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Types of Remediation

When applied to the environment, remediation refers to removing pollutants from soil, water and air. Physical removal, microbial remediation, UV treatment, phytoremediation and isolation are the most commonly used remediation techniques. Determining which strategy to use depends on the type of pollutant and what substance is polluted.

  1. Physical Removal

    • The most common form of remediation involves simply removing the pollutant source and contaminated soils from the area. Polluted soils are typically taken to a landfill, or treated and then taken to a landfill. The recently initiated clean-up of the Hudson River involves the dredging of large quantities of PCB-contaminated soils, which will then be taken to a landfill.

    UV Remediation

    • Certain pollutants are readily broken down when exposed to ultraviolet radiation since UV light can sever chemical bonds. UV treatment is most effective when used on a liquid solution containing pollutants. Adding a catalyst like hydrogen peroxide can greatly enhance the remediation efficiency of UV treatment. UV treatment is growing in popularity since it can efficiently destroy harmful pathogens and emerging pollutants.

    Phytoremediation

    • Phytoremediation is remediation done by plants. These plants can remove pollutants from the environment in a variety of ways. Sometimes pollutants are taken up by the roots and stored in the body of the plant. Some pollutants can be put to beneficial use by plants, while other pollutants are actually broken down by biological reactions in the plant's root zone or by being exposed to UV light after being transported from the soil to the plant's leaves. Plants used in phytoremediation are very tolerant of polluted environments. If pollutants, such as heavy metals, are stored in the plant's body, these plants should be removed and placed in a landfill in order to ensure undesired pollutants don't reenter the environment.

    Microbial Remediation

    • Microbial remediation, also called bioremediation, involves the breakdown of pollutants by microorganisms. The microbes often use the pollutant as a food source. Microbes are commonly used to treat sewage and oil spills, but can break down a wide range of pollutants. Microbes can be added to polluted soil to speed treatment. Occasionally, mixing the soil can often speed clean-up efforts by spreading bacteria and oxygen through the contaminated zone.

    Isolation

    • Often when a contaminant is difficult or extremely expensive to remove or destroy, it is simply isolated from the surrounding environment. This is typically done with clay, concrete, manmade liners or a combination of these. The idea is to create a barrier around the contaminant that no water or pollutants can pass through. This is also a common strategy with nuclear waste.

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