Studies On The Craft Of Nitrogen-removal And The Process Control With Biological Aerated Filter (BAF)

This research examined the craft of nitrogen-removal and the process control with biological aerated filter(BAF). the reactor start and the influence factors, space character, back-flushing characteristic, reactor biofilm characteristic and biofacies change were investigated. The results indicated: 1.The novel hanging membrane was able to successfully hang the membrane in a very short time; on the condition that the range of hydraulic loading value was from 0.4 m3/(m2·h) to0.9 m3/(m2·h), gas-water ratio was 5: 1, the range of pH value was from 7.5 to 8.2, the ammonia nitrogen loading was lower than 1.16 kg NH 4+ ?N/m3·d, and the organic loading was lower than 2.6kgCOD/m3·d, the reactor had a better processing effect. 2.The best bed height of organic removal was different from that of ammonia nitrogen removal in the biological aerated filter. Along fluent direction the ammonia nitrogen removal lags to the removal of CODcr. It was indicated that the active layer of carbonizes bacteria was in the upper of reactor and the active layer of nitrifying bacteria was in the lower of reactor. 3.The optimum back-flushing time is seven minutes, and the back-flushing interval is no more than five days. After the back-flushing the CODcr removing rate resumed the normal removal ability fast than the ammonia nitrogen. Influence by back-flushing on nitrifying bacteria was more than that on carbonizes bacteria and denitrifying bacteria 4.There are comparative abundant biological phases in the reactor in the course of operating, and it will change regularly with the change of space and operation state. Along the fluent direction the superiority protozoa in biomembrane are the flagellata, the free swimming ciliate, the sessile ciliate in turn, demonstrating the obvious plug flow characteristic. 5.Differing from other biological membrane methods, biological aerated filter reactor had the functions of holding back and absorbtion suspended substance. The degradation pathway of nitrogen was Simultaneous Nitrification and Denitrification (SND), and Anaerobic Ammonium Oxidation was investigated 6.The dynamics equation of the removes experience speed in reactor is ekhC NH 3? N= CNH3?N,0?, and the value of k is 0.6186.