Ji Yantian, Xu Duo, Bai Shuangyun, Du Bowen, Chen Hongyang, Wang Tiecheng, Yin Xianqiang
College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi, 712100, PR China.
College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi, 712100, PR China; Key Laboratory of Plant Nutrition and the Agri-environment in Northwest China, Ministry of Agriculture and Rural Affairs, Yangling, Shaanxi, 712100, PR China.
Environ Pollut. 2025 Sep 15;381:126600. doi: 10.1016/j.envpol.2025.126600. Epub 2025 Jun 4.
Discharge plasma is gaining increasing attention in environmental science due to its advanced oxidative properties. While discharge plasma is capable of degrading most of the pollutants in contaminated water, it is not effective in degrading the accompanying microplastics (MPs). Notably, residual MPs in plasma-treated water may become carriers of other pollutants in the environment. The adsorption and co-transport behaviors of two MPs with Cd(II), before and after Dielectric Barrier Discharge (DBD) plasma treatment, were examined via batch and column experiments. The results showed that plasma-treated MPs exhibited significantly enhanced adsorption capacity for Cd(II), attributed to grafted polar functional groups on their surfaces. Density Functional Theory (DFT) calculations revealed that the enhancement resulted from reduced steric hindrance, along with stronger hydrogen bonding and van der Waals interactions. Co-transport experiments revealed that plasma treatment significantly promoted the carrier role of MPs in facilitating Cd(II) transport. Specifically, plasma-treated MPs mitigated Cd(II) deposition at the column base under favorable conditions for transport. Derjaguin-Landau-Verwey-Overbeek (DLVO) theory provided a satisfactory explanation for the observed transport behaviors of plasma-treated MPs and Cd(II). These findings highlight the potential environmental risks posed by plasma-treated MPs as carriers of Cd(II) and the need for further studies on their long-term ecological impacts.
由于其先进的氧化特性，放电等离子体在环境科学中越来越受到关注。虽然放电等离子体能够降解受污染水中的大部分污染物，但它在降解伴随的微塑料（MPs）方面并不有效。值得注意的是，经等离子体处理的水中残留的 MPs 可能会成为环境中其他污染物的载体。通过批次实验和柱实验研究了两种 MPs 在介质阻挡放电（DBD）等离子体处理前后与 Cd(II) 的吸附和共迁移行为。结果表明，经等离子体处理的 MPs 对 Cd(II) 的吸附能力显著增强，这归因于其表面接枝的极性官能团。密度泛函理论（DFT）计算表明，这种增强是由于空间位阻减小，以及更强的氢键和范德华相互作用。共迁移实验表明，等离子体处理显著促进了 MPs 在促进 Cd(II) 迁移方面的载体作用。具体而言，在有利于迁移的条件下，经等离子体处理的 MPs 减轻了 Cd(II) 在柱底部的沉积。Derjaguin-Landau-Verwey-Overbeek（DLVO）理论对经等离子体处理的 MPs 和 Cd(II) 所观察到的迁移行为提供了令人满意的解释。这些发现突出了经等离子体处理的 MPs 作为 Cd(II) 载体所带来的潜在环境风险，以及对其长期生态影响进行进一步研究的必要性。
