Research On Preparation Of Lanthanum Cerium Doped Nano TiO₂ And Its Adsorption Properties For Pb²⁺ And Cd2

The pollution of heavy metals has become one of the most considerable problems of water pollution, such as Pb and Cr elements, these elements are cause by water emissions including residential water emissions, in particular, the result of illegal discharges of a number of industrial enterprises regardless of national policy,such reports frequently reported on TV and newspaper,but such emissions has never been effectively curbed, which have caused serious pollution to the environment and ecosystem,and have caused direct impact on human and ecological health of animal and plant. At present, there are many methods for the treatment of heavy metal polluted water body, among which the adsorption method is a traditional classical method.Nano titanium dioxide is a new type of multifunctional material,Some researches have been made on such aspects as photocatalytic activity, photoelectric properties and catalytic synthesis,but as reported on a study of heavy metal pollution in water treatment is not much, especially improve TiO₂ as adsorbents on the adsorption properties, preparation of materials optimization and adsorption thermodynamics, kinetics of research is rarely reported.Based on the problems existing in the material, taking into account the nano materials because of its superior physical properties has been applied in catalysis, separation, and photoelectricity, this paper selects better adsorption concentration ability of heavy metals of nanometer titanium dioxide material as matrix, using lanthanum and cerium doping technology, hope to get the separation and enrichment of the better performance of the heavy metal adsorption material. The main research contents and results are as follows:Preparation of lanthanum and cerium doped nano titanium dioxide by ultrasonic sol gel method, and the main influencing factors of the gelation process were discussed,The results showed that in the preparation of sol, water, ethanol and rare earth ions, the mixed solution of dropping speed should be 5-10 drops / min, the ratio of the components is n_TBT : n_EtOH : n_AA : n_H2O = 1 : 17 : 1 : 4, the material preparation conditions were determined.The results of adsorption of Pb and Cd showed that the adsorption of Pb and Cd on Ce doped TiO₂ was about 30% higher than that of the undoped material.The effect of lanthanum doped titanium dioxide on the adsorption of trace metal ions lead and cadmium is about 40% higher than that of the undoped material. Experimental results obtained with 40 mg /L as the metal ion concentration and removal of a ton of water required 2.1 kg lanthanum doped titanium dioxide nano materials, visible doped TiO₂ nanomaterials for treatment of heavy metal pollution in water is feasible, can be used as a supplement and improvement to the traditional method. Therefore, the adsorption capacity of lanthanum and cerium doped nano titanium dioxide on Trace Lead and cadmium was significantly increased than that of undoped materials.Through the analysis of FTIR SEM XRD and BET, the results showed that the Rare Earth Elements Lanthanum and cerium were successfully doped into the nano titanium dioxide matrix.Compared with non modified nano titanium dioxide, lanthanum or cerium modified nano titanium dioxide of lead and cadmium adsorption has increased significantly, which when temperature rises to 70? and lanthanum modified of nano materials, the maximum adsorption capacity can reach 18.98 mg / g.The kinetic equation of adsorption of lead and cadmium ions in all kinds of nano titanium dioxide is in accordance with the quasi two level equation, and can reach the adsorption equilibrium very quickly. The thermodynamic equation of Pb and Cd adsorption showed that the adsorption of Pb and Cd was endothermic process.To sum up, the modified nano titanium dioxide materials prepared by the study have the advantages of simple operation, low cost, easy fabrication process and so on. The adsorption of lead and cadmium ions on modified nanoTiO₂ materials was obviously improved, and the adsorption process was fast. Complements the versatility of rare earth ions doped nano titanium dioxide, synthesis or of new and efficient adsorption materials provided the valuable reference pathway, and provide reference data for selection of new materials and meaningful for the effective treatment of wastewater contaminated by heavy metals.