磁性微碳球改性材料修复Pb污染土壤的影响因素与作用机理OA

Pb(Ⅱ)is a toxic heavy metal identified as a class one carcinogen by the World Health Organization's International Agency for Research on Cancer(WHO/IARC).How to remove Pb from soil is an important issue in soil pollution remediation.In this paper,magnetic ceramsite supported microcarbon spheres were prepared by hydrothermal synthesis and modified by polyethylene glycol(MCCSPG)for remediation of soil Pb pollution.This functional material,MCCSPG,was used for soil Pb remediation.The results showed that MCCSPG had a good adsorption and removal effect on soil Pb,with a total Pb average removal rate of 94.11% and effective Pb removal rate of 95%.Among the factors affecting the soil Pb removal rate,the amount of material added,the duration of exposure,and the initial Pb content in the soil were positively correlated with the removal rate before reaching adsorption equilibrium.The soil Pb removal rate was highest at a pH of 4.9,indicating that the material had maximum adsorption capacity at this pH value which is 48 mg/g.There is not only chemical adsorption but also a considerable amount of physical adsorption of Pb in soil by MCCSPG.The adsorption process accords with Freundlich isothermal adsorption and quasi-first-order kinetic model.The rising stage of adsorption lasts for a long time and the starting point of adsorption capacity is low.It takes more than 12 days for materials to be put into soil to adsorb Pb to reach the maximum adsorption capacity.