S-ISCO™ Overview

S-ISCO™ (surfactant enhanced in-situ chemical oxidation) process uses biodegradable, food-grade surfactants (VeruSOL™) (consisting of a U.S. FDA-GRAS mixture of citrus-based cosolvents and plant oil-based surfactants) to solubilize immiscible organic compounds making them more available for destruction in-place using injected oxidant systems.
More info>> (S-ISCO White Paper)

S-ISCO™ Process

Surfactant-Enhanced In-Situ Chemical Oxidation (S-ISCO™) is a new field verified Coelution Technology™ capable of reducing the amount of source NAPL in soils and reducing the flux of groundwater constituents associated with these sites. S-ISCO™ remediates NAPLs and contaminant species that are strongly sorbed to soil and sediment. It is well known that In Situ Chemical Oxidation (ISCO) reactions predominantly take place in the aqueous phase in the subsurface, and have limited impact on contaminants bound to soil and in the NAPL phase. In a recent study published by the State of Colorado, Division of Oil and Public Safety in 2007, assessment of ISCO application at 20 sites with some degree of NAPL present was investigated.

Of the 20 sites where ISCO was implemented 15 sites resulted in lack of success and 3 additional sites had uncertain success. Interactions with contaminants bound to soil or in the NAPL phase are not effectively addressed using ISCO treatment alone, but are addressed using the S-ISCO™ process. Other than associated with sampling, the S-ISCOTM process does not generate any wastes on site as compared to excavation, thermal or stabilization processes. Additionally, the carbon-greenhouse gas footprint of this new process is dramatically lower than with energy and material intensive processes, such as excavation, thermal and stabilization-containment remedies.

S-ISCO™ is a Green Coelution Technology ™ developed by VeruTEK Technologies, Inc. (VeruTEK™) which includes plant-based ingredients. S-ISCO™ uses a patent-pending surfactant-cosolvent mixture, VeruSOL™, which enables aqueous phase oxidant reactions to destroy solubilized NAPLs. VeruSOL™ is a biodegradable, U.S. FDA Generally Recognized as Safe (GRAS) plant oil-based cosolvent and surfactant system (i.e., coconut oil, castor oil, and citrus extracts). Once NAPL constituents are dissolved in the aqueous phase using VeruSOL™, a choice of a variety of chemical oxidation technologies can be effectively used to destroy the contaminants and reduce contamination.

Because the rate of partitioning of contaminants into the aqueous phase determines the overall rate of reaction, as the concentration of VeruSOL™ is increased, the partitioning and subsequent rate of chemical oxidation is increased. Therefore, using VeruSOL™ in S-ISCO™ increases the rate at which contaminants transfer to the aqueous phase, resulting in faster and more complete NAPL and soil decontamination utilizing oxidation reactions. This is significant over other methods of remediation such as ISCO. Solubilization of NAPL constituents with continued immobilization of NAPL in the soil pore space are controlled using S-ISCOTM which is key to this process.

The addition of VeruSOL™ increases DNAPL and adsorbed compound solubility in water between one to three orders of magnitude without physical mobilization of the NAPL. The scientific merit of this discovery revolves around VeruTEK's ability to match the fate, transport and reactions of the green cosolvents and surfactants with the activity of oxidants, particularly free-radical based chemical oxidants. S-ISCOTM involves coeluting both the cosolvent surfactant mixture with the oxidant enabling concurrent dissolution and oxidation. The inherent properties of plant-oil based surfactants to resist immediate chemical oxidation is key to VeruTEK's ability to simultaneously transport the surfactant and oxidants through the subsurface and target NAPL contaminated zones.

The injected VeruSOL™ surfactants have a lipophilic end that is attracted to non-polar constituents in NAPL. The other end is hydrophilic and is attracted to the water. The surfactant creates a microemulsion of the NAPL in the oxidant solution. A microemulsion is a solution composed of oil, water and surfactant and/or cosolvent or cosurfactant. Nanometer-sized micelles form with the immiscible liquid as dispersed in the aqueous phase with surfactant at theinterface. There are oil-in-water and water-in-oil microemulsion systems. An oil-in-watermicroemulsion is a Winsor Type I emulsion.

VeruTEK's green surfactant/cosolvent mixture achieves Winsor Type I solubilization, where the NAPL is solubilized as a single-phase microemulsion and dissolution of constituents occur without NAPL mobilization. Logically these systems have high solubilization while requiring low amounts of chemical additives. Winsor Type I microemulsification will solubilize less NAPL than in either Winsor Type II or III systems, which allows for control of the S-ISCO™ process.

VeruTEK's patent pending S-ISCOTM process avoids Winsor Type II systems, that is, water-in-oil mixtures with oil as the continuous phase and water inside the micelle, which results in mobilization of the NAPL, typical of Surfactant Enhanced Aquifer Remediation (SEAR) flushing product recovery processes. Winsor Type III microemulsions are formed between the two types where the systems changes from hydrophilic to lipophilic. In this mid-phase the interfacial tension drops extremely low. Winsor Type III emulsions promote NAPL mobilization and require a delicate balance of various parameters, typically difficult to achieve for subsurface applications.

Winsor Type III Emulsions are not formed as part of the S-SICOTM process. The field of surfactant chemistry is well developed and excellent reviews and papers exist that describe Winsor systems and interactions of surfactants and surfactant-cosolvent mixtures with NAPLs of environmental significance. Solubilization of NAPLs using Winsor Type I systems have also been well documented and relationships between solubility enhancement andoctanol/water partition coefficients, relationships between several molar solubilization ratios(MSRs) and hydrophile-lipophile balance (HLB) for several single component NAPLs for a particular non-ionic surfactant system.

