Department of Chemistry, Aarhus University, DK-8000 Aarhus C, Denmark.
Environ Sci Process Impacts. 2024 Jul 17;26(7):1216-1226. doi: 10.1039/d4em00124a.
Micro- and nanoplastic particles have been detected in most environmental compartments. The presence of microplastics in the remote marine atmosphere and close to large lakes suggests bubble mediated water-air transfer as a source of airborne microplastics, however, quantitative estimates of plastic emission from surface waters remain uncertain. In this work, we elucidate the emission of submicron polystyrene nanospheres by bubble bursting in a laboratory setting from low salinity waters (salinity 0-1.0 g kg), polystyrene particle diameter (103, 147 and 269 nm), aqueous particle number concentrations in the range 4 × 10-2 × 10 cm, and bubble formation rate (0.88-3.35 L min of air). Production of polystyrene aerosols was demonstrated using a scanning mobility particle sizer and confirmed by analysis of filter samples using pyrolysis gas chromatography coupled to mass spectrometry. We show that production of polystyrene aerosol particles scales linearly with the number concentration of plastic particles in the water. Our results suggest that small amounts (0.01 g kg) of salt increase polystyrene particle production. To the best of our knowledge this is the first study of bubble mediated water-air transfer of plastic particles as small as 100 nm.
微塑料和纳米塑料颗粒已在大多数环境介质中被检测到。微塑料在偏远的海洋大气中和大型湖泊附近的存在表明，气泡介导的水-气转移是空气传播微塑料的来源，然而，从地表水中定量估计塑料排放仍然不确定。在这项工作中，我们阐明了在实验室条件下，低盐度水（盐度 0-1.0 g kg）、聚苯乙烯颗粒直径（103、147 和 269nm）、水中颗粒数浓度在 4×10-2×10cm 范围内，以及气泡形成速率（0.88-3.35 L min 的空气）下，通过气泡破裂从低浓度水中排放亚微米聚苯乙烯纳米球。使用扫描迁移率颗粒粒径仪证明了聚苯乙烯气溶胶的产生，并通过对使用热解气相色谱-质谱联用仪分析的过滤样品进行分析得到了证实。我们表明，聚苯乙烯气溶胶颗粒的产生与水中塑料颗粒的数浓度呈线性关系。我们的结果表明，少量（0.01 g kg）的盐会增加聚苯乙烯颗粒的产生。据我们所知，这是首次研究小至 100nm 的塑料颗粒通过气泡介导的水-气转移。
