%0 Journal Article
%T 2+ adsorption and desorption by constant charge soil colloids<br>小分子有机酸对恒电荷土壤胶体Pb2＋吸附-解吸的影响
%A Yati Yang
%A Xudong Wang
%A Yiping Zhang
%A Aihua Qu
%A <br>
%J 应用生态学报
%D 2003
%I 
%X The isothermal curves of Pb2+ adsorption-desorption by soil colloids followed Freundlich and Langmuir equation. The adsorption constant Ka showed the trend of old manured loessal soil > yellow loessal soil > dark cultivated loessal soil > yellow cinamon soil, which was consistent with surface charge density sigma 0, an indicator of the strength of Pb2+ adsorption by each soil colloid. Low molecular-weight organic acids (LMWOAs) made Pb2+ adsorbed amount decreased and adsorption affinity increased, and the effect of citric acid was larger than that of oxalic acid. The constant Kd of residual Pb2+ adsorption after desorption showed the trend of old manured loessal soil > yellow cinamon soil > dark cultivated loessal soil > yellow loessal soil, which reflected the adsorption strength of residual Pb2+ after desorption, and was related to the contents of organic matter and free ferric oxide. The isothermal curves of Pb2+ desorption from soil colloids were obvious higher than those of Pb2+ adsorption. In NaNO3 and oxalic acid background solution, the isothermal curves of Pb2+ adsorption were far away from those of Pb2+ desorption, showing that the hysteretic degree between adsorption and desorption was very large. The isothermal curves of Pb2+ desorption from soil colloids were closed to those of Pb2+ adsorption in citric acid background solution, which showed that the Pb adsorption and desorption was reversible.
%K 恒电荷土壤胶体
%K 吸附
%K 解吸
%K Pb^2＋
%K 小分子有机酸
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=90BA3D13E7F3BC869AC96FB3DA594E3FE34FBF7B8BC0E591&jid=42FEDDFE54F8BCD9D5FD1926ABDD7722&aid=C75BD8D6E4D3069B&yid=D43C4A19B2EE3C0A&vid=F3583C8E78166B9E&iid=708DD6B15D2464E8&sid=8827E7669C34610F&eid=FEE377A727789A99&journal_id=1001-9332&journal_name=应用生态学报&referenced_num=5&reference_num=17