Question

Soil vapor extraction (SVE) is used to remove volatile organic pollutants, such as chlorinated solvents, from soil at hazardous waste sites. Vent wells are drilled, and a vacuum pump is applied to the subsurface.

1. How does this remove pollutants?
2. Why does heating combined with SVE speed the process?

Short answer

At hazardous waste sites, soil vapor extraction (SVE) is used to remove volatile organic pollutants from the soil, such as chlorinated solvents.

Drilled vent wells are used, and a vacuum pump is used to remove air from the ground. The pollutants are removed on the basis of the chemical properties of the volatile impurities.Highly mobile pollutants get removed by simple vacuum cleaning whereas less volatile pollutants need an elevated temperature for cleaning.

Step-by-step solution

Soil Vapor Extraction

Soil Vapor Extraction (SVE) is a process in which the organic volatile pollutants are extracted from the soil using low-pressure, high-temperature zones.

This process is used to remove volatile pollutants from the soil in hazardous sites. Vent wells are drilled and using low pressure, high-temperature formula, these pollutants are removed.

Process for removal of pollutants

The organic volatile pollutants present in the soil have variable nature and thus composition. Some of the pollutants can be removed by simply evaporating the compounds under reduced pressure. However, some of the pollutants are less volatile and only low pressure is not enough for the same, thus heating is also required. Heating combined with the process enables the vaporization of impurities easily and thus the speed of the SVE process increases.