Pleurotus ostreatus spent mushroom substrate for the degradation of polycyclic aromatic hydrocarbons: the case study of a pilot dynamic biopile for the decontamination of a historically contaminated soil

BACKGROUND: Polycyclic aromatic hydrocarbons (PAHs) are hazardous contaminants. Bio-based technology is among recommended practices for the recovery of PAH contaminatedmatrices. The objective of the study was to validate the exploitation of spent mushroom substrate (SMS), an organic waste deriving from the industrial production of Pleurotus ostreatus, as bulking agent in a dynamic biopile pilot plant, because of the SMS potential oxidative capacity towards aromatic recalcitrant compounds. The dynamic biopile pilot plant treated 7 tons of a historically PAH contaminated soil (6469±423mg PAHs kg−1), classified as dangerous waste. RESULTS: Themixing of SMSwith soilwasmandatory for the depletion of PAHs, which after 8months,were at significantly lower concentrations (112±5mg PAHs kg−1). The treated soil was capable of reintroduction to the industrial site of origin. However, a residual genotoxicity of soil elutriates at the end of the process wasmeasured on root tips of Vicia faba L. CONLUSIONS: The SMS derived from the industrial production of P. ostreatus is exploitable as a versatile low cost organic substrate with oxidative capacity towards PAHs and its exploitation as a bulking agent in biopiles is advantageous for the disposal of the organic waste.