Institute of Marine Science and Technology, Shandong University, Qingdao 266237, PR China.
Institute of Marine Science and Technology, Shandong University, Qingdao 266237, PR China.
Environ Pollut. 2020 Jul;262:114347. doi: 10.1016/j.envpol.2020.114347. Epub 2020 Mar 7.
Microplastics have attracted much attention in recent years as they can interact with pollutants in water environment. However, nanoplastics (NPs) with or without the surface functionalization modification have not been thoroughly explored. Here, the sorption behaviors of two fluoroquinolones (FQs), including norfloxacin (NOR) and levofloxacin (LEV) on polystyrene NPs (nano-PS) and carboxyl-functionalized polystyrene NPs (nano-PS-COOH) were investigated. The results showed that sorption isotherms were nonlinear and well fitted by Langmuir model. The sorption capacities of NOR and LEV on nano-PS-COOH were higher than those on nano-PS, and their physical interactions, including polar interaction, electrostatic interaction and hydrogen bonding may be the dominant mechanisms. Moreover, the increase of pH firstly increased the sorption of two FQs on NPs and then decreased because NOR and LEV had a reverse charge at different pH values. Salinity and dissolved organic matter both inhibited the sorption process. These findings show that NPs with or without the surface functionalization modification have different sorption behaviors for environmental pollutants, which deserve our further concern.
近年来，由于微塑料能够与水环境中的污染物相互作用，因此受到了广泛关注。然而，带有或不带表面功能化修饰的纳米塑料（NPs）尚未得到彻底研究。在这里，研究了两种氟喹诺酮类药物（FQs），包括诺氟沙星（NOR）和左氧氟沙星（LEV）在聚苯乙烯 NPs（纳米-PS）和羧基功能化聚苯乙烯 NPs（纳米-PS-COOH）上的吸附行为。结果表明，吸附等温线是非线性的，并用朗缪尔模型很好地拟合。NOR 和 LEV 在纳米-PS-COOH 上的吸附容量高于在纳米-PS 上的吸附容量，其物理相互作用，包括极性相互作用、静电相互作用和氢键可能是主要机制。此外，pH 值的增加首先增加了两种 FQs 在 NPs 上的吸附，然后降低，因为 NOR 和 LEV 在不同 pH 值下带相反的电荷。盐度和溶解有机物都抑制了吸附过程。这些发现表明，带有或不带表面功能化修饰的 NPs 对环境污染物具有不同的吸附行为，值得我们进一步关注。
