| The problem of the increasingly serious pollution by phosphorus and the lack of resource due to its non-renewable properity force us to find a stable and efficient phosphorus recovery method urgently.However,there are great defects in the traditional method of phosphorus removal.How to deal with phosphorus in the wastewater better has become one of key points of our major in the present and also the future.Phosphorus removal process based on phosphate reduction reaction has become one of the research hotspots in recent years.Theoretically,it has the advantages of low energy consumption,easy recovery of phosphorus and being able to treat high phosphorus wastewater.On the basis of ASBR producing phosphine,ASBBR and SBR had been established to culture PRB.The study on the characteristic of phosphorus removal in each reaction system was carried out and the migration of the microorganism population structure was analyzed.The following are the main research results:Three sets of phosphate reduction system in different domestication methods were established.In the start stage,1#ASBR,2#ASBBR and 3#SBR were cultured with different period respectively.The removal rate of phosphate(TPw)in reached 26.50~36.91 %,26.12~31.14 %,36.53~55.86 %,and removal rate of COD reached 95.12~97.83 %,93.71~95.46 %,92.02~95.60 %.In this process,the total gas production and the output of phosphine are gradually improved,and the FGP levels are about 432.79 pg,2212.65 pg and1907.77 pg,respectively,indicating that the new domestication method in this experiment canincrease the yield of phosphine.During the stable period,the average particle size of sludge in3#SBR was the largest,reaching 380.197 ?m.The results of scanning electron microscopy showed that the bacterial morphology in each system was different obviously,indicating that the long-term culture in different methods will greatly change the dominant species and their sludge morphology.In the experiment of the influence factors of the two sets of new reaction systems,the optimal operation condition of 2#ASBBR is C/P=100:1,pH=8(initial)and T=45?,indicating that the difference with the original working condition in small.The optimal operation condition of 3#SBR is C/P=150:1,pH=9(initial),T=45?,and high aeration,thus the optimum operating conditions of the system after the facultative acclimation can be obviously changed.Monitoring dynamically the typical cycle of each system in stable state,showed that MBP had a significant positive correlation with alkaline phosphatase in each system,the trend was rising first and then falling,indicating that the increase of alkaline phosphatase activity was beneficial to the production of phosphine.By comparing the output characteristics of phosphine in each system,it is found that 1#ASBR is mostly stored in the solid phase with MBP,and 3#SBR is easier to escape from FGP.It can be concluded that the sludge has a adsorbability to phosphine itself,and a certain air flow disturbance can promote the desorption of phosphine.The phosphine production of 2#ASBBR has a sudden jump at a specific point,indicating that under certain conditions,the biofilm system is more conducive to the reduction of phosphate.From the results of High-Throughput Sequencing,it can be seen that 2#ASBBR and3#SBR have different degrees of population structure reduction compared with 1#ASBR,and the affinity with 1# and 2# is better.It can be concluded from the distribution of population types before and after domestication that the main functional bacteria involved in phosphine production belong to Proteobacteria.In addition,as compared with the anaerobic system,the microbial enrichment behavior under the facultative system is more unique,the abundance of Firmicutes and Saccharibacteria increases obviously.It is presumed that the new facultative dephosphorization bacteria may be contained in the system,but it needs to be further confirmed. |
PDF Full Text Request