Sustainable Soil Upgrading by Developing Cost-effective, Biogeochemical Remediation Approaches

Over the last two decades, the advances made in in-situ remediation have mainly originated from an engineering perspective, focusing on the intended interaction between remedial agents and contaminants. However, any remediation treatment also affects the “natural” soil conditions. These sideeffects are usually seen only as an impediment to the remediation effort, and lasting effects on soil properties and functioning rarely play a role in the selection of a remediation approach.

Deltares aan het werk, upsoil

The UPSOIL research line led by Deltares examined the smart coupling of existing remediation technologies with, as the underlying principle, the taking of these soil-related aspects into account when designing remediation strategies. Deltares focused on the interaction between the remediation approach and the contaminant conditions and soil system characteristics during the first active remediation phase in which the bulk of the contaminant is removed. The concepts were tested and the coupling of remediation technologies was studied in laboratory and field pilot tests at contaminated sites in Austria, Belgium and Poland.

Deltares’ role in the project was to help practitioners to select the most cost-effective and sustainable approach overall, eliminating barriers for their application and lowering the cost of soil and groundwater remediation. Deltares formulated tools that environmental practitioners can use to select remediation approaches. These selection tools comprise flow charts, tables and figures that promote a balanced use of multiple technologies. The balance is based on an integral consideration of contaminant conditions, soil system characteristics and soil functions. A first set of tools will help environmental practitioners to select the most sustainable and cost-effective chemical oxidation technology for the active phase. Additional selection tools are provided for the coupling of in-situ chemical and biological remediation technologies.

Some of the lessons learned during the project could not be captured in selection tools. These do’s and don’ts have been laid down in rules that guide the environmental practitioner during the
selection of the appropriate technology. One of the key messages is that thorough laboratory and field pilot testing prior to fullscale application is paramount to cost-effective remediation.