OXIDATION OF ODOROUS AND NONODOROUS ALGAL METABOLITES BY PERMANGANATE, CHLORINE, AND CHLORINE DIOXIDE

The six algal metabolites, at concentrations of 20-225 mu g/l, were ox idized with potassium permanganate, chlorine, or chlorine dioxide at d oses of 0,25-3 mg/l. Flavor profile analysis (FPA) was used to determi ne the odors of the solutions before and after oxidation. Linoleic and palmitic acids, which are odorless compounds, were oxidized to odorou s products by all three oxidants. The odor intensity of beta-cyclocitr al (grape, sweet tobacco) and phenethyl alcohol (rose, floral) was onl y slightly decreased by any of the oxidants. Oxidation by permanganate or chlorine either eliminated or greatly reduced the odors associated with linolenic acid (watermelon) and 2t,6c-nonndienal (cucumber); chl orine dioxide was ineffective at reducing the cucumber odor of 2t,6c-n onadienal. Oxidation, at doses typically applied for drinking water tr eatment, can result in the destruction of certain algae-related odors but in the formation of other odors.