School of Water and Environment, Chang'an University, No. 126 Yanta Road, Xi'an, 710054, Shaanxi, China; Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region of the Ministry of Education, Chang'an University, No. 126 Yanta Road, Xi'an, 710054, Shaanxi, China.
School of Water and Environment, Chang'an University, No. 126 Yanta Road, Xi'an, 710054, Shaanxi, China; Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region of the Ministry of Education, Chang'an University, No. 126 Yanta Road, Xi'an, 710054, Shaanxi, China.
Chemosphere. 2022 Aug;301:134789. doi: 10.1016/j.chemosphere.2022.134789. Epub 2022 Apr 30.
Microplastics (MPs) are one of the emerging classes of pollutants that can be infiltrated into any aqueous solutions from disposed toxic metals and antibiotics, further exacerbating the potential biotoxicity of MPs. However, the research on the interaction between MPs and various pollutants is limited. Therefore, in this study, the changes in toxicity of polybutylece terephthalate (PBT) MPs were assessed following adsorption of heavy metals and antibiotics. The adsorption behavior of Cd(II) and tetracycline (TC) on ultraviolet (UV) light-aged PBT was investigated. The results demonstrated that the Cd(II) adsorption behavior could be described by the pseudo-second-order kinetic and Langmuir isothermal models, while the TC adsorption behavior has well fitted using Elovich and Sips models. The whole adsorption process occurred via either external diffusion or internal diffusion. The interactions between aged PBT and pollutants were evaluated under different environmental conditions, such as solution pH and the concentrations of dissolved organic matter and cations. The amounts of Cd(II) and TC adsorbed were higher in the competitive systems than the single solution, which might attribute to the formation of Cd(II)-TC complexes and aged PBT functional group changes. The results of two-dimensional correlation spectroscopy (2D-COS) describes the sequence of functional group transformation during the uptake of Cd(II)-TC by aged PBT in binary systems. These findings identify a strong interaction between aged PBT and contaminants, establishing the potential fate of aged MPs under natural aquatic environment conditions.
微塑料（MPs）是新兴污染物的一类，可以从处置的有毒金属和抗生素中渗透到任何水溶液中，进一步加剧 MPs 的潜在生物毒性。然而，关于 MPs 与各种污染物相互作用的研究有限。因此，在这项研究中，评估了重金属和抗生素吸附后聚对苯二甲酸丁二醇酯（PBT） MPs 毒性的变化。研究了紫外（UV）光老化 PBT 对 Cd(II)和四环素（TC）的吸附行为。结果表明，Cd(II)的吸附行为可以用伪二阶动力学和 Langmuir 等温模型来描述，而 TC 的吸附行为则可以用 Elovich 和 Sips 模型很好地拟合。整个吸附过程通过外部扩散或内部扩散发生。在不同的环境条件下，如溶液 pH 值、溶解有机物和阳离子浓度，评估了老化 PBT 与污染物之间的相互作用。在竞争体系中，Cd(II)和 TC 的吸附量高于单一体系，这可能归因于 Cd(II)-TC 配合物的形成和老化 PBT 功能基团的变化。二维相关光谱（2D-COS）的结果描述了在二元体系中，老化 PBT 吸收 Cd(II)-TC 时功能基团转化的顺序。这些发现表明老化 PBT 与污染物之间存在强烈的相互作用，确定了老化 MPs 在自然水生态环境条件下的潜在命运。
