第27卷第1期暨南大学学报(自然科学版) Vol . 27No . 1 2006年2月 Journa l of Jinan Unive rsity (N atural Science ) Feb . 2006
稀土元素与腐殖酸在水合氧化铁
体系中的吸附机制
耿安朝1, 章 申2
(1. 厦门大学海洋与环境学院, 福建厦门361005; 2. 中国科学院地理科学与资源研究所, 北京100101)
[摘 要] 实验考察稀土元素(La 3+、Ce 3+、Ho 3+、Yb 3+) 在水合氧化铁表面的吸附动力学过程, 对比研究腐殖酸对吸附机制的影响. 当腐殖酸与稀土元素共存时, 腐殖酸通过化学吸附优先占据氧化铁表面的吸附点位, 颗粒物表面特性因覆盖有机膜而得到修饰. 初期的动力学过程主要表现为腐殖酸的竞争吸附, 随后转变为吸附态腐殖酸对稀土元素的表面结合. 轻稀土因较强的结合能力而比重稀土易于被吸附去除, 这与天然水体中发生的稀土元素分异现象保持一致.
[关键词] 稀土元素; 腐殖酸; 水合氧化铁; 吸附机制
[中图分类号] X131. 3 [文献标识码] A [文章编号] 1000-9965(2006) 01-0096-07Adsor pt i o n m echan is m of ra r e ea r th ele m en ts and hum i c a c i ds
i n the syste m of i r o n oxyhydr ox i de
GENG An 2chao 1, ZHA N G Shen
Xi am en 361005, China; 2. 2(1. College of Oceanography and Environ mental Science, Xiamen Unive rsity, Institut e of Geographi ca l Sc i ences and Natura l R es ources
Re search, Chi nese Academy of Sc iences, Beijing 100101, China )
[Abstra ct] Kinetics of r a r e earth ele m ents(La3+, Ce 3+, Ho 3+, Y b 3+) adsor pti on t o the ir on oxyhydr oxide were investigated, and the effects of hu m ic acid on ads or p ti on mecha 2nis m wer e r evealed . Coexisting hu m ic acid with rare earth ele m ents (R EEs ) , the sur face sites of ir on oxyhydr oxide m ight be occupied p ree m inently by the hum ic ac id thr ough the che m ica l adsor ption, and the characteristics of the solids are dec orated by cove ring the or 2ganic m e m brane . The adsor ption kinetic s of REEs initially show s the co mpetitive ads or p 2ti on w ith hum ic acid, and then is the surf ace binding with the adsor bed hum ic acid . The LR EEs tend to be ads orbed on the solids and r emoved fr om the liquid due to the ir str onger binding ability with hu m ic acid than the HR EEs, which is consistent w ith the fr acti onati on of the R EEs taking p lace in the na tur a l waters .
[Key word s] rare earth elements ; hum ic acid; ir on oxyhydr oxide; adsor pti on m echanis m
[收稿日期] 2005-05-16
[基金项目] 国家教育部资助优秀青年教师项目(1999)
[作者简介] 耿安朝(1962-) , 男, 教授, 博士, 研究方向:城市生态学与环境地球化学
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第27卷第1期暨南大学学报(自然科学版) Vol . 27No . 1 2006年2月 Journa l of Jinan Unive rsity (N atural Science ) Feb . 2006
稀土元素与腐殖酸在水合氧化铁
体系中的吸附机制
耿安朝1, 章 申2
(1. 厦门大学海洋与环境学院, 福建厦门361005; 2. 中国科学院地理科学与资源研究所, 北京100101)
[摘 要] 实验考察稀土元素(La 3+、Ce 3+、Ho 3+、Yb 3+) 在水合氧化铁表面的吸附动力学过程, 对比研究腐殖酸对吸附机制的影响. 当腐殖酸与稀土元素共存时, 腐殖酸通过化学吸附优先占据氧化铁表面的吸附点位, 颗粒物表面特性因覆盖有机膜而得到修饰. 初期的动力学过程主要表现为腐殖酸的竞争吸附, 随后转变为吸附态腐殖酸对稀土元素的表面结合. 轻稀土因较强的结合能力而比重稀土易于被吸附去除, 这与天然水体中发生的稀土元素分异现象保持一致.
[关键词] 稀土元素; 腐殖酸; 水合氧化铁; 吸附机制
[中图分类号] X131. 3 [文献标识码] A [文章编号] 1000-9965(2006) 01-0096-07Adsor pt i o n m echan is m of ra r e ea r th ele m en ts and hum i c a c i ds
i n the syste m of i r o n oxyhydr ox i de
GENG An 2chao 1, ZHA N G Shen
Xi am en 361005, China; 2. 2(1. College of Oceanography and Environ mental Science, Xiamen Unive rsity, Institut e of Geographi ca l Sc i ences and Natura l R es ources
Re search, Chi nese Academy of Sc iences, Beijing 100101, China )
[Abstra ct] Kinetics of r a r e earth ele m ents(La3+, Ce 3+, Ho 3+, Y b 3+) adsor pti on t o the ir on oxyhydr oxide were investigated, and the effects of hu m ic acid on ads or p ti on mecha 2nis m wer e r evealed . Coexisting hu m ic acid with rare earth ele m ents (R EEs ) , the sur face sites of ir on oxyhydr oxide m ight be occupied p ree m inently by the hum ic ac id thr ough the che m ica l adsor ption, and the characteristics of the solids are dec orated by cove ring the or 2ganic m e m brane . The adsor ption kinetic s of REEs initially show s the co mpetitive ads or p 2ti on w ith hum ic acid, and then is the surf ace binding with the adsor bed hum ic acid . The LR EEs tend to be ads orbed on the solids and r emoved fr om the liquid due to the ir str onger binding ability with hu m ic acid than the HR EEs, which is consistent w ith the fr acti onati on of the R EEs taking p lace in the na tur a l waters .
[Key word s] rare earth elements ; hum ic acid; ir on oxyhydr oxide; adsor pti on m echanis m
[收稿日期] 2005-05-16
[基金项目] 国家教育部资助优秀青年教师项目(1999)
[作者简介] 耿安朝(1962-) , 男, 教授, 博士, 研究方向:城市生态学与环境地球化学
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