抄録
Threshold odor number (TON) was measured for samples of effluents from wastewater treatment plants and river water receiving treated wastewater in the Tama and Nomi rivers to identify factors affecting the odor of treated wastewater in river environments. The TONs of the effluents were between 87 and 373. TON decreased with biodegradation and volatilization in a section of the Tama river, although the transfer rate of odor from water to air was much smaller than that of oxygen from air to water. The acetaldehyde concentrations of the effluents were more than the odor threshold concentration, although no clear correlation between acetaldehyde concentration and TON was obtained.
