Progress 06/01/22 to 11/17/25
Outputs
Target Audience:The target audiences of this research are environmental chemists and toxicologists, photochemists, and researchers and practitioners involved in assessing, monitoring, and regulating the use of pesticides in agriculture. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?There have been numerous opportunities for professional development for the graduate student (Luana de Brito Anton) working on the project. Luana participated 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. Luana was chosen to participatein 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. Luana participated in NYU's "PhD Live" program in April 2025, where she was chosen through a competitive process to present her research to a broad audience at the university - she shared her research funded by this grant and won first place in the pitch competition. Luana is defended her PhD dissertation and graduated in May 2025. She continued work on this grant in summer 2025 until she began a prestigious postdoctoral researcher position at Stockholm University in Fall 2025. Luana gave oral presentations on her research funded by this grant at the Association of Environmental Engineering and Science Professors Conferences in Summer 2023 and Summer 2025, the ACS National Conferences in Spring 2024 and Spring 2025, the New York Water Environmental Association Annual Meetings in February 2024 and 2025, and the NYWEA University night in 2024 (USDA was acknowledged during all of those talks). During her time working on this project, Luana gained a large amount of experience in mentoring junior researchers:Luana mentored 9 undergraduate and 6 high school student researchers in the lab. These more junior students directly participated in research activities related to the funded project, and therefore also gained experience working in a laboratory environment and learned concepts related to the environmental fate of pesticides. How have the results been disseminated to communities of interest?In addition to the two published papers we have reported, there is one paper currently in review and another in preparation. The papers in prep will be uploaded to the USDA database once they are published. Results have also been disseminated through the following presentations: 1.de Brito Anton, L.,Silverman, A. I., Apell, J.Photodegradation Modeling Using Molar Absorptivity, Quantum Yields, and Bimolecular Rate Constants.AEESP Conference, Duke University. June 2025 (Oral). 2.de Brito Anton, L.,Silverman, A. I., Apell, J. Moving Towards Mechanistic Understanding of Photodegradation for Predictive Modeling. 2025 New York Water Environment Association (NYWEA) 97th Annual Technical Conference, Environmental Contaminants Technical Session (Oral). 3.de Brito Anton, L.,Silverman, A. I., Apell, J. Estimating Direct Photolysis Half-Lives with Narrowband Light Sources. 2024 Gordon Research Seminar (GRS) & Gordon Research Conference (GRC) Environmental Sciences: Water 2024 (Poster). 4.de Brito Anton, L.,Silverman, A. I., Apell, J. Photodegradation of Pesticides in Water Systems for Predictive Modeling. 2024 New York Water Environment Association (NYWEA) 2024 University Night (Oral). 5.de Brito Anton, L.,Silverman, A. I., Apell, J. Wavelength-Dependent Photolysis of Actinometers.2024 American Chemical Society (ACS) Conference Spring 2024 (Oral). 6.de Brito Anton, L.,Silverman, A. I., Apell, J. Photodegradation of Pesticides in Water Using Model Photosensitizers. 2024 New York Water Environment Association (NYWEA) 96th Annual Technical Conference (Oral). 7.Akhter, S.,Fernandez Germani, S.,de Brito Anton, L.,Silverman, A.I., Apell, J. Photodegradation of Pesticides in Water for Predictive Modeling. 2023 NYU Tandon Sustainable Engineering Initiative (SEI) Research Exposition (Oral). 8.de Brito Anton, L.,Silverman, A. I., Apell, J.Wavelength Dependence of Direct Photolysis Quantum Yields of Pesticides.AEESP Conference, Northeastern University. June 2023 (Poster). What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
All proposed Objectives were completed: Objectives 1 - The procedure developed to quantify and report molar absorptivity was found to be robust. Objective 2 - We quantifiedquantum yields of direct photodegradation of 30 pesticidesusing more light sources than originally planned. During the first phase of this work we found that the reported quantum yields for reference compounds used as actinometers were inaccurate. These 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. Results from this work, along with recommendations of best practices for determining direct photolysis quantum yields were published in our first publication (DOI:10.1039/D4EM00084F), and were the foundation for characterizing the wavelength-dependent quantum yields of all of the test pesticides. An additional paper describing direct photolysis quantum yields for each pesticide and light source in in preparation; we aim to submit this publication to a peer reviewed journal in early 2026. Objectives 3, 4, and 5 - we evaluated the indirect photolysis of 28 pesticides in 7 model experimental systems (two model systems were used to determine bimolecular reaction rates constants with singlet oxygen, two with hydroxyl radical, and three with triplet state dissolved organic matter) and we calculated bimolecular reaction rate constants between each pesticide-PPRI (photochemically produced reactive intermediate) pair. These results were published in our second publication (DOI:10.1039/D5EM00199D). Objective 6 and 7 - We 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. A manuscript describing this work, including discussion related to the impact of chemical structure on photodegradation rates, is currently under review in Environmental Science: Processes and Impacts, and is expected to be published shortly.
Publications
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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)
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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
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