A Novel Method of Water Purification: Optimizing Foam Fractionation for Effective Broad- Spectrum Removal of DBP and DBP Precursors in Chlorinated Drinking Water

Overview

University In the 20th century, water treatment plants began using disinfectants like chlorine to eliminate waterborne diseases such as cholera and typhoid. However, this process results in the formation of disinfection byproducts (DBPs), toxic compounds formed when disinfectants react with natural organic matter (NOM) in water. The precursors to DBPs are the organic and inorganic substances that participate in these reactions. Epidemiological studies have demonstrated a significant association between DBP exposure and an 80% increased risk of bladder cancer in males, along with detrimental reproductive outcomes in females. Despite EPA guidelines for DBP removal in water treatment plants, approximately 70% of halogenated byproducts in conventional drinking water remain unidentified, making them difficult to remove. Current treatment methods (e.g., granular activated carbon, nanofiltration, and reverse osmosis) for removing precursors and DBPs incur significant energy demands and operational expenses. Foam fractionation is a water purification technique that separates surfactant -containing foam from liquid solutions using bubbling columns to induce phase separation. Foam fractionation has never been used or optimized for DBP and DBP precursor removal in chlorinated water. Many DBPs and precursors are amphiphilic; this surfactant -like property facilitates their effective removal through foam fractionation. A pilot-scale foam fractionator was developed; a statistical analysis of the findings reveal a direct relationship between key variables (foaming stability, air flow rate, foaming agent concentration and type) and the removal efficiency of the target analytes (precursors). Results demonstrate that foam fractionation is both a viable and sustainable alternative for removing DBP and DBP precursors from chlorinated freshwater.