Experimental Study On Effect Of Magnetic Flocculation Technology For Deep Phosphorus Removal In Urban Wastewater

With the continuous improvement of people's living standards,phosphorus emissions have increased,and the discharge of phosphorus has been difficult to meet the Class A standard of “Emission Standards for Pollutants for Municipal Wastewater Treatment Plants”(GB18918-2002),leading to increasingly prominent issues such as the eutrophication of water bodies.In this study,through investigation and investigation,the experimental study and feasibility analysis were conducted for the technology of magnetic flocculation depth phosphorus removal for the effluent of a sewage treatment plant.The sewage treatment plant is divided into eastern and western regions.The source of sewage in the eastern region is the domestic sewage of urban residents,and the main form of phosphorus is phosphate.The source of sewage in the West District is the domestic sewage of urban residents and some casing wastewater,and the main form of phosphorus is mainly organic phosphorus.Therefore,in this study,the wastewater from the eastern and western districts of the wastewater treatment plant was studied as an object of study and further studies were conducted.For the study of magnetic flocculation technology for the treatment of effluent from urban sewage treatment plants,the best coagulant types and the optimal dosing amounts of coagulants,coagulants,and magnetic powders were determined through static tests.And determine the best precipitation time and the best dosing sequence.The test results showed that the removal rates of total phosphorus,COD and suspended solids were 97%,73.09% and 87.71% respectively in the wastewater from the Eastern District when PAC 30 mg/L,PAM 1 mg/L,magnetic powder 40 mg/L,and sedimentation time were 20 minutes.Western District sewage in PAC 80mg/L,PAM 1.5mg/L,magnetic powder is 40mg/L,precipitation time 20 min,the total phosphorus,COD,suspended solids removal rate were 76.17%,71.62%,88.66%.By comparing the treatment effect of the eastern and western regions,the total phosphorus concentration of the effluent in the eastern district is 0.15mg/L,which meets the Class a emission standard of the “Emission Standard of Pollutants for Municipal Wastewater Treatment Plants”(GB18918-2002).The total phosphorus concentration of the effluent in the Western Region is 1.43mg/L.can not meet the Class a emission standards.Comprehensive analysis shows that the magnetic flocculation technology has a poor effect on the removal of organic phosphorus.For COD,suspended solids have a better removal effect,and the sedimentation time is 33% shorter than the traditional coagulation sedimentation time.Based on the optimal parameters determined by the static tests,a continuous experimental study was conducted on the magnetic flocculation treatment of effluent from urban sewage treatment plants.The results show that the technology still has a good removal effect on the total phosphorus in the water in the continuous test,and the removal rate can reach more than 97%.It shows that magnetic flocculation technology is feasible in practical application.The technical analysis of the magnetic flocculation technology for the deep treatment of urban sewage was conducted.The results show that compared with the traditional coagulation and sedimentation technology,the magnetic flocculation technology is relatively low in terms of chemical cost and infrastructure cost,and it is feasible.In China,there is a broad prospect for promotion and application.