Department of Civil & Environmental Engineering, Washington State University, Pullman, WA 99164, USA.
Department of Civil & Environmental Engineering, Washington State University, Pullman, WA 99164, USA.
Water Res. 2021 Jun 1;197:117066. doi: 10.1016/j.watres.2021.117066. Epub 2021 Mar 17.
Interactions of nanoscale plastics with natural organic matter (NOM) and silica surfaces were investigated using a quartz crystal microbalance with dissipation monitoring (QCM-D). Polyethylene and polystyrene are the most used plastic polymers and most likely to accumulate in the environment, and thus their nano-scale interactions were investigated in this study. Deposition and release of polyethylene and polystyrene nanoscale plastics were investigated on silica and NOM-coated surfaces in the presence of different salt types (NaCl, CaCl, MgCl) and ionic strengths (IS). Polyethylene nanoscale plastics showed negligible deposition on silica surface, while significant deposition of polystyrene nanoscale plastics was observed on silica surface. However, both polyethylene and polystyrene nanoscale plastics showed significant deposition on NOM-coated surfaces, with polystyrene showing higher deposition. Increased IS resulted in greater deposition of both polyethylene and polystyrene nanoscale plastics on NOM-coated surfaces due to the functional groups, following DLVO theory. Deposited polyethylene nanoscale plastics on NOM-coated surfaces can be remobilized whereas deposition of polystyrene nanoscale plastics was irreversible on both silica and NOM-coated surfaces. Overall, higher deposition of nanoscale plastics on NOM-coated surfaces indicates that fate and mobility of nanoscale plastics in the environment will be significantly governed by their interactions with NOM.
采用石英晶体微天平（QCM-D）结合耗散监测技术，研究了纳米级塑料与天然有机物（NOM）和二氧化硅表面的相互作用。聚乙烯和聚苯乙烯是应用最广泛的塑料聚合物，极有可能在环境中积累，因此本研究对其纳米级相互作用进行了研究。在不同盐类（NaCl、CaCl、MgCl）和离子强度（IS）存在的情况下，研究了纳米级聚乙烯和聚苯乙烯塑料在二氧化硅和 NOM 涂层表面上的沉积和释放。纳米级聚乙烯塑料在二氧化硅表面上几乎没有沉积，而纳米级聚苯乙烯塑料在二氧化硅表面上则有明显的沉积。然而，纳米级聚乙烯和聚苯乙烯塑料都在 NOM 涂层表面上有明显的沉积，且聚苯乙烯的沉积量更高。根据 DLVO 理论，由于官能团的存在，增加 IS 会导致更多的纳米级聚乙烯和聚苯乙烯塑料在 NOM 涂层表面上的沉积。沉积在 NOM 涂层表面上的纳米级聚乙烯塑料可以被再移动，而纳米级聚苯乙烯塑料在二氧化硅和 NOM 涂层表面上的沉积则是不可逆的。总的来说，纳米级塑料在 NOM 涂层表面上的更高沉积表明，纳米级塑料在环境中的命运和迁移将受到其与 NOM 相互作用的显著影响。
