This paper will focus on the application of Ivey-sol non-ionic surfactant technology to improve the in-situ remediation of petroleum hydrocarbon contamination is soil and bedrock aquifers.
Normally hydrophobic organic chemicals (HOC) exhibit limited solubility in groundwater as the contaminants tend to partition onto the soil and bedrock matrix. This partitioning can account for as much as 90-95% or more of the total contaminant mass. As a consequence, the hydrocarbon contaminants exhibit moderate to poor recovery during pump and treatment; limited bioavailability to microorganisms; and limited availability to oxidative and reductive chemicals when applied to in-situ and or ex-situ applications. Hence certain HOC’s can persist in the soil and or bedrock matrix for long periods of time.
The sorption (i.e., adsorption and adsorption) of contamination onto solids is often considered the principal limiting factor affecting the effectiveness of the many remediation technologies. This coupled with complex site geology; including sands and gravels, to fine grained silts and clays and fractured bedrock; only further complicate their application.
Ivey-sol is a non-ionic surfactant technology, comprised of several proprietary formulations, are capable of selectively desorbing and dissolving contaminants as microscopic ‘surfactant-hydrocarbon-water’ partial encapsulations, called partial micelles, well below their critical micelle concentration (CMC). In addition, Ivey-sol can lower the surface tension of water from 72 dynes to less than 30 dynes increasing the wetting and permeability properties of water in fine grain soils and fractured bedrock.
Ivey-sol surfactants affect the sorption of HOC and surfactants at the solid-liquid interface (i.e., the surface–H2O–NAPL interface). As a result, they increase the solubility of the contaminants in the groundwater for the improved removal by P&T, or treatment by bioremediation, and or chemical oxidative or reductive treatment processes.
Through desorbing contamination and lowering the surface tension, Ivey-sol formulations address two principal factors affecting the successful application of remediation technology. They overcome the contaminant absorption limitations, and improve the transitivity of the water by reducing the surface tension allowing greater effective water penetration into and through finer grained less permeable, soil substrate.