Isotherm and kinetic studies on the adsorption of humic acid molecular size fractions onto clay minerals

作     者：Mohamed E.A.El-Sayed Moustafa M.R.Khalaf James A.Rice 

作者机构：Department of Chemistry and BiochemistrySouth Dakota State UniversityBrookingsSD 57007USA SoilsWaterand Environmental Research InstituteAgriculture Research CenterEl-GizaEgypt Chemistry DepartmentFaculty of ScienceMinia UniversityEl-Minia 61519Egypt 

出 版 物：《Acta Geochimica》 (地球化学学报（英文）)

年 卷 期：2019年第38卷第6期

页      面：863-871页

核心收录：

学科分类：081704[工学-应用化学] 07[理学] 070304[理学-物理化学(含∶化学物理)] 08[工学] 0817[工学-化学工程与技术] 0703[理学-化学] 

基　　金：funded by a Fulbright Visiting Scholar fellowship to Mohamed El-sayed and performed at South Dakota State University 

主　　题：Kaolinite Montmorillonite Leonardite humic acid Humic acid fractions Kinetics Equilibrium 

摘      要：Humic acid(HA)can adsorb onto mineral surfaces,modifying the physicochemical properties of the ***,understanding the sorption behavior of HA onto mineral surfaces is of particular interest,since the fate and transport of many organic and inorganic contaminants are highly correlated to HA adsorbed onto clay *** to the extreme heterogeneity of HA,the extracted IHSS Leonardite humic acid(LHA)used in this work was fractionated using an ultrafiltration technique(UF)into different molecular size fractions(Fr1,0.2μm;Fr2,0.2 pm-300,000 daltons;Fr3,300,000-50,000 daltons;Fr4,50,000-10,000 daltons;Fr5,10,000-1000 daltons).Equilibrium and the kinetics of LHA and fraction adsorption onto kaolinite and montmorillonite were *** results demonstrated that the maximum adsorption capacity of LHA,Frl,Fr2,Fr3,Fr4,and Fr5 was 5.99,13.69,10.29,7.02,5.9&and 5.09 on kaolinite while it was 8.29,22.62,13.17,8.91,8.62,and 5.69 on montmorillonite,*** adsorption equilibrium data showed that the adsorption behavior of LHA and its fractions could be described more practically by the Langmuir model than the Freundlich *** rate of humic acid fraction adsorption onto clays increased with decreasing molecular size fraction and increasing carboxylic group ***-first-and second-order models were used to assess the kinetic data and the rate *** results explained that LHA and its fractions adsorption on clay minerals conformed more to pseudosecondo rder.