title: Analysis of performance of an anaerobic sequencing batch reactor submitted to increasing organic load with different influent concentrations and cycle lengths.
abstract: The performance of an anaerobic sequencing batch reactor (ASBR) was assessed when submitted to increasing organic load with different influent concentrations and cycle lengths. The 5-L mechanically stirred (75 rpm) ASBR contained 2 L of granular biomass and treated 2 L of synthetic wastewater per cycle. Volumetric organic loads (VOLs) from 0.66 to 2.88 g of chemical oxygen demand (COD)/(L x d) were applied by using influent concentrations from 550 to 3,600 mg of COD/L in 8- and 12-h cycles. Reactor stability was maintained for VOLs from 0.66 to 2.36 g of COD/(L x d), with organic matter removal efficiencies for filtered samples (epsilonF) between 84 and 88%. For VOLs from 0.78 to 2.36 g of COD/(L x d) at an influent concentration of 2,000 mg of COD/L, when cycle length was reduced from 12 to 8 h, epsilonF did not vary, yet showed a very distinct behavior from the other conditions. In addition, two operation strategies were studied for VOLs with approximately similar values of 2.36 and 2.08 g of COD/(L x d). One involved operation with an influent concentration of 2,000 mg of COD/L and an 8-h cycle, whereas the other involved an influent concentration of 2,600 mg of COD/L and a 12-h cycle. Only the former resulted in system stability and efficiency. These results indicate that besides organic load, influent concentration and cycle length play a significant role in ASBR systems.
authors.affiliation: Escola de Engenharia Mauá, Instituto Mauá de Tecnologia, Praça Mauá 1, CEP 09.580-900, São Caetano do Sul, SP, Brazil.
authors.forename: Fabiana Xavier
authors.initials: FX
authors.lastname: Chebel
authors.forename: Suzana Maria
authors.initials: SM
authors.lastname: Ratusznei
authors.forename: José Alberto Domingues
authors.initials: JA
authors.lastname: Rodrigues
authors.forename: Marcelo
authors.initials: M
authors.lastname: Zaiat
authors.forename: Eugênio
authors.initials: E
authors.lastname: Foresti
mesh_terms: D000693:Anaerobiosis; D018533:Biomass; D019149:Bioreactors; D012722:Sewage / Q000737:chemistry / Q000382:microbiology*
chemical_list: D012722:Sewage