title: Role of mass transfer in overall substrate removal rate in a sequential aerobic sludge blanket reactor treating a non-inhibitory substrate.
abstract: A laboratory study was undertaken to explore the role of mass transfer in overall substrate removal rate and the subsequent kinetic behavior in a glucose-fed sequential aerobic sludge blanket (SASB) reactor. At the organic loading rates (OLRs) of 2-8 kg chemical oxygen demand (COD)/m3-d, the SASB reactor removed over 98% of COD from wastewater. With an increase in OLR, the average granule diameter (dp=1.1-1.9 mm) and the specific oxygen utilization rate increased; whereas biomass density of granules and solids retention time decreased (13-32 d). The intrinsic and apparent kinetic parameters were evaluated using break-up and intact granules, respectively. The calculated COD removal efficiencies using the kinetic model (incorporating intrinsic kinetics) and empirical model (incorporating apparent kinetics) agreed well with the experimental results, implying that both models can properly describe the overall substrate removal rate in the SASB reactor. By applying the validated kinetic model, the calculated mass transfer parameter values and the simulated substrate concentration profiles in the granule showed that the overall substrate removal rate is intra-granular diffusion controlled. By varying different dp within a range of 0.1-3.5 mm, the simulated COD removal efficiencies disclosed that the optimal granular size could be no greater than 2.5 mm.
authors: Department of Environmental Engineering, Kun Shan University, Tainan City 710, Taiwan. huangjsd@mail.ncku.edu.tw
authors: Ju-Sheng
authors: JS
authors: Huang
authors: Chun-Wen
authors: CW
authors: Tsao
authors: Yen-Chun
authors: YC
authors: Lu
authors: Hsin-Hsien
authors: HH
authors: Chou
mesh_terms: D000332:Aerobiosis; D057919:Biological Oxygen Demand Analysis; D018533:Biomass; D019149:Bioreactors; D007700:Kinetics; D008956:Models, Chemical; D010100:Oxygen / Q000378:metabolism; D012722:Sewage / Q000382:microbiology*; D014865:Waste Disposal, Fluid / Q000379:methods
chemical_list: D012722:Sewage; D010100:Oxygen