Date of Award

2006

Degree Type

Thesis

Degree Name

Doctor of Philosophy

Program

Chemical and Biochemical Engineering

Supervisor

Dr. Dimitre Karamanev

Abstract

The present work represents the beginning of the research of biomachining of copper by iron oxidizing bacteria Acidithiobacillus ferrooxidans. First step was the production of large amount of bacteria in an iron-free media. Copper sulfide was used as a substrate. It was proven that the direct copper sulfide biooxidation exists but the process is very slow. The second step was to use the produced in step one bacteria for direct oxidation of metallic copper. A detailed surface analysis was performed. All the results from the direct mechanism of biooxidation were significant but not industrially applicable because of the slow rate of biooxidation.

In consequence of these two steps, the indirect biooxidation was chosen to be better copper biooxidation approach. A big challenge was how to minimize the chemical oxidation of copper by ferric ions. This problem was resolved by developing a new bioelectrochemical system. In addition, Computational Fluid Dynamics, CFD, simulations of indirect copper biooxidation were performed. The obtained results confirmed the applicability of the indirect biooxidation for biomachining of copper.

The choice of proper masking technique is an important part of microdevice production. The study of the effect of UV light on the activity of Acidithiobacillus ferrooxidans was performed. It was found that UV radiation is an appropriate masking method for bioma­ chining of copper.

Share

COinS
 
 

To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.