CAS Key Laboratory of Urban Pollutants Conversion, Department of Chemistry, University of Science and Technology of China, Hefei 230026, China.
CAS Key Laboratory of Urban Pollutants Conversion, Department of Chemistry, University of Science and Technology of China, Hefei 230026, China.
Environ Res. 2018 Oct;166:377-383. doi: 10.1016/j.envres.2018.06.034. Epub 2018 Jun 20.
Concerns regarding the release of microplastics (MPs) into the environment led us to explore the relationship between the different environmental factors and physicochemical properties of MPs, as well as the change of interaction between MPs and organic pollutants. In this study, the effects of environmental factors (ageing conditions), such as pH, temperature, ionic strength, ageing time, and humic acid (HA) concentration, on the characteristics of MPs and their adsorption toward tetracycline (TC) were systematically investigated. The results showed that ageing factors such as pH, ionic strength, and temperature were found to have little impact on the adsorptive capacity of MPs for TC. However, MPs aged in HA solution exhibited a significant decreased adsorptive capacity for TC. HA, which has numerous functional groups, can cover the surface of MPs and change their hydrophobicity, thereby reducing the adsorption affinity to TC. The electrostatic repulsion between adsorbed HA and TC molecules may also decrease the adsorption of TC. In addition, the competing effect of HA for adsorption sites on the surface of MPs further reduces the adsorption of TC. The data presented in this work provide useful information for understanding the transfer of antibiotics by aged MPs, which is of fundamental importance to assess the environmental impact of MPs.
对微塑料 (MPs) 释放到环境中所产生的担忧促使我们探索不同环境因素与 MPs 的物理化学特性之间的关系，以及 MPs 与有机污染物之间相互作用的变化。在这项研究中，我们系统地研究了环境因素（老化条件），如 pH 值、温度、离子强度、老化时间和腐殖酸 (HA) 浓度，对 MPs 特性及其对四环素 (TC) 的吸附能力的影响。结果表明，老化因素如 pH 值、离子强度和温度对 MPs 对 TC 的吸附能力影响不大。然而，在 HA 溶液中老化的 MPs 对 TC 的吸附能力显著降低。HA 具有许多功能基团，可以覆盖 MPs 的表面并改变其疏水性，从而降低对 TC 的吸附亲和力。吸附的 HA 和 TC 分子之间的静电排斥也可能降低 TC 的吸附。此外，HA 对 MPs 表面吸附位的竞争效应进一步降低了 TC 的吸附。本工作提供的数据为了解老化 MPs 传递抗生素的情况提供了有用的信息，这对于评估 MPs 的环境影响至关重要。
