模拟酸雨对红壤稀土元素释放的影响研究  

Study on Release of Rare Earth Elements from Red Soils under Influence by Simulated Acid Rain

作　　者：许中坚[1] 张华[1] 史红文[1] 刘广深[2] 

机构地区：[1]湖南科技大学化学化工学院,湖南湘潭411201 [2]浙江大学环境科学研究所,浙江杭州310029

出　　处：《水土保持学报》2007年第4期12-15,共4页Journal of Soil and Water Conservation

基　　金：国家自然科学基金资助项目(49973031);湖南省自然科学基金资助项目(05JJ30017);湖南省高校青年骨干教师培养对象资助项目;湖南科技大学博士基金资助项目(E50475)

摘　　要：模拟酸雨作用下红壤中稀土元素的释放水平大小依次为Pr＞Ce＞Nd＞Tb＞Sm＞La＞Er＞Ho＞Gd＞Dy＞Eu＞Y＞Lu≈Yb,轻稀土元素的释放水平要高于重稀土元素.酸雨对稀土元素的释放有明显的促进作用,且不同元素的CAR1/CCK、CR2/CCK比较接近(CAR1、CAR2和CCK分别表示pH4.5的酸雨、pH3.5的酸雨和对照3种情况下淋出液中稀土元素的含量).CAR1/CCK介于1.43～1.93之间,平均为1.61;CAR2/CCK介于1.76～2.27之间,平均为2.06,经过9 150～10 650 mm的模拟酸雨淋溶以后,pH4.5的酸雨使稀土总累积释放量平均提高37.61%,pH3.5的酸雨使稀土总累积释放量平均提高78.05%.稀土总释放量与Fe、Mn的释放量相关分析表明:多数红壤稀土总释放量与Fe、Mn的释放量呈显著或极显著性相关.初步推断红壤中的稀土释放可能是由于吸附载体Fe-Mn氧化物因H+的输入而解离所致.Under the influence of simulated acid rain,the average release level of rare earth elements from the tested soils was Pr>Ce>Nd>Tb>Sm>La>Er>Ho>Gd>Dy>Eu>Y>Lu≈Yb.Generally,the release level of light rare earth elements was higher than that of heavy rare earth elements.As a whole,acid rain was propitious to the release of rare earth elements,and the effect degree of acid rain on different rare earth elements was similar.The value of CAR1/CCK(CAR1,CCK,average concentrations of rare earth elements leached by acid rain of pH4.5 and the control respectively) varied from 1.43 to 1.93,and the average is 1.61.CAR2/CCK(CAR2,average concentrations of rare earth elements leached by acid rain of pH3.5) varied from 1.76 to 2.27,and the average is 2.06.On receiving simulating rainfall of 9 150~10 650 mm,average total cumulative release amount of rare earth elements increased 37.61% and 78.05% stimulated by acid rain of pH4.5 and pH3.5 respectively.In most cases,there was a remarkable correlation between the cumulative release amount of rare earth elements and that of Fe(or Mn).Probably because rare earth elements are absorbed by Fe-Mn oxides,acid rain dissolves these oxides and simultaneously boosts the release of rare earth elements.

关 键 词：酸雨 红壤 稀土 释放 

分 类 号：X517[环境科学与工程—环境工程] S151.9[农业科学—土壤学]