DeepEarth Technologies, Inc., (DTI) is a technology development and field services company specializing in the remediation of toxic and hazardous chemical contaminants in soil and groundwater.

DTI has developed and marketed a new patented concept of in-situ chemical oxidation (ISCO) technology that has harnessed classical hydrogen peroxide chemistry so that the oxidation reaction can be controlled. This break-through has revolutionized in-situ and ex-situ remedial challenges and has opened the door to treating a broad spectrum of contaminants under conditions previously thought to be impossible. 

DeepEarth Technologies, Inc. (DTI) is an environmental remediation company specializing in the use of the patented Cool-Ox™ technology for in-situ and ex-situ clean up of contaminated soils. This technology also forms the basis for the Cool-Ox,™ Bio-Spunge™ Reactor and the Pit-Stop™ Process for odor control and treatment of contaminants in excavations.

The Cool-Ox™ process is a hydrogen peroxide based technology designed to address a wide variety of remediation challenges presented by organic contaminants in various types of soils (especially clay) and groundwater. Although other hydrogen peroxide technologies may sound similar, only Cool-Ox™ is based on a unique chemistry that truly delivers results.

What makes Cool-Ox™ different? Unlike Fenton chemistry where liquid hydrogen peroxide is used as the source of the oxidizing radicals, the Cool-Ox™ technology uses an aqueous suspension of solid peroxygen compounds. These compounds hydrolyze to generate hydrogen peroxide in the proximity of the contaminants. A key to the success of the technology is that the relative insolubility of these compounds allows the oxidizers to be produced over an extended period of time (up to three months). This long term production of oxidizer greatly enhances the probability of the oxidizing compounds contacting the contaminants as well as providing an ongoing source of molecular oxygen for the enhancement of aerobic microbial proliferation.

While the Cool-Ox™ process continues to provide excellent results, DTI continues on-going work with its academic associates and clients to perfect DTI application techniques for both soil and groundwater. This research has produced major breakthroughs in the understanding of enhanced bioactivity initiated by the application of the abiotic Cool-Ox™ chemical oxidation technology.

DTI welcomes the opportunity to show that the Cool-Ox™ technology will deliver an economical solution to most sites contaminated with hydrocarbons and various organic chemicals.

The versatility of the Cool-Ox™ process has led to the development of several complimentary process applications dealing successfully with a broad spectrum of contaminants. One of the many advantages of applying the Cool-Ox™ technology is the over-riding proof that the process works very well in tight sands, silty sands and heavy clays.

Cool-Ox™ Technologies

The patented Cool-Ox™ process is an in-situ (and ex-situ) remediation technology that combines controlled chemical oxidation with accelerated biodegradation subsequent to the oxidation phase. The process is based upon using hydrogen peroxide as the generator of the oxidizing radicals. However, unlike the Fenton or Fenton-like processes that use liquid hydrogen peroxide, the Cool-Ox™ process generates hydrogen peroxide from solid peroxygens that are injected into the soil or groundwater in an aqueous suspension. Once in place, the peroxygens react with water to produce hydrogen peroxide. This reaction is widely understood.

In conventional Fenton or Fenton-like processes, the liquid hydrogen peroxide reacts with iron salts that are introduced to produce the oxidizing radicals. This reaction is largely uncontrollable and usually produces excessive amounts of heat. Even where the iron is introduced in a separate injection sequence, the reaction can be robust. Similarly, other processes that have begun using solid peroxygens with introduced iron salts find it difficult to avoid volatilization of contaminants because of the heat produced. The Cool-Ox™ process has eliminated these problems.

The distinguishing feature of the Cool-Ox™ technology is that it does not require the injection of metal catalysts to activate the production of oxidizing radicals in the substrata; thus, the creation of heat is eliminated. Therefore, a very important characteristic of the Cool-Ox™ technology is that the chemical reaction is controllable.

Because most peroxygens are only sparingly soluble in aqueous solutions, their dissolution rate is quite slow. Therefore, once injected they remain in the contaminated media for an extended period of time before they become soluble. This low solubility characteristic also allows peroxygens to be hydraulically distributed by the injection equipment thereby, increasing the radius of influence from the injection point. This significantly increases the probability of the oxidizer contacting the contaminants. However, the greatest distinguishing feature of the Cool-Ox™ process is that it does not require the introduction of iron salts to produce the radicals necessary for chemical oxidation. Therefore, the reagents are iron free.cop

The Cool-Ox™ formulations include compounds that activate the catalytic metals that are intrinsic in the soil matrix being treated and eliminates the need to artificially introduce iron salts either into the oxidizing reagent or by sequential injections. The use of these reagents also imposes a second control factor (the first is the low solubility of the peroxygens) on the reaction rates of the oxidizers. Knowing how to manipulate these factors allows the oxidation reactions to proceed without producing heat. Therefore, the probability of volatilizing contaminants because of heat generation is eliminated when the Cool-Ox™ process is employed. This increased control eliminates the risk associated with other exothermic oxidizing processes, and as an added plus, there are no hazardous metals such as lead, chrome, or arsenic in the Cool-Ox™ formulations.

An additional and extremely important characteristic of the Cool-Ox™ process is the pH at which the oxidation reactions proceed. Unlike the Fenton or Fenton-like reactions that require a low acidic pH, the optimum pH of the Cool-Ox™ process is slightly basic at pH 8. This is critical when treating contaminants found in limestone or soils containing high concentrations of carbonates where a low pH would be buffered toward neutrality. Equally important is the factor that almost all phenolic, chloro-phenolic, and chlorinated organic compounds exhibit organic acid characteristics. In general, these compounds become increasing soluble in aqueous solutions as the pH is increased. Once soluble, they are quite susceptible to oxidation via the Cool-Ox™ process. Thus, a broad family of troublesome recalcitrant compounds such as creosotes, PCP, PCBs, PAHs, fuel hydrocarbons, dioxins as well as a host of herbicides and pesticides are treatable using the Cool-Ox™ process. Unlike permanganates, where the oxidation reaction is inhibited by hydrocarbons, the Cool-Ox™ process can concurrently remediate mixed plumes consisting of halogenated and hydrocarbon constituents.

