Analysis of Odor Compounds in Sewerage Process Water and Deodor Methods

The concentration of 21 odor compounds of water and air, odor index and DOC of the water were measured at nine sewerage process stations. The odor indexes of water decreased as the sewage treatment progressed. According to the dilution ratio given by dividing the concentration of an odor compound in the head space of a triangle flask with its threshold, it was suggested that sulfur-containing compounds are the main cause of odor at the upstream treatment process including the biological reaction process. Since the odor index obtained by the triangle flask method had a positive correlation with the concentration of aldehydes in water, it was suggested that the decrease in odor index depends on the concentration of aldehydes. The dilution ratios in air supported the suggestion that sulfur-containing compounds are the main cause of odor at the upstream treatment process, and acetaldehyde is the main cause of odor at the outflow of final sedimentation and final effluent. The concentration of acetaldehydes of air at the final effluent was 15 times as high as that of a natural environment. Deodor methods by both photocatalysis and ozonation treatment were considered feasible for decreasing the odor of the final effluent.