BENCH TESTING OF 2-STAGE ANAEROBIC DIGESTION PROCESSES

摘要

Historically, biosolids stabilization has consisted of single stage anaerobic and aerobic digestion processes. These processes have proven to be effective at reducing the organic content of wastewater sludges, however, new regulatory requirements and the desire to further enhance performance has lead to new developments in digestion technology. Recent advances in biosolids stabilization are characterized by improved volatile solids destruction, higher biogas production, improved operational stability, better sludge dewaterability, higher pathogen reduction, and lower process volume requirements. This paper presents results of bench testing performed on 2-stage anaerobic digestion processes as part of evaluation for upgrading the anaerobic digestion process at Waupun, Wisconsin. Both acid-gas and temperature-phased anaerobic digestion processes where bench tested to determine performance and applicability to the Waupun WWTF. Results of the investigation show, for the particular characteristics of the Waupun sludges, the temperature-phased anaerobic digestion process provided superior performance.