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Decontamination process

Thanks to the use of our unique technologies, RSI Environmental succeeds in destroying persistent contaminants like PCBs, PFAS, HCBs, dioxins, furans, pesticides, organochlorine compounds and more.

The steps

1

Weighing
First of all, we register the shipment. A project number is assigned to each shipment in order to track it through the process. The weights are recorded directly into a database along with all other relevant information. The shipment is checked to ensure that the material matches the information received from the client. Once done, the shipment is accepted and unloaded into the warehouse.

2

Pre-treatment storage
The contaminated soil and residual hazardous waste are stored in a highly secure warehouse until the treatment. The materials are separated so their origin can be easily tracked.

3

Conditioning
To facilitate the thermal treatment, the contaminated soil and residual hazardous waste are strained to separate debris larger than 5 cm. These larger debris are crushed for optimal thermal desorption. After this, the material is blended to ensure the stability of operating parameters. It should be noted that there is no dilution done during the soil conditioning process.

4

Decontamination
The contaminated soil and residual hazardous waste are transported to the rotary kiln (primary combustion chamber) by a belt conveyor (equipped with a scale) and feeder screws to allow more precise control of the feed rate. For optimal thermal desorption, the rotary kiln temperature is kept above 650°C. After more than 20 minutes, all the organic material are desorbed and evaporated. The gas containing the organic contaminants swirls to the secondary combustion chamber, which continuously operates at more than 1000°C. At this temperature, the hazardous organic compounds (contaminants) are destroyed by thermal oxidation. The oxidized gas passes through a cooling chamber where, in less than three seconds, the temperature is reduced to less than 200°C by injecting atomized water. It is important that the cooling process happens very quickly to avoid reformation of the combustion by-products (dioxins, furans, PAHs). Afterward, hydrated lime and activated carbon are injected into the previously cooled gas. Hydrated lime neutralizes the acidity in the gas, and activated charcoal adds extra safety to the process by absorbing any organic compounds that may be left. Lastly, the gas is purified in the filtration system to remove any fine particles, then released through the stack. It should be noted that the six exhaust gas stacks are continuously monitored to ensure compliance with applicable laws and regulations.

5

Cooling
To avoid particles emissions, the decontaminated waste is cooled and moistened in a completely sealed environment. From the outlet of the primary combustion chamber, the decontaminated material is directed to a fluidized bed conveyor to be air-cooled. At the end of the conveyor, particles larger than two centimeters are separated so they can be directly extracted. Particles less than two centimeters are fed into a mixer to be rehydrated. The air used to cool the decontaminated soil goes through a filtration system of cyclones and dust collectors before being released into the atmosphere. The fine particles collected by the filtration system are also sent to the mixer for rehydration.

6

Post-treatment storage
The cooled and rehydrated decontaminated material is temporarily stored in a reserved area. The material processed each day is separated into a specific bay. The material remains in storage until the certified laboratory analysis results come back to confirm that the material is free of any organic contamination. When the results are published, a certificate of destruction is issued, stating that the material is free of any organic contamination.

7

Final disposal
Usage of soil after treatment depends on the terms of the Soil Protection and Contaminated Sites Rehabilitation Policy (MDDEP 1998) and is determined based on the concentrations of residual metals. Soil containing metal concentrations under the range A of the policy can be reused without restriction. Soil containing metals concentration between the ranges of A and C can be reused as daily cover layer in a landfill. Finally, soil containing concentrations above the C range must be buried in an authorized landfill for contaminated soil.

Soil recycling

At RSI Environmental, our mission is to recycle the largest amount of soil possible and to reduce landfill to a minimum to help mitigate the environmental responsibility for future generations. Our high-temperature thermal treatment centre allows us to carry out this mission.


The thermal treatment technology was developed by Bennett Environmental and involves placing the soil in a rotary kiln for about 45 minutes and counter-currently injecting a flame to increase the internal temperature of the kiln to between 650 and 850 degrees Celsius. To achieve this, a primary burner of 27,000,000 BTUs feeds the flame. Since 2013, using the energy contained in residual hazardous waste and biomass in the kiln has allowed for a significant reduction in propane consumption.

Afterwards, the contaminants that have been evaporated are entrained into a secondary combustion chamber where the temperature increases to between 1000 and 1100 degrees Celsius. At this temperature, all the molecules are decomposed to their simplest states, and by adding oxygen, new gasses such as CO2, SO2, and H2O, etc., are created.
Then, neutralizing products are injected, and the gas is instantly cooled to about 130 degrees Celsius. Finally, the gas passes into a dust collector to remove the last of the fine particles, if necessary. The gas released from the stack is continuously monitored to ensure that all emissions are below established standards.
RSI Environmental’s unique technology is the only in North America to have shown effectiveness of greater than 99.99999% destruction. RSI is the only facility able to neutralize certain contaminants such as pesticides, dioxins, furans, phenols, and PCBs. Once the destruction confirmation analysis has been confirmed, the treated material is then recycled, sold or disposed of at an authorized site. All the rocks and metals extracted during the process are sorted mechanically and sold.

STORAGE

The RSI Environmental facility has a storage capacity of more than 70,000 tonnes. The contaminated material receiving and storage building is operated under a negative pressure system. This system ensures that no fugitive dust or vapors escape into the environment during unloading or storage. The warehouse is equipped with a ventilation system, and all emissions are filtered in compliance with Atmospheric Quality Standards and Criteria.

Water is recovered from the warehouse and transported to the water treatment system. Within the storage area, a variety of equipment is utilized to prepare the received material for storage and ultimate treatment. Typical equipment includes front-end loaders, grinders, crushers and various screening mechanisms.

Clients greatly appreciate RSI’s ability to receive material resulting from a spill or release at their location, 24 hours a day without any preliminary analysis.

Hazardous waste management

Hazardous waste recycling for sustainable management
The thermal desorption technology used by RSI Environmental is a very effective hazardous waste treatment. RSI professionals takes care of the hazardous waste collection and treatment of materials to be recycled. By doing business with us, you can be assured that the hazardous materials will be safely disposed following all the hazardous waste regulations in Canada and United States.
All industrial activity has a potential impact on the environment. At RSI, we help industries meet both productivity and sustainability needs. Nowadays, industries and municipalities have made their decisions based on a sustainable perspective in order to become good corporate citizens. By reducing waste and increasing recycling, RSI reaches its objective in finding a way to a sustainable future.

Hazardous waste disposal and recycling
At RSI, hazardous wastes, especially those coming from petrochemical industries, are mixed with contaminated soil for harvesting energy resulting from the combustion. Afterwards, this energy is re-used to supply our waste treatment plant. Our process is environmentally protective.

In this way, we were able to reduce greenhouse gas emissions (GHG) by 64 500 metric tons from 2013 to 2018. Industrial waste management and recycling is a good example of sustainability in industries.

Sustainability for industries
Our services focus on reducing waste disposal and promoting waste recycling instead, by recovering contaminated soil. We are always very careful to proceed to our task in a secure way. We also have the ability to respond to environmental emergencies, like in case of an oil spill or the release of any chemical waste in the environment.
RSI Environmental takes care of collection, transportation, disposal, treatment and recycling of hazardous waste for a wide range of industries. 
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At a time when all citizens are concerned about the quality of environment, RSI Environnement safely decontaminates and processes contaminated soils, then transforms them into clean and reusable soils.
80 Melezes Street
Saint-Ambroise (Québec)
G7P 2N4
Canada
1 800-676-7849
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