Hydrodynamic Mixing Effects on Macro- and Micro-Emulsification of Nonaqueous Phase Liquids into Water

EPA Grant Number: R826158
Title: 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
EPA Project Officer: Lasat, Mitch
Project Period: January 16, 1998 through January 15, 2000
Project Amount: $206,335
RFA: Exploratory Research - Physics (1997) RFA Text |  Recipients Lists
Research Category: Water , Land and Waste Management , Air , Engineering and Environmental Chemistry

Description:

The kinetics of microemulsion formation are of importance in many practical environmental engineering applications, yet have received relatively little systematic study. The primary objective of this study is to investigate the dynamics of NAPL emulsification in well-defined flow systems, primarily under conditions where microemulsification of oil-in-water occurs, transitioning through hydrodynamic and interfacial conditions where macroemulsification occurs. In these investigations, the following hypothesis will be tested: Interfacial instability leading to microemulsification and rates of emulsification depend not only on fluid properties (e.g. interfacial tension), but also on hydrodynamic mixing conditions.

Approach:

To test this hypothesis, the following specific experimental and theoretical examinations will be conducted: (1) Experimentally characterize interfacial stability as a function of fluid properties and flow parameters; (2) experimentally determine rates of emulsification as a function of fluid properties and flow parameters; and (3) examine the validity of predictions from hydrodynamic stability theory and dimensional reasoning.

Expected Results:

In this study, the rates of micro- and macro- emulsification will be measured under well-controlled mixing conditions with NAPL phases of environmental significance. The rates of formation of different microemulsion phases (single phase vs. middle phase) will be compared under nearly identical mixing regimes. Experimental protocols utilizing both a rotating ring apparatus and an oscillating grid apparatus will be evaluated. The applicability of analytical and semi-empirical models of hydrodynamic interfacial instability to such systems will be evaluated. An expected benefit of this work is improvement in the design stage of surfactant formulation based on hydrodynamic and fluid characteristics. The research needs identified in the solicitation (for NCERQA-1C) that will be addressed in this work include: A better fundamental understanding of environmental physical processes, and development of descriptive models for the transport of anthropogenic substances, specifically under engineered conditions.

Publications and Presentations:

Publications have been submitted on this project: View all 2 publications for this project

Journal Articles:

Journal Articles have been submitted on this project: View all 1 journal articles for this project

Supplemental Keywords:

DNAPL, solvents, organics, restoration, innovative technology, environmental chemistry and physics, TCE, gasoline, chemical transport., 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, solvents

Relevant Websites:

http://surfactants.net/s-peop.htm

Progress and Final Reports:

  • 1998 Progress Report
  • Final Report