The contamination of the subsurface by organic compounds in the form of non-aqueous phase liquids... more The contamination of the subsurface by organic compounds in the form of non-aqueous phase liquids (NAPLs) is among the most challenging environmental problems. Field investigations have shown that due to their low solubility and high interfacial tension, many NAPLs can persist in porous media for decades and even centuries. Among the more promising technologies for NAPL source zone remediation is in-situ cosolvent flushing which involves the injection of chemical agents for the enhanced solubilization and/or mobilization of the NAPL. In this study, we examined the significance of the cosolvent (ethanol) contact time on the DNAPL (Trichloroethylene-TCE) recovery from contaminated groundwater. Batch tests were first conducted to evaluate the operational parameters such as solubility, interfacial tension, and miscibility as a function of cosolvent content. Flushing experiments were performed using a two-dimensional tank (in the vertical plane with L= 80 cm, H=40 cm, and W=5 cm). The ef...
The accidental release of organic contaminants in the form of non-aqueous phase liquids (NAPLs) i... more The accidental release of organic contaminants in the form of non-aqueous phase liquids (NAPLs) is a widespread and challenging environmental problem. Successful remediation of sites contaminated with NAPLs is essential for the protection of human health. An effective remediation method is the injection of chemical additives (cosolvents) together with water upgradient of the NAPL-contaminated area (flushing). The additives alter the physio-chemical properties of NAPLs, such as interfacial tension, and enhance their solubilities. Solubilized contaminants are carried downgradient and collected through recovery wells. The goal of the work presented here was the development of a numerical model that simulates accurately the experimental results of a DNAPL (TCE) flushing process using ethanol as a cosolvent. The effect of different ethanol contents (0%, 20% and 50%) on the remediation process were tested and evaluated. Experiments were conducted using a two-dimensional sand box, to allow for the impact of density variations on DNAPL mobility. The experimental results were used to calibrate a multiphase flow model based on a modified version of the UTCHEM simulator that includes an interfacial tension calculation. This IFT method enables UTCHEM to accurately simulate the process of ethanol concentration-dependent interfacial tension lowering.
The contamination of the subsurface by organic compounds in the form of non-aqueous phase liquids... more The contamination of the subsurface by organic compounds in the form of non-aqueous phase liquids (NAPLs) is among the most challenging environmental problems. Field investigations have shown that due to their low solubility and high interfacial tension, many NAPLs can persist in porous media for decades and even centuries. Among the more promising technologies for NAPL source zone remediation is in-situ cosolvent flushing which involves the injection of chemical agents for the enhanced solubilization and/or mobilization of the NAPL. In this study, we examined the significance of the cosolvent (ethanol) contact time on the DNAPL (Trichloroethylene-TCE) recovery from contaminated groundwater. Batch tests were first conducted to evaluate the operational parameters such as solubility, interfacial tension, and miscibility as a function of cosolvent content. Flushing experiments were performed using a two-dimensional tank (in the vertical plane with L= 80 cm, H=40 cm, and W=5 cm). The ef...
The accidental release of organic contaminants in the form of non-aqueous phase liquids (NAPLs) i... more The accidental release of organic contaminants in the form of non-aqueous phase liquids (NAPLs) is a widespread and challenging environmental problem. Successful remediation of sites contaminated with NAPLs is essential for the protection of human health. An effective remediation method is the injection of chemical additives (cosolvents) together with water upgradient of the NAPL-contaminated area (flushing). The additives alter the physio-chemical properties of NAPLs, such as interfacial tension, and enhance their solubilities. Solubilized contaminants are carried downgradient and collected through recovery wells. The goal of the work presented here was the development of a numerical model that simulates accurately the experimental results of a DNAPL (TCE) flushing process using ethanol as a cosolvent. The effect of different ethanol contents (0%, 20% and 50%) on the remediation process were tested and evaluated. Experiments were conducted using a two-dimensional sand box, to allow for the impact of density variations on DNAPL mobility. The experimental results were used to calibrate a multiphase flow model based on a modified version of the UTCHEM simulator that includes an interfacial tension calculation. This IFT method enables UTCHEM to accurately simulate the process of ethanol concentration-dependent interfacial tension lowering.
Uploads
Papers by Derya AYDIN