Research Of A Novel Technology Of The Moving Bed Biofilm Reactor(MBBR) Sewage Treatment Based On Denitrifying Phosphorus Bacteria

Some difficult to handle problems always existed in the process of biological method removal nitrogen and phosphorus at the same time. Recently, with the appearance of denitrifying phosphorus removal technology and the deeply research of its mechanism, Denitrifying Phosphorus removal Bacteria (DPB) was confirmed as a kind of which removal nitrogen and phosphorus simultaneously. Compared with traditional biotechnology, under the same nitrogen removal ratio, diplex utilization of the carbon source was performed in denitrifying phosphorus removal technology.The key of its biological mechanism lies in the microbe could absorb a great amount of phosphorus by using nitrate nitrogen as electron acceptor during hypoxia.This research aims at exploring a method for cultivation and domestication DPB on suspended packing, and characterizing the effect of oxygen supply on the reaction ratio of removal nitrogen and phosphorus. Also characterized the variation rule of COD、NH4+N、TN and TP by adjusting the ratio of C/N/P under the same oxygen supply.Analysis the variation of main pollution indicators about COD、 NH4+-N、NO3--N and TP in the early, medium, stable phase of domestication. All the results further proved that the biochemical mechanism of removal nitrogen and phosphorus by DPB, which offered control parameters to achieve better effect of removal nitrogen and phosphorus.This project used a novel technology of the moving bed biofilm reactor sewage treatment based on DPB, in which the problem of packing start-up hang film should be considered first. The active sludge from the secondary settling tank of Lijiao sewage treatment plant in GuangZhou was used as domesticated species mud, using continuous in and out water means.Wastewater from high water tank through gravity flow into the reactor and the effluent into the secondary settling tank.The results shows that when hydraulic detention time is6h and suspension packing media-filling rate is40%, the removal of COD、NH4+-N and TN by MBBR is good and stable under different C/N/P ratio. The average removal ratio is above90%、94.8%and62.39%, respectively. However, the C/N/P ratio has a great effect on the removal of TP, average removal ratio reaches58.03%when C/N/P ratio is100/10/1.8.A amount of mass concentration of DO could guarantee the high removal efficiency of COD、NH4+-N in the reactor, and is an great factor of simultaneous TN and TP removal, and the optimal mass concentration of DO in the reactor is3mg/L. Due to the anaerobic-anoxic microenvironment in the inner of suspended carrier biofilm, a spot of DPB exist in the reactor. Static experiment was performed to estimate the ratio of DPB in PAOs. After the anaerobic phosphate release, the sewage in system shows an great ability of aerobic P-uptake, the value is6.64mg/(gMLVS S).The value of anoxic P-uptake is0.42mg/(g MLVSS) at the same time. And the ratio of DPB in PAOs is about6.33%.All above results further proved the exist of anaerobic-anoxic microenvironment in the inner of suspended carrier biofilm, but not insufficiency. The main removal TP in system was PAOs which using O2as electron acceptor,and the DPB only account for a part of.