IHSS&IWA26 / BRNO / CZECHIA / 23–28 August 2026 BOOK OF ABSTRACTS 50 Analysis and Characterization Tuesday, 25 August 2026 / Hall B+C SL19 Which Disinfectant Generated Drinking Water DBP Mixture with the Least Developmental Toxicity? Jiarui Han1,2, Yu Li3, Xiangru Zhang1,*, William A. Mitch4 1 Department of Civil and Environmental Engineering, Hong Kong University of Science & Technology, Hong Kong SAR, China 2 Department of Chemistry, Hong Kong Baptist University, Hong Kong SAR, China 3 School of Environment, South China Normal University, Guangzhou 510006, China 4 Department of Civil and Environmental Engineering, Stanford University, 473 Via Ortega, Stanford, California 94305, United States Chlorine disinfection of drinking water, while pivotal in preventing waterborne diseases, produces disinfection byproducts (DBPs) that are associated with cancers and developmental disorders [1,2]. Alternative disinfection strategies that can reduce the formation of regulated trihalomethanes and haloacetic acids are increasingly utilized in drinking water treatment with the aim to mitigate DBP-associated risks [3]. Given the continuous discovery of highly toxic DBPs and the recognition that regulated species contribute little to the overall toxicity of disinfected water [4,5], there is an urgent need to reassess and optimize disinfection strategies. In this work, we systematically evaluated the developmental toxicity from chlorination and prevalent alternative strategies (chlorine, chlorine dioxide, or ozone with subsequent chloramination), which were carefully calibrated to achieve the disinfection goal with equivalent disinfection efficiency and detectable residuals. Our results revealed that chlorine or chlorine dioxide with subsequent chloramination consistently resulted in 25–35% lower developmental toxicity than chlorination alone, despite the increased formation of iodinated DBPs. However, while ozonation produced the drinking water with the lowest developmental toxicity for low-bromide/ iodide source water, it resulted in the highest developmental toxicity for source waters with elevated bromide/iodide content, which was up to twice as potent as that from chlorination. In addition, we found that enhanced bromide/ iodide content consistently increased the developmental toxicity across all disinfection strategies. We further demonstrated that by incorporating the synergistic contributions of organic and inorganic DBPs, the model based on their concentrations can well predict the developmental toxicity across disinfection strategies and source waters. Our work aids to answer the longlasting question on which disinfection strategy can balance microbial safety with chemical risks, supporting the development of more sustainable water treatment practices.
RkJQdWJsaXNoZXIy NDA4Mjc=