To test the feasibility of biological treatment of heavy and weathered hydrocarbon-contaminated soil using dynamic biopiles, a pilot test was carried out in a authorized facility to test different types of treatment (application of green or fungal composted soil improver, application of surfactant products, and application of a biological strategy integrated with an oxidative pretreatment) in order to degrade even the most recalcitrant hydrocarbon fraction.

The treated soil, hailing from a refinery, represents a contaminated matrix recalcitrant to biological remediation since compositional fingerprint analysis showed the presence of a heavy hydrocarbon fraction C26÷C40 with a high degree of weathering.

A pilot test with dynamic biopiles was performed at the facility Sistemi Ambientali S.r.l. (Calcinate, BG). In a first step, the pilot test involved setting up 2 biopiles of approx. 18 mc to test separately the addition of a green composted soil improver and a fungal soil improver. To increase the bioavailability of the more recalcitrant fraction, a surfactant product was added. In the second step of the test, the efficacy of an oxidative treatment with persulfate, applied at the pretreatment or finishing stage, was tested.