Sugars and Other Polyols Can Enhance Chlorination Rates of Phenolic Compounds in Chlorinated Waters

Sugars are among the myriad organic compounds present in aqueous systems (e.g., wastewater) that undergo chlorine disinfection. Herein, we investigate the potential influence of 14 sugars and other polyols on chlorination rates of several disinfection byproduct (DBP) precursors, including phenols and related aromatic compounds. The effects of polyol structure, pH, buffer composition, and temperature were evaluated for their possible influence on DBP precursor chlorination rate enhancement by polyols. Of the 14 polyols tested, 13 increased chlorination rates of the model DBP precursor, ethylparaben. Sucrose was the most potent accelerant of ethylparaben chlorination, capable of doubling the chlorination rate at pH 7.0 when present at 50 mM (relative to no added sucrose). The structures of polyols influenced their effects on chlorination rates. In some instances, minor (e.g., isomeric) differences in polyol structure imparted sizable effects on chlorination rates of ethylparaben. In addition to ethylparaben, eight other phenolic compounds (including N-Boc-l-tyrosine) were examined. Chlorination rates of all examined phenolic compounds increased in the presence of sucrose as a model polyol. The co-occurrence of polyols, chlorine, and DBP precursors in wastewater suggests that interactions among these reactants could enhance rates of organochlorine formation in these systems.