Y. Chen
Georgia Institute of Technology,
United States
Summary:
The chlorination of drinking water was one of the most significant public health achievements of the 20th century, virtually eliminating many waterborne diseases. However, modern chlorinated water still raises safety concerns due to trace levels of regulated and unregulated disinfection byproducts (DBPs) and a growing list of known, unknown, and emerging contaminants (KUECs) that pose chronic health risks. The challenge is amplified by stringent regulations, such as the recent per- and polyfluoroalkyl substances (PFAS) limit of 4 ppt, because conventional chemical-based treatment processes are largely ineffective at removing DBPs and KUECs. This reality demands alternative strategies that go beyond traditional chemical addition. In this talk, we introduce the “Minus Approach,” a paradigm shift in drinking water treatment designed to minimize DBPs and KUECs without compromising microbiological safety. Unlike the conventional “Plus Approach,” which relies heavily on chemical coagulants, disinfectants, and advanced oxidation processes, the Minus Approach prioritizes membrane-based physical separation to remove DBP precursors, KUECs, and pathogens from the primary treatment stream. Concentrates, if necessary, can be treated separately. This strategy enables significant reduction of harmful byproducts while using only minimal secondary disinfectant doses to control microbial regrowth in distribution systems. The Minus Approach is further enhanced by AI-driven inverse membrane design, enabling optimized performance and adaptability. By reducing chemical dependency and targeting contaminants at their source, this approach delivers biologically stable water with lower health risks and improved sustainability metrics. Adopting the Minus Approach represents a critical step toward next-generation water treatment, one that aligns with public health goals, regulatory demands, and environmental stewardship.