Wu Jiayan, Liu Jieyu, Wu Pingxiao, Sun Leiye, Chen Meiqing, Shang Zhongbo, Ye Quanyun, Zhu Nengwu
School of Environment and Energy, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou 510006, PR China.
School of Environment and Energy, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou 510006, PR China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou 510006, PR China; Guangdong Provincial Key Laboratory of Solid Wastes Pollution Control and Recycling, Guangzhou 510006, PR China; Guangdong Engineering and Technology Research Center for Environmental Nanomaterials, Guangzhou 510006, PR China.
J Hazard Mater. 2022 Aug 5;435:128964. doi: 10.1016/j.jhazmat.2022.128964. Epub 2022 Apr 28.
The ubiquitous AlO is anticipated to interact with nanoplastics, affecting their fate and transport in aquatic environments. In this study, the heteroaggregation and deposition behaviors of polystyrene nanoplastics (PSNPs) on AlO were systematically investigated under different conditions (ionic strength, pH, and natural organic matter). The results showed that significant heteroaggregation occurred between PSNPs and AlO particles under acidic and neutral conditions. When the NaCl concentration was increased from 50 to 500 mM, the heteroaggregation ratio gradually increased. However, poly (acrylic acid) (PAA) inhibited the heteroaggregation of PSNPs-AlO due to steric repulsion. The deposition of PSNPs on AlO surfaces was inhibited as the NaCl concentration or pH values increased. Due to charge reversal and steric repulsion, humic acid (HA) and fulvic acid (FA) prevented the deposition of PSNPs onto AlO surfaces, and the former was more effective in reducing the deposition rate. The interaction mechanism between PSNPs and AlO was revealed by using various characterization techniques and density function theory (DFT) calculation. The results demonstrated that in addition to the dominant electrostatic interaction, there were also weak hydrogen bonds and van der Waals interactions. Our research is of great significance for predicting the migration and fate of PSNPs in aquatic environments.
普遍存在的氧化铝预计会与纳米塑料相互作用，影响其在水生环境中的归宿和迁移。在本研究中，系统研究了不同条件（离子强度、pH值和天然有机物）下聚苯乙烯纳米塑料（PSNPs）在氧化铝上的异质凝聚和沉积行为。结果表明，在酸性和中性条件下，PSNPs与氧化铝颗粒之间发生了显著的异质凝聚。当NaCl浓度从50 mM增加到500 mM时，异质凝聚率逐渐增加。然而，聚丙烯酸（PAA）由于空间位阻排斥作用抑制了PSNPs-氧化铝的异质凝聚。随着NaCl浓度或pH值的增加，PSNPs在氧化铝表面的沉积受到抑制。由于电荷反转和空间位阻排斥作用，腐殖酸（HA）和富里酸（FA）阻止了PSNPs在氧化铝表面的沉积，且前者在降低沉积速率方面更有效。通过使用各种表征技术和密度泛函理论（DFT）计算揭示了PSNPs与氧化铝之间的相互作用机制。结果表明，除了主要的静电相互作用外，还存在弱氢键和范德华相互作用。我们的研究对于预测PSNPs在水生环境中的迁移和归宿具有重要意义。
