乳化纳米铁浆液在含水层中的迁移特征研究

Transport characteristics of emulsified nanoscale-zero-valent-iron in saturated porous media

本文主要研究地下水修复试剂乳化纳米铁(EZVI)在含水层中的迁移特性和影响因素.一维模拟柱实验考察EZVI的穿透曲线和模拟柱中分布情况.结果表明:乳化植物油对纳米铁的改性显著提高了纳米铁在含水层中的迁移能力,EZVI的迁移距离为未改性纳米铁的2~3倍;EZVI中的乳化植物油会随水流迁移,分别形成纳米铁反应带和植物油反应带;岩性对迁移的影响表现为介质粒径越大,越有利于EZVI的迁移,且EZVI在粗砂中的迁移能力是细砂的1.9倍;注入速率通过影响纳米铁迁移到含水层介质表面的几率影响迁移行为,注入速率越大,迁移距离越长;共存离子对乳化纳米铁的迁移性能影响不大,会引起微量的铁的损失.最佳迁移效果的条件是3cm/min的注入速度,2g/L的注入浓度.

The scope of this research is to investigate the transport characteristics and influencing factors of remedial agent-emulsified nanoscale-zero-valent-iron（EZVI）. One-dimensional column experiments were conducted to obtain breakthrough curves and substrate distribution of EZVI, and results indicated that： the modification of NZVI by emulsified oil improved the transportability of NZVI, and the migration distance of EZVI was 2~3 times increased compared with that of NZVI. The excess of emulsified oil in EZVI suspension transported down-gradient with groundwater flow, forming two reaction zones with NZVI and emulsified oil, respectively. Larger size of the sand grain facilitated the transport of EZVI, and the migration distance in coarse sand was about 1.9 times longer than that in the fine sand. The injection velocity affected the transport by controlling single collector efficiency, and higher collection probability was achieved by higher injection velocity. The co-existing ions have little effect on the EZVI transport ability. When the injection velocity of EZVI was 3 cm/min, and the slurry concentration was 2 g/L, the transport showed best performance.