<< Chapter < Page | Chapter >> Page > |
Kitchen Synthesis of Nanorust
J.T. Mayo, Courtney Payne, Lauren Harrison, Cafer Yavuz, Dr. Mary McHale, Professor Vicki Colvin
Objectives
Grading
Your grade will be determined according to the following:
Background
Having clean drinking water is one of the most fundamental necessities of life. There are many different forms of possible contamination, but among the most well-studied and problematic inorganic contaminants is arsenic. Arsenic is one of the oldest known carcinogens. In 1999, the US National Academy of Sciences reported that arsenic can cause bladder, lung and skin cancer, and possibly cause liver and kidney cancer. The physical symptoms of arsenic poisoning include: extreme fatigue, nausea, vomiting, partial paralysis, and reproductive damage. National Research Council. Arsenic in drinking water . Washington, DC, National Academy Press, 1999. Arsenic is naturally occurring in water due to its abundance in certain types of rocks, but it can have anthropogenic origins as well.
Arsenic can be found all over the world, but is currently a particular problem in Third World countries due to the costly nature of water purification. It is especially abundant in Bangladesh, but arsenic has also been found in the ground water of Argentina, Chile, India, Mexico, Taiwan and Thailand. Additionally, closer to home, most states in the western US have levels of arsenic concentrations of greater than 10 parts per billion (10 ppb). This was not a cause for concern until the Environmental Protection Agency (EPA) in 2006 lowered the maximum allowable level of arsenic from 50 ppb to 10 ppb. In 2001, approximately 13 million Americans were drinking water that had elevated levels of arsenic in the water. http://www.epa.gov/safewater/arsenic/index.html
Previous methods for arsenic removal have included: manganese greensand columns that have been pretreated with dilute acid, coagulation/microfiltration, iron oxide based filtration, and activated alumina. The “Arsenic Removal Using Bottom Ash” or “ARUBA” method, invented by Ashok Gadgil of the Lawrence Berkeley National Laboratory, involves coating the surface of the contaminants with bottom ash and ferric hydroxide. Bottom ash is sterile waste material from coal-fired power plants which would make the cost of remediation about 0.5 cents per kg ARUBA of which generally 4-5 grams of ARUBA is needed for 1 liter of water, initially containing 400 ppb arsenic.
Nanomagnetite synthesis for arsenic removal has been hailed as Forbes: ‘Top 5 Nanotech Breakthroughs of 2006’ and Esquire listed it as ‘Six Ideas That Will Change the World’ in 2007. Basically, the technique entails forming iron oxide nanocrystals that possess very unique and size-dependent characteristics for environmental remediation of arsenic contaminated water.
Notification Switch
Would you like to follow the 'General chemistry lab spring' conversation and receive update notifications?