| Eutrophication phenomenon has become one of the most serious global water quality problems. As we all know, large quantities of nutrient substances, such as phosphorus and nitrogen present in wastewater is the main cause of eutrophication phenomenon. Among all the nutrient elements, phosphorus is considered as the key element leading to water eutrophication. So phosphorus removal is the important strategy in controlling eutrophication. In recent years, biological phosphorus removal was investigated extensively, and more and more studies had been carried out using the Polyphosphate Accumulating Organism (PAOs) to remove phosphorus. However, many aspects of mechanism were still little to know. It led the EBPR to be unstable.Filter through two separate binding assays single strain phosphorus removal, separation from Chaohu sediment phosphorus screened six strains, through a combination of these six strains measured the effect of phosphorus mixed flora and studied bacteria affect the ratio of phosphorus added effect. The results showed that when two strains screened to match, will produce significant antagonism, phosphorus removal decreased significantly. In15group combination, the combination of phosphorus removal D3+D6best, phosphorus removal rate reached58.2%. Because of the two strains was screened for each combination of the effect is not obtained as a sieve effect combined with each other bacteria, three kinds of bacteria employed in combination with a combination of internal strain was screened for the numbered1and2respectively, C1, C2, C3-combinations and D3, D4, D6combinations, a combination of two effects are not as good as the combined effects of the two species. C2:D3optimal ratio is2:1, phosphorus removal rate reached55%, C1:C2optimal ratio is2:1, phosphorus removal rate reached59.4%, D3:D6best ratio is1:2, phosphorus removal rate reached62.5%. The result of sequence analysis and homology comparison suggested the two strains were similary to Exiguobacterium sp.Through the various factors that affect the strain effect D3and D6were polyphosphate single factor optimization experiments, the results indicate that the anaerobic/aerobic PAO alternating operation is necessary to stage two poly phosphate process. In later changed to aerobic training, PAO uptake rate is very fast, basically completed within12h phosphorus uptake process. For two strains, the optimal incubation time for the two days. The optimum temperature of two strains of phosphorus are about20℃. However, two strains of adaptable temperature, in the temperature range of8℃～30℃showed a higher phosphorus removal rate. D3strains can grow well in the range of pH7to11and phosphorus, phosphorus removal rates of up to84.5%; strains D6phosphorus removal rate reached maximum at pH7℃9when92.7%. Lack of trace elements greater impact on the D6strain, compared to the case of trace elements whose OD values fell33.2%phosphorus removal rate decreased from93.1%to77.1%. D3strain affected is relatively small, compared to the case of trace elements whose OD values fell27.5%phosphorus removal rate decreased from84.7%to74%. The optimum carbon and phosphorus are two strains of sodium acetate; strains D6can better be using different types of carbon and phosphorus.Natural water in Chaohu targeting experiments conducted biological phosphorus removal. Experimental results show that the two strains screened efficient phosphorus D3and D6strain by the formation of a mixed flora can exhibit better ability to phosphorus in the natural water bodies. Therefore, the immobilized bacteria used in mixing natural water phosphorus removal is feasible, which also govern the urban landscape water eutrophication provide a theoretical basis. |
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