In-situ control of DNAPL density using polyaphrons

Area of Science:

• Environmental Science
• Chemical Engineering
• Geology

Background:

• Dense nonaqueous phase liquids (DNAPLs), like chlorinated solvents, pose significant subsurface contamination risks due to their high density and deep migration.
• Conventional remediation efforts can inadvertently drive DNAPLs deeper, complicating cleanup and increasing environmental hazards.

Purpose of the Study:

• To introduce a novel method for in situ manipulation of DNAPL buoyancy using specialized emulsions.
• To present polyaphrons as a viable technology for altering DNAPL density and facilitating remediation.

Main Methods:

• Development and application of polyaphrons, a type of high internal phase ratio emulsion (HIPRE).
• Selective delivery of a light organic phase liquid to DNAPL-contaminated zones.
• Destabilization of polyaphrons using polyvalent cations to induce mixing with DNAPLs.

Main Results:

• Polyaphrons demonstrate indefinite stability and unique flow properties in porous media.
• Mixing of the light internal phase with DNAPLs successfully reduced the overall density of the nonaqueous phase.
• Reversal of DNAPL negative buoyancy was achieved, demonstrating potential for enhanced remediation.

Conclusions:

• Polyaphrons offer a promising strategy for in situ control of DNAPL densities.
• This technology can be applied before or during remediation to improve contaminant removal efficiency.
• The ability to modify DNAPL buoyancy presents a significant advancement in environmental remediation techniques.