In the framework of the REGROUND project, a contaminated site in north of Spain was remediated using ColFerroX technology. The site was used historically for the production of nitrogen based products such as fertilizers. Waste materials (e.g. slag from furnaces, wastes from coal-washing and partially burned pyrites and pyrite ashes reach with heavy metals) were dumped on the surface. The contaminants eventually leached into the groundwater and were transported towards the neighboring sites and to a downstream river.
Contamination levels were high in both groundwater and sediment phases. Dissolved concentrations of 20-45 mg/L for zinc, 1-20 mg/L copper, 50-3000 µg/L arsenic, 100-700 µg/L lead were measured among others. Metal contaminants were also present in the sediment phase as high as several grams per kg of solid weight.
The aim of the study was to demonstrate the applicability of the ColFerroX technology to immobilize heavy metals at an industrial site in realistic dimension.