SUMMARY

Objective

The Learning Lab examines the critical aspects of mixing remediation sorbents or other additives into soil at field-scale. It is important for site owners, engineering consultants, mixing contractors and sorbent suppliers to understand the importance of accurate sorbent application in the field.

Description

Sorbents are widely used for binding up environmental contaminants in soil to prevent them leaching, with the objective of reducing risk to human health and the environment. Bench-scale tests are routinely undertaken to determine the optimal dose and type of sorbent that will best meet the leachability reduction objectives of the project. Bench-scale testing is relatively reliable because it can be carried out under controlled conditions with thorough mixing and multiple replicates.

When the treatment process is scaled up to full-scale field application, a number of potential errors can be introduced during the sorbent addition, soil mixing and validation processes. This Learning Lab explores some of these issues using examples from global soil stabilization projects.

Aspects explored include soil particle size reduction, PFAS and soil heterogeneity, and sorbent dosing efficiencies with different types of soil and mixing equipment. The lessons learnt are applicable to site owners, engineering consultants, mixing contractors and sorbent suppliers.