水环境中微塑料对重金属的吸附及其影响因素

Review on the adsorption of heavy metals with microplastics in water environment and its influencing factors

微塑料(microplastics,MPs)其自身是一种新兴污染物,且还可作为载体吸附重金属等其它污染物,对生态环境造成威胁.本文以Web of Science核心数据库及Science Direct数据库作为数据源,搜集了2016—2022年间发表的有关微塑料对重金属吸附的文献,分析了不同环境条件下微塑料对重金属的吸附及其影响影响因素,还比较了室内实验结果与实际环境的差异.结果表明,不同微塑料对重金属吸附量不同,其差异主要与微塑料官能团、结构,重金属水合离子半径等因素有关.其中,聚苯乙烯(polystyrene,PS)较其它微塑料更易吸附重金属,而铅(Pb)则更易被微塑料吸附.另外,微塑料老化程度、粒径大小以及盐度、pH值等因素也都会影响微塑料对重金属吸附.研究还发现,真实水环境中微塑料对重金属的吸附量总体上小于室内实验结果,也就是说,室内实验往往高估了微塑料对重金属的吸附.

Microplastics(MPs)are an emerging pollutant that can be used as a vector to adsorb and transport heavy metals and other pollutants,posing a threat to the environment.In this paper,the core database of Web of Science and Science Direct database were used as data sources to collect the literature on the adsorption of heavy metals with MPs published from 2016 to 2022,and analyze the metal adsorption of MPs and the influencing factors.The difference between the lab experiments and the actual environment was also studied.The results showed that the difference of metal adsorption capacity for various MPs was mainly related to the functional groups,crystallinity,and the radius of heavy metal hydration ions.Polystyrene(PS)can adsorb more heavy metals than the other MPs,and lead(Pb)can be adsorbed more easily by MPs.In addition,the aging degree and particle size of MPs,and the pH and salinity of environmental conditions may also greatly affect the metal adsorption of MPs.It was also observed that the metal adsorption capacity of MPs in real water environment was smaller than the results from lab experiments.This means that lab experiments may often overestimate the metal adsorption capacity of MPs.