Preparation And Application Of Metal-organic Frameworks/Composites

It is necessary to develope new energy due to the acking of fossil fuels and the serious environmental pollution.Nuclear energy is becoming the new energy strategic choice in China because of its efficient;clean and less environmental dependence.The nuclear equipment in the normal operation and sudden nuclear accidents will inevitably produce radioactive waste water;and other radioactive pollutants;resulting in environmental pollution and serious harm on human health.In this paper;the typical radionuclide of strontium in radioactive waste water is focused andnew composite materials were synthesized and modified to improve its adsorption efficiency.It is applied to the adsorption of strontium.At the same time;the application of new composite materials in the adsorption of typical heavy metal of lead in wastewater was explored.Firstly;this paper focuses on the metal organic frameworks materials(MOFs).The adsorption properties of calcium-MOFs adsorbent were prepared and characterized.At the same time;the magnetic properties of Fe3O4/Ca-BTC were synthesized;and the adsorption performance was further investigated.The effects of adsorption temperature;pH;humic acid;ionic strength and competitive adsorption on the adsorption capacity of Ca-BTC were investigated.The effects of adsorbent concentration;initial concentration of adsorption solution and adsorption time on Ca-BTC adsorption capacity were carried out as well.On the optimal conditions;(T = 298 K;pH = 7);the initial concentration of adsorption solution is 1000 mg·L 1 and the adsorbent mass is 100 mg.The adsorption time is 600 min and the maximum adsorption capacity of the material is 239.75 mg·g-1.The adsorption kinetic model;the adsorption isotherm model and the thermodynamic fit show that the adsorption process is more consistent with the second-order kinetics and Langmuir adsorption isotherm model;which indicates that the adsorption sites are evenly distributed on the surface of the adsorbed material.?H<0;?S<0 and ?G<0;which means he adsorption process of the material is exothermic entropy and spontaneous so that the adsorption capacity decreases with the increasing of the temperature.Fe3O4/Ca-BTC was successfully prepared;and the adsorption capacity of lead and lead was up to 489.82 mg·g-1.The removal rate was 100%and the adsorption amount of strontium was 154.12 mg·g-1;with the material recovery rate as high as 82.31%.The scanning electron microscope shows that the Fe304 microspheres are uniformly supported on the rod-like structure;and the rod-like structure is uniform.The XPS characterization shows that the adsorption of the magnetic material is mainly chemical adsorption.Ca-BTC is a rod-like structure with a size of about 30 u m.The results of infrared characterization show that there are new bonds in the adsorbed material and the fracture of the old bond;and the XRD and FTIR characterization showed that the adsorbed material was Sr-BTC.X-ray energy dispersive spectroscopy(EDS);electron microscopy scanning energy spectrum analysis(Mapping);X-ray photoelectron spectroscopy(XPS)spectroscopy and other characterization further proved that the adsorption process is mainly ion-exchange chemical adsorption.