季节性冻融作用对土壤吸附稀土元素镧的影响  

The effect of seasonal freeze-thaw on the soil adsorption of rare earth elements lanthanum

作　　者：肖作义[1] 马耀祖 郑春丽[1,2] 李左夫 白昕冉 杨泽茹 XIAO Zuo-yi;MA Yao-zu;ZHENG Chun-li;LI Zuo-fu;BAI Xin-ran;YANG Ze-ru(School of Energy and Environment,Inner Mongolia University of Science&Technology,Baotou 014010,China;Key Laboratory of Integrated Exploitation of Baiyun Obo Multi-Metal Resources,Inner Mongolia University of Science&Technology,Baotou 014010,China)

机构地区：[1]内蒙古科技大学能源与环境学院,内蒙古包头014010 [2]内蒙古科技大学白云鄂博矿多金属资源综合利用省部共建国家重点实验室,内蒙古包头014010

出　　处：《应用化工》2018年第9期1841-1845,共5页Applied Chemical Industry

基　　金：国家自然科学基金项目(NSFC41561094);内蒙古青年科技英才支持计划项目(NJYT 14-B12);内蒙古科技厅应用技术研发项目(201501083);内蒙古自治区人才开发基金项目;内蒙古自治区青年创新人才-草原英才后备人才项目;内蒙古自治区新世纪321人才工程项目;内蒙古自治区自然科学基金博士基金项目(2016BS0511)

摘　　要：通过室内模拟,研究冻融作用对土壤理化性质的影响,并分析不同冻融频次对土壤吸附稀土元素镧的影响,探究其影响机制。结果表明,随着冻融频次的增加,土壤pH升降变化幅度不大;有机质在冻融频次为二次时,达到最大值42. 61 g/kg,且随着冻融频次的增加呈现下降趋势;游离氧化铁由7. 67 g/kg下降到3. 62 g/kg后上升到13. 47 g/kg。同时,土壤对稀土元素镧的吸附量随冻融频次的增加而逐渐减小。经过8次冻融,土壤对镧的最大吸附量由1. 89 mg/g下降到1. 09 mg/g,说明冻融作用对土壤吸附稀土元素镧有抑制作用,这与冻融作用改变了土壤的理化性质有关。冻融作用改变了土壤对稀土元素镧的吸附机制,使专性吸附向非专性吸附转变,促进了稀土元素镧向土壤中的解吸和释放,增加了土壤中镧的生态风险。This study treated the rare earth element lanthanum as the experimental object to research the influence of the freeze-thaw on the soil physical and chemical properties,and analyze the different freezing and thawing frequency influence on soil adsorption of rare earth element lanthanum,and explore its effect mechanism.The results showed that:With the increasing of freeze-thaw frequency,the change of soil pH was not great.The organic matter reached a maximum of 42.61 g/kg when the freeze-thaw frequency was twice,and with the extension of the freeze-thaw cycle it decreased.The free iron oxide rose from 7.67 g/kg to 3.62 g/kg and then up to 13.47 g/kg.As the initial lanthanum concentration phase,the adsorption capacity of lanthanum on rare earth elements decreased with the increasing of freeze-thaw frequency.After eight times of freeze-thaw,the maximum soil of lanthanum decreased from 1.89 mg/g to 1.09 mg/g,which explained freeze-thaw reduced the adsorption quantity of rare earth element lanthanum in soil.It had something to do with changes of soil physical and chemical properties by freeze-thaw.The freeze-thaw caused the change of the soil adsorption mechanism of lanthanum,which caused the transformation of the obligatory adsorption to non-obligatory adsorption.So it was beneficial to the desorption and release of lanthanum in the soil.

关 键 词：季节性冻融 理化性质 稀土元素镧 吸附 

分 类 号：TQ028.15[化学工程]