Comparative bioparticle and hydrodynamic characteristics of conventional and tapered anaerobic fluidized-bed bioreactors

摘要

By maintaining the same operational conditions of one conventional fluidized-bed bioreactor (CFB) and two tapered fluidized-bed bloreactors (TFBs), the performance of the TFBswith taper angles of 5deg and 2.5deg were found to be superior to that of the CFB with a taper angle of 00.Experimental results together with statistical analyses showed that the bloparticle and hydrodynamic characteristics of the TFBs were significantly different from those of the CFB. Also, bloparticle stratification occurred in the three bioreactors. The bioflim thickness (8) and the specific blomass (ii)of the three bioreactors varied in the following decreasing order 50>2.50>00 under the same volumetric loading. Meanwhile, the specific energy dissipation rate (w) and the bloparticle washout rates (W0.214±O.219; 0.537±0.493g BAC din 3day1) of the two TFBs were considerably lower than that of the CFB (W l.086±0.916g BACdnf3 day1). A lower w value results in increases in #delta# and #beta#, and a lower dry density of the biofilin (P_d).Accordingly, the performance enhancement with TFBs should be related to their lower #omega# and W,thicker #delta# and larger #beta# values.