Treatability of 18 taste and odor compounds in drinking water using oxidation

The occurrence of taste and odor (T&O) compounds in drinking water can lead to public concern about quality when left unaddressed, therefore suitable treatment is needed. This study evaluated the treatability of 18 T&O compounds using chlorine, permanganate, and ozone in MilliQ and river water. Nine T&O compounds showed complete oxidation (>99% removal) in all water matrices by ozone. Most of the remaining T&O compounds were removed to >50% by ozone. Alkalinity, pH, and natural organic matter (NOM) had a significant impact on the decay of ozone. Chlorine and permanganate were ineffective (removal <30%) for 2-methylisoborneol (2-MIB), geosmin, hexanal, pyrazines, and haloanisoles. Although chlorine achieved complete removal for alkyl sulfides and indole, it was only partially effective for aldehydes and ketones. Permanganate was more effective than chlorine in oxidizing unsaturated aldehydes and ketones. Increased NOM and pH reduced oxidation effectiveness for chlorine, but not permanganate.