Evaluation of surfactants for HCH mobilisation

Envirotecnics carried out laboratory trials to evaluate the use of surfactants for the mobilisation of hexachlorocyclohexane (HCH) in the non-aqueous phase present in the Sardas landfill (Aragon). The goal was selecting the best surfactant and the perfect dosage for a pilot trial at the Sardas landfill, using SEAR (Surfactant Enhanced Aquifer Remediation) technology.

The leachate from the Sardas landfill, which has multiple compounds, was used for the laboratory tests.

The surfactant mixture that showed the best results was chosen for the tests. The choice was based on the properties of individual surfactants and blends (hydrophilic/lipophilic balance and emulsifying capacity).

Laboratory tests (batch and soil column trials) showed a reduction in DNAPL mobilisation in the presence of fine particulate soils. The potential for HCH (DNAPL) mobilisation under natural conditions may be limited due to the presence of fine matter (silts and clays) in natural soil. This is thus a key parameter to take into account for aquifer remediation processes.

Feasibility study