【作者】 朱宁；

【导师】 关连珠；

【作者基本信息】 沈阳农业大学 ， 土壤学， 2005， 硕士

【摘要】 本文通过室内分析的方法研究了棕壤中各粒级微团聚体及其各组成成分,即<10μm、10～50μm、50～250μm三粒级微团聚体;有机质、游离氧化铁、无定形氧化铁、碳酸钙,对Cu²⁺、Cd²⁺的吸附特性及其吸附机制的影响。研究结果表明: 棕壤各粒级微团聚体对Cu²⁺、Cd²⁺的吸附能力明显高于原土,且随粒级的减小对Cu²⁺、Cd²⁺的吸附能力增强。从吸附机制来看,各粒级微团聚体对Cu²⁺、Cd²⁺的吸附机制基本相同,表现为:<10μm微团聚体以络合机制为主,10～50μm微团聚体以络合机制和静电吸附机制为主,50～250μm微团聚休以静电吸附机制为主。 棕壤各粒级微团聚体中的组成成分对Cu²⁺、Cd²⁺的吸附特性及其吸附机制具有一定的影响。具体表现为:有机质对Cu²⁺、Cd²⁺吸附能力的影响大于其它组分。在各粒级微团聚体中,微团聚体粒级越小,有机质的含量越大,对Cu²⁺、Cd²⁺吸附能力越强;从吸附机制来看,去除有机质后,虽仍存在着静电吸附,但络合吸附明显减弱,而未知吸附机制吸附的Cu²⁺、Cd²⁺数量有所增强,尤以<10μm粒级微团聚体突出。 各粒级微团聚体中的游离氧化铁对Cu²⁺、Cd²⁺的吸附也有一定的影响。各粒级微团聚体中,游离氧化铁对Cu²⁺、Cd²⁺的吸附量随粒级的减小有明显的增加;从吸附机制来看,去除游离氧化铁以后,棕壤各粒级微团聚体对Cu²⁺、Cd²⁺的静电吸附能力有所上升,络合吸附能力有所下降,未知吸附能力也有所下降。 各粒级微团聚体中的无定形氧化铁对Cu²⁺、Cd²⁺的吸附仍有一定的影响。各粒级微团聚体中的无定形氧化铁对Cu²⁺、Cd²⁺的吸附量随粒级的减小有明显的增加;从吸附机制来看,去除无定形氧化铁以后,棕壤各粒级微团聚体对Cu²⁺、Cd²⁺的静电吸附能力有小幅度的增加,而络合吸附能力轻微的降更多还原

【Abstract】 The research based on the analysis of the several different particle fractions of microaggregates extracted from the brown earth( 10μm,10 - 50μm,50 ~ 250μm) and the component (organic matter, free iron, amorphous iron oxide,CaCO3 )in it. The adsorption character and mechanism of Cu2+ and Cd2+ on it was investigated. The results showed:Compared with brown earth , the microaggregates present the stronger adsorption ability. The smaller particle is,the stronger adsorption ability is. According to the adsorption mechanism ,the adsorption mechanism of Cu~2+ and Cd~2+ is similar, the particle of < 10μm is the most active to the complexation mechanism, the complexation mechanism and exchange mechanism is equal in the particle of 10 - 50μm, 50 ~ 250μm is mainly exchange.In the brown earth and several different particle fractions of microaggregates. The contribution of the organic matter is greater than the other components. The content of the organic matter increase as the panicle decrease. So the effects of the organic matter present stronger. According to the adsorption mechanism, after dissecting the organic matter, the mechanism of exchange retained, but the complexation ability decreased remarblly. And the complexation mechanism increased.The free iron in the soil also present some effects to the adsorption of Ou~2+ and Cd~2+. The adsorption of Cu~2+ and Cd~2+ increased in the free iron with the decreased of the particle of the microaggregates. To the adsorption mechanism, after dissecting the free iron, the exchange ability of Cu~2+ and Cd~2+ increased, the complexation ability decreased, the complexation ability also decreased.The amorphous iron oxide in the soil also present some effects to the adsorption of Cu~2+ and Cd~2+ The adsorption of Cu~2+and Cd~2+ increased in the amorphous iron oxide with the decreased of the particle of the microaggregates. To the adsorption mechanism, after更多还原