M.S. Thesis: The Effects of Arsenic on Thiobacillus Ferrooxidans
By Mandi Caudill
Department of Earth and Environmental Engineering
Fu Foundation School of Engineering & Applied Science
Columbia University
May 2003
Arsenic is a heavy metal that occurs both naturally in the earth’s crust and is caused by anthropologic means such as mining and combustion of fossil fuels. It is also an acute poison. Arsenic contamination of drinking water is an issue that has been receiving national and global attention. On a national level, the United States Environmental Protection Agency recently reduced the allowable limits of arsenic in drinking water from 50 parts per billion to 10 parts per billion. Internationally, the mass poisoning of the Bangladeshi people through groundwater drinking sources has received worldwide awareness.
Bioremediation is a technology that has begun to be perceived as a feasible option for water and soil clarification and remediation. However to make bioremediation a viable alternative to more traditional treatment technologies, more research needs to be conducted. Because the valance state of arsenic species determines its toxicity, bioavailability, and solubility, understanding the way in which various types of microbes and plants change arsenic speciation is imperative in the design of bioremediation techniques.
Laboratory experiments were conducted to determine the effects of As(III) and As(V) on Thiobacillus ferrooxidans. Even though Thiobacillus ferrooxidans is a widely studied bacterium due to its use in bioleaching of mining ores, new characteristics have been discovered through this study.