典型土壤黏粒矿物吸持土壤溶解性有机质的动力学和热力学特征  

Kinetic and thermodynamic characteristics of typical soil clay-grained minerals adsorbing soil dissolved organic matter(DOM)

作　　者：尚雪莹 刘艳娇 王钺博 朱翔 宇滕辉 SHANG Xue-ying;LIU Yan-jiao;WANG Yue-bo;ZHU Xiang-yu;Hui Henry TENG(Institute of Surface-Earth System Science,School of Earth System Science,Tianjin University,Tianjin 300072,China)

机构地区：[1]天津大学地球系统科学学院,表层地球系统科学研究院,天津300072

出　　处：《岩石矿物学杂志》2025年第2期451-462,共12页Acta Petrologica et Mineralogica

基　　金：国家自然科学基金项目(41702035,41830859)。

摘　　要：土壤有机碳库是碳循环研究的热点议题之一,其中溶解性有机质(DOM)最具流动性和活性,而黏粒矿物是土壤中最活跃的矿物组分,对DOM稳定具有重要影响,因此,从吸持动力学和热力学角度详细探究了3种常见的土壤黏粒矿物水铝英石、高岭石和赤铁矿对植物源溶解性有机质(PDOM)的吸持特征及其控制机制。结果表明,黏粒矿物可以有效吸持PDOM,水铝英石对PDOM的吸持量高于高岭石和赤铁矿,但其单位面积上的吸持能力弱于其他两者;动力学和热力学数据表明,水铝英石的吸持以物理方式为主,而高岭石和赤铁矿则以化学方式为主;3种矿物的界面特性差异导致吸持量和吸持能力不同,其中比表面积是导致吸持量差异的主要因素,而吸持能力的强弱取决于反应体系的pH值、吸附位点的密度和可用性。本研究为理解土壤黏粒矿物对有机质的固持提供了基础依据。Soil organic carbon pools are one of the hot topics in carbon cycle research,among which dissolved organic matter(DOM)is the most mobile and active,and clay-grained minerals are the most active mineral components in soil.Clay-grained minerals have a significant impact on the stability of DOM.Therefore,the adsorption characteristics and control mechanisms of three common soil clay-grained minerals,allophane,kaolinite and hematite,on DOM were explored in detail from the perspectives of adsorption kinetics and thermodynamics.The results indicate that three minerals can effectively adsorb PDOM,and the adsorption capacity of allophane on PDOM is higher than that of kaolinite and hematite,but its adsorption capacity per unit area is weaker than the other two;Kinetic and thermodynamic data indicate that the PDOM uptake by allophane may be largely controlled by physical means,while that by kaolinite and hematite are chiefly through chemical forces.Differences in the interfacial properties of the three minerals lead to different absorption characteristics.Among them,the specific surface area is the main factor leading to the difference in the total amount of adsorption,while the adsorption strength depends on the pH value of the reaction system,the density and availability of the adsorption sites.This study provide a basis for understanding the sequestration of organic matter by soil clay-grained minerals.

关 键 词：水铝英石 高岭石 赤铁矿 植物源溶解性有机质 吸持 

分 类 号：P579[天文地球—矿物学]