ON-SITE PILOT DEMONSTRATION OF THE STATIC GRANULAR BED REACTOR (SGBR)

A new anaerobic biological process developed by Ellis and Mach (U.S. Patent No. 6,709,591) called the “Static Granular Bed Reactor” (SGBR) was used to treat slaughterhouse wastewater from the Hormel Foods Corporation. The SGBR consists of a dense bed of anaerobic granules operated in a downflow mode without flow recirculation (Mach and Ellis, 2000). The pilot-scale system operated on a continuous basis from a range of 48 to 16-hour HRT conditions at ambient temperature (23 ± 3°C). Throughout the entire study, the organic loading rate (OLR) ranged from 1.09-4.55 g COD/L·d, and the average total COD removal efficiency was greater than 90%. Limitations typically found in treating slaughterhouse wastewater were not experienced. Compared to other high-rate anaerobic systems treating slaughterhouse wastewater, the total COD removal efficiency of the SGBR system was higher and more consistent. From the operational results, hydraulic control and solids (biomass) wasting was recommended for controlling headloss through the SGBR. This study also demonstrated the ability of the SGBR to withstand daily changes in influent wastewater characteristics, the ability to recover from long periods without sustained feeding, and the capability for rapid startup.