The Link between Odors and Regrowth of Fecal Coliforms after Dewatering

Recent research has examined the link between odor generation and fecal coliform regrowth, and theorized that both were related to residual biological activities. However, more supporting full-scale field experiments were needed to strengthen this linkage. Five full-scale wastewater treatment plants including both Class A and Class B digestion processes were analyzed for their odor generation and fecal regrowth profiles. The results showed that 100% matching occurrences of both odorant generation and fecal regrowth were observed in all samples analyzed. In other words, when odorant production occurred, regrowth was also measured. The results further strengthen the linkage between biosolids odor and fecal coliform regrowth, in that the two phenomena likely co-exist. The results also imply that methods used for odor control can likely also reduce regrowth in some cases if the approach tackles the availability of substrate which fuels both issues.