Study on the Effect and Mechanism of PE Microplastics on Cadmium Adsorption in Soil
ZHOU Yue
MA Gui
LIAO Caiyun
ZHOU Yanyan
DING Jiafu
Abstract：Microplastics affect the sorption of heavy metals by soils and alter their migration and transformation in soils.In this paper,the changes in the soil adsorption performance of cadmium(Cd)in the presence of polyethylene microplastics(PE-MPs)with different particle sizes(13,48,150 μm)were investigated,to explore the related mechanisms with the help of scanning electron microscopy-X-ray spectroscopy,X-ray diffraction,X-ray photoelectron spectroscopy,and Fourier trans-form infrared spectroscopy.The results showed that the effect of PE-MPs on soil adsorption of Cd2+ was manifested as in-hibiting the adsorption of Cd2+ and promoting the desorption of Cd2+;this effect was more obvious when the dose of PE-MPs was higher or the particle size was larger.Regardless of the presence or absence of PE-MPs,the sorption process of Cd2+ by soil was more consistent with quasi-secondary kinetics and the Freundlich model,indicating that the processes were multilayer sorption controlled mainly by chemisorption.The adsorption mechanism of Cd2+ by soil is mainly surface complex-ation and precipitation.PE-MPs can cover the active sites on the soil surface and interfere with the interaction of Cd2+ with oxygen-containing functional groups in the soil,thus weakening the chemisorption of Cd2+ by soil.It can be seen that PE-MPs can enhance the mobility of Cd in soil and increase the risk of Cd pollution to the soil ecosystem.
Keywords：polyethylene microplasticssoilcadmiumadsorptiondesorption
Publication Date：2023-11-28
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：7( 123-129 )