The WRF is a 97 MGD plant that processes approximately 5,500 dry tons of WAS at about 7.1% TS annually. The MicroSludge system comprised a central processing skid and two cell disrupters and processed approximately one quarter of the WAS generated at the plant. In addition to the full-scale trial, MicroSludge processed TWAS was also tested at both lab and pilot scale.

The MicroSludge pilot (100 gallon) digesters were operated successfully and stably at 20, 15, 10 and 7 days hydraulic residence time (HRT).

• Generated more biogas (with higher methane content),
• Achieved greater COD reduction and VS reduction, and
• Reduced total particulate solids when compared to control digesters.

Pilot digesters fed only with TWAS were also operated and achieved 51% more biogas at 15 days HRT than the control digester.

The MicroSludge System operated 24/7 for the duration of the full-scale trial, achieving very high levels of sludge cell lysis. However, extremely variable and unequal loading between the control and test digesters, and in particular the high levels of trucked liquid waste fed to the control and test digesters (often accounting for 65% of total organic loading) made it extremely difficult to interpret full scale data. The trial results will form part of WERF’s 05-CTS-3 Evaluation of Processes to Reduce Activated Sludge Solids Generation and Disposal, to be published at a later date.

Meet the Paradigm team at WEFTEC 09, or at the Canadian Residuals & Biosolids Conference to learn more about the Des Moines beta test, and also about the planned full-scale install of MicroSludge at Metro Vancouver’s Lulu Island WWTP in 2010.