Competitive evaluation and performance characterization of the Static Granular Bed Reactor
Research demonstrated the Static Granular Bed Reactor (SGBR) to be a competitive and practical high rate anaerobic system for industrial and municipal wastewaters. Studies were performed to complete three primary goals. First, the SGBR was compared to the Upflow Anaerobic Sludge Blanket (UASB) reactor to demonstrate that the SGBR is a viable alternative in terms of performance. Next, the feasibility of municipal wastewater treatment was tested with the SGBR in both lab and pilot scale systems. Finally, the hydraulic profile was measured for the SGBR to provide a basis for modeling.;Performance between the SGBR and UASB reactor was compared in a side by side study and an experimentally designed study, which was performed to show whether or not differences in performance were statistically significant. Performance excelled for both reactors in terms of soluble COD (sCOD) removal, which exceeded 95% for the two systems. The statistical study found the SGBR to perform better than the UASB reactor.;Treatment of municipal wastewater was rigorously tested with the SGBR. The first study was conducted at room temperature in a lab scale reactor. Five-day, carbonaceous biochemical oxygen demand (CBOD5) in SGBR effluent was less than 30 mg/L when the system was operated at HRTs of 48, 24, and 8 hours. A laboratory study of municipal wastewater treatment was performed at 8 and 15°C to simulate colder weather conditions. During the low temperature study, solids entrapment appeared to be the primary organics removal mechanism for the system. Finally, a pilot reactor was set up to compare performance with initial success of the laboratory study at room temperature. Effluent CBOD5 concentrations averaged near 50 mg/L and effluent TSS averaged less than 20 mg/L for the pilot scale study.;A tracer study was performed using lithium for the SGBR, and a parallel study performed with a UASB reactor to provide a basis for comparison. Based on the dispersion model, the SGBR was well mixed with a reactor dispersion number of 1.19. The UASB reactor had slightly more plug flow characteristic, but was still well mixed with a reactor dispersion number of 0.89.