Polystyrene Nanoplastics-Enhanced Contaminant Transport: Role of Irreversible Adsorption in Glassy Polymeric Domain
Polystyrene Nanoplastics-Enhanced Contaminant Transport: Role of Irreversible Adsorption in Glassy Polymeric Domain
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DOI：
10.1021/acs.est.7b05211
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发表时间：
2018-03-06
影响因子：
11.4
通讯作者：
Chen, Wei
中科院分区：
文献类型：
--
作者：
Liu, Jin;Ma, Yini;Chen, Wei
纳米塑料（NPs）正在成为全球关注的新兴污染物。一个潜在的风险是，纳米颗粒可能作为载体，增加共存污染物的传播。在这项研究中，我们研究了聚苯乙烯纳米塑料（PSNPs，100 nm），作为一个模型NP，对五种不同极性的有机污染物在饱和土壤中的迁移的影响。低浓度的PSNPs的存在显著增强了非极性（芘）和弱极性（2，2 '，4，4'-四溴二苯醚）化合物的转运，但对三种极性化合物（双酚A，双酚F和4-壬基苯酚）的转运基本上没有影响。NP对非极性/弱极性与极性污染物的运输的显着不同的影响不能用不同的吸附亲和力来解释，但与解吸滞后的极性依赖程度是一致的。值得注意的是，仅观察到非极性/弱极性污染物的解吸滞后，这可能是因为非极性化合物倾向于吸附在聚苯乙烯的玻璃状聚合物结构的内部基质中（导致吸附物的物理截留），而极性化合物有利于表面吸附。验证了这一假设与补充吸附和解吸实验的芘和4-壬基苯酚使用致密的，玻璃状聚苯乙烯聚合物和一个灵活的，橡胶状聚乙烯聚合物。总体而言，这项研究的结果强调了潜在的重大环境影响的纳米粒子作为污染物载体。
Nanoplastics (NPs) are becoming an emerging pollutant of global concern. A potential risk is that NPs may serve as carriers to increase the spreading of coexisting contaminants. In this study, we examined the effects of polystyrene nanoplastics (PSNPs, 100 nm), used as a model NP, on the transport of five organic contaminants of different polarity in saturated soil. The presence of low concentrations of PSNPs significantly enhanced the transport of nonpolar (pyrene) and weakly polar (2,2',4,4'-tetrabromodiphenyl ether) compounds, but had essentially no effects on the transport of three polar compounds (bisphenol A, bisphenol F, and 4-nonylphenol). The strikingly different effects of NPs on the transport of nonpolar/weakly polar versus polar contaminants could not be explained with different adsorption affinities, but was consistent with the polarity-dependent extents of desorption hysteresis. Notably, desorption hysteresis was only observed for nonpolar/weakly polar contaminants, likely because nonpolar compounds tended to adsorb in the inner matrices of glassy polymeric structure of polystyrene (resulting in physical entrapment of adsorbates), whereas polar compounds favored surface adsorption. This hypothesis was verified with supplemental adsorption and desorption experiments of pyrene and 4-nonylphenol using a dense, glassy polystyrene polymer and a flexible, rubbery polyethylene polymer. Overall, the findings of this study underscore the potentially significant environmental implication of NPs as contaminant carriers.