Flow-Through Photocatalytic Reactor for Innovative, Sustainable Removal of Water Disinfection Byproducts

Abstract

Disinfection byproducts (DBPs) formed during water chlorination pose potential risks to human health and the environment, creating a need for efficient and sustainable removal technologies. Despite advances in photocatalytic degradation of organic pollutants, integrated systems for DBP removal remain limited, particularly those combining immobilized photocatalysts, energy-efficient irradiation, and comprehensive safety evaluation. In this study, we address this research gap by developing a novel flow-through photocatalytic system based on porous ceramic foams coated with immobilized titanium(IV) oxide (TiO2) and irradiated using low-energy, cost-effective UV-LEDs (λmax = 365 nm). The system was evaluated for the removal of various DBPs, including monochloroacetic acid (MCAA), 5-chlorosalicylic acid (CSA), 4-chlorophenol (CP), 2,4-dichlorophenol (DCP), 2,4,6-trichlorophenol (TCP), 2-chloronitrophenol (CNP), and bromodichloromethane (BDCM). The developed continuous-flow photoreactor with recirculation achieved over 85% mineralization of the DBP mixture, accompanied by complete chloride release. The environmental safety of the process was confirmed through toxicity assessment using Lemna minor and Daphnia magna and by monitoring potential TiO2 release from the immobilized ceramic foams using high-resolution inductively coupled plasma mass spectrometry. These results demonstrate the high efficiency, environmental safety, stability, and practical potential of the proposed UV-LED-driven photocatalytic system for DBP removal from water.