Reaearch On Cooperative Phosphorus Removal By Flocculating Settling And Biological Process

With the growth of the industrial and agricultural production in recent years, the content of phosphorus in water has been increasing and the eutrophication becomes heavier. As a result, the control and reduction of phosphorus content in the water have received more and more attention. At present, the aim to reduce the phosphorus concentration in water is mainly achieved by collecting and strengthening treatment of domestic sewage and industrial wastewater.Traditional methods to remove phosphorus include chemical precipitation, biolo gical method and biological phosphorus removal method adopted in recent years whic h is finished by synergy of the two methods above. Chemical precipitation, which is a method used earlier, has been replaced gradually by biological method because a hug e amount of agentia are used, settling sludge cause secondary pollution easily. So opt imizing flocculation reaction condition by experiments, finding the best flocculant co mbination by compounding of two or more flocculant and developing new flocculant have been the main research directions of removing phosphorus with flocculant for tr aditional flocculent settling phosphorus removal method.In this experiment optimization of reaction conditions of four common flocculants including ferric sulfate, aluminium sulfate, ferric chloride and polymeric aluminium chloride and research of precipitate phosphorus removal effect were emphasized. As a result, the waste water containing phosphorus concentration of4.2mg/l, Iron salts of phosphorus removal effect optimal. Then phosphorous removing effect by preliminarily choosing reasonable compounding combination was researched.And advanced treatment of excess phosphorus in effluent which was low organic loading (C/N<5) domestic sewage after multistage A/O treatment was explored. Finally the best combination and optimum flocculation reaction condition were received.The best effect of phosphorus removal was gotten by SBR test that a single flocculant was added by referring to existing research results gotten by synergy reaearch of flocculant and biological phosphorus removal and research results of compounding phosphorus removal of the four flocculants. For the average intake of phosphorus waste water concentration of5.4mg/l, aluminum sulfate coordination treatment works best, standards required for pharmaceutical dosing quantity is22.6mg/l. The results directed research of phosphorus removal at high efficiency by synergy of a single flocculant and multistage A/O craft and research of compounding of multiple flocculants and multistage A/O craft. Finally experimental target that phosphorus and nitrogen in low organic loading domestic sewage containing high loading phosphorus and nitrogen were removed at high efficiency with A/O reactor was received.