Abstract
A fluidized bed reactor with Amberlite IRA-938 as a support medium was employed for accomplishing the high efficient biological nitrification. Effects of the hydraulic retention time (HRT) and the influent glucose concentration on the efficiency of the biological nitrification were investigated.
More than 90% of influent NH4-N was nitrified even at a HRT of 0.5h. The maximum nitrification rate in this study was 1300mg-N·l-1·d-1, which was much greater than that obtained in activated sludge process. This high nitrification rate was attributed to the macroporus characteristics of Amberlite because Amberlite could maintain a large number of nitrifying bacteria in its inside. Results of batch experiments on the nitrification rate indicated that the oxidation of NH4-N proceeded in the outer region of the Amberlite and that of NO2-N did in the inner region.
In both experiments with influent glucose concentrations of 10mg·l-1 at a HRT of 0.5h and 20mg·l-1 at a HRT of 2h, more than 90% of influent NH4-N was nitrified. Therefore, this type of fluidized bed reactor could be applied to the advanced treatment of sewage.
