Abstract
For the oxidation of low concentrations of NH4+-N, the authers have developed a novel biofilm-membrane reactor, in which biomass is fixed on the surface of rotating membrane disks. The results obtained from this study were summarized as follows: (1) The NH4+-N oxidation efficiency of the biofilm-membrane rector is much higher than that of conventional biofilm reactors. This is explained by the two major reasons, i. e., increasing NH4+-N flux to the biofilm by advection and high rotational speed, and obtaining the treated water from the bottom of the biofilm. (2) Bacterial extracellular polymers seem to have severe influences on the membrane clogging. By adjusting the quantity of fixed biomass, however, the operation could be continued as long as 1000 hours without any cleaning.
