Date of Publication

8-12-2025

Document Type

Bachelor's Thesis

Degree Name

Bachelor of Science in Chemistry

Subject Categories

Chemistry

College

College of Science

Department/Unit

Chemistry

Thesis Advisor

Francis M. dela Rosa
Eric R. Punzalan

Defense Panel Member

Mariafe N. Calingacion
Joan Candice V. Ondevilla

Abstract/Summary

Trimethoprim (TMP), an antibiotic used for treating urinary tract infections and gastrointestinal infections, has been classified as a contaminant of emerging concern (CEC) due to detected amounts in water bodies, including surface water (30–150 ng/L) and wastewater effluent (20–37,000 ng/L). In addition, the European Watchlist (2022) monitors a list of substances in water that may pose a risk to the environment and human health. In the list issued, TMP was identified to be one of them. Furthermore, conventional wastewater treatments were insufficient in removing TMP. Advanced oxidation process (AOP) was found to be a promising solution. Hence, in this study, VUV/Fe2+/Percarbonate was used to determine TMP degradation efficiency. Parameters such as pH, Fe2+, and percarbonate concentration were optimized using response surface methodology (Box-Behnken Design). ANOVA results reported that both pH and Fe2+concentrations have significant effects on the system’s degradation efficiency. The optimized experimental conditions (pH=3, [SPC] = 1.8977mM, [Fe2+] = 250 µM) at 1 min resulted in a 99.99% degradation efficiency. It followed a pseudo-first-order kinetics, giving kobs of 0.147 s-1. Furthermore, •OH, CO₃•⁻, and O₂• radical contributions were identified using radical scavenging solutions, tert-butyl alcohol, phenol, and ascorbic acid, respectively. The main radicals in the system were identified to be •OH and CO₃•. Moreover, inorganic ions (NO₃⁻, H₂PO₄⁻, Cl⁻, HCO₃⁻, and SO₄²⁻) and natural organic matter (NOM) represented by humic acid (HA) were tested. An optimal degradation efficiency of 99.99% was reduced to 64.58%, 81.35%, 98.60%, 99.26%, 99.77% and 95.73%, respectively. A mixture of all ions and HA was found to inhibit TMP degradation, resulting in 37.76%. The significant inhibition of the mixture of ions was attributed to i) hydroxyl radical scavenging, ii) complex iron formation, and iii) VUV light shielding effect.

Abstract Format

html

Language

English

Format

Electronic

Keywords

Trimethoprim

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Embargo Period

8-19-2026

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Available for download on Wednesday, August 19, 2026

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