Soil Vapour Extraction (SVE) is a physical treatment for removing contaminants from the soil. Specifically, the purpose of this technology is to extract contaminants from the soil as vapour. It can be used to remove volatile and semi-volatile compounds from the unsaturated (vadose) zone. From an operational standpoint, the system requires digging extraction wells for the removal of the vapour; vacuum blowers are used to create a slight vacuum. These wells are often grouped together with injection wells, to increase the air flow and raise the rate of contaminant removal.

Before they are introduced into the atmosphere, the extracted gases must undergo preliminary treatment using activated carbon adsorption or, otherwise, through catalytic oxidation or condensation of the solvents extracted.

The introduction of ambient air will often notably increase the rate of biological removal of biodegradable contaminants.

When the area below the water table is also contaminated, SVE is often used in conjunction with Air Sparging (AS), in which air is injected into the saturated subsurface to strip the volatile and semi-volatile contaminants from the liquid phase and flush them up into the vadose zone, from which they can be permanently removed through the SVE system's extraction wells.

The diagram below illustrates how an SVE/AS system typically operates.

Riccoboni has used both of the systems described above in multiple different remediation projects, some complete, others ongoing, gaining specialised expertise in this field and positioning itself as a primary operator in the field of on-site treatment processes.

Notably, the experience we have accrued has allowed us to achieve successes in circumstances usually less than amenable to the use of technology, ones characterised by a predominance of fine materials (such as silty sand and sandy silt) and by the presence of superficial or brackish groundwater or of semi-volatile compounds.

Soil Vapour Extraction Systems