Transformation of Trace Organic Contaminants Involving Reactive Oxygen Species Driven By Solar Lights
The presence of trace organic compounds (TOrCs) in wastewater effluent and surface waters has raised attention due to their health and environmental effects. Some TOrCs are naturally attenuated via biodegradation, photo-degradation and/or adsorption, but some persist in the environment as contaminan...
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ndltd-arizona.edu-oai-arizona.openrepository.com-10150-6263332018-01-18T03:00:31Z Transformation of Trace Organic Contaminants Involving Reactive Oxygen Species Driven By Solar Lights Vo, Hao T.H. Vo, Hao T.H. Arnold, Robert G. Sáez, A. Eduardo Arnold, Robert G. Sáez, A. Eduardo Sierra-Alvarez, Reyes Slack, Donald C. Advanced oxidation process Direct photolysis Indirect photolysis Photolysis Reactive oxygen species Singlet oxygen The presence of trace organic compounds (TOrCs) in wastewater effluent and surface waters has raised attention due to their health and environmental effects. Some TOrCs are naturally attenuated via biodegradation, photo-degradation and/or adsorption, but some persist in the environment as contaminants in surface and ground waters. Thus, it is crucially important to understand their transformation pathways and their mechanisms following their discharge into the environment. This work presents research in three parts: • The first part represents an investigation of photo-transformation of TOrCs (e.g., furfuryl alcohol, p-cresol, gemfibrozil) under UV254, UVA and natural sunlight, and involving reactive oxygen species including singlet oxygen, hydroxyl radicals, triplet excited states, and specific inorganic radicals that are created by effluent organic matter (EfOM). Singlet oxygen was the only ROS, generated from effluent organic matter (EfOM) that mainly contributed to the photo-transformation of these selected TOrCs. A comprehensive mechanism and complementary kinetic model were proposed to predict the trajectories of TOrC removals via reaction with singlet oxygen. Simulations built on predicted quantum efficiencies accounted for light shading and competitive effects. Agreement between measurements and simulations was excellent. • The second part of the dissertation summarizes expected removal efficiencies for fifty-five TOrCs in alternative engineered and natural treatment processes including conventional biological treatment, advanced oxidation processes (AOP), reverse osmosis (RO), granular activated carbon (GAC), and sunlight photolysis. • The last section of the dissertation follows the trajectories of a series of TOrCs and total estrogenic activity in the Santa Cruz River, following their discharge from a wastewater treatment plant in the Tucson area. The study suggests that some TOrCs tend to persist in the environment while others experience photo (or other) transformations that diminish their concentrations or activities with distance and time of travel in the river. The attenuation of estrogenic activity was dependent on sunlight and the presence of specific (unidentified) wastewater components. 2017 text Electronic Dissertation http://hdl.handle.net/10150/626333 http://arizona.openrepository.com/arizona/handle/10150/626333 en_US Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. The University of Arizona. |
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en_US |
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Advanced oxidation process Direct photolysis Indirect photolysis Photolysis Reactive oxygen species Singlet oxygen |
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Advanced oxidation process Direct photolysis Indirect photolysis Photolysis Reactive oxygen species Singlet oxygen Vo, Hao T.H. Vo, Hao T.H. Transformation of Trace Organic Contaminants Involving Reactive Oxygen Species Driven By Solar Lights |
description |
The presence of trace organic compounds (TOrCs) in wastewater effluent and surface waters has raised attention due to their health and environmental effects. Some TOrCs are naturally attenuated via biodegradation, photo-degradation and/or adsorption, but some persist in the environment as contaminants in surface and ground waters. Thus, it is crucially important to understand their transformation pathways and their mechanisms following their discharge into the environment. This work presents research in three parts:
• The first part represents an investigation of photo-transformation of TOrCs (e.g., furfuryl alcohol, p-cresol, gemfibrozil) under UV254, UVA and natural sunlight, and involving reactive oxygen species including singlet oxygen, hydroxyl radicals, triplet excited states, and specific inorganic radicals that are created by effluent organic matter (EfOM). Singlet oxygen was the only ROS, generated from effluent organic matter (EfOM) that mainly contributed to the photo-transformation of these selected TOrCs. A comprehensive mechanism and complementary kinetic model were proposed to predict the trajectories of TOrC removals via reaction with singlet oxygen. Simulations built on predicted quantum efficiencies accounted for light shading and competitive effects. Agreement between measurements and simulations was excellent.
• The second part of the dissertation summarizes expected removal efficiencies for fifty-five TOrCs in alternative engineered and natural treatment processes including conventional biological treatment, advanced oxidation processes (AOP), reverse osmosis (RO), granular activated carbon (GAC), and sunlight photolysis.
• The last section of the dissertation follows the trajectories of a series of TOrCs and total estrogenic activity in the Santa Cruz River, following their discharge from a wastewater treatment plant in the Tucson area. The study suggests that some TOrCs tend to persist in the environment while others experience photo (or other) transformations that diminish their concentrations or activities with distance and time of travel in the river. The attenuation of estrogenic activity was dependent on sunlight and the presence of specific (unidentified) wastewater components. |
author2 |
Arnold, Robert G. |
author_facet |
Arnold, Robert G. Vo, Hao T.H. Vo, Hao T.H. |
author |
Vo, Hao T.H. Vo, Hao T.H. |
author_sort |
Vo, Hao T.H. |
title |
Transformation of Trace Organic Contaminants Involving Reactive Oxygen Species Driven By Solar Lights |
title_short |
Transformation of Trace Organic Contaminants Involving Reactive Oxygen Species Driven By Solar Lights |
title_full |
Transformation of Trace Organic Contaminants Involving Reactive Oxygen Species Driven By Solar Lights |
title_fullStr |
Transformation of Trace Organic Contaminants Involving Reactive Oxygen Species Driven By Solar Lights |
title_full_unstemmed |
Transformation of Trace Organic Contaminants Involving Reactive Oxygen Species Driven By Solar Lights |
title_sort |
transformation of trace organic contaminants involving reactive oxygen species driven by solar lights |
publisher |
The University of Arizona. |
publishDate |
2017 |
url |
http://hdl.handle.net/10150/626333 http://arizona.openrepository.com/arizona/handle/10150/626333 |
work_keys_str_mv |
AT vohaoth transformationoftraceorganiccontaminantsinvolvingreactiveoxygenspeciesdrivenbysolarlights AT vohaoth transformationoftraceorganiccontaminantsinvolvingreactiveoxygenspeciesdrivenbysolarlights |
_version_ |
1718611073862467584 |