Insight into interactions of polystyrene microplastics with different types and compositions of dissolved organic matter
Insight into interactions of polystyrene microplastics with different types and compositions of dissolved organic matter
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DOI：
10.1016/j.scitotenv.2022.153883
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发表时间：
2022-02-21
影响因子：
9.8
通讯作者：
Guo, Xuetao
中科院分区：
文献类型：
--
作者：
Ding, Ling;Luo, Yuanyuan;Guo, Xuetao
微塑料（MP）作为一种新兴污染物，进入环境后可能与环境中广泛存在的溶解性有机物（DOM）发生相互作用，从而影响MP的迁移转化。DOM与MPs相互作用的特点和机理受到多种因素的制约，目前的作用机制尚不清楚。因此，我们探索了MP与不同类型和组成的DOM（富里酸（FA）和胡敏酸（HA））的组合。吸附实验表明，MP对所有四种DOM都有很高的吸附亲和力，特别是FA。同时，利用激发-发射矩阵（EEM）分析和荧光猝灭法（EEM-PARAFAC）对MP-DOM的亲和性进行了研究。所有DOM样品中芳香族物质和疏水性物质占主导地位。对于所有测试的DOM类型，猝灭曲线随DOM的类型和组成而变化很大。此外，三种荧光组分随时间推移表现出显著的荧光淬灭。利用二维傅里叶变换红外（FTIR）相关光谱（COS）分析进一步从分子水平上阐明了MP与DOM的相互作用机理，发现MP中的含氧官能团是DOM最优先的结合结构.本研究旨在探索自然条件下多金属颗粒物的环境行为和次生多金属颗粒物的形成。
Microplastics (MPs), as newly emerging pollutants, may interact with dissolved organic matter (DOM) widely present in the environment after entering the environment, thereby influencing the migration and transformation of MPs. The interaction characteristics and mechanism between DOM and MPs are restricted by many factors, and the current mechanism remains unclear. Thus, we explored the combination of MP with different types and compositions of DOM (fulvic acid (FA) and humic acid (HA)). Adsorption experiments revealed that MP has high adsorption affinity for all four DOMs, particularly FA. Meanwhile, the affinity of MP-DOM was also examined using excitation- emission matrix (EEM) analyses and fluorescence quenching method (excitation emission matrix-parallel factor analysis (EEM-PARAFAC)). Aromatic substances and hydrophobic substances dominate all DOM samples. For all DOM types tested, the quenching curve varies considerably with the type and compositions of DOM. In addition, three fluo-rescent components exhibited significant fluorescence quenching over time. The interaction mechanism of MPs and DOM at the molecular level was further elucidated by utilizing two-dimensional (2D) Fourier transformation infrared (FTIR) correlation spectroscopy (COS) analysis, which revealed that the oxygen-containing functional group in MPs was the most preferred DOM binding structure. This work was facilitated to explore the environmental behavior of MPs and formation of secondary MPs under natural conditions.