Together with its American partner TRS, HMVT has conducted a successful test to purify soil contaminated with PFAS. The test concerned land from the former Soesterberg air base, a location that will be redeveloped into a nature reserve, recreation area and homes in the future. As a result of the former activities, however, the soil and groundwater have become contaminated with PFAS, in this case mainly the substance PFOS.
Redevelopment of the site will be necessary to redevelop the area. However, PFOS / PFAS are very resistant substances and the soil and groundwater are very difficult to remediate. In this context, market parties were asked for remediation ideas and were given the opportunity to conduct experiments with the soil. The PFAS problem is also very important in America. Our partner TRS is specialized in remediation of soils by means of heating and has established that with sufficient heating of the soil the PFAS molecules can be evaporated from the soil. The crux here is that the soil must be kept at a sufficient temperature for a sufficient period of time so that all PFAS can evaporate from the soil. It is known that when the soil is brought to 350 to 400 Degrees Celsius for about 7 days, almost all PFAS can evaporate from the soil. The PFAS vapors are cooled, causing the PFAS to condense in the released soil moisture. This soil moisture must either be processed externally or cleaned locally. Any remaining PFAS vapors can be cleaned with activated carbon.
In May, we collected approximately 13 liters of soil from the site and subjected it to an evaporation test. The result is that heating at 350 Degrees Celsius for approx. 7 days reduces PFAS concentrations of more than 1,000 µg / kgds to below detection level. Completely in line with expectations, this means that a remediation result of more than 99.9% has been obtained. A very good result, of course.
The soil heating method is based on Conductive Heating. The beauty of this heating method is that it does not depend on the type of soil. It does not matter whether it concerns clay, loam, sand or rocky soil: every grain, all pores are heated. This PFAS soil remediation technology is therefore extremely suitable for releasing the difficult clay and loam soils in the Netherlands.
Would you like to know more about this PFAS soil remediation technique?
Please contact Marco van den Brand