摘要
为克服纳米级零价铁(nanoscale zero-valent iron,NZVI)在地下环境中易团聚及基于水溶液迁移的重力流和优先流等不足,利用批次和模拟柱实验探讨NZVI在水、十二烷基硫酸钠(SDS)溶液以及泡沫3种媒介输送作用下在包气带中的迁移特性,并研究SDS质量分数对包气带中NZVI迁移的影响。研究结果表明:当SDS质量分数一定时,泡沫质量随着搅拌转速增大而增加;搅拌速度越大,泡沫中NZVI的质量浓度越大,但随着泡沫质量的增加和离心作用增强,NZVI在泡沫的分布越不均匀;理论值为2.8 g/L的纳米零价铁对泡沫的稳定性影响不大。SDS溶液作为输送媒介时,SDS质量分数对纳米铁在介质中迁移促进作用能力强弱依次为0.25%,0.20%,0.50%,1.00%。当SDS泡沫作为输送媒介,SDS质量分数为0.25%时,NZVI在介质中的迁移性最强,其次是SDS质量分数为0.20%与0.50%,1.00%的迁移性最弱。
Laboratory experiments including batch and column studies were conducted to overcome the aggregation of nanoscale zero valent iron （NZVI） and the intrinsic problems, such as preferential flow and gravity flow. The feasibility using water, surfactant foam and solution to deliver NZVI in unsaturated porous media was investigated and further study explored the impact of SDS concentrations on the transport of NZVI in porous media. The results show that the foams quality and ability to carry NZVI improve with the increase of the stirring speed of agitator. However, the distribution of NZVI in foams gradually becomes non-uniform with the increase of NZVI mass concentration. The presence of NZVI does not reduce foam stability. The total exiting rate of NZVI content is in the following order （from big to small）： 0.25%, 0.20%, 0.50%, 1.00% and the transport ability of NZVI in porous media at different SDS concentrations also follows the order above. However, the abilities of acceleration of NZVI transport by SDS foams are significantly different under various SDS concentrations. SDS concentration 0.25% is the best vaIue, followed by 0.20% and 0.50% and 1.00% is the worst value to accelerate NZVI transport in porous media.
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2015年第4期1569-1576,共8页
Journal of Central South University:Science and Technology
基金
国家自然科学基金资助项目(41302183)
国家博士后科学基金资助项目(2013M530987)
吉林大学研究生创新基金资助项目(2014097)~~
关键词
强化
纳米零价铁
迁移
包气带
enhancement
nanoscale zero-valent iron
delivery
vadose zone
