
- Identifiers
- 99900525164201842
- Language
- English
- Resource Type
- Thesis