Grantee Research Project Results
1998 Progress Report: Hydrodynamic Mixing Effects on Macro- and Micro-Emulsification of Nonaqueous Phase Liquids into Water
EPA Grant Number: R826158Title: Hydrodynamic Mixing Effects on Macro- and Micro-Emulsification of Nonaqueous Phase Liquids into Water
Investigators: Jafvert, Chad T. , Hondzo, Midhat , Lyn, Dennis A.
Institution: Purdue University , Purdue Research Foundation
Current Institution: Purdue University
EPA Project Officer: Aja, Hayley
Project Period: January 16, 1998 through January 15, 2000
Project Period Covered by this Report: January 16, 1998 through January 15,1999
Project Amount: $206,335
RFA: Exploratory Research - Physics (1997) RFA Text | Recipients Lists
Research Category: Water , Land and Waste Management , Air , Safer Chemicals
Objective:
The primary objective of this study is to investigate the dynamics of NAPL emulsification in well-defined flow systems.
Progress Summary:
The first stage of this project consists of determining the dependence of the interfacial tension (IFT) of water-nonaqueous phase liquid (NAPL) systems on the change in the liquid properties. These properties are the concentration of the surface-active agent (surfactant), cosurfactant, and NaCl (for ionic strength control). To date, interfacial tensions between water and three nonaqueous phase liquids have been determined with and without these other additives. The NAPLs are tetrachloroethylene (TCE), as a dense nonaqueous phase liquid (DNAPL), and toluene and octane, as two light nonaqueous phase liquids (LNAPLs). Experiments have been performed with two surfactants: sodium dodecylsulfate (NaDS) and Aerosol OT (AOT). As cosurfactants, butanol and Tween 20 have been employed. To determine the IFT dependence on each of the additives, experiments were conducted at fixed concentrations of all but one additive at varying concentrations of one substance and keeping the concentration of the two others constant. Interfacial tensions were measured with a DuNouy ring tensiometer for values greater than 5 dynes/cm. For values less than 5 dynes/cm, a Temco model 510 spinning drop tensiometer, purchased for this project, was employed. These experiments are continuing.
In the second stage of this project, we are examining how mixing effects interfacial stability. For these studies, both the annular reactor and an oscillating grid reactor have been constructed. Initial experiments with both reactors have been performed.
Project Changes: Because funding of this project initiated in mid-January, it was too late to recruit students for the spring semester, delaying actual work for almost one semester. One student was hired early on, but left the project after 4 months. Two students were hired in August 1998 and have remained on the project since that time. Another student was hired over this past summer to facilitate project completion. An important change is that one of the PIs (Midhat Hondzo) has permanently left Purdue, joining the faculty of the University of Minnesota. He will continue to be involved in the project while at Minnesota; however, there are no plans to transfer funds to Minnesota for his involvement. He will continue to participate on the students graduate examination committees. In addition, there was approximately a 6-month delay in acquisition of the spinning drop tensiometer after it was ordered from Temco. This delay was unexpected. During this time, the reactors were designed and constructed and initial experiments with the ring tensiometer were performed. These events have delayed task completion and expenditure of funds, and we anticipate that additional time beyond December 31 will be required to complete all tasks (without any request for additional funds).
Future Activities:
In the final year of the grant we will complete the planned research and prepare manuscripts to publish the results.
Journal Articles:
No journal articles submitted with this report: View all 2 publications for this projectSupplemental Keywords:
interfacial tension, surfactants, mixing, emulsion, LNAPL, DNAPL, toluene, TCE., Scientific Discipline, Toxics, Water, Physics, Environmental Chemistry, HAPS, Engineering, Chemistry, & Physics, Environmental Engineering, environmental monitoring, fate and transport, microemulsion kinetics, contaminant transport, hydrodynamic stability theory, chemical composition, chemical detection techniques, chemical transport modeling, interfacial phenomena, Trichloroethylene, chemical kinetics, environmental contaminants, fluid properties, NAPLs, solventsProgress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.