Contamination caused by non-aqueous phase liquids (NAPLs) in aquifers and soil is an important challenge that requires effective remediation techniques. One potential approach is through the use of CO₂ foams to displace NAPLs from permeable media. CO₂ foams generated only by surfactants are not stable enough for the efficient removal of NAPLs contamination. This shortcoming may be alleviated via the use of nanoparticles (NPs)-surfactant mixtures as a stabilizing agent. This work focuses on the evaluation of the optimum concentration of fly ash nanoparticles for stabilizing CO₂ foam with the combined action of the surfactant. The performance of this foam is evaluated in remediating a contaminated 41 mm × 36 mm surrogate permeable medium in a microfluidic device. Mixtures of fly ash, a by-product of coal-burning power plants, and alpha-olefin sulfonate (AOS) and lauramidopropyl betaine (LAPB) surfactants are used to generate stable foams. The results show that a 1000 mg/L AOS-LAPB surfactant solution along with 1000 mg/L of fly ash NPs produces the best performance. Formation of deposits in the matrix is observed. These deposits, which are more prominent at higher NP concentrations, appear to adversely affect displacement, displacement efficiency and remediation of the medium. This study demonstrates that using fly ash nanoparticles and optimizing their concentration can effectively stabilize CO₂ foams and improve the displacement efficiency for aquifer and soil remediation.

含水层和土壤中的非水相液体 (NAPL) 造成的污染是一项重要的挑战，需要有效的修复技术。一种可能的方法是通过使用 CO ₂泡沫从可渗透介质中置换 NAPL。仅由表面活性剂产生的CO ₂泡沫不够稳定，无法有效去除 NAPL 污染。可以通过使用纳米颗粒 (NPs)-表面活性剂混合物作为稳定剂来缓解这一缺点。这项工作的重点是评估用于稳定 CO _{2 的}粉煤灰纳米粒子的最佳浓度在表面活性剂的联合作用下产生泡沫。这种泡沫的性能在修复微流体装置中受污染的 41 mm × 36 mm 替代渗透介质时进行了评估。飞灰（燃煤发电厂的副产品）、α-烯烃磺酸盐 (AOS) 和月桂酰胺丙基的混合物甜菜碱 (LAPB) 表面活性剂用于产生稳定的泡沫。结果表明，1000 mg/L AOS-LAPB 表面活性剂溶液和 1000 mg/L 飞灰 NPs 产生最佳性能。观察到在基质中形成沉积物。这些沉积物在 NP 浓度较高时更为突出，似乎对介质的置换、置换效率和修复产生不利影响。本研究表明，使用飞灰纳米粒子并优化其浓度可以有效地稳定 CO ₂泡沫并提高含水层​​和土壤修复的置换效率。