离子型稀土矿区土壤中高岭土对氨氮的吸附研究  

Study on adsorption of ammonium by kaolinite in soil of ionic rare earth mining area

作　　者：靖青秀[1,2] 郭欢[1] 黄晓东[1] 王巍[1] 钟盛文[1] 黄亚祥 

机构地区：[1]江西理工大学冶金与化学工程学院,江西赣州341000 [2]中南大学冶金与环境工程学院,湖南长沙410083

出　　处：《中国矿业》2016年第12期64-70,共7页China Mining Magazine

基　　金：国家自然科学基金项目资助(编号:51564016);中共省委组织部赣鄱英才555工程高端柔性引进人才项目"稀土功能材料"资助(编号:2012);江西理工大学校级重点科研项目资助(编号:NSFJ2015-K06)

摘　　要：我国南方离子型稀土矿区土壤氨氮污染严重,高岭土是矿区土壤的主要黏土成分之一。本文对高岭土黏土矿物与氨氮污染间的吸附特点及吸附动力学等进行了研究。结果表明：随着氨氮初始浓度、温度的升高,高岭土对氨氮的吸附量与吸附速率均提高;pH〈9.2时,高岭土对氨氮的吸附量随pH值增大而增大;pH〉9.2时,二者间的吸附量随pH值增大急剧降低;高岭土对氨氮的等温吸附符合Langmuir模型和Freundlich模型,吸附动力学符合准二级动力学方程;对于实际的我国南方的离子型稀土开采矿区,在矿区土壤的温度存在主要区间（298~310K）、pH值存在范围（3.0~6.0）内,随原地浸矿时温度、浸矿液浓度或pH值的升高,矿区土壤中氨氮的吸附残留量均会增大;可通过使用较低浓度的原地浸矿液、控制较低的土壤pH值和温度,加强对矿区污染土壤中氨氮的去除。Ammonium pollution increases in severity during mining of ionic rare earth ores in southern China.Kaolinite is one of the main clay minerals in soils of ionic rare earth ores.It was selected as the adsorbent and the adsorption characteristics of it for ammonium were investigated.The results indicated the adsorption capacity and rate of ammonium by kaolinite increased with increasing the initial concentration of NH_4~＋-N and temperature.The adsorption capacity increased with increasing pH value when the latter was lower than 9.2;whereas it was dramatically decreased with pH value increasing when pH value was higher than 9.2.The isothermal adsorption matched the Langmuir and Freundlich isotherms.The adsorption process followed closely the pseudo-second kinetic equation.In ranges of temperature（e.g.298 Kto 310K）and pH value（e.g.3.0to 6.0）characterized the actual ionic rare earth mining area soil in several provinces in south China,the adsorption capacity of the mining soil for ammonium would increase with increasing leaching agent concentration,temperature or pH value.The ammonium removal in the polluted mining soil can be strengthened through using lower concentration of in-situ leaching solution and controlling lower pH value and temperature of the soil.

关 键 词：高岭土 氨氮污染 吸附 离子型稀土矿区 

分 类 号：X53[环境科学与工程—环境工程] TD85[矿业工程—金属矿开采]