NOVELTY - Treating (M1) volatile organic compounds produced during a fermentation process involves either method A: producing volatile organic compound during fermentation process; generating chlorine dioxide (ClO2) gas; dissolving ClO2 gas to form ClO2 solution; and introducing aqueous ClO2 solution into the volatile organic compound. The introducing step reduces concentration of the volatile organic compounds.    USE - For treating volatile organic compounds (such as acetyl aldehyde, acrolein, ethyl acetate, ethanol, and isoamyl alcohol) produced during fermentation process (claimed).    ADVANTAGE - The ClO2 solution has efficiency, as ClO2 in the stream, of at least 90%. The method is less costly and more; hence reduces VOC's produced during the fermentation processes.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) treating (M2) volatile organic compounds produced during a fermentation process involves producing volatile organic compound during fermentation process; and introducing ClO2 having efficiency as ClO2 of at least 90% into the volatile organic compound; where the introducing step reduces concentration of the volatile organic compounds; and    (2) an apparatus for treating volatile organic compounds produced during a fermentation process, comprising ClO2 generator comprising an inlet for introducing at least one chlorine-containing feed chemical and an outlet for exhausting a ClO2 gas stream from the generator; batch tank fluidly connected to the ClO2 generator outlet, where the batch tank receives the ClO2 gas stream from the ClO2 generator outlet, and comprises an inlet for introducing a water stream and an outlet for exhausting an aqueous ClO2 solution from the batch tank; and volatile organic compound producing fermentation vessel fluidly connected to the batch tank. The fermentation vessel receives the aqueous ClO2 solution from the batch tank. The introducing the ClO2 solution from the batch tank to the vessel reduces concentration of the volatile organic compounds.