Study Of Fluoride Ion Removal Using Lanthanum-Loaded Activated Carbon And Lanthanum-loaded Fiber

Fluoride is beneficial for calcification of dental enamel and bone formation,but it is toxic.Once excess intake of fluoride, various diseases would be leaded. For example, brittle bones, brain damage,osteoporosis, arthritis, cancer and thyroid disorder.Today there are29nations suffering such a problem to different extent in the world,the problem is that water of their drinking contains more fluoride than the norm recommended. And more than260million people are suffering the problem in China. Therefore, To study economical and effective defluoridation processes is necessary.The main defluoridation process include electrodialysis, reverse osmosis, ion exchange,chemical precipitation and adsorption. Because adsorption is efficient and simple, and containing low concentration pollutants especially effective in treating water, it has already been used widely. And for removing fluoride from water, it is one of the most extensively used treatment methods. As an important physico-chemical water treatment method. To use the suitable adsorbents is the key to successfully adopt the adsorption in treating water. In recent years,the exploitation of the novel, the interests of many scholars has been attracted cheap and effective adsorption materials in treating wastewater to save the cost. For fluorid adsorption,this papaer study two methods of produeing novel sorbent:to modify the surface properties.Lanthanum (Ⅲ)-loaded activated carbon was prepared in the current study through lanthanum impregnation for fluoride removal from aqueous solutions. The results of batch adsorption tests showed that solution pH values had a major impact on fluoride adsorption with optimal removal (above96%) observed in acidic solutions. The estimated maximum uptake capacity was20.4mg/g, and the adsorption isotherm could be well fitted by the Langmuir equation,Lanthanum(Ⅲ)-loaded Amidoxime chelating fiber was prepared in the current study for fluoride removal from aqueous solutions. Experimental results indicated that the optimum pH range for fluoride adsorption was5-7and the adsorbent also showed high defluoridation capacity around pH4-10. The adsorption isotherms can be described by the Langmuir equation and the estimated maximum adsorption capacity was40.1mg·g-1. The adsorption kinetics can be well fitted by the pseudo-second-order rate model.