title: Post-treatment of UASB effluent in an expanded granular sludge bed reactor type using flocculent sludge.
abstract: The performance of an EGSB (expanded granular sludge bed) reactor type using flocculent sludge was evaluated for the post-treatment of effluent from UASB reactor treating domestic sewage. A pilot-scale 157.5-L EGSB reactor was monitored during a 331-day period. The original concept of the EGSB reactor was based on granular sludge use and by applying of high upflow liquid velocities (Vup). However, even using flocculent sludge from a UASB full-scale (Mangueira Plant, Recife, Brazil), good mixing conditions and high retention of biomass were achieved. By applying a 4-h hydraulic retention time and Vup values up to 3.75 m/h, effluent chemical oxygen demand concentrations in the EGSB were below 87 mg/L and 55 mg/L, for total and filtered samples, respectively. Total suspended solid (TSS) concentrations in the effluent were below 32 mg/L. Good performance and stable reactor operation during the whole experimental period were observed. Therefore, the EGSB reactor type using flocculent sludge can also be used for post-treatment of very dilute anaerobic effluent from reactors treating domestic sewage.
authors.affiliation: Federal University of Pernambuco, Department of Civil Engineering, Av. Acadêmico Hélio Ramos s/n, Cidade Universitaria, 50740-530 Recife, Pernambuco, Brazil. kato@ufpe.br
authors.forename: M T
authors.initials: MT
authors.lastname: Kato
authors.forename: L
authors.initials: L
authors.lastname: Florencio
authors.forename: R F M
authors.initials: RF
authors.lastname: Arantes
mesh_terms: D019149:Bioreactors; D005427:Flocculation; D010100:Oxygen / Q000032:analysis; D012722:Sewage / Q000737:chemistry / Q000382:microbiology*; D014865:Waste Disposal, Fluid / Q000379:methods*; D014872:Water Movements
chemical_list: D012722:Sewage; D010100:Oxygen