Research On Chemical Speciation Of Phosphorus And Mechanism Of Phosphorus Removal In A~2/O Sewage Treatment Process

With the rapid development of agriculture and industry, there have been a lot of red tides and algal blooms phenomena all over the world. The production and life of human have been impacted directly by them. The fundamental reason of these phenomena is the eutrophication of water. So eutrophication of water has become the main problem plaguing mankind currently. The main reason leading to eutrophication of water is that a large number of nutrient elements have been discharged into water. In the nutritional elements of the water, the "culprits" causing eutrophication of water are nitrogen and phosphorus, especially phosphorus, it plays an important role in the eutrophication process.The sewage and suspended solids of the total process in the No.5sewage treatment plant(Phase II) in Kunming are selected as the object of study. Combined with the Kunming University of Science and Technology Analysis and Testing Fund (2011476), chemical speciation, contents, proportion, regular pattern of transport and transformation of phosphorus in sewage and suspended solids in various processes were studied. All the experiments were accomplished in the laboratory of municipal engineering and research center for analysis and measurement in Kunming University of Science and Technology. The thesis includes the following sections:(1) Twelve sampling points in A2/O synchronization nitrogen and phosphorus removal process were selected in the experiments of phosphorus fractionation in sewage. By the option I of the separation and determination, phosphorus in sewage is divided into total phosphorus (TP), dissolved total phosphate (DTP), soluble orthophosphate, particulate phosphate (PP) and other soluble phosphate. The concentration of the phosphorus follows rules:total phosphorus (TP)>dissolved total phosphate (DTP)>soluble orthophosphate>particulate phosphate (PP)>other dissolved phosphate. It is very similar to the trend of total phosphorus and total soluble phosphate and soluble orthophosphate, and total phosphorus is affected greatly by dissolved total phosphate and soluble orthophosphate, but the rate of change about the particulate phosphate and other soluble phosphate is very little, and the contents of them are little, too. (2) Nine sampling points in A2/O synchronization nitrogen and phosphorus removal process were selected in the experiments of phosphorus fractionation in suspended solids. By the SMT method, phosphorus in sewage is divided into total phosphorus (TP), inorganic phosphorus (IP), organophosphorus (OP),NaOH-P (Fe/Al-P) and HC1-P (Ca-P). The content of the phosphorus follows rules:total phosphorus> inorganic phosphorus>organic phosphorus> NaOH-P (Fe/Al-P)> HCl-P (Ca-P). The trend of the total phosphorus content is close to that of organic phosphorus. The change of inorganic phosphorus is very small, the content of NaOH-P (Fe/Al-P) is high, but content of HCl-P (Ca-P) is very little.(3) The concentration and contents of the various forms of phosphorus in sewage and suspended solids has been studied, and total phosphorus were compared. The trend charts, histogram and the proportion of the various forms of phosphorus in the sewage and the suspended solids are obtained after analyzing these dates. And the reasons of the changing about the concentration and content are analyzed.