Progress 06/01/24 to 05/31/25
Outputs
Target Audience:The target audience include environmental engineering researchers and practitioners that focus on the fate and transport of chemical contaminants (such as pesticides) in the environment. Additionally, government agencies (e.g., EPA, USDA) that set regulations regarding the application, testing, and safety of pesticides. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Since submission of the last annual REEport progress report, there have been numerous opportunities for professional development for the graduate student (Luana de Brito Anton) working on the project. Luanaparticipated in the Gordon Research Conference (GRC) focused on Environmental Sciences (Water) in June 2024, and the American Chemical Society's (ACS) Lasting Encounters between Aspiring and Distinguished Scientists (LEADS) Conference in November 2024. She gave oral presentations on her research funded by this grantat the ACS conference in March 2025 andthe New York Water Environmental Association Annual Meeting in February 2025 (USDA was acknowledged during both of those talks). Luana was chosen to participate in NYU's "PhD Live" program in April 2025, where she was chosed through a competative process to present her research to a broad audience at the university. Luana is defending her PhD dissertation at the end of April 2025, will graduate in May 2025, and will begina prestigious postdoctoral researcher position at Stockholm University, starting in Fall 2025. How have the results been disseminated to communities of interest?Since submission of the last annual REEport progress report, results have been disseminated through oral presentations at national (ACS National Conference Spring 2025) and local technical (NYWEA 96th Annual Technical Conference and Exhibition) conferences and other academic and professional events (e.g., university-sponsored research expo). We submitted our second paper describing the results of this work tothe peer-reviewed journal Environmental Science: Processes & Impacts. What do you plan to do during the next reporting period to accomplish the goals?During the next reporting period we planto complete data analysis and writing oftwo additional manuscripts, one related to Objective 2 and one related to Objectives 6 and 7. We aim to submit those papers to peer-reviewed journals before the end of the project period (December 2025). Once those papers are submitted, we will have completed all Objectives proposed for the funded grant.
Impacts
What was accomplished under these goals?
In previous years we completed Objectives 1 and 2. Since submission of the last annual REEport progress report, we have finished a full set of experiments evaluating indirect photolysis of 28 pesticides in 7 model experimental systems (two model systems used to determine bimolecular reaction rates constants with singlet oxygen, two with hydroxyl radical, and three with triplet state dissolved organic matter), fulfilling Objectives 3, 4, and 5. We have conducted photolysis experiments with pesticides in environmentally relevant solutions (i.e., with two sources of natural organic matter: a standard isolate and an agricultural soil leachate), and have compared predicted values of overall photodegradation (direct + indirect) with observed reaction rates for natural waters, thereby fulfilling goal of Objective 6. We previously published one manuscript describing research conducted as part of this grant (Obj 1), we recently submitted a manucript to Environmental Science: Processes and Impacts describing work related to Objectives 3, 4, and 5; that manuscript is under review. We arein the process of writing two additional manuscripts, one related to Objective 2 and one related to Objectives 6 and 7. We aim to complete and and submit these final two papers before the end of the project period (December 2025).
Publications
- Type:
Other Journal Articles
Status:
Under Review
Year Published:
2025
Citation:
de Brito Anton, L., Silverman, A., Apell, J. Comparing Photodegradation Model Systems: Measuring Bimolecular Rate Constants between Singlet Oxygen, Hydroxyl Radical, and Organic Contaminants. Submitted to Environmental Science: Processes & Impacts March 2025)
|
Progress 06/01/23 to 05/31/24
Outputs
Target Audience:The target audience include environmental engineering researchers and practitioners that focus on the fate and transport of chemical contaminants (such as pesticides)in the environment. Additionally, government agencies (e.g., EPA, USDA)that set regulations regarding the application, testing,and safety of pesticides. Changes/Problems:Some of the pesticides evaluated had very slow to no photodegradation with exposure to photochemically produced reactive species such as singlet oxygen and triplet excited states. To better evaluate the indirect photodegradation of this subset of compounds, we shifted some of the experimental procedures, including repeating experiments at lower pesticide concentrations to increase sensitivity. These revised experimental procedures do not change the scope of work, and will be used in further experiments to ensure the accuracy of new results. What opportunities for training and professional development has the project provided?ThePhD student supported by this project, Luana de Brito Anton, has presented their work at several significant events, including a university-sponsored research expo, the New York Water Environment Association (NYWEA) 96th Annual Technical Conference and Exhibition, the NYWEA 2024 University Night, and the American Chemical Society (ACS) National Conference Spring 2024. An abstract for a poster presentation has also been accepted at the Environmental Sciences Water Gordon Research Conference (GRC), which is occurring in June 2024. Luana was accepted to and participate in the Tandon Faculty First Look program at NYU, which is a two day program that introduces PhD students to the academic job market and faculty careers. Additionally, Luana has been selected to participate in the American Chemical Society's Lasting Encounters between Aspiring and Distinguished Scientists (LEADS) Conference in November 2024. How have the results been disseminated to communities of interest?The current results have been disseminated through oral presentations at national (ACS National Conference Spring 2024) and local technical (NYWEA 96th Annual Technical Conference and Exhibition) conferences and other academic and professional events (e.g., university-sponsored research expo, NYWEA 2024 University Night). Our work on characterizing actinometers to determine precise quantum yields has been published in the peer-reviewed journal Environmental Science: Processes & Impact: de Brito Anton, L., Silverman, A., Apell, J. Determining Wavelength-Dependent Quantum Yields of Photodegradation: Importance of Experimental Setup and Reference Values for Actinometers. Environmental Science: Processes & Impacts 2024. Advance Article. https://doi.org/10.1039/D4EM00084F What do you plan to do during the next reporting period to accomplish the goals?In the upcoming year, we will conclude the photolysis experiments with model sensitizers and perform experiments with two sources of natural organic matter (a standard isolate and an agricultural soil leachate). We will compare the observed reaction rate constants with the data predicted from the model systems to validate these model systems, addressing objectives 6 and 7. We are planning to prepare a minimum of two peer-reviewed journal articles describing the research funded by this grant.
