老化微塑料吸附重金属镉及其毒性效应  

Impact of ageing microplastics on heavy metal cadmium adsorption and its combined toxicity effect

作　　者：王沛恒 王树楠 王贝贝 赵世博 刘世亮[1] 赵颖[1] 滕应[2] WANG Peiheng;WANG Shunan;WANG Beibei;ZHAO Shibo;LIU Shiliang;ZHAO Ying;TENG Ying(College of Resources and Environment,Henan Agricultural University,Zhengzhou,450002,China;Key Laboratory of Soil Environment and Pollution Remediation,Institute of Soil Science,Chinese Academy of Sciences,Nanjing,210008,China)

机构地区：[1]河南农业大学资源与环境学院,郑州450002 [2]中国科学院南京土壤研究所,土壤环境与污染修复重点实验室,南京210008

出　　处：《环境化学》2023年第6期1803-1812,共10页Environmental Chemistry

基　　金：河南省自然科学基金(222300420191);国家自然科学基金(42207023);河南农业大学拔尖人才项目资助.

摘　　要：微塑料广泛存在于各种环境介质中,且能够作为载体影响其他污染物环境行为.本文主要探究了不同老化程度的微塑料PE和PP对重金属镉(Cd)的吸附特性及生物毒性.结果表明,微塑料颗粒随老化程度的增加其对Cd的吸附能力逐渐增强.通过模型拟合发现,初始微塑料和老化微塑料对重金属Cd的吸附动力学符合准二级模型,热力学符合Freundlich吸附模型.实验结果表明,微塑料吸附Cd的量与环境pH值及微塑料浓度密切相关.随pH值升高,由于微塑料表面的去质子化作用Cd的吸附量逐渐增加.然而,随着微塑料浓度升高,微塑料颗粒表面吸附位点的竞争作用则导致Cd吸附量的降低.微塑料吸附Cd后其复合污染的生物毒性有所增加,二者的复合生物毒性与微塑料老化程度、Cd吸附量正相关,存在明显的协同效应.本研究为充分认识微塑料及老化微塑料在环境中的行为作用提供理论依据,为准确评估微塑料与其他污染物复合污染的生态风险提供参考.Microplastics widely exist in various environment,which can be served as a carrier to affect the environmental behavior of other pollutants.In the present study,the cadmium adsorption characteristics on different aged microplastics PE and PP were explored,and the combined biological toxicity were also investigated using Photobacterium phosphoreum T3.The adsorption capacity of Cd increased with the aging degree of microplastics increases.And the sorption kinetics was in accord with the pseudo second-order rate equation the thermodynamics was in accord with the Freundlich sorption model.In addition,the results showed that the adsorption of Cd by microplastics was strongly associated with the environmental pH and concentration of microplastics.The adsorption of Cd is positively associated with pH value,which should be attribute to the deprotonation on the surface of microplastics.On the contrary,the adsorption amount of Cd decreased with the concentration of microplastics increases,due to the competition of adsorption sites on the surface of microplastics.The toxicity of microplastics adsorbed by Cd was also determined using Photobacterium phosphoreum T3.The result showed that the biological toxicity of microplastics combined with Cd is positively associated with the ageing degree and the amount of Cd adsorbed,which indicated that there was a synergy between microplastics and cadmium.The present study provides a scientific reference for accurately assessing the ecological risk of microplastics combined with other pollutants.

关 键 词：微塑料 镉 环境行为 生物毒性 

分 类 号：X505[环境科学与工程—环境工程] X171.5