Preparation And Properties Of Uranium Adsorption Materials Based On Microalgae Template

With the rapid development of society and economy,the new energy represented by nuclear power plant has brought a lot of power energy to people,but it also produces a lot of uranium containing wastewater,which is harmful to human health and life safety.Therefore,it is of great significance to find efficient,low-cost and pollution-free adsorbent to enrich uranyl ions in domestic water.In this paper,a variety of microalgae composites were prepared using Haematococcus pluvialis as template to simulate the removal of uranyl ions from domestic water.MgO@Haematococcus pluvialis composite was synthesized by hydrothermal method and calcination method using freeze-dried Haematococcus pluvialis as template.The structure of the materials was characterized by XRD and FT-IR.The original morphology of MgO and adsorption capacity of MgO were improved by adding Haematococcus pluvialis in the process of MgO preparation.The effects of different pH,uranium concentration and temperature on the adsorption effect of U（Ⅵ）were investigated.The final experimental results show that the Langumir isothermal model is more consistent with the adsorption process at 25℃and pH=4.The maximum adsorption capacity of UO₂²⁺by Langmuir equation is 1994.820 mg·g^-1.The magnetic Fe/Zn-LDO@Haematococcus pluvialis material was prepared and the structural characteristics of the material were investigated by XRD,FT-IR,BET,etc.According to the final results of the adsorption experiment,the adsorption effect is the best when the pH value of magnetic Fe/Zn-LDO@Haematococcus pluvialis material is 6 at 25℃.According to the thermodynamic fitting results,the adsorption model of the material is more consistent with the Langmuir isothermal model,and the maximum adsorption capacity of magnetic Fe/Zn-LDO@Haematococcus pluvialis fitted by the Langmuir equation is 509.580 mg·g^-1.According to the magnetic characteristics of the material can be separated from the outside with magnets,recycling.The freeze-dried Haematococcus pluvialis was modified by hydrothermal method,and finally the magneticγ-Fe₂O₃@Haematococcus pluvialis composite was obtained successfully.The morphology and structure of the composite were characterized by XRD,SEM,XPS,FT-IR,EDS,BET,and static adsorption experiments were also carried out.The effects of time,temperature,concentration,pH value and other factors on the adsorption properties of uranyl ions were studied.The results show that the adsorption effect of uranium is the best when the initial pH is 6.From the point of view of adsorption kinetics,the adsorption process is more consistent with the pseudo-second-order kinetic model.After thermodynamic model fitting,it can be seen that the material adsorption process is more consistent with Langmuir equation at 25℃and pH=6,and with the increase of initial uranyl ion concentration in solution,the material shows better adsorption effect.