title: Biomass retention and performance of anaerobic fixed-film reactors treating acetic acid wastewater.
abstract: An acetic-acid-based synthetic wastewater of different organic concentrations was successfully treated at 35 degrees C in anaerobic downflow fixed-film reactors operated at high organic loading rates and short hydraulic retention times (HRTs). Substrate removal and methane production rates close to theoretical values of complete volumetric chemical oxygen demand (COD) removal and maximum methane conversion were obtained. A high concentration of biofilm biomass was retained in the reactor. Steady-state biofilm concentration increased with increased organic loading rate and decreased HRTs, reaching a maximum of 8.3 kg VFS/m(3) at a loading rate of 17 kg COD/m(3) day. Biofilm substrate utilization rates of up to 1.6 kg COD/kg VFS day were achieved. Soluble COD utilization rates at various COD concentrations can be described by half-order reaction kinetics.
authors.affiliation: Department of Civil Engineering, Kuwait University, Box 5969, Kuwait.
authors.forename: M F
authors.initials: MF
authors.lastname: Hamoda
authors.forename: K J
authors.initials: KJ
authors.lastname: Kennedy