Key Lab of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130021, China; National and Local Joint Engineering Laboratory for Petrochemical Contaminated Site Control and Remediation Technology, Jilin University, 2519 Jiefang Road, Changchun 130021, China.
Key Lab of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130021, China; National and Local Joint Engineering Laboratory for Petrochemical Contaminated Site Control and Remediation Technology, Jilin University, 2519 Jiefang Road, Changchun 130021, China; Department of Chemical Sciences, Topfaith University, Mkpatak, Nigeria.
J Hazard Mater. 2022 Jun 15;432:128641. doi: 10.1016/j.jhazmat.2022.128641. Epub 2022 Mar 8.
Colloidal biliquid aphron (CBLA) is a strong density modifier for dense nonaqueous phase liquids (DNAPLs). However, the underlying mechanisms responsible for density modification and displacement is not yet clear. Here, a series of batch column and sandbox experiments were conducted to achieve substantial removal and irreversible density reduction of tetrachloroethylene (PCE). The mass of PCE retained in the column and sandbox was less than 1% under suitable injection conditions, and the density of PCE in the effluent was less than that of water (fluctuated in the range of 0.74-0.96 g/cm). The displacement process was controlled by the high viscosity ratio of CBLA to PCE (52.3). The emulsified and dissolved phase of PCE formed after reaction with CBLA, and the light nonaqueous phase liquid (LNAPL) phase formed after injecting demulsifier solution. The phase analysis played a significant role in monitoring the changes in concentration and density of PCE. The density-modification displacement technique using CBLA reduced the mass of residual PCE by a factor of 165 compared to surfactant flushing, and there was no risk of downward migration of PCE. This study contributes to a better remediation of entrapped DNAPL in contaminated aquifer.
胶状双液相共体（CBLA）是一种强密度调节剂，可用于调节高浓度非水相液体（DNAPL）的密度。然而，其调节密度和驱替的潜在机制尚不清楚。本研究通过一系列批柱和沙箱实验，实现了四氯乙烯（PCE）的大量去除和不可逆的密度降低。在合适的注入条件下，柱和沙箱中保留的 PCE 质量小于 1%，且流出物中 PCE 的密度小于水（波动范围为 0.74-0.96 g/cm3）。驱替过程受 CBLA 与 PCE 之间高粘度比（52.3）的控制。反应后形成的 PCE 的乳化相和溶解相，以及注入破乳剂溶液后形成的轻质非水相液体（LNAPL）相。相分析在监测 PCE 的浓度和密度变化方面发挥了重要作用。与表面活性剂冲洗相比，使用 CBLA 的密度改性驱替技术将残留 PCE 的质量降低了 165 倍，而且不存在 PCE 向下迁移的风险。本研究有助于更好地修复受污染含水层中夹带的 DNAPL。
