多聚物吸附纳米零价铁在多孔介质中的迁移

针对纳米零价铁在多孔介质中的迁移特点，本文通过实验室柱实验和腐蚀实验分析了不同聚丙烯酸（PAA）包覆浓度下的纳米零价铁（nZVI）在石英砂介质中的迁移和其接触不同电解质溶液6h的反应活性.利用迁移距离和穿出率，表征了不同纳米铁材料的迁移性能.应用pH值、氧化还原电位（ORP）、Fe²⁺浓度、X射线衍射（XRD）和Fe⁰含量随时间变化图像表征纳米零价铁腐蚀程度.实验结果表明，PAA显著提高了纳米零价铁材料的迁移距离.10%聚丙烯酸包覆浓度下，实验室合成纳米零价铁的迁移效果最佳，穿出率可达58.65%.在6h的腐蚀实验中，10%聚丙烯酸包覆的零价铁含量有一定的降低，但是零价铁损失相对于20% PAA包覆的零价铁少.综合考虑迁移性和反应活性，10% PAA包覆浓度下实验室合成纳米零价铁是适用于地下水污染原位修复的最佳材料.

Transport of PAA modified nanoscale zero-valent iron in water saturated porous media

To investigate the transport capability of nZVI in porous media, laboratory experiments including column and corrosion studies were conducted to investigate the transport capability of nanoscale zero-valent iron (nZVI) coated by different concentrations of polyacrylic acid (PAA) in quartz-sand filled porous medium and to observe their activity change after 6 hours' exposure to different electrolyte solutions. Utilizing transport distance and penetration rate, the transport performance of different iron materials in porous sandy media was characterized. The corrosion rate of nZVI in electrolyte solution was characterized by pH, ORP, Fe²⁺ concentration, XRD and Fe⁰ content changing curves with time. PAA adsorption on nZVI surface effectively improved transport performance of nZVI, but the corrosion raised by the PAA adsorption had been observed. Laboratory synthesized nanoscale zero-valent iron coated by 10% PAA presented the best performance in column test, with the penetration rate of 58.65% and Fe⁰ content moderately lost after 6 hours corrosion in electrolyte solution, which was less than the sample with 20% PAA adsorbed. Considering both the mobility in porous media and the reserved reactivity after aging for the nZVI with PAA modified, this study concludes that laboratory synthesized nZVI coated by 10% PAA is preferred for in-situ groundwater contamination remediation.