Skip to main content


Buy Article:

$9.50 plus tax (Refund Policy)

Or sign up for a free trial

A temperature-phased anaerobic digester (TPAD) and batch, staged-temperature anaerobic digester (B-STAD) were maintained in parallel with a conventional mesophilic control to compare VS destruction, VFA concentrations, and biomass activity. The TPAD system consisted of sequential 8-L thermophilic (55°C) and 16-L mesophilic (35°C) digesters. The B-STAD was similar, except that 0.4 L/day of mesophilic biomass was recycled to the thermophilic digester. The mesophilic control digester was a 24-L, single-stage unit. All systems were fed 1.6 L/d of municipal wastewater sludge (70/30% v/v blend of primary and thickened waste activated sludge), and had total system SRT values of 15 days. Daily batch feeding was employed to preclude short-circuiting that reduces fecal coliform inactivation. The VS destruction values of the systems were not statistically different, and averaged 58%. The TPAD and B-STAD achieved higher fecal coliform inactivation than the control. The TPAD system required nutrient addition to increase the pH in the thermophilic digester and reduce final VFA concentrations which may have initially been high due to toxicity from long-chain organic acids produced in the thermophilic phase. Recycling of mesophilic biomass to the thermophilic phase, as performed in the B-STAD configuration, and trace nutrient supplementation are described as potential methods of maintaining neutral thermophilic pH values and reducing VFA concentrations in batch fed systems. Alkalinity addition to the TPAD system also maintained neutral pH values in the thermophilic phase, but did not reduce final VFA concentrations.
No Reference information available - sign in for access.
No Citation information available - sign in for access.
No Supplementary Data.
No Data/Media
No Metrics

Document Type: Research Article

Publication date: 2004-01-01

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 These proceedings are not peer reviewed.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
  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more