不同植被土壤对重金属Pb的吸附及其模拟

Characteristics of Pb Adsorption of different land uses soils from wetland

采集湿地四种不同覆被类型土壤(光滩、互花米草、芦苇以及水杉人工林),对比研究其对Pb 的吸附特征并进行模型模拟。结果表明,四种覆被土壤对Pb的吸附量大小为芦苇>互花米草>光滩>水杉。在0~800mg·kg^(-1)范围内,四种覆被土壤对Pb的最大吸附量依次为22304mg·kg^(-1)、16780mg·kg^(-1)、15020mg·kg^(-1)和7250mg·kg^(-1);四种覆被土壤对Pb的等温吸附曲线最优拟合模型是Langmuir模型;拟合结果显示,芦苇、互花米草覆被土壤对Pb 的吸附能力大于水杉覆被土壤,亲和力则均低于水杉覆被土壤。

This experiment mainly studied the adsorption characteristics of Pb adsorption of four land use soils (mud flat,Phragmites auatralis,Spartina alterniflora,Metasequoia?glyptostroboides) from Chongming dongtan wetland.The isothermal adsorption was simulated by using Langmuir,Freundlich,Temkin models.The results showed:The order of Pb adsorption capacity in four soils is Phragmites auatralis > spartina alterniflora > mud flat > Metasequoia?glyptostroboides.In the range 0~800mg·kg^(-1)Pb,the maximum adsorption amount of the four soils was in order 22304mg·kg^(-1),16780mg·kg^(-1),15020mg·kg^(-1)and 7250mg·kg^(-1).The optimal isothermal model for Pb adsorption was Langmuir model.The adsorption capacities of the soils with Phragmites auatralis and spartina alterniflora were greater than that of Phragmites auatralis.The parameters 1/n indicated that the affinity of soils under the Phragmites auatralis and the spartina alterniflora covering was lower than that of soil with Metasequoia?glyptostroboides plantation.