The Cool-Ox™ process has been demonstrated to be very effective at treating contaminants on limestone bedrock and in high carbonate clay strata with no indication of a reaction with either material mainly because of the basic nature of the process and because the oxidation reaction is controlled. Therefore, it is not expected that the Cool-Ox™ process would impact slurry walls, either from chemical reactions or hydraulic pressure standpoints.

Because the reaction does not create heat, the volatilization of the VOCs is eliminated. This is an extremely important safety factor when dealing with compounds having low toxicity thresholds and/or the potential for flammability. The technology is enjoying success at treating excavations where contaminants such as aromatics or PAHs create significant odor problems. Unlike conventional deodorants that simply mask or isolate the contaminants, the Cool-Ox™process oxidizes the molecule thereby, converting it to an alcohol or polyol. These reaction products are converted to wetting agents and exhibit surfactant characteristics by forming a thick lather resembling shaving cream as shown in the Pit-Stop™ photos. Thus, the odor bodies are actually converted to odor control agents.

Another important feature is that the Cool-Ox™ reaction is self initiating. That is, the reaction starts when the oxidizer contacts organic contaminants. This characteristic precludes the need to catalytically “start” the reaction as is the case with persulfates.

The Cool-Ox™ Bio-Spunge™ Reactor

Although it is expected that the bulk of the contaminant remediation will be accomplished by direct chemical oxidation, a vital role subsequent to the oxidation phase will be bio-degradation. DTI has discovered that once the oxidation reactions of the remedial work have begun taking place, the oxidation by-products create an environment ideal for the proliferation of intrinsic microbial degraders. To enhance this bio-process, DTI has developed formulations that promote accelerated biodegradation while still maintaining the vitality of the oxidation reaction. The establishment of these intrinsic microbial communities is referred to as the Cool-Ox™ Bio-Spunge™ Reactor.

DTI has determined through experience gained by field applications, that a broad range of organic chemical contaminants are readily oxidized using the patented Cool-Ox™ technology. Although the technology has the capability of converting the contaminants completely to carbon dioxide, this total mineralization process would prove to be prohibitively expensive because of the amount of oxidizer required. However, it has been observed at nearly every site treated, that significant contaminant reductions have been achieved with concentrations of Cool-Ox™ reagents that are significantly lower than the stoichiometric ratios one would predict necessary. A study of the oxidation mechanism provided the answer to this question.

DTI has determined that a myriad of organic compounds are readily oxidized (hydroxylated) by the addition of a hydroxyl group to the molecule or the substitution (replacement) of a halogen atom by a hydroxyl group onto the molecule. This chemical reaction has been illustrated in organic chemistry textbooks and has been successfully applied, under field conditions, by DTI and DTI principles on numerous occasions. Once this conversion is complete, the resultant compounds are quite biodegradable thus setting the stage for the indigenous microbes to complete the remedial work.

In-Situ Remediation Of Groundwater

The keys to the development and successful application of the Cool-Ox™ Bio-Spunge™ Reactor for the in-situ remediation of groundwater contaminants are:

The extended life of the peroxygen compounds,
The conversion of the contaminants to biodegradeable co-etabolites,
The buffering systems conversion to nutrients subsequent to the oxidation phase,
The absence of heat produced from chemical reactions
The verification that the oxidation process actually enhances aerobic microbial activity (for more information on this phenomenon, please Contact Us.
With the development of the Cool-Ox™ process, DTI became aware that at nearly all sites treated with the Cool-Ox™ reagents, the proliferation of indigenous aerobic microbes increased by as much as six orders of magnitude. Upon visual inspection of samples collected from numerous sites, it was obvious that the appearance of the soil had changed from a clean material to that resembling the type of natural sponges found in marine environments. DTI also noted that contaminant concentrations found in groundwater down gradient from the injection zones, had significantly decreased; in most cases by orders of magnitude. Once this discovery was made, DTI developed Cool-Ox™ reagent formulations to improve both the efficiency of the oxidation reactions and optimize indigenous microbial proliferation.

The scanning electron microscopic photographs (contributed by Dr. H. Eric Nuttall – University of New Mexico, Albuquerque) below depict clean sand particles (left) and the same soil after treatment (right). Note, the Extra-Cellular Polymeric Substances (ECPS), giving the appearance of the matrix seen in live sponges, hold the microbes in place while allowing the groundwater to flow through. This forms the matrix of the Cool-Ox™ Bio-Spunge™ Reactor. This configuration increases the surface area, thus increasing the probability of contact between contaminants and microbial degraders

Photos courtesy of Dr. Eric Nuttall, University of New Mexico

When the bio-fortified Cool-Ox™ reagents are properly placed in the groundwater plume including the soil/groundwater interface, the indigenous microbes produce the ECPS biofilm depicted. If the injection points are properly placed and the reagent contains the formulation necessary to encourage the proliferation of microbes as well as the production of the biofilm, a filtration system (such as that depicted in the drawing below) is produced that allows the microbes to filter the groundwater as it passes through the formation. No other technology is presently available that ties chemical oxidation to subsequent bioremediation in the efficient manner as the Cool-Ox™ process.