Abstract
In the face of the growing threat posed by ethylparaben (EP), a persistent endocrine disruptor, this study introduces an effective catalyst-free approach (i.e., relying solely on UV-driven photolysis without embedded semiconductor or metallic photocatalysts such as TiO(2), ZnO, or MOFs) for its removal. Commercial polybutylene terephthalate (PBT) nonwoven membranes were transformed into active purification platforms via an adsorption-assisted photolysis mechanism. By applying simple and targeted surface treatments-including hydrogen peroxide (H(2)O(2)) etching, ultraviolet (UV) irradiation, and sodium hydroxide (NaOH) hydrolysis-we successfully grafted oxygen-containing functional groups (-OH, C[double bond, length as m-dash]O, -COO(-)) onto the membrane surface. Quantitative FTIR analysis showed treatment-specific changes: UV irradiation decreased ester carbonyl groups by 76.9%, H(2)O(2) etching achieved a 99.8% reduction at 30% concentration, and NaOH hydrolysis resulted in an 87.4% decrease with formation of carboxylate. Under optimized conditions, modified membranes achieved removal efficiencies of 84% (15% H(2)O(2), 30 min), 85% (UV, 60 min), and 86% (1.0 M NaOH, 20 min)-representing 24-26% absolute improvement over UV photolysis alone (60%). Kinetic modeling confirmed that 80-90% of EP removal occurs via a rapid interfacial pathway (k (1) = 0.049-0.068 min(-1)), while bulk photolysis contributed negligibly (k (2) → 0). SEM imaging confirmed preservation of the microfibrous structure (79-90% porosity) throughout all treatments. This work demonstrates that controlled surface oxidation transforms standard polymers into an effective, quantifiably superior platform for water purification, offering a catalyst-free solution based on industrially relevant surface-engineering techniques that addresses key practical barriers (such as complex fabrication and catalyst leaching) to emerging contaminant removal.