National Engineering Laboratory for Efficient Utilization of Soil and Fertilizer Resources, College of Resources and Environment, Shandong Agricultural University, Tai'an, 271018, China.
Environ Sci Pollut Res Int. 2021 Jun;28(23):29900-29907. doi: 10.1007/s11356-021-12780-6. Epub 2021 Feb 11.
Carbon nanotubes (CNTs) are widely used and may pose potential environmental risks to soil and groundwater systems. Therefore, it is important to improve current understanding of the fate and transport of CNTs in porous media. In this study, the transport behavior of multi-walled carbon nanotubes (MWCNTs) with different surface modifications were examined in water-saturated sand columns under different pH (5 and 7) and ionic strength (0.1, 1, and 5 mM) conditions. COOH-MWCNTs have the strongest mobility among the five types of MWCNTs, followed by pristine MWCNTs. NH-MWCNTs, Cu-MWCNTs, and Fe-MWCNTs have the weaker mobility. The transport of five types of MWCNTs decreased with the increase of ionic strength, while increased with the increase of pH value. The results suggested that the transport of MWCNTs can be affected by the electrostatic attraction between the functional groups on the surface of MWCNTs and quartz sand. Moreover, the pH and ionic strength of the solution also played an important role in enhancing the transport of MWCNTs, which have great significance for evaluating the transport and fate of MWCNTs in natural environment.
碳纳米管（CNTs）被广泛应用，可能对土壤和地下水系统构成潜在的环境风险。因此，提高对 CNTs 在多孔介质中迁移和转化的认识非常重要。本研究在不同 pH 值（5 和 7）和离子强度（0.1、1 和 5 mM）条件下，采用饱和砂柱实验，研究了不同表面修饰的多壁碳纳米管（MWCNTs）在水中的迁移行为。在这五种 MWCNTs 中，COOH-MWCNTs 的迁移能力最强，其次是原始 MWCNTs。NH-MWCNTs、Cu-MWCNTs 和 Fe-MWCNTs 的迁移能力较弱。五种 MWCNTs 的迁移能力随离子强度的增加而降低，随 pH 值的增加而增加。结果表明，MWCNTs 的迁移可以受到 MWCNTs 表面官能团与石英砂之间静电吸引的影响。此外，溶液的 pH 值和离子强度对增强 MWCNTs 的迁移也起着重要作用，这对评估 MWCNTs 在自然环境中的迁移和归宿具有重要意义。
