Adsorption Of Uranium By Polyacrylonitrile Beads Immobilized With Bovine Serum Albumin

With the development of modern industry,people's demand for energy is growing day by day.Nuclear energy is an excellent one,not only to avoid a lot of fuel consumption and transportation,but also to reduce environmental pollution.Among them,uranium is a very important element of nuclear energy.The uranium on the land is relatively poor and uneven distribution,but in the ocean,70%of the earth,it is very rich.Therefore,the extraction of uranium from seawater has a broad future.In this paper,a new adsorbent was synthesized by immobilizing bovine serum albumin on the beads made from polyacrylonitrile.In the second chapter,the immobilization conditions of bovine serum albumin were optimized to maximize the protein content on polyacrylonitrile beads.In the third chapter,the factors influencing the adsorption of uranium were studied.In the fourth chapter,the cytotoxicity of uranium was studied and discussed,and the toxicity of uranium to the cells before and after adsorption was compared,it can reveal the results from the side.The results showed that when the concentration of bovine serum albumin was 0.7mg/mL,the immobilization time was 18h,the pH value of solution was 7 and the concentration of glutaraldehyde was 10%,the protein immobilization conditions were the best and the maximum loading of the protein is 12mg/g.The groups of the surface of the beads before and after modification were analyzed by infrared spectroscopy(FTIR),which proved that the nitrile group(-CN)was indeed modified into other groups.At the same time,the surface of the beads was observed by scanning electron microscopy(SEM).In the adsorption of uranium,the adsorption equilibrium time is 150 minutes,the optimum pH is 6.0,the optimal temperature is 25?,the optimal concentration of uranium solution is 10mg/L.The maximum adsorption capacity of the beads is about 4mg/g.The cations in the solution have a great effect on the adsorption of uranium.They can compete with uranium for the adsorption units on the surface of the beads.With Al3+ being the most affected and the adsorption rate as low as 18.3%.Uranium can be desorbed by Na2CO3,the efficiency can be 98%or more.In the process of repeated use of the beads,the adsorption effect gradually decreased.It has to reconnect the protein.The beads can have a good adsorption performance in a week(adsorption rate>60%),but it willbe very low after then.The relative viability of HSF cells and HAEC cells decreased with the increase of uranium concentration,which proved the cytotoxicity of uranium.Compared with the untreated uranium solution,the relative survival rate of the treated uranium solution was significantly improved.It was found that the toxicity of uranium to cells was reflected in G2/M phase through the cell cycle experiments.