University of Houston, Houston, TX, USA.
University of Houston, Houston, TX, USA.
J Contam Hydrol. 2020 Mar;230:103602. doi: 10.1016/j.jconhyd.2020.103602. Epub 2020 Jan 14.
Non-aqueous phase liquid (NAPL) remediation techniques using surfactants, such as enhanced pump and treat (also known as Surfactant-Enhanced Aquifer Remediation, "SEAR") and micellar flooding provide a faster and more efficient way to recover NAPL from the subsurface. Micellar flooding is a recovery technique that relies on the ability of surfactants to mobilize the NAPL phase by reducing the interfacial tension between the aqueous phase and the NAPL. The application of micellar flooding for NAPL recovery has been limited to laboratory studies and some pilot-scale field applications primarily due to concerns that the technology might lead to uncontrolled movement of NAPL. This paper presents results from a full-scale field application of the micellar flood process designed to mobilize and recover an LNAPL (Jet fuel) from a surficial sandy aquifer located at a tank facility in western Jutland, Denmark. Phase behavior and flow experiments were conducted with field samples to identify suitable surfactant formulations. A field-scale simulation model was developed that indicated that a line-drive pattern with hydraulic control wells would be optimal for NAPL recovery. In addition to monitoring during the field implementation, monitoring was conducted immediately after and for a period of >1 year. The field implementation resulted in >90% recovery (approximately 36,000 Kg of LNAPL) based on the mass balance using laser-induced fluorescence (LIF) and chemical soil analysis (total petroleum hydrocarbon or TPH and BTEX) data. Post-surfactant flood site monitoring consisted of sampling water from multi-levels and from recovery wells. Groundwater samples were analyzed for total petroleum hydrocarbon (TPH) and benzene, toluene, ethylbenzene and xylene (BTEX). The pre-treatment and post-treatment mass discharges were also monitored, which led to a relationship between mass discharge with the mass reduction in the source zone. Also, the mass discharge Γ-model commonly used for DNAPL modeling was successfully implemented for LNAPL remediation. Studies of field applications of surfactant remediation processes are not readily available; it is especially rare to present a study of micellar flooding implementation for full-scale remediation processes.
非水相液体 (NAPL) 的修复技术采用表面活性剂，例如强化抽提（也称为表面活性剂强化含水层修复，“SEAR”）和胶束驱油，为从地下环境中回收 NAPL 提供了更快、更有效的方法。胶束驱油是一种回收技术，它依赖于表面活性剂通过降低水相与 NAPL 之间的界面张力来使 NAPL 相迁移的能力。胶束驱油在 NAPL 回收中的应用仅限于实验室研究和一些小规模的现场应用，主要是因为担心该技术可能导致 NAPL 的不受控制的迁移。本文介绍了在丹麦日德兰半岛西部一个罐区的地表砂质含水层中，为了使轻非水相液体（Jet 燃料）迁移和回收而进行的胶束驱油全过程现场应用的结果。通过现场样本进行了相态和流动实验，以确定合适的表面活性剂配方。开发了一个现场尺度的模拟模型，该模型表明，采用水力控制井的线状驱替模式将是 NAPL 回收的最佳模式。除了在现场实施过程中进行监测外，还在实施后立即进行了监测，并持续了>1 年。根据使用激光诱导荧光 (LIF) 和化学土壤分析（总石油烃或 TPH 和 BTEX）数据的质量平衡，现场实施实现了>90%的回收（约 36000kg 的 LNAPL）。在使用胶束驱油后的场地监测中，从多个层次和回收井中抽取水样。地下水样本用于分析总石油烃（TPH）和苯、甲苯、乙苯和二甲苯（BTEX）。还监测了预处理和后处理的质量排放量，这导致了质量排放量与源区质量减少之间的关系。此外，成功地实施了常用于 DNAPL 建模的质量排放 Γ 模型，用于 LNAPL 修复。表面活性剂修复过程的现场应用研究并不容易获得；特别是很少有关于胶束驱油在全规模修复过程中的应用的研究。
