The Study Of Quartz Adsorption Of Uranium In Phosphorus-enriched Water System

Due to excessive exploitation of natural resources,and the rapidly accumulation of population,food shortages is becoming increasingly serious,nowadays.China,a large agricultural country with large number of population,needs most of the phosphate fertilizers to ensure food production for 1.4 billion people.Past research has shown that more than eighty percent of China’s phosphate rock bed are sedimentary phosphate.The mineral deposits contain high radioactive elements uranium and thorium.Because of China’s basic national conditions,the water system presents phosphorus-rich uranium.With strong complexation between uranium and phosphorus which makes water environment problems are serious.Quartz,an important adsorbent material,is a natural mineral exist extensively,which is concerned about the majority of scholars.Adsorption of uranium in phosphorus-rich water systems mainly focus on goethite before,rather than quartz.Meanwhile,there are little report of the study of quartz adsorption of uranium in phosphorus-enriched water system.The thesis depend on the Natural Science Foundation Project.By changing various conditions in the experiment,study on how adsorption of uranium in phosphorus-rich water systems through quartz.The results show that pH is the important factor in the experiment.Under acidic conditions,adsorption can increase with pH in the range from 2.0 to 6.0,but decreace with pH in the range from 6.0 to 7.0.Under alkaline conditions,with the increase of pH,the adsorption capacity gradually increase and then decrease.The adsorption can reach maximum when pH at 9.0.If solution was in the range from 2.0 to 11.0,uranium adsorption on quartz was stronger in the absence of phosphate than situation in the presence of phosphate.Under acidic conditions,The low concentrations of phosphate solution systems have more strong adsorption than others.However,if solution was alkaline,The high concentrations of phosphate solution systems have more strong adsorption than others.Uranium adsorption on quartz in the presence of phosphate was discussed at different concentrations of NaCl at 0.02 mol/l,0.1 mol/l,and 0.5mol/l.Ionic strength had little impact on uranium adsorption on quartz.The result of adsorption is much lower with the high ionic strength than others.Quartz for adsorption of uranium is not increases with the increase of solid-liquid ratio.Solid-liquid ratio increases is not necessarily in favor of adsorption.Uranium adsorption onquartz in the presence of phosphate was discussed at different value of solid solution ratio(5 g/l,10 g/l,20 g/l).Adsorption percentage can increase with solid solution ratio and reach maximum at the solid solution ratio of 20 g/l within low concentrations of phosphate solution.Nevertheless,adsorption percentage can reach maximum at the solid solution ratio of 5 g/l within high concentrations of phosphate solution.Different minerals have different laws uranium adsorption.