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.

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Apr 21st, 10:00 AM Apr 21st, 11:30 AM

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.
http://cornerstone.lib.mnsu.edu/urs/2014/poster_session_A/38