Contaminated Land Remediation Techniques

Environmentalism consists of ways to keep the Earth safe for its inhabitants. Pollution is one element that causes major harm to the planet. As remediation is synonymous with "providing a remedy for" something, environmental remediation consists of the removal of pollutants, contaminants and otherwise toxic materials from the soil, sediment, and ground and surface water.

Biological Treatment

• One land remediation technique is biological treatment, which consists of several categories outlining specific techniques. In windrowning, the contaminated soil is aerated and mixed through a mechanical process that involves adding nutrients and the sporadic addition of water. Similar to windrowning is landfarming, in which contaminated soil is thinly spread across a treatment area. In composting and biopiling, bulking agents are mixed with contaminated material.

Physicochemical Techniques

• Physicochemical techniques of land remediation include four categories. While hazardous waste solidifies, it is encapsulated into a solid material, and the waste's solubility, mobility and toxicity stabilize. When using the soil vapor-extraction technique, venting and gas treatment systems are sometimes employed. Soil washing involves mixing water and contaminated soil in an extractor vessel.

Thermal Techniques

• Thermal techniques include thermal desorption, pyrolysis and incineration. With thermal desorption, organics are physically separated from the soil without decomposition. Pyrolysis is defined as a chemical decomposition of the toxins in the soil by heating it. By incinerating the soil, the organic contaminants are permanently destroyed.

Engineering and Containment Techniques

• Engineering and containment techniques for land remediation involve using structures and devices to keep water away from contaminated soil. Low-permeability cut-off walls are installed below the ground and include slurry walls, ground barriers and sheet piping. Capping systems are impermeable membranes and materials used to contain the contaminated materials permanently. Carbon absorption and air-stripping are both used in subsurface drainage. Lastly, pump-and-treat systems are used in the removal of contaminant masses.