Institute of Chemical Technology and Engineering, Poznan University of Technology, Berdychowo 4, 60-965, Poznan, Poland.
Department of Molecular Environmental Biotechnology, Helmholtz Centre for Environmental Research - UFZ, Permoserstraße 15, 04318, Leipzig, Germany.
Appl Microbiol Biotechnol. 2024 Nov 26;108(1):523. doi: 10.1007/s00253-024-13353-6.
Recently, there has been significant focus on microplastics in the environment, especially regarding their role in sorption-desorption processes of emerging contaminants, impacting pollutant migration between aquatic and terrestrial ecosystems. Notably, the newest pollutants in such environments are the herbicide formulations known as ionic liquids (ILs), which integrate the structure of classic herbicidal anion with surface-active cations acting as an adjuvant. In our study, we synthesized herbicidal ILs by combining 2,4-D anion with cetyltrimethylammonium [CTA] and didecyldimethylammonium [DDA] cations. We investigated whether ILs and the mixture of salts, when exposed to polyethylene (PE) microplastics, differ in properties. We analyzed their sorption on defined PE particles, evaluated toxicity on Pseudomonas putida KT2440 using trans/cis ratio of unsaturated fatty acids, and assessed biodegradability with OECD 301F standard test. Results indicate IL cations and anions behave as distinct entities, questioning IL synthesis feasibility. Hydrophobic adjuvants were found to adsorb onto PE microplastic surfaces (5-60% [CTA] > [DDA]), posing potential threats of surface-active xenobiotic accumulation. This highlights the need to explore microplastics' role as sorbents of hazardous adjuvants in agriculture, potentially competing with humic acids and affecting xenobiotic bioavailability. Consequently, xenobiotics may persist longer in the environment, facilitated by microplastic mobility between aquatic and terrestrial ecosystems. KEY POINTS: • Microplastics act as sorbents, accumulating xenobiotics and limiting biodegradation. • Sorption of surfactant cations on microplastics reduces soil bacteria toxicity. • Research confirms independent action of ions from ionic liquids in the environment.
最近，环境中微塑料引起了广泛关注，特别是其在新兴污染物的吸附-解吸过程中的作用，影响了水生态系统和陆地生态系统之间污染物的迁移。值得注意的是，这些环境中的最新污染物是被称为离子液体（ILs）的除草剂配方，它将经典除草剂阴离子的结构与作为助剂的表面活性剂阳离子结合在一起。在我们的研究中，我们通过将 2,4-D 阴离子与十六烷基三甲基铵 [CTA] 和双十烷基二甲基铵 [DDA] 阳离子结合来合成除草离子液体。我们研究了 ILs 与盐混合物在暴露于聚乙烯（PE）微塑料时的性质是否不同。我们分析了它们在确定的 PE 颗粒上的吸附情况，使用不饱和脂肪酸的反式/顺式比评估了对 Pseudomonas putida KT2440 的毒性，并用 OECD 301F 标准测试评估了生物降解性。结果表明，IL 阳离子和阴离子表现为不同的实体，质疑 IL 合成的可行性。疏水性助剂被发现吸附在 PE 微塑料表面上（5-60% [CTA]>>[DDA]），这可能会导致表面活性的外来化合物积累的潜在威胁。这凸显了需要探索微塑料作为农业中危险助剂的吸附剂的作用，这可能会与腐殖酸竞争并影响外来化合物的生物可用性。因此，微塑料的流动性可能会使环境中的外来化合物更持久，从而在水生态系统和陆地生态系统之间迁移。关键点：• 微塑料作为吸附剂，积累外来化合物并限制生物降解。• 表面活性剂阳离子在微塑料上的吸附降低了土壤中细菌的毒性。• 研究证实了离子液体中的离子在环境中的独立作用。
