Skip to main content

Combining Mesophilic Anaerobic Digestion with Post-Aerobic Digestion to Enhance Volatile Solids Reduction and Reduce Sidestream Ammonia

Buy Article:

$17.50 plus tax (Refund Policy)

Or sign up for a free trial

Abstract:

Anaerobic-aerobic phased digestion, or post-aerobic digestion, is a promising advanced digestion process applying the sequential operation of anaerobic digestion followed by aerobic digestion. Post-aerobic digestion provides total nitrogen removal without the need for chemical addition in addition to enhanced volatile solids reduction. Since nitrification occurs in the post aerobic digester, digester biomass may also represent an external source of nitrifiers for bioaugmentation. The City of Meridian, ID pilot tested bioaugmentation using post-aerobic digestion. Two 106-L activated sludge reactors with settling for biomass retention and one 16.5 L post-aerobic digester were constructed at the Meridian wastewater treatment plant. The activated sludge reactors were operated at a solids retention time (SRT) resulting in unstable nitrification. One reactor was bioaugmented with post-aerobic digester biomass. Bioaugmentation resulted in stable nitrification for ten days of reactor operation. However, the slow recovery of stable nitrification after an upset of the bioaugmented reactor suggests further optimization of the system is required to ensure stable bioaugmentation is maintained. No detrimental effects due to recycling of digested biosolids were observed in the bioaugmented reactor and the results of the current study suggest that further investigation of this new wastewater treatment concept is warranted. The performance of post-aerobic digestion was also demonstrated here. The post-aerobic digester achieved 80% ammonia removal and complete denitrification without the need for chemical addition. Thirty percent volatile solids reduction was achieved at a digester SRT of 9 days. The observed volatile solids reduction is twice as high as previous studies have reported at the same SRT and represents a significant decrease in the mass of biosolids for disposal if implemented full scale.

Keywords: Anaerobic-aerobic phased digestion; bioaugmentation; post-aerobic digestion; sidestream nitrogen removal

Document Type: Research Article

DOI: https://doi.org/10.2175/193864710802767236

Publication date: 2010-01-01

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
X
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