Polycyclic aromatic hydrocarbons
Published on: Mar 4, 2016
Transcripts - Polycyclic aromatic hydrocarbons
Polycyclic Aromatic Hydrocarbons (PAH’s) in Soil Located NearFassnight Creek Meagan Nunn Shaina Dunn Megan Walcher Carl Hendrix Dan Dougherty December 3, 2012
Background of PAH’s Definition Group of organic contaminants that form from the incomplete combustion of hydrocarbons, such as coal and gasoline A compound that is formed from two or more benzene rings
Why are PAHs a Concern? Most of the compounds are highly carcinogenic at relatively low levels. They are relatively insoluble in water Toxic to aquatic life Several are suspected human carcinogens Stay in the environment for a long period of time All vary in behavior
Exposure Possibilities for PAH’s Breathing air contaminated by coal tar or wild fires Eating foods that have been grilled Transportation (roads and fume exhaust) Smoking tobacco Open trash burning
Our Exposure Focus Coal tar sealants are used to seal roadways and parking lots and believed to release PAHs into soil and ultimately waterways.
Possible PAH’s Nonpolarorganic molecules that comprise two or more benzene rings arranged in various configurations
The Goal of Our Study Todetermine if there are any PAHs present in the soil near Fassnight Creek. This is strictly a qualitative study to determine whether or not any are present.
Method Collect 100 gram soil samples from 3 different locations along Fassnight Creek. Source: National and Bennet Control: Near Art Museum Fort and Linwood Parkview Christian Church Allsamples are about 3 yards from runoff Allow the samples to air dry for 48 hours
Method Continued… In the lab, remove any debris (leaves, stones, roots, etc) Use a mortar and pestle to grind the soil to a fine powder Store in plastic bottles
Method Continued… Take about 5g portions of the samples and place the portions in beakers Add 50mL of a 50-50 mix of acetone+ hexane Cover with watch glass and put on hotplate and simmer for 10-15 minutes Let cool and filter into flasks Add anhydrous sodium sulfate (about 5g) to remove excess water Filter the solution again
Method Continued… Cook each sample down to about 2 mL
Future Studies Quantitative study determine the kinds of PAHs present and the amount present
Thank You We would like to send out a special thank you to Dr. Biagioni for helping us with the experiment and providing the lab area to do it.
Sources thetruthwins.com (Danger Sign Picture) http://www.medterms.com/script/main/a rt.asp?articlekey=24287 http://toxics.usgs.gov/definitions/pah.html maine.gov (Cigarette Picture) http://www.epa.gov/wastes/hazard/wast emin/minimize/factshts/pahs.pdf spellboundlabs.co.za (Mortar and Pestle Picture)