This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: Dmitriy Andreev 5/12/2009 A Comparison of Atrazine Sequestration Using Cotton Balls and Charcoal Abstract In this experiment, the effects of cotton (which is structurally similar to chitosan) and charcoal on atrazine sequestration were investigated. The first step was to isolate the atrazine from the water sample. This was done by firstly adding cynauric chloride to the atrazine containing water sample and then reacting it with piperazine, followed by a reaction with trichlorotriazine. This series of reactions not only separated the atrazine from the water sample but it also made the atrazine more biodegradable to ease the process of adsorption of the atrazine. The next step was to carry out an experiment to test the efficiency of atrazine sequestration using charcoal. This was done by mixing three different types of activated charcoal (i.e. powdered, F400 and F300 charcoal) with the atrazine solutions and comparing the effect that they have on the absorption and percentage transmittance of the solutions. The same was done for cotton, however, rather than having three different types of cotton, it was only the treated cotton balls and untreated cotton balls that were mixed with the atrazine solutions. By comparing the results obtained from the activated charcoal and the cotton balls, it was concluded that cotton balls treated with piperazine were more efficient at sequestering atrazine from a atrazine based dye solution. Introduction This experiment will deal with chemical modification of a series of commercially available cross-linked poly(styrene) polymers of different mesh sizes to generate BOC-protected piperdine groups that will be able to sequester atrazine from solution. Atrazine is one of the most broadly used herbicides in North America to control broadleaf weeds, however, atrazine and its metabolites are have been identified as one of the main sources of contamination in water in agricultural areas. It has even been found that exposure to atrazine and its metabolites has lead to cancer developing in humans as well as animals. As a result of these negative impacts, intensive research is being carried out to investigate methods that can remove triazine herbicides (such as atrazine) from several media. These methods include adsorption onto solid supports such as clay materials, and linear, cross-linked or molecularly imprinted polymers. At present, activated charcoal is used to remove such triazine herbicides from drinking water. Nevertheless, this proves to be an inefficient method since activated charcoal lacks selectivity for pollutants and as a result absorbs innocuous organic compounds. This means that natural organic matter (NOM) competes with atrazine for the adsorption on charcoal causing displacement of the adsorbed atrazine. Thus the adsorption capacity of the charcoal decreases with time or NOM throughput....
View Full Document
This note was uploaded on 03/25/2008 for the course CHEM 102 taught by Professor Williamson during the Spring '08 term at Texas A&M.
- Spring '08