A Study Of The Flow Characteristics Of Three-phase Circulating Fluidized Bed And The Treatment Of Low Concentration Landfill Leachate By This Reactor

Some flow characteristics of the fluid in the three-phase circulating fluidized bed with polymer porous carriers are studied in this thesis. And a test of aerobic digestion and NH3 - N removal of the landfill leachate, which has been treated by anaerobic digestion, was fulfilled in this fluidized bed reactor.The results, which is from the test of the flow characteristics of the fluid in the three-phase circulating fluidized bed , show that the flow efficiency of the fluid in this circulating fluidized bed with polymer porous carriers is excellent, and its minimum fluidization velocity and transport velocity are more small compared with some other carriers, so the energy-dissipating in the operation of the reactor is very low. Solids content in the riser has little influence on gas holdup, and solids holdup can be raised effectively with a certain gas holdup, so the treatment ability of reactor can be improved by high microorganism concentration in some biochemical process. Gas holdup can be increased suitably with a certain solid concentration to enhance the efficiency of the reactor. Circulating process is beneficial for the renewal of biofilm.The results of the test of landfill leachate treatment demonstrate that, this circulating fluidized bed not has high aerobic digestion but has well ability of simultaneous nitrification and denitrificatim(SND). When the wastewater is all from the landfill leachate, which has been treated by anerobic digestion, and its concentration reaches to stableness , with the total HRT of 5h, average influent COD and NH3-N are respectively 1377.3mg/l and 217.5mg/l, average effluent CODand NH3 - N are 248mg/I and 50.1mg/I, and the average removal rates of COD and NH3 -N are 82% and 77%. This fluidized bed reactor has excellent treatment efficiency, low energy-dissipating, powerful capacity change-resist and convenient operation.All the results indicated that the treatment of low concentration organic wastewater in three-phase circulating biological fluidized bed with polymer porous carriers is feasible.