Date of Publication

4-4-2024

Document Type

Master's Thesis

Degree Name

Master of Science in Chemistry

Subject Categories

Chemistry

College

College of Science

Department/Unit

Chemistry

Thesis Advisor

Eric R. Punzalan
Francis M. dela Rosa

Defense Panel Chair

Marissa G. Noel

Defense Panel Member

Derrick Ethelbhert C. Yu
Ma. Katrina V. de Paz

Abstract/Summary

The emerging global concern for the increasing concentration of antibiotics in wastewater poses a significant danger to developing antibiotic-resistant bacteria. Conventional treatment technologies could not eliminate trace amounts of these antibiotics in wastewater treatment. New methods were explored; among them, the Advanced Oxidation Process (AOP) and Advanced Reduction Process (ARP) showed great potential for efficient degradation of antibiotics. UV/Persulfate and UV/Sulfite systems were utilized in this study to measure their degradation efficiency relative to Trimethoprim. Optimization of parameters such as the initial pH of solution and PS or SF dosage was investigated using the Response Surface Methodology (Full Factorial Design). The optimum parameters generated by the model for the UV/PS system are at 0.994 mM PS and pH is 4, while the optimum parameters for the UV/SF system are 1.489 mM SF at pH 4. The predicted degradation efficiency was 103.56% for UV/PS and 42.99% for UV/SF system, whereas the actual efficiencies were 100% and 43.43%, respectively. Transformation products (TPs) were identified via LC-MS/MS, which revealed transformation pathways involving hydroxylation, oxidation and demethylation. The toxicological evaluation of the transformation products was evaluated using ECOSAR software, and it was estimated that four TPs from the UV/PS system may be harmful to Daphnia and green algae while the TP from UV/SF was found to have no toxicity on fish, Daphnia and green algae. Moreover, the presence of Ca2+ and CO32- ions can significantly inhibit the efficiency of the UV/SF system while no significant inhibition was observed in the UV/PS system.

Abstract Format

html

Language

English

Format

Electronic

Keywords

Persulfates; Sulfites; Trimethoprim; Antibiotics; Oxidation-reduction reaction

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Embargo Period

4-22-2025

Available for download on Tuesday, April 22, 2025

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