title: Influence of the liquid-phase mass transfer on the performance of a packed-bed bioreactor for wastewater treatment.
abstract: This paper reports on the influence of the liquid-phase mass transfer on the performance of a horizontal-flow, anaerobic, immobilized-biomass (HAIB) reactor treating low-strength wastewater. The HAIB reactor was subjected to liquid superficial velocities (vs) ranging from 10 to 50 cm h(-1), corresponding to hydraulic detention time (theta h) of 10-2 h. The best performance was achieved at an overall theta h of 3.3 h due to the interdependence of biochemical reactions and mass transfer mechanisms for process optimization. The HAIB reactor was provided with four intermediate sampling ports, and the values of v(s) were fixed to permit sampling at different ports corresponding to thetah of 2 h as vs increased. The chemical oxygen demand removal (COD) efficiencies increased from 68% to 82% with the increase of v(s) from 10 to 50 cm h(-1). It could be concluded that the performance of the HAIB reactor was improved significantly by increasing vs, thus decreasing the liquid-phase mass transfer resistance.
authors.affiliation: Departamento de Hidráulica e Saneamento, Escola de Engenharia de São Carlos, Universidade de São Paulo, SP, Brazil.
authors.forename: A
authors.initials: A
authors.lastname: Sarti
authors.forename: L G
authors.initials: LG
authors.lastname: Vieira
authors.forename: E
authors.initials: E
authors.lastname: Foresti
authors.forename: M
authors.initials: M
authors.lastname: Zaiat
mesh_terms: D019149:Bioreactors; D007700:Kinetics; D008962:Models, Theoretical; D015203:Reproducibility of Results; D013997:Time Factors; D014865:Waste Disposal, Fluid / Q000295:instrumentation* / Q000379:methods; D018508:Water Purification / Q000295:instrumentation / Q000379:methods