School of Civil & Environmental Engineering, Hollister Hall, Cornell University, Ithaca, NY 14853, USA.
Water Res. 2010 Feb;44(4):1028-37. doi: 10.1016/j.watres.2009.03.033. Epub 2009 Apr 1.
A one-dimensional model has been evaluated for transport of hydrophobic contaminants, such as polycyclic aromatic hydrocarbon (PAH) compounds, facilitated by synthetic amphiphilic polyurethane (APU) nanoparticles in porous media. APU particles synthesized from poly(ethylene glycol)-modified urethane acrylate (PMUA) precursor chains have been shown to enhance the desorption rate and mobility of phenanthrene (PHEN) in soil. A reversible process governed by attachment and detachment rates was considered to describe the PMUA binding in soil in addition to PMUA transport through advection and dispersion. Ultimately, an irreversible second-order PMUA attachment rate in which the fractional soil saturation capacity with PMUA was a rate control was found to be adequate to describe the retention of PMUA particles. A gamma-distributed site model (GS) was used to describe the spectrum of physical/chemical constraints for PHEN transfer from solid to aqueous phases. Instantaneous equilibrium was assumed for PMUA-PHEN interactions. The coupled model for PMUA and PHEN behavior successfully described the enhanced elution profile of PHEN by PMUA. Sensitivity analysis was performed to analyze the significance of model parameters on model predictions. The adjustable parameter alpha in the gamma-distribution shapes the contaminant desorption distribution profile as well as elution and breakthrough curves. Model simulations show the use of PMUA can be also expected to improve the release rate of PHEN in soils with higher organic carbon content. The percentage removal of PHEN mass over time is shown to be influenced by the concentration of PMUA added and this information can be used to optimize cost and time require to accomplish a desired remediation goal.
已经评估了一种一维模型，用于在多孔介质中通过合成两亲性聚氨酯 (APU) 纳米粒子来传输疏水性污染物，如多环芳烃 (PAH) 化合物。已经表明，由聚乙二醇改性的异氰酸酯丙烯酸酯 (PMUA) 前体链合成的 APU 颗粒可以提高土壤中菲 (PHEN) 的解吸速率和迁移率。考虑到吸附和解吸速率控制的可逆过程来描述 PMUA 在土壤中的结合，除了 PMUA 通过平流和弥散的运输。最终，发现不可逆的二阶 PMUA 附着速率足以描述 PMUA 颗粒的保留，其中 PMUA 与土壤的分数饱和度是速率控制的。伽马分布位点模型 (GS) 用于描述 PHEN 从固相向水相转移的物理/化学约束谱。假设 PMUA-PHEN 相互作用是瞬时平衡的。PMUA 和 PHEN 行为的耦合模型成功地描述了 PMUA 增强 PHEN 的洗脱轮廓。进行了敏感性分析以分析模型参数对模型预测的重要性。伽马分布中的可调参数 alpha 形状了污染物解吸分布轮廓以及洗脱和突破曲线。模型模拟表明，PMUA 的使用也有望提高高有机碳含量土壤中 PHEN 的释放速率。随着时间的推移，PHEN 质量的去除百分比受添加的 PMUA 浓度的影响，这些信息可用于优化成本和时间，以达到预期的修复目标。
