Optimization Investigation Of Internal Circulating And Anoxic Fluid Bed Reactor To Improve The Sewage Treatment Efficiency

This paper modified the existing internal circulation three phase fluidized bed device by referring to the circulation power mode in the circulation reactor--plug flow type and jet type,and designed two kinds of inner circulation anoxic biological fluidized bed reactors with different dynamic modes.This paper first conducted the simple hydrodynamic study on the plug flow type and jet type inner circulation anoxic fluidized bed by cold-model experiment.The relationships between turbine speed and diameter,liquid level height,nozzle diameter and position,solid holdup rate and circulation characteristics and mixing characteristics of anoxic reactor were investigated.It is concluded through the comparison and study of the circulation and mixing characteristics of two anoxic reactors that: the push flow type reactor had better mixing effect and the jet type reactor was more energy saving.It can be chosen according to the actual needs of choice in the actual application.Then,the push flow type anoxic fluidized bed and aerobic fluidized bed are applied to A/O process by series connection,the experimental results show that at T = 28 ? 34 ?,p H = 7.5 ? 8,HRT = 3.8 h,C/N = 3 ? 5 and nitrate liquid reflux ratio regulation was between 1.6 ? 3.7,COD and TN removal rate of inner anoxic fluidized bed was relatively high with the best treatment effect.After the device was tested for continuous operation for nearly 50 days,the test results showed that: A/O biological fluidized bed had good removal effect on COD,ammonia nitrogen and total nitrogen in sewage with the average removal rate of 94%,90% and 81%,respectively and the effluent water quality met the national discharge standards.