Evaluation of Bacterial Pathogen and Indicator Densities After Dewatering of Anaerobically Digested Biosolids: Phases II and III

Previous WERF project suggest that a sudden increase in indicator bacteria, mainly fecal coliform and/or E. coli, was being measured immediately after dewatering compared to just prior to dewatering. The increase in indicator bacteria immediately after dewatering has been termed "sudden increase" or SI while the increase during cake storage has been termed "regrowth". Additional study found no evidence of a comparable sudden increase in pathogenic bacteria. The research focused on understanding the sudden increase after dewatering, as well as the increase measured during storage, and examined the impact of different process parameters on the extent of the increases. The research also sought to determine if potentially pathogenic bacteria, such as Salmonella, also increased after dewatering of Class A and Class B biosolids. Published by WERF 164 pages. Fact sheet, soft cover and online PDF (2007/2008)

Originally funded as WERF project 04-CTS-3T.