IN SITU
The treatment takes place in the contaminated area. The lixiviation risk is minimized working at depths of 20 to 35 cm.
The hydrocarbon contaminated soils and mud are treated with vegetable matrices BIOX in order to reduce viscosity and to balane the contaminant's pH that is embedded in the soil organic matter.
In the case of having TPH above 70.000 ppm, it is necessary to treat the ground with Biosurfactants BIOX that are isolated in labs from endemic organisms.
The variety of BIOX polymers provide sources of nitrogen and phosphorus that are indispensable to begin the bio-stimulation of the endemic microorganisms that are present in the polluted soils.

Quantification of the concentration of petroleum hydrocarbons
The sampling design can be at random or systematic and composed at various depths. Variables such as pH, TPH concentrations, and quantitative analysis of heavy metals are collected according to the Ecuadorian regulations for oil operations.

This quantification procedure is useful to determine the percentage of carbon contributed by petroleum and the estequiometric growth relationship-hydrocarbon degradation.

Biodegradation Potential
The petroleum hydrocarbons are biodegradable only if these are bio-available. In many cases, the contaminants are embedded in organic matter. This generates huge piles of oil, humic acids and carbohydrates inaccessible to all microorganisms.

For this reason, BIOX protocols make hydrocarbons available in solution, therefore the endemic microorganisms can attract them from the water-air interface and use them as energy source.

The capacity of biodegradation varies according to the hydrocarbon type, time of intemperization and soil type.

Microorganisms culture
Once the BIOX protocol is applied to improve hydrocarbons desorption, a inoculation of endemic microorganisms is performed, in order to increase their number in the treated soils.

From the micro organism populations that oxidize petroleum some of them are cultured based on oxigenase and desoxygenase enzyme production. The bacterias are identified and stored at -70 centigrades for future use.

Oxygenation
Mechanic oxygenation: Applied before and during the process. For the improved oxygenation, BIOX products are used to improve the performance, immiscible substrates and processes of acclimation and desertion are used.
Natural oxygenation: normally occurs in aerobic degradation systems. Its power increases when peroxides and BIOX products are used to generate molecular oxygen to concentrations of up to 8mM.

Factors that have influence on bioremediation:
- PH
- Humidity
- Separation agents
- Bacteria populations
- Oxygenation

Infiltration/penetration of bio- molecules
The process of infiltration in situ (Technology Evaluation Report-EPA) consists of:

Making excavations to determine the presence and saturation of hydrocarbons.
Determining the natural ways of contaminant elusion.
Manufacturing oil and fat traps with three chambers.
Building chambers to keep ramnolipid, sophorolipid, phospholipids and
lipoalcohol solutions.

The mixture of anionic and cationic biosurfactants and anphipathic molecules is used to:

- Decrease the interfacial tension and capillary forces.
- Create a stable Winsor III type microemulsion.
- Make soluble individual molecules which are able to form micelles or a simple
microemulsion phase.

BIOX biological molecules are used to determine the location of oil and fat traps as sites of saturation.

After this, bioremediation is performed with living bacteria.

When industrial chemical detergents (generally utilized to clean oil contaminated sites) are used, the soil becomes a toxic substrate filled with inert and hard to degrade particles that will inhibit the growth of endemic microorganisms.

The In Situ bioremediation processes by filtration/penetration are synergic. After the biosurfactant treatment, the amount of hydrocarbons is reduced considerably. The BIOX peroxide is later added as element of the IAKLA reaction which was modified by BIOX according to Ecuador's geographic conditions. The IAKLA reacts with metals to form hydroxyl radicals (OH), which in this environment are very reactive and capable of reacting with hydrocarbons to reduce and transform them. In this way, the hydrocarbon molecules are ready to be degraded by bacteria.

The two most important reactions produced by the presence of hydroxyls for the hydrocarbon degradation are:

Adding: OH + C6H6 -> (OH)C6H6
Subtracting
Hydrogen Molecules:
OH + CH3OH -> CH2OH + H20

The amount of added hydroxyl radicals will decrease gradually. If more is added, there will be a COD decline. This processes should be controlled daily employing BIOX protocols:

Sustrat -> Intermediary A -> Intermediary B -> Intermediary C ->
Intermediary D -> Intermediary E -> CO2

This procedure intercalates with the biosurfactant addition process. The main idea is to reduce the hydrocarbons to small molecules without reaching total degradation, so they can be easily eluted.

In addition, free oxygen is utilized via the catalase reaction to generate molecular oxygen that will sustain the aerobic degradation of infiltrated sites.


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Av. 6 de Diciembre y Pasaje California 222 - Telf.:(593.2)2253401-2243881-2447013 Telefax:(593.2)2252089
Email: ivanaveiga@biorremediacion.org /maveiga@biorremediacion.org / luiscabrera@biorremediacion.org
Quito - Ecuador