PILOT STUDY OF PRE-TREATMENT TO MESOPHILIC ANAEROBIC DIGESTION FOR IMPROVED BIOSOLIDS STABILIZATION
Mesophilic anaerobic digestion of sludge pre-treated by thermal hydrolysis or thermophilic acidogenesis was very stable as measured by volatile acids-to-alkalinity ratio and pH. Volatile solids destruction and gas production were comparable or better than in the control digester. However, the organic loading of the digester fed with sludge treated by thermal hydrolysis was three to four times greater than the control. This is possible because of thermal hydrolysis partial transfer into solution of particulate organic matter in undigested sludge, thus making it more readily available for the active biomass in the reactor. Thermal hydrolysis meets the EPA temperature and time requirements to achieve Class A biosolids and, after anaerobic digestion, complete absence of fecal coliforms is observed. The two-phase system also achieved Class A biosolids as measured by fecal coliform concentrations. A progressive wash-out of fecal coliforms was observed in the mesophilic, methanogenic phase from initial numbers of the Class B biosolids used as seed. The enhanced mixing (more than one turnover per hour) and the draw-fill operation of the thermophilic digester are believed to have contributed to the superior fecal coliform inactivation.
No Reference information available - sign in for access.
No Citation information available - sign in for access.
No Supplementary Data.
Document Type: Research Article
Publication date: 2002-01-01
More about this publication?
- Proceedings of the Water Environment Federation is an archive of papers published in the proceedings of the annual Water Environment Federation® Technical Exhibition and Conference (WEFTEC® ) and specialty conferences held since the year 2000. These proceedings are not peer reviewed. A subscription to the Proceedings of the Water Environment Federation includes access to most papers presented at the annual WEF Technical Exhibition and Conference (WEFTEC) and other conferences held since 2000. Subscription access begins 12 months after the event and is valid for 12 months from month of purchase. A subscription to the Proceedings of the Water Environment Federation is included in Water Environment Federation (WEF) membership.
WEF Members: Sign in (right panel) with your IngentaConnect user name and password to receive complimentary access. Access begins 12 months after the conference or event
- Subscribe to this Title
- Membership Information
- About WEF Proceedings
- WEFTEC Conference Information
- Learn about the many other WEF member benefits and join today
- Ingenta Connect is not responsible for the content or availability of external websites