Abstract (EN):
A fluidized-bed biological reactor was used for wastewater denitrification. Sand particles were the biofilm support and molasses the carbon source. Experimental studies were carried out in order to understand the reactor start-up, changes of biofilm density with biofilm thickness, reactor hydrodynamics and axial concentration profiles of nitrate and nitrite species in the bed. A simple model was developed based on a reaction scheme NO3 - ¿ NO2 - ¿ products of two consecutive zero-order reactions. The model also includes mass transport of nitrate and nitrite species by diffusion inside the biofilm. Three situations can occur: (i) the biofilm is fully penetrated by both species, (ii) the biofilm is partially penetrated by nitrate and fully penetrated by nitrite, and (iii) the biofilm is partially penetrated by both species. Model calculations of axial concentration profiles show a good agreement with experimental data. A methodology is suggested for the design of fluidized-bed biological reactors including the following steps: (i) to get biomass growth rate and denitrification kinetics from batch systems, (ii) to check denitrification kinetics and obtain diffusivity measurements and biofilm density as a function of biofilm thickness in a rotating-disc biofilm reactor, and (iii) to use previous basic information in the simulation of fluidized-bed biological reactors. © 1988.
Idioma:
Inglês
Tipo (Avaliação Docente):
Científica
Nº de páginas:
14