3. Organic compounds can degrade in sunlight Direct Photolysis Fe NO3 DOM Fe NO3 Indirect Photolysis DOM
4. Experimental Approach Filter (1 µm) 4 wetlands : Ohio Hawaii Florida Georgia Store at 4°C Herbicide: Acetochlor or Isoproturon HPLC Solar Simulator
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7. 1. Different wetlands cause different photoreactivity Distilled water Yocom Wetland, Ohio Okeefenokee Swamp, Georgia Kawainui Wetland, Hawaii Everglades, Florida Half-life, days Acetochlor
8. We even see a difference over small time periods in the same wetland… Half-life, days Yocom Wetland, Ohio Acetochlor
9. 2. The two herbicides react differently in the same water Yocom Wetland, Ohio Okeefenokee Swamp, Georgia Kawainui Wetland, Hawaii Everglades, Florida Half-life, days
10. 3. Wetland chemistry drives reactivity Yocom Wetland, Ohio Acetochlor Total Nitrogen, μM NO 3 /NO 2 , μM
11. Different compounds degrade via different mechanisms Fe NO3 DOM Fe NO3 OH DOM Acetochlor and Isoproturon Just Isoproturon 3 DOM Gerecke et al. 2001, ES&T
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13. Acknowledgements Advisers Prof. Yo Chin Prof. Linda Weavers Collaborators Prof. John Lenhart Prof. Larry Brown Chin Research Group OSU Environmental Engineering Research Group Funding National Science Foundation Graduate STEM Fellows in K-12 Education Program Ohio Water Development Authority Research and Development Grant OSU Environmental Science Graduate Program
