2014 Volume 45 Issue 6 Pages 429-438
Field investigations on wastewater quality and odor emissions at a potato starch factory were conducted from July 2007 to May 2008. Odor index of decanter effluent and separator effluent in penetration ponds ranged from 43 to 51, suggesting that anaerobic decomposition of wastewater with high concentration of organic matters especially in decanter effluent inflicted odor emissions with time. Intensive putrid odor like lower fatty acids with the highest odor index of 32 was perceived at the boundary downwind from the penetration ponds, and the highest odor index of 25 was obtained at the farmland after application of wastewater, indicating the concern about a wide-spread effect of odor. Among odorous substances emitted from wastewater, n-valeric acid, isovaleric acid and n-butyric acid were considered to be associated with perceived odors at the sites. It was suggested that odor index at the site could be evaluated relatively by using that estimated based on the concentrations of these acids in wastewater.
