Sturm Michael T, Schuhen Katrin, Horn Harald
Wasser 3.0 gGmbH, Neufeldstr. 17a-19a, 71687 Karlsruhe, Germany; abcr GmbH, Im Schlehert 10, 76187 Karlsruhe, Germany; Karlsruhe Institute of Technology (KIT), Engler-Bunte-Institut (EBI), Chair of Water Chemistry and Water Technology, Engler-Bunte-Ring 9a, 76131 Karlsruhe, Germany.
Wasser 3.0 gGmbH, Neufeldstr. 17a-19a, 71687 Karlsruhe, Germany.
Sci Total Environ. 2022 Feb 1;806(Pt 4):151388. doi: 10.1016/j.scitotenv.2021.151388. Epub 2021 Nov 2.
Since microplastics were recognized as a global environmental problem in the early 2000s, research began on possible solutions such as the removal of microplastics from waters. A novel and promising approach for this purpose is microplastics agglomeration-fixation using organosilanes. In this study, it is investigated how biofilm coverage of microplastics affects this process. The biofilm was grown on the microplastics by cultivating it for one week in a packed bed column operated with biologically treated municipal wastewater enriched with glucose. The biofilm was characterized using confocal laser scanning microscopy (CLSM), scanning electron microscopy (SEM), and Fourier-Transform infrared spectroscopy (FT-IR). The results show a partial coverage of the microplastics with attached bacteria and extracellular polymeric substances (EPS) after 7 days of incubation. Comparing five polymer types (polyethylene, polypropylene, polyamide, polyester, and polyvinyl chloride) and three organosilanes, the biofilm coverage caused a reduced removal efficiency for all combinations tested as it changes the surface chemistry of the microplastics and therefore the interaction with the organosilanes tested in this study. Treatment of biofilm covered microplastic with ultrasound partly recovers the removal. However, the results underline the importance of simulated environmental exposure when performing experiments for microplastic removal.
自21世纪初微塑料被认定为全球性环境问题以来，针对诸如从水体中去除微塑料等可能的解决方案的研究便已展开。为此，一种新颖且有前景的方法是使用有机硅烷进行微塑料团聚固定。在本研究中，探究了微塑料上生物膜的覆盖情况如何影响这一过程。通过在装有添加了葡萄糖的经生物处理的城市废水的填充床柱中培养一周，使生物膜在微塑料上生长。使用共聚焦激光扫描显微镜（CLSM）、扫描电子显微镜（SEM）和傅里叶变换红外光谱（FT-IR）对生物膜进行表征。结果显示，孵育7天后，微塑料表面部分被附着的细菌和胞外聚合物（EPS）覆盖。比较五种聚合物类型（聚乙烯、聚丙烯、聚酰胺、聚酯和聚氯乙烯）和三种有机硅烷后发现，生物膜覆盖会降低所有测试组合的去除效率，因为它改变了微塑料的表面化学性质，进而改变了与本研究中所测试的有机硅烷的相互作用。用超声波处理覆盖有生物膜的微塑料可部分恢复去除效果。然而，这些结果强调了在进行微塑料去除实验时模拟环境暴露的重要性。