Impacts
What was accomplished under these goals?
In the past year, we have made progress on objectives 3, 4, and 5. We have completed experiments with two model photosensitizer systems to determine bimolecular reaction rate constants with hydroxyl radicals. The experiments to determine bimolecular reaction rate constants with singlet oxygen are approximately 90% complete, as are the experiments using three model sensitizers to determine bimolecular reaction rate constants with triplet excited states. Additional experiments and literature review are being conducted to understand transformation mechanisms of a small subset of compounds that do not display expected first order decay kinetics.? Additionally, we have completed experiments evaluating the wavelength-dependent quantum yields of the target pesticides. Results from this work, along with recommendations for determining direct photolysis quantum yields and half-lives of pesticides in environmental and engineered systems, is being written now and will be submitted for publication within the next few months.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2024
Citation:
de Brito Anton, L., Silverman, A., Apell, J. Determining Wavelength-Dependent Quantum Yields of Photodegradation: Importance of Experimental Setup and Reference Values for Actinometers. Environmental Science: Processes & Impacts 2024. Advance Article. https://doi.org/10.1039/D4EM00084F
|
Progress 06/01/22 to 05/31/23
Outputs
Target Audience: Given that the model systems developed in this work prove reliable, these protocols will be documented as Standard Operating Procedures and will be made publically available. These SOPs will be disseminated to scientific researchers and USDA and EPA scientists working in pesticide fate and transport,in an effort to update the recommended testing guidelines currently used by companies for the pesticide registration process. Changes/Problems:Becuase the quantum yields of the actinometers that were planned to be used were either not reported at all of the necessary wavelengths or the reported quantum yields could not be replicated, substantial work was undertaken to fully and accurately charatcterize these chemicals. The accurate characterization of these actinometers will be the basis for the determination of quantum yields for all of the selected pesticides. Consequently, this work was crucial for the overall success of the project even though it was not orginally anticpated to be needed. This work will also be very valuable for the photochemistry community. What opportunities for training and professional development has the project provided?The graduate student supported by this project has had the opportunity to present at a university-sponsored workshop. An abstract for a poster presentation has also been accepted to a national conference (AEESP 2023) and will be presented in June 2023. How have the results been disseminated to communities of interest?The current results will be dissemenated through a national conference in June 2023 and submitted for publication in June 2023. What do you plan to do during the next reporting period to accomplish the goals?In the upcoming year, the direct photolysis experiments will be concluded and the remaining objectives to characterize the indirect photodegradation of the selected pesticides (objective 3-5) will be started and largely completed. Objectives 6 and 7 will be worked on at the same time.
Impacts
What was accomplished under these goals?
In the past year, we have addressed objectives 1 and 2. The pocedure developed to quantify and report molar absorptivity has proven to be robust. We hafve also characterized more light sources than originally planned. During the first phase of this work - quantifying direct photodegradation rates - we found that the reported quantum yields for reference compounds were inaccurate. These reference compounds, known as actinometers, are used to quantify the incident irradiance in laboratory systems. Without accurate measurements of their quantum yields, all subsequent determinations of direct photolysis quantum yields for pesticides would be inaccurate. A substantial amount of work was conducted to characertize multiple photoreactor setups and 11 light sources. These results will be submitted for publication in the upcoming months and will be the foundation for characterizing the walelength-dependent quantum yields of all of the test pesticides. The determination of wavelength-dependent quantum yields of pesticides is approximately 80% complete.
Publications
|
|