Flocculation time is conventionally believed to be proportional to the fiocculation effciency of a cylindrical fluidized bed flocculator. However, in a single-stage velocity gradient situation, the flocculation effici...Flocculation time is conventionally believed to be proportional to the fiocculation effciency of a cylindrical fluidized bed flocculator. However, in a single-stage velocity gradient situation, the flocculation efficiency decreases when the optimal flocculation time is exceeded. A multi-stage velocity gradient was established in a cylindrical fluidized bed flocculator, based on the hydraulic classification theory. This multi-stage velocity gradient fluidized bed flocculator （MGF） created a more suitable environment for floc growth and protection, which was confirmed by the size distribution of flocs along the bed height. Correspondingly, the abatement efficiencies for Kaolin slurry and dyed wastewater treatment in the MGF were enhanced by 5-10%, and by 7-20%, respectively, compared with those in the single-stage velocity gradient fluidized bed flocculators （SGFs）. The initial bed height distribution ratio along the velocity gradients was an important factor for MGF optimization.展开更多
基金the financial support from the Natural Sciences Foundation of China(50908096,50908097)
文摘Flocculation time is conventionally believed to be proportional to the fiocculation effciency of a cylindrical fluidized bed flocculator. However, in a single-stage velocity gradient situation, the flocculation efficiency decreases when the optimal flocculation time is exceeded. A multi-stage velocity gradient was established in a cylindrical fluidized bed flocculator, based on the hydraulic classification theory. This multi-stage velocity gradient fluidized bed flocculator （MGF） created a more suitable environment for floc growth and protection, which was confirmed by the size distribution of flocs along the bed height. Correspondingly, the abatement efficiencies for Kaolin slurry and dyed wastewater treatment in the MGF were enhanced by 5-10%, and by 7-20%, respectively, compared with those in the single-stage velocity gradient fluidized bed flocculators （SGFs）. The initial bed height distribution ratio along the velocity gradients was an important factor for MGF optimization.
