以黏土模拟低渗透包气带环境,探究了混溶流体在包气带中的迁移规律。实验结果表明：混溶流体在横向和垂向的最大迁移距离与流体泄漏量均符合幂函数变化规律y=ax^b。随着流体注入体积的增加,横向和垂向迁移距离不断增大,迁移速率逐渐减小。文章提出以横纵比作为反映流体在包气带中迁移变化规律的重要指标。横纵比总体呈下降趋势,具体分为两个阶段：流体注入体积为0-3 046 m L时,横纵比呈先上升后稳定的趋势,横纵比大于1。此阶段流体以横向发育为主,污染羽剖面呈扁平状椭圆;当流体注入体积大于3 046 m L,横纵比逐渐减小到1以下并持续减小。此阶段流体以垂向发育为主,污染羽剖面逐渐转变为竖直长条状椭圆。
Sucrose-modified nanoscale zero-valent iron（SM-NZVI） was prepared with liquid phase reducing method, and characterized by transmission electron microscopy（TEM） and X-ray diffraction（XRD） for the shape and structure The size of SM-NZVI particles was about 100--150 nm and they displayed better dispersity. The degradation of ni- trobenzene（NB） in water by SM-NZVI was carried out in batch experiments. The results indicate that the efficiency of NB reduction via SM-NZVI increased by 44.24% compared with that via NZV, I, and coexistent Ca2＋, Mg2＋, HCO3- and other ions showed little effect on NB reduction but negative influence on aniline（AN） production. Furthermore, the kinetic researches indicate that NB reduction with SM-NZVI could be described by pseudo first-order kinetic model at different initial pH values and iron dosage. The oxidation products of iron were mainly Fe304 and Fe203 with irregular shape.
LI HuiZHAO Yong-shengZHAO RanMA Bai-wenCHEN Zi-fangSU YanZHOU Rui