Surfactant-Enhanced In-Situ Chemical Oxidation (S-ISCO™) is a new field verified Coelution

Technology™ capable of reducing the amount of source NAPL in soils and reducing the flux of

groundwater constituents associated with these sites. S-ISCO™ remediates NAPLs and

contaminant species that are strongly sorbed to soil and sediment. It is well known that In Situ

Chemical Oxidation (ISCO) reactions predominantly take place in the aqueous phase in the

subsurface, and have limited impact on contaminants bound to soil and in the NAPL phase. In a

recent study published by the State of Colorado, Division of Oil and Public Safety in 2007,

assessment of ISCO application at 20 sites with some degree of NAPL present was investigated.

Of the 20 sites where ISCO was implemented 15 sites resulted in lack of success and 3 additional

sites had uncertain success. 5 Interactions with contaminants bound to soil or in the NAPL phase

are not effectively addressed using ISCO treatment alone, but are addressed using the S-ISCO™

process. Other than associated with sampling, the S-ISCOTM process does not generate any

wastes on site as compared to excavation, thermal or stabilization processes. Additionally, the

carbon-greenhouse gas footprint of this new process is dramatically lower than with energy and

material intensive processes, such as excavation, thermal and stabilization-containment remedies.

S-ISCO™ is a Green Coelution TechnologyTM developed by VeruTEK Technologies, Inc.

(VeruTEK™) which includes plant-based ingredients. S-ISCO™ uses a patent-pending

surfactant-cosolvent mixture, VeruSOL™, which enables aqueous phase oxidant reactions to

destroy solubilized NAPLs. VeruSOL™ is a biodegradable, U.S. FDA Generally Recognized as

Safe (GRAS) plant oil-based cosolvent and surfactant system (i.e., coconut oil, castor oil, and

citrus extracts). Once NAPL constituents are dissolved in the aqueous phase using VeruSOL™,

a choice of a variety of chemical oxidation technologies can be effectively used to destroy the

contaminants and reduce contamination. Because the rate of partitioning of contaminants into

the aqueous phase determines the overall rate of reaction, as the concentration of VeruSOLTM is

increased, the partitioning and subsequent rate of chemical oxidation is increased. Therefore,

using VeruSOL™ in S-ISCO™ increases the rate at which contaminants transfer to the aqueous

phase, resulting in faster and more complete NAPL and soil decontamination utilizing oxidation

reactions. This is significant over other methods of remediation such as ISCO. Solubilization of

NAPL constituents with continued immobilization of NAPL in the soil pore space are controlled

using S-ISCOTM which is key to this process.

The addition of VeruSOL™ increases DNAPL and adsorbed compound solubility in water

between one to three orders of magnitude without physical mobilization of the NAPL. The

scientific merit of this discovery revolves around VeruTEK's ability to match the fate, transport

and reactions of the green cosolvents and surfactants with the activity of oxidants, particularly

free-radical based chemical oxidants. S-ISCOTM involves coeluting both the cosolventsurfactant

mixture with the oxidant enabling concurrent dissolution and oxidation. The inherent

properties of plant-oil based surfactants to resist immediate chemical oxidation is key to

VeruTEK's ability to simultaneously transport the surfactant and oxidants through the subsurface

and target NAPL contaminated zones.

The injected VeruSOL™ surfactants have a lipophilic end that is attracted to non polar

constituents in NAPL. The other end is hydrophilic and is attracted to the water. The surfactant

creates a microemulsion of the NAPL in the oxidant solution. A microemulsion is a solution

composed of oil, water and surfactant and/or cosolvent or cosurfactant. Nanometer-sized

micelles form with the immiscible liquid as dispersed in the aqueous phase with surfactant at the

interface. There are oil-in-water and water-in-oil microemulsion systems. An oil-in-water

microemulsion is a Winsor Type I emulsion.

VeruTEK's green surfactant/cosolvent mixture achievesWinsor Type I solubilization, where the

NAPL is solubilized as a single-phase microemulsion and dissolution of constituents occur

without NAPL mobilization. Logically these systems have high solubilization while requiring

low amounts of chemical additives. Winsor Type I microemulsification will solubilize less

NAPL than in either Winsor Type II or III systems, which allows for control of the S-ISCO™

process. VeruTEK's patent pending S-ISCOTM process avoids Winsor Type II systems, that is,

water-in-oil mixtures with oil as the continuous phase and water inside the micelle, which results

in mobilization of the NAPL, typical of Surfactant Enhanced Aquifer Remediation (SEAR)

flushing product recovery processes. Winsor Type III microemulsions are formed between the

two types where the systems changes from hydrophilic to lipophilic. In this mid-phase the

interfacial tension drops extremely low. Winsor Type III emulsions promote NAPL mobilization

and require a delicate balance of various parameters, typically difficult to achieve for subsurface

applications. Winsor Type III Emulsions are not formed as part of the S-SICOTM process. The

field of surfactant chemistry is well developed and excellent reviews and papers exist that

describe Winsor systems and interactions of surfactants and surfactant-cosolvent mixtures with

NAPLs of environmental significance. 6,7 Solubilization of NAPLs using Winsor Type I systems

have also been well documented and relationships between solubility enhancement and

octanol/water partition coefficients8, relationships between several molar solubilization ratios

(MSRs) and hydrophile-lipophile balance (HLB) for several single component NAPLs for a

particular non ionic surfactant system.9

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S-ISCO™ Overview

S-ISCO™ Process