Catalyst-driven strategies for organic matter and disinfection byproduct removal: Comparing adsorption, ozonation, and catalytic ozonation

Effective removal of natural organic matter (NOM) and its disinfection byproduct (DBP) precursors is vital for ensuring drinking water safety. This study systematically compared adsorption, sole ozonation, and catalytic ozonation using TiO2, goethite, silver nanoparticles, and iron-coated pumice as catalysts. Treatment performance was evaluated based on reductions in dissolved organic carbon (DOC), UV absorbance at 220, 254, and 272 nm, and DBP formation potentials (trihalomethanes (THMs) and haloacetic acids (HAAs)). Catalytic ozonation with TiO2 exhibited superior performance, achieving ~87 % DOC removal and > 93 % reduction in UV254 and UV272 absorbance. It also led to a > 94 % decrease in THM and HAA formation potentials, resulting in estimated carcinogenic risks well below regulatory thresholds set by the WHO and EPA. These risk estimates carry inherent uncertainties, particularly for emerging DBPs, yet remain valid indicators for comparing treatment efficacy. Goethite also demonstrated high DBP precursor removal (~73 %) with relatively low operational cost, while iron-coated pumice achieved moderate effectiveness (~67 %) but suffered from reduced longevity. Adsorption and sole ozonation were notably less effective. Statistical analysis confirmed significant performance differences among the catalysts, with TiO2 emerging as the most efficient and cost-effective option. The enhanced performance of TiO2 was attributed to its strong oxidative properties and affinity for both aromatic and aliphatic NOM fractions. These findings underscore the potential of catalyst-enhanced ozonation as a powerful strategy for NOM and DBP control, providing a technically and economically viable path toward meeting increasingly stringent drinking water standards and reducing long-term public health risks. © 2025 Elsevier Ltd.