Event Title
Degradation of Aquatic Pollutants via Photoproduced Reactive Intermediates: Investigation of Factors that Determine which Reactive Intermediates are Produced
Location
CSU Ballroom
Start Date
21-4-2014 10:00 AM
End Date
21-4-2014 11:30 AM
Student's Major
Chemistry and Geology
Student's College
Science, Engineering and Technology
Mentor's Name
John Thoemke
Mentor's Email Address
john.thoemke@mnsu.edu
Mentor's Department
Chemistry and Geology
Mentor's College
Science, Engineering and Technology
Description
Dissolved organic matter (DOM) results from the accumulation of biomolecular fragments in natural surface waters, and plays a role in numerous environmental processes. There are two broad classification of DOM, with microbial DOM originating from biological activity in the water column, and terrestrial DOM originating from decayed plant material that enters a water body. In sunlit surface waters, a significant portion of the light is absorbed by DOM, leading to energetically excited states of DOM. These excited states then form highly reactive species, known as photoproduced reactive intermediates (PPRIs). These may include 3DOM*(excited triple state DOM) and 1O2 (singlet oxygen). The PPRIs interact with a wide range of pollutants and play a key role in determining the ultimate environmental fate of many. In this research project, water samples from a variety of Minnesota lakes and rivers were classified and their relative yields of 3DOM* and 1O2 determined. Probe molecules 2,4,6-trimethyl phenol (TMP) and furfuryl alcohol (FFA) were used to measure the reactivity of 3DOM* and 1O2 respectively. We compared the rate of TPM depletion by 3DOM* to the rate of FFA depletion by 1O2 to determine the relative amounts of the two PPRIs produced in each of the water samples. We have learned that the yields of both 3DOM* and 1O2 are higher for DOM that is predominantly microbial in origin, compared to that of terrestrial origin.
Degradation of Aquatic Pollutants via Photoproduced Reactive Intermediates: Investigation of Factors that Determine which Reactive Intermediates are Produced
CSU Ballroom
Dissolved organic matter (DOM) results from the accumulation of biomolecular fragments in natural surface waters, and plays a role in numerous environmental processes. There are two broad classification of DOM, with microbial DOM originating from biological activity in the water column, and terrestrial DOM originating from decayed plant material that enters a water body. In sunlit surface waters, a significant portion of the light is absorbed by DOM, leading to energetically excited states of DOM. These excited states then form highly reactive species, known as photoproduced reactive intermediates (PPRIs). These may include 3DOM*(excited triple state DOM) and 1O2 (singlet oxygen). The PPRIs interact with a wide range of pollutants and play a key role in determining the ultimate environmental fate of many. In this research project, water samples from a variety of Minnesota lakes and rivers were classified and their relative yields of 3DOM* and 1O2 determined. Probe molecules 2,4,6-trimethyl phenol (TMP) and furfuryl alcohol (FFA) were used to measure the reactivity of 3DOM* and 1O2 respectively. We compared the rate of TPM depletion by 3DOM* to the rate of FFA depletion by 1O2 to determine the relative amounts of the two PPRIs produced in each of the water samples. We have learned that the yields of both 3DOM* and 1O2 are higher for DOM that is predominantly microbial in origin, compared to that of terrestrial origin.
Recommended Citation
Mohamed, Abdikadir. "Degradation of Aquatic Pollutants via Photoproduced Reactive Intermediates: Investigation of Factors that Determine which Reactive Intermediates are Produced." Undergraduate Research Symposium, Mankato, MN, April 21, 2014.
https://cornerstone.lib.mnsu.edu/urs/2014/poster_session_A/38
