Adsorption of Pb, Cd to Fe, Mn oxides in natural freshwater surface coatings developed in different seasons
Adsorption of Pb, Cd to Fe, Mn oxides in natural freshwater surface coatings developed in different seasons作者机构:CollegeofEnvironmentandResourcesJilinUniversityChangchun130023China
出 版 物:《Journal of Environmental Sciences》 (环境科学学报(英文版))
年 卷 期:2005年第17卷第1期
页 面:30-36页
核心收录:
学科分类:083001[工学-环境科学] 0830[工学-环境科学与工程(可授工学、理学、农学学位)] 08[工学] 0815[工学-水利工程]
基 金:SubjectConstructionofDoctoralDegreebytheMinistryofEducationofP.R.China(No.20020183056)
主 题:iron oxides manganese oxides Pb and Cd adsorption natural water
摘 要:Metal oxides(Fe, Mn oxides) in natural surface coatings(biofilms and associated minerals) are believed to play a significant role in the fate and transport of trace metal in aquatic environments. Seasonal variation of Fe, Mn oxides and organic materials in surface coatings, which were developed periodically on glass slides in Nanhu Lake, Jilin Province, China over the time frame of three seasons, was investigated in order to understand the influence of metal oxides on Pb and Cd adsorption to heterogeneous surface coating materials(biofilm). Pb and Cd adsorption was measured under controlled laboratory conditions(mineral salts solution with defined speciation, ionic strength 0 05 mol/L, 25℃ and pH 6 0). The classical Langmuir adsorption isotherm was applied to estimate equilibrium coefficients of Pb and Cd adsorption to the surface coatings. In general, components in the surface coatings varied greatly with seasons altering and obtained higher concentrations in summer while the content of iron oxides always exceeded that of manganese oxides. Correlation analyses between the maximum adsorption of Pb and Cd and components in the surface coatings developed periodically indicated that Pb phase association with Mn oxides and Cd phase association with Fe oxides as well as Mn oxides were statistically significant. Effect of Mn oxides on Cd adsorption was confirmed in view of its higher content in the surface coatings. The importance of ferromanganese oxides for Pb and Cd adsorption to the natural surface coatings developed in different seasons was evidenced.