摘要
微塑料可以在水中吸附重金属并作为载体共同迁移,且微塑料会在水中受光照而老化,影响其吸附能力和吸附机制.本研究通过XRD、FTIR、SEM/EDS等分析手段对聚丁二酸丁二醇酯基可降解微塑料(PBS-MPs)进行了表征,探究了光老化过程对PBS-MPs吸附水中Pb(Ⅱ)的影响及其机制.结果表明,光老化能增加PBS-MPs表面亲水性含氧基团及活性吸附位点数量,对Pb(Ⅱ)的最大吸附容量从64.13μg·g^(-1)提升至362.06μg·g^(-1);Pb(Ⅱ)在P-PBS上的吸附符合Elovich动力学模型,吸附机制包括表面络合、静电作用和孔填充/扩散作用.光老化会强化可降解微塑料对水中Pb(Ⅱ)的吸附,从而促进Pb(Ⅱ)的迁移,二者共存可对水环境带来更为严重的生态风险.
Microplastics can adsorb heavy metal ions and act as vectors in water environment.However,photoaging affects the adsorption capacity and adsorption mechanism of microplastics.In this study,the adsorption of Pb(Ⅱ)on the Poly(butylene succinate)derived-microplastics(PBS-MPs)surface before and after photoaging were investigated,and the effect of photoaging was analyzed by X-ray diffraction,Fourier transform infrared spectroscopy and Scanning electron microscope-Energy dispersive spectrometer.The results showed that PBS-MPs gained additional hydrophilic oxygencontaining groups and active adsorption sites in the photoaging process.The maximum adsorption capacity of Pb(Ⅱ)on PBS-MPs increased from 64.13μg·g^(-1) to 362.06μg·g^(-1) after photoaging.Elovich model fitted the best to describe the adsorption behavior of Pb(Ⅱ)on PBS-MPs.The adsorption mechanism included surface complexation,electrostatic interaction and pore filling/diffusion.Overall,photoaging can strengthen the adsorption and migration of heavy metals on the surface of degradable microplastics,resulting in a greater impact on water environment.
作者
杜捷晖
李远
王学江
DU Jiehui;LI Yuan;WANG Xuejiang(College of Environmental Science and Engineering,Tongji University,Shanghai 200092)
出处
《环境科学学报》
CAS
CSCD
北大核心
2023年第7期183-193,共11页
Acta Scientiae Circumstantiae
基金
国家自然科学基金(No.22176149,21976136)。
