title: Comparison of semi-batch vs. continuously fed anaerobic bioreactors for the treatment of a high-strength, solids-rich pumpkin-processing wastewater.
abstract: The objective of this work was to compare two different high-rate anaerobic bioreactor configurations--the anaerobic sequencing batch reactor (ASBR) and the upflow anaerobic solid removal (UASR) reactor--for the treatment of a solid-rich organic wastewater with a high strength. The two, 4.5-L reactors were operated in parallel for close to 100 days under mesophilic conditions (37°C) with non-granular biomass by feeding a pumpkin wastewater with ∼4% solids. The organic loading rate of pumpkin wastewater was increased periodically to a maximum of 8 g COD L(-1) d(-1) by shortening the hydraulic retention time to 5.3 days. Compositional analysis of pumpkin wastewater revealed deficiencies in the trace metal cobalt and alkalinity. With supplementation, the ASBR outperformed the UASR reactor with total chemical oxygen demand (COD) removal efficiencies of 64% and 53%, respectively, achieving a methane yield of 0.27 and 0.20 L CH4 g(-1) COD fed to the ASBR and UASR, respectively. The better performance realized with the ASBR and this specific wastewater was attributed to its semi-batch, dynamic operating conditions rather than the continuous operating conditions of the UASR reactor.
authors: a Department of Biological and Environmental Engineering , Cornell University , Ithaca , NY 14853 , USA.
authors: Isabel
authors: I
authors: del Agua
authors: Joseph G
authors: JG
authors: Usack
authors: Largus T
authors: LT
authors: Angenent
mesh_terms: D001421:Bacteria, Anaerobic / Q000378:metabolism*; D019149:Bioreactors / Q000382:microbiology*; D028464:Cucurbita / Q000382:microbiology*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005735:Garbage; D062065:Wastewater / Q000032:analysis / Q000382:microbiology*; D014874:Water Pollutants, Chemical / Q000302:isolation & purification / Q000378:metabolism*; D018508:Water Purification / Q000295:instrumentation* / Q000379:methods
chemical_list: D062065:Wastewater; D014874:Water Pollutants, Chemical
keywords: anaerobic digestion; anaerobic sequencing batch reactor; high-strength wastewater; pumpkin wastewater; upflow anaerobic solid removal reactor