Behavior of ammonium adsorption by clay mineral halloysite
Behavior of ammonium adsorption by clay mineral halloysite
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粘土矿物埃洛石吸附铵的行为
DOI：
10.1016/s1003-6326(17)60185-7
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发表时间：
2017-07-01
影响因子：
4.5
通讯作者：
Wang, Wei
中科院分区：
文献类型：
--
作者：
Jing, Qing-xiu;Chai, Li-yuan;Wang, Wei
中国南方离子型稀土矿在开采过程中铵污染日益严重。高岭土作为离子型稀土矿土壤中的主要粘土矿物之一，对铵离子的吸附起着重要作用。研究了高岭土对铵的饱和吸附量、吸附影响因素及吸附动力学。结果表明：在303 K、pH为5.6、初始铵离子浓度为600 mg/L（约为实际初始原位浸出浓度的一半）的条件下，高岭土对铵离子的饱和吸附量为1.66 mg/g；随着初始NH4浓度、pH值和温度（288 ~ 313 K）的增大，高岭土对铵的吸附量增大。高岭土的等温吸附符合Langmuir和Freundlich等温吸附。离子型稀土采掘土对铵的吸附过程良好。吸附过程符合准秒动力学方程。
Ammonium pollution becomes severe during mining of ionic rare earth-ores in southern China. As one of the main clay minerals in soils of ionic rare earth mines, halloysite plays an important role in ammonium adsorption. In this study, the saturated adsorption capacity, factors affecting adsorption and adsorption kinetics of halloysite for ammonium were investigated. The results indicated that the ammonium adsorption of halloysite was saturated with 1.66 mg/g at 303 K, pH of 5.6 and initial ammonium concentration of 600 mg/L (about half of the actual initial in-situ leaching concentration). When the initial concentration of NH4| -N, pH values and temperatures (288 K to 313 K) increased, the ammonium adsorption capacity of halloysite increased. The ammonium isothermal adsorption of halloysite matched the Langmuir and Freundlich isotherms. The adsorption process of ionic rare earth mining soils for ammonium was favorable. And the adsorption process followed closely the pseudo-second kinetic equation.