微塑料富集金属铅元素的能力与特征分析

以微塑料为载体,考察了其对溶液中铅离子的富集能力。首先利用2%HNO_3为解吸溶液,并用超声波仪进行辅助解吸,然后用电感耦合等离子体质谱仪(ICP-MS)测定其吸附的铅含量,从而研究微塑料吸附铅离子的能力。对微塑料的材质、吸附时间、粒径、离子浓度、选择性以及共存离子等进行了考察,分析了微塑料吸附铅离子的特征。实验结果表明:不同材质的微塑料对铅离子的吸附能力不同,其中聚氯乙烯(PVC)、聚丙烯(PP)吸附量最高,分别达到1.32μg/g和0.63μg/g。微塑料粒径越大,其对铅离子的吸附量越低。随着吸附时间和铅离子浓度的增加,微塑料对铅离子的吸附效率出现先升后降的趋势。共存离子实验表明,当溶液中存在其他离子时,不同材质的微塑料对铅离子的吸附能力受到不同程度的影响,当铅离子和铜离子共存时,2种离子存在竞争性吸附现象。该文探索了微塑料对铅离子的吸附特性,可为深入研究海洋中微塑料富集重金属及其环境行为提供理论基础。

Analysis on Ability and Characteristics of Microplastics to Enrich Metal Lead

With microplastics as the vector,the enriching capability of microplastics towards lead ions was studied.Firstly,the lead ions absorbed on microplastics were desorbed with 2％ nitric acid by ultrasound,and then the lead content was determined by inductively coupled plasma mass spectrometry (ICP-MS) to investigate the adsorption ability.In the present study,the microplastics material,adsorption time,particle size,ion concentration,method selectivity and coexisting ions were investigated to analyze the adsorption characteristics of lead on microplastics.The results showed that different materials of microplastics had different adsorption abilities to lead.Polyvinyl chloride (PVC) and polypropylene (PP) had the best adsorption abilities among all the tested materials,with adsorbances of 1.32 μg/g and 0.63 μg/g,respectively.The adsorbance of microplastics to lead reduced with the increase of the particle size.With the increase of the adsorption time and lead ion concentration,the adsorption efficiency of microplastics to lead increased first and then decreased.The results of coexisting ions experiments indicated that adsorption capacities of different microplastics were influenced by the coexisting ions.There was a competitive adsorption phenomenon when copper and lead coexisted.In this study,the adsorption characteristics of microplastics to lead ion were studied,which could provide a theoretical basis for the further research on enrichment of microplastics to the heavy metals and their environmental behavior in marine environment.