Skip to main content

The Effect of the Microsludge Treatment Process on Anaerobic Digestion Performance

Buy Article:

$9.50 plus tax (Refund Policy)

Or sign up for a free trial

Thickened waste activated sludge (TWAS) from biological treatment processes is less amenable to anaerobic digestion than primary sludge. This is due to TWAS being composed mostly of cellular material and extracellular polymeric substances (EPS) instead of more easily digestible carbohydrates and fats that are typically found in primary sludge. In an attempt to improve TWAS digestion performance, a process for pretreating TWAS before digestion, known as the MicroSludge process, was tested at the Los Angeles County Sanitation Districts' (Districts) Joint Water Pollution Control Plant (JWPCP) in Carson, CA. The MicroSludge process is a chemical/mechanical system that uses caustic soaking to weaken cell walls and EPS, and a high-pressure shearing valve to lyse the cell walls and break down EPS to increase the overall solubility of the TWAS. The MicroSludge process was evaluated using both full-scale and bench-scale mesophilic anaerobic digesters operated at various conditions. In most of the tests, the TWAS was digested with primary sludge. Pure TWAS was digested in some of the bench-scale tests. Digestion performance was determined by volatile solids destruction (VSD) and gas production. In addition to digestion performance, the effects of the MicroSludge process on dewatering performance and odor generation were examined. The results from the study indicate that the MicroSludge system significantly increased the solublization of TWAS. Under the operating conditions at JWPCP, VSD increased from 54 to 57%, and gas production increased by less than 5%. The MicroSludge process may have slightly improved dewatering performance with a small increase in cake solids content, and dewatered cake from the test digester was approximately 40% less odorous than cake from a control digester. Despite the minor improvement in digestion, odor control and dewatering performance, the Districts determined that the MicroSludge treatment process was not cost effective for treating TWAS at the JWPCP.
No Reference information available - sign in for access.
No Citation information available - sign in for access.
No Supplementary Data.
No Article Media
No Metrics


Document Type: Research Article

Publication date: 01 October 2007

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