State Key Laboratory of Pollution Control and Resource Reuse, Ministry of Education Key Laboratory of Yangtze River Water Environment, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China; Shanghai Institute of Pollution Control and Ecological Security, International Joint Research Center for Sustainable Urban Water System, Shanghai, 200092, PR China.
State Key Laboratory of Pollution Control and Resource Reuse, Ministry of Education Key Laboratory of Yangtze River Water Environment, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China; Shanghai Institute of Pollution Control and Ecological Security, International Joint Research Center for Sustainable Urban Water System, Shanghai, 200092, PR China.
Water Res. 2019 Jan 1;148:469-478. doi: 10.1016/j.watres.2018.10.071. Epub 2018 Oct 30.
Nanoplastics (NPs) have been identified as newly emerging particulate contaminants. In marine environments, the interaction between NPs and other engineered nanoparticles remains unknown. This study investigated the cotransport of NPs with fullerene (C) in seawater-saturated columns packed with natural sand as affected by the mass concentration ratio of NPs/C and the hydrochemical characteristics. In seawater with 35 practical salinity units (PSU), NPs could remarkably enhance C dispersion with a NPs/C ratio of 1. NPs behaved as a vehicle to facilitate C transport by decreasing colloidal ζ-potential and forming stable primary heteroaggregates. As the NPs/C ratio decreased to 1/3, NPs mobility was progressively restrained because of the formation of large secondary aggregates. When the ratio continuously decreased to 1/10, the stability and transport of colloids were governed by C rather than NPs. Under this condition, the transport trend of binary suspensions was similar to that of single C suspension, which was characterized by a ripening phenomenon. Seawater salinity is another key factor affecting the stability and associated transport of NPs and C. In seawater with 3.5 PSU, NPs and C (1:1) in binary suspension exhibited colloidal dispersion, which was driven by a high-energy barrier. Thus, the profiles of the cotransport and retention of NPs/C resembled those of single NPs suspension. This work demonstrated that the cotransport of NPs/C strongly depended on their mass concentration ratios and seawater salinity.
纳米塑料（NPs）已被确定为新出现的颗粒状污染物。在海洋环境中，NPs 与其他工程纳米颗粒之间的相互作用尚不清楚。本研究考察了在天然砂填充的海水饱和柱中，纳米塑料/富勒烯（C）的共输运行为，研究了纳米塑料/C 质量浓度比和水化学特性的影响。在 35 个实用盐度单位（PSU）的海水中，纳米塑料可以显著增强 C 的分散性，纳米塑料/C 比为 1。纳米塑料通过降低胶体 ζ 电位并形成稳定的初级异质聚集体，充当载体促进 C 的传输。当纳米塑料/C 比降低至 1/3 时，由于形成大的次级聚集体，纳米塑料的迁移性逐渐受到限制。当比例继续降低至 1/10 时，胶体的稳定性和传输受 C 而不是 NPs 控制。在这种情况下，二元悬浮液的传输趋势与单一 C 悬浮液相似，表现为成熟现象。海水盐度是另一个影响 NPs 和 C 的稳定性及其相关传输的关键因素。在 3.5 PSU 的海水中，纳米塑料和 C（1:1）在二元悬浮液中表现出胶体分散，这是由高能量势垒驱动的。因此，NPs/C 的共输运和保留剖面类似于单一 NPs 悬浮液的剖面。这项工作表明，NPs/C 的共输运强烈依赖于它们的质量浓度比和海水盐度。
