Impact of Residual NAPL on Water Flow and Heavy Metal Transfer in a Multimodal Grain Size Soil under Saturation Conditions: Implications for Contaminant Mobility

摘要

This paper presents the study of the influence of residual NAPL on the transport of various heavy metals trough a mixed contaminated soil under saturation conditions. The concepts of soil structure, preferential flow, heavy metal transfer: retention and transport and multiphase hydrodynamics are investigated for various conditions. Residual NAPL causes water to bypass regions it occupies towards regions having less flow resistance, hence creating preferential flow and transport. Residual NAPL can also obstruct small pore entries and mask active surface sites. Thus, it can influence heavy metal net transfer. Our results show that mobility of heavy metals is altered by the presence of NAPL. This behavior has important implications from both contamination assessment and remediation perspectives.