A higher mass flux from the effected DNAPL migration and distribution patterns by brine flow in saturated porous media

• Published in: Chemical engineering science 2024-08, Vol.295, p.120161, Article 120161
• Main Authors: Cheng, Zhou, Wu, Yuheng, Wu, Ming, Li, Zhaohui, Deng, Yirong, Wu, Jinze, Hao, Yanru, Mo, Cehui, Li, Qusheng, Wu, Jianfeng, Wu, Jichun, Hu, Bill X., Lu, Guoping
• Format: Article
• Language: English
• Subjects: Mass flux; Migration; PCE; Porous media; Saltwater flow
• ISSN: 0009-2509; 1873-4405
• DOI: 10.1016/j.ces.2024.120161

[Display omitted] •The media wettability and interfacial tension of PCE/groundwater were obviously affected by salinity.•Salinity has obvious effects on the migration and distribution of PCE.•The salinity groundwater flow resulted in a greater GTP compared to freshwater flow in the porous media.•The contaminant mass flux of PCE could be promoted by the salinity groundwater flow. This study investigated the influence of groundwater salinity on DNAPL migration and distribution in saturated physically homogeneous and heterogeneous porous media. Interfacial tension (IFT) of PCE/aqueous phase containing NaCl and contact angles through the aqueous phase measured results showed that the contact angle decreased and IFT increased with NaCl concentration, leading to the fact that the wettability of quartz sand can be changed from water-wet to strong water-wet. Three sets of two-dimensional (2-D) sandbox experiments conducted with different salinity showed DNAPL migrated faster in the vertical direction in salinity, yielding decreased residual DNAPL entrapped in the migration path. In addition, the salinity-induced strong water-wet media promoted DNAPL trapping at relatively lower saturation both in the coarse or medium sand, and the volume of PCE entrapped as ganglia increased in the salinity cells. The salinity enhanced the dissolution of PCE from the source zone due to the PCE zone architecture change.