The Mechanism Of Phosphorus Removal In The Biofilm System Filled With Magnetic Bubble Stone

With the development of technology and the improvement of people's living standards,sewage eutrophication phenomenon becomes more and more seriously,and phosphorus is the main factor.In the biological membrane method magnetic carrier has the advantages of low energy consumption and recycled easily,so it is widely researched and application.In this paper,domestic sewage of Northeast Normal University was seted as the research object,this paper mainly producted a new biological magnetic carrier which was prepared with magnetic fluid and bubble stone,and it is applied to the carrier biofilm reactor for wastewater treatment.In the process of treatment used the biological membrane method,this paper measured the removal efficiency of total phosphorus,inorganic phosphorus and organic phosphorus in the device of magnetic bubble stone and ordinary bubble stone,studied the different form of phosphorus how to removal,studied the adsorption mechanism of phosphorus bacteria in the biofilm and the vehicle itself.The results are as follows:(1)The experimental results show that,the average removal efficiency of the total phosphorus,inorganic phosphorus and organic phosphorus in magnetic bubble stone device were 9.99%,17.75% and 1.39% higher than in the ordinary bubble stone device.At the same time the phosphorus were mainly removed in the form of inorganic phosphorus in the two devices,(2)Four alkali phosphorus accumulating bacteria that included Alcaligenes sp.,Pseudomonas alcaligenes sp.,Citrobacter sp.,Pantoea agglomerans sp.were isolated from the magnetic bubble stone device.In ordinary bubble stone device that isolated three phosphorus accumulating bacteria including Serratia marcescens sp.,Pseudomonas putida sp.,Citrobacter sp..To measure the phosphorus content bacteria,it was shown that the bacteria phosphorus content in the magnetic devices was 0.87%higher than in the ordinary devices.(3)Through the growth curve and p-uptake efficiency of correlation analysis showed that they had the extremely significant correlation,it knew that the phosphorus removal effect was related to the growth of bacteria.And the results showed that magnetic could not only increase the number of phosphorus accumulating bacteria cells but also could improve the growth speed of phosphorus accumulating,the magnetic could make the bacteria into the logarithmic growth period in advance.(4)Compare before and after adsorption isothermal adsorption curve,it showed that the adsorption capacity of phosphorus accumulating bacteria in the magnetic device was 1.448mg/L higher than the ordinary device.To use the SEM and combine the EDS spectrum analysis,the result showed that the adsorption mechanism of phosphorus in wastewater mainly included the surface adsorption and ion exchange.(5)The adsorption isotherm and adsorption kinetics experiments based on the carrier itself,the result showed that the maximum number of saturated adsorption in the magnetic bubble stone was 31.269mg/g and that in the ordinary bubble stone was21.359mg/g,it showed that the maximum number of saturated adsorption in the magnetic bubble stone was greater than that in the ordinary bubble stone.Through XRD and FR-IT showed that magnetic bubble stone removed phosphorus in water by physical adsorption and chemical precipitation,the phosphorus removal of ordinary bubble stone was the function of physical adsorption.