泡沫去除含水层硝基苯微观过程及其稳定化机理

Microscopic-process of foam removing nitrobenzene from aquifer and its stabilization mechanism

为了研究泡沫在地层多孔介质中的微观渗流行为、去除污染物的过程和机理,以及纳米SiO_2颗粒对泡沫稳定性能的影响,制作了真实砂岩微观模型并利用硬脂酸钠对纳米SiO_2颗粒进行了改性以稳定泡沫.结果表明,泡沫在多孔介质中的生成、破灭和运移是同时发生的,其生成方式与注入气流速度有关,破灭与气体扩散有关,运移则是以大部分被孔道所捕集而少部分以气泡链的形式进行;泡沫去除污染物硝基苯的方式包括乳化增溶、剥离携带和封堵作用,其中封堵作用是主要方式;疏水改性的纳米SiO_2颗粒对泡沫的稳定性有极大的提升,添加的纳米颗粒浓度越大,稳定性越强;纳米SiO_2颗粒稳定的泡沫在模拟中迁移时仍具有较强的稳定性,随着泡沫注入体积的增大,注入压力及阻力因子增大,封堵效应增强.

In order to study the microscopic percolation of foam, the process and mechanism of removing organic solvents, and the effect of nano-silica particles on the foam properties in the porous media, sandstone micromodel was made and nano-silica particles was modified with sodium stearate. The results showed that the formation, breakdown and migration of foam in porous media were simultaneous. The formation was related to the velocity of injection flow, the breakdown was related to the gas diffusion;A small portion of foam was carried out in the form of a bubble chain while most foam was trapped by pore. The removal of pollutants included emulsification, foam stripping and plugging, and plugging was the main way. Modified nano-silica particles can improve the stability of foam obviously, and there was a positive correlation between concentration and stability. The foam stabled by nano-silica particles still has strong stability when the foam was migrated in the simulation column. With the increase of the foam injection volume, the injection pressure and resistance factor increased, and the blocking effect is enhanced.