Real world soil-NAPL wettability: Tools for site assessment and implications for site remediation

点击翻译按钮获取中文摘要

Federal, provincial and municipal governments as well as industry have a vested interest in cleaning up our brownfield sites (abandoned properties with soil and groundwater contamination). Many of these sites are prime real estate sites located in high density areas. Cleaning up these sites not only protects the environment but will generate significant revenues for all stakeholders involved. Many of these sites are impacted by non-aqueous phase liquids (NAPLs) such as gasoline, oil, heating fuel, industrial solvents, coal tars, etc. In predicting the movement and distribution of these NAPLs below the ground surface and in developing remediation strategies for these sites, researchers and engineers often assume that water preferentially wets subsurface soils and NAPL is the non-wetting fluid. The wettability of soils impacts the mobility and distribution of NAPL in the subsurface, which in turn impacts the effectiveness of remediation technologies employed for site remediation. In the environmental remediation field, many researchers and practitioners have failed to address the fact that many of these soils may be or become partially wetting to the NAPL, which significantly impacts the NAPL distribution at the pore scale and the effectiveness of different remediation technologies. The focus of this study is to develop a better understanding of the mobility and distribution of NAPL in intermediate-wet and NAPL-wet soils and to propose remediation strategies that are more appropriate for NAPL-impacted brownfield sites with intermediate-wet and NAPL-wet soils. Canada is home to anestimated 30,000 brownfield sites, many of which exhibit contamination of soil and groundwater due to the disposal or release of NAPLs. Restoration of these sites provides significant economic, environmental and social benefits to Canada. In addition, the development of remediation strategies for NAPL-impacted sites, while recognizing that a fraction of the subsurface soils may be NAPL-wet, will allow Canadian consulting firms, and specifically our industry partners, to continue to lead and expand internationally in the site remediation field.