Department of Chemical and Biomolecular Engineering, Tulane University, New Orleans, Louisiana 70118, USA.
Environ Sci Technol. 2009 Nov 15;43(22):8616-21. doi: 10.1021/es901968g.
Effective in situ injection technology for the remediation of dense nonaqueous phase liquids (DNAPLs) such as trichloroethylene (TCE) requires the use of decontamination agents that effectively migrate through the soil media and react efficiently with dissolved TCE and bulk TCE. We describe the use of a novel decontamination system containing highly uniform carbon microspheres in the optimal size range for transport through the soil. The microspheres are enveloped in a polyelectrolyte (carboxymethyl cellulose, CMC) to which a bimetallic nanoparticle system of zero-valent iron and Pd is attached. The carbon serves as a strong adsorbent to TCE, while the bimetallic nanoparticle system provides the reactive component. The polyelectrolyte serves to stabilize the carbon microspheres in aqueous solution. The overall system resembles a colloidal micelle with a hydrophilic shell (polyelectrolyte coating) and hard hydrophobic core (carbon). In contact with bulk TCE, there is a sharp partitioning of the system to the TCE side of the interface due to the hydrophobicity of the core. These multifunctional systems appear to satisfy criteria related to remediation and are made with potentially environmentally benign materials.
有效原位注入技术修复密集非水相液体（DNAPLs）如三氯乙烯（TCE）需要使用去污剂，这些去污剂有效地在土壤介质中迁移并与溶解的 TCE 和总 TCE 有效反应。我们描述了使用一种新型去污系统，该系统含有高度均匀的碳微球，其尺寸最佳，适合在土壤中运输。这些微球被包裹在一种聚电解质（羧甲基纤维素，CMC）中，其中附着有零价铁和 Pd 的双金属纳米粒子系统。碳是 TCE 的强吸附剂，而双金属纳米粒子系统提供了反应性成分。聚电解质用于稳定水溶液中的碳微球。整个系统类似于胶体胶束，具有亲水性外壳（聚电解质涂层）和硬疏水性核心（碳）。与散装 TCE 接触时，由于核心的疏水性，系统会急剧地分配到界面的 TCE 侧。这些多功能系统似乎满足与修复相关的标准，并且由潜在环境友好的材料制成。
