东篱科研大数据发现系统（DRDS）

位置：成果数据库 > 期刊 > 期刊详情页

长江三角洲地区典型土壤对镉的吸附及其与有机质、pH和温度的关系

ISSN号：0564-3929
期刊名称：《土壤学报》
时间：0
分类：S153[农业科学—土壤学;农业科学—农业基础科学]
作者机构：[1]中国科学院南京土壤研究所土壤与环境生物修复研究中心,南京210008, [2]土壤与农业可持续发展国家重点实验室,南京210008, [3]中国科学院研究生院,北京100039
相关基金：国家自然科学基金项目（40432005;40125005）、国家重点基础研究发展规划项目（2002CB410810）和中荷战略科学联盟项目（2004CB720403）资助.

关键词：吸附, 热力学参数, 镉, 长江三角洲, 影响因素, Sorption, Thermodynamic parameter, Cd, Yangtze River Delta, Influencing factors

中文摘要：

土壤重金属吸附-解吸反应影响重金属的迁移性、生物有效性和潜在毒性,研究土壤重金属的吸附-解吸过程及其机制对土壤污染评价、修复及环境容量预测至关重要。本文研究了长江三角洲地区四种典型土壤对Cd的吸附行为及有机质、pH和温度对土壤Cd吸附的影响,并运用热力学参数K°、ΔG°、ΔH°和ΔS°解释了土壤镉的吸附机制。研究结果表明,在本实验条件下,四种典型土壤镉吸附反应均很好地符合Fre-undlich模型。土壤镉吸附Kf值大小为：滩潮土（石质淡色潮湿雏形土）（238.8dm^3kg^-1）〉乌黄土（底潜铁聚水耕人为土）（115.4dm^3kg^-1）〉青紫泥（普通潜育水耕人为土）（54.40dm^3kg^-1）〉黄泥砂土（铁聚潜育水耕人为土）（10.74dm^3kg^-1）,滩潮土镉吸附Kf是黄泥砂土的24倍。土壤镉吸附量随溶液初始pH和土壤pH升高而增大;去除有机质后的土壤对镉的吸附量降低。吸附反应热力学表明,K°和ΔS°随温度升高而增大,ΔG°随温度升高而降低。ΔG°为负值表明镉吸附反应为自发反应,ΔH°为正值表明土壤镉吸附为吸热反应。

英文摘要：

The mobility, bioavailability and toxicity of soil metals are most likely controlled by sorption-desorption reactions. A better understanding of the sorption-desorption processes and mechanisms is crucial for assessment and remediation of heavy metal polluted soils, and for prediction of the metal sorption capacity of soils. Laboratory batch experiments were carried out to study Cd sorption by four representing soils from Yangtze River Delta in China. The thermodynamic parameters including K°, △G°,△H° and △S° were calculated by using sorption data for two different temperatures 25 ± 0.5℃ and 35 ± 0.5℃. Results showed that Cd sorption can be well described by Freundlich model. The sorption Kf values decreased in the order： Lithic Ochri- Aquic Cambosols （238.8 dm^3kg^-1）〉 Endogleyic Fe-accumulic Stagnic Anthrosols （115.4 dm^3kg^-1）〉 Typic Gleyic Stagnic Anthrosols （54.40 dm^3kg^-1）〉 Fe-accumulic Gleyic Stagnic Anthrosols （10.74 dm^3kg^-1）. The Cd sorption capacity of Lithic Ochri-Aquic Cambosols was 24 times as much as that of Fe-accumulic Gleyic Stagnic Anthrosols. The Cd sorption capacity of soils decreased after removal of organic matter. For four tested soils, Cd sorption increased with solution pH. The K° and △S° values increased with temperature, while △G° values decreased with temperature. The negative values of △G° suggested that Cd sorption was a spontaneous process. The positive △H° values indicated that Cd sorption was an endothermic process for four tested soils.

同期刊论文项目