Denitrifying Phosphorus Accumulating Bacteria Screening And Denitrification And Phosphorus Removal Characteristics Research

Recently years, with ecomomy developing quickly and the speed of the using of sources, Lake Eutrophication play a important role influencing on social and economic sustainable development in China. Some areas people who live along lakes or rivers have no clean water drinking. It is serious increasingly that the nitrogen, phosphorus compound causes the phenomenon of water entrophication and water pollution. Therefore, the treatment of wastewater needs to take off nitrogen and phosphorus compounds from the sewage.The biological denitrifying phosphorus removing simultaneously has been widely used in the treatmet of wastewater for its economic advantage. With the discovery of denitrifying phosphorate removal bacteria (DPB), and its biological mechanism been reasearched. DPB has been confirmed as a microorganism on denitrifying and phosphorus removal, the trait of DPB is using nitrate as a electron receiver and absorbing phosphorus under anoxic condition. This experiment is to cultibate DPB by traditional biological screening methods test the physiological characteristics of strain, and finally can be applied to biological nutrient removal technology directly.Using especially culture medium which is using sodium acetate and popotassium hydrogen phosphate as the sole nitrogen and phosphorus source, and denitrifying nitrates to gas, two stains of DPB qdcs18, qdcs28were separated from the matured activated sludge. According to the morphological observation, physiological biochemical tests and sequence analysis of the16S rDNA, strain qdcsl8and qdcs28were identified to be as Pseudomonas sp.Varying carbon sources, salinity, pH and temperature were investigated to identify the optimal conditions for nitrogen and phosphorus removal. The results were as follows: when sodium citrate was used as carbon sources,salinity2%, pH7.2-9, and temperatute30℃, the removal of the NO3--N and PO43-P by strain qdcs18is over80%; When sodium citrate was used as carbon sources, salinity2%, pH7-9, and temperature35℃, the removal of the NO3--N and PO43-P by strain qdcs28is over80%. The results of salinity tolerance were as follows:the optimal salinity range of strain qdcs18was0-7%; strain qdcs28was0-5%. So the two strains can toletant a high range of dalinity, which have great application value for the removal of nitrogen and phosphorus in the wastewater with high salinity.