To decontaminate contaminated soils, there are numerous environmental remediation methods that are used to lessen the possibility of causing further damage to the site and the environment, especially during heavy rains. This includes on-site treatment and off-site disposal of contaminated soil.
But because these can’t provide full cleanup of contaminated land, environmental remediation contractors employ more than one technique.
The three methods used to remediate contaminated soil are:
• Physical removal and containment of contaminated soils
• Floor washing
• Bioremediation
Isolation and Containment of Contaminated Soils
Land containing contaminated soil is cleaned up by physically removing the contaminated soil. In this cleanup method, people dump the soil in a landfill or incinerate it. However, the disadvantage of this method is that it can cause new problems, such as air pollution by burning toxic material or imprisoning contaminated soil without decontaminating it.
Liquid or solid contaminants can mix chemically or physically with soil particles. The type of contamination will determine the treatment method to be used.
Heavy metals typically break down into compounds that cannot react with other materials, while toxic organic chemicals like solvents and pesticides are incinerated.
In landfills, the containment method is used and incorporates the use of impermeable layers of plastic liner and dense layers of clay. To prevent the spread of contamination from rainwater runoff, the soil is insulated on site.
floor washing
This is a pump and treat method in which chemical solvents are used to remove toxic materials from the soil. Contaminated soil is cleaned in place without the need for digging.
Chemicals are pumped into the soil so that harmful toxins are removed from the soil by moving them to wells that pump them out for processing. This method works best if the soil below the contaminated area is clay-like, meaning it is not permeable.
Chemical treatments using organic and inorganic acids and chelating agents are used to remove heavy metals. However, this method generates secondary hazardous waste that would even require further treatment.
Solvents and heating oil are contaminants and may be present in the soil as liquids and may slowly and eventually dissolve into groundwater. In this case, to dissolve these contaminants, environmental contractors use chemicals like surfactants related to detergents and cosolvents like ethanol or methanol.
bioremediation method
This method is considered the safest for the environment. It involves inciting the growth of microorganisms that naturally feed on debris to degrade organic contaminants in the soil. This can be done on site or after excavation.
Microorganisms break down contaminants as they use them as a food source during aerobic processes, which require oxygen.
In general, remediation contractors will use the sludge bioremediation method if they have used the bioremediation method after soil removal. This will keep the soil suspended and microbes in contact with contaminants by mixing the soil with water.
Another bioremediation method is solid phase where the excavated soil is placed in an isolated area where it is tilled with water and nutrients to facilitate the growth of microorganisms.
Remedial contractors work on environmental construction projects and help with disaster recovery. They are a team of environmental experts who can help you tackle any challenging pollution problem using good teamwork, best technique and the right technology.
