Application of fungal substrate from commercial mushroom production — Pleuorotus ostreatus — for bioremediation of creosote contaminated soil

Degradation of polycyclic aromatic hydrocarbons in aged-creosote contaminated soil by applying spent mushroom compost, oyster mushroom, was studied in medium sized polyethylene columns. Two different commercial sources of inoculum were compared, and the effect of organizing soil and substrate in layers or mixing it together was investigated. Degradation of 3-ring compounds were similar for the two fungal inoculums. For the hard degradable PAHs (4- and 5-ring) there was a significant difference. The 4- and 5-ring PAHs were degraded better when soil and fungal substrate were homogenized rather than layered. Fish oil added to spent mushroom compost and mixed with creosote contaminated soil gave best degradation of PAHs. This treatment, incubated for 7 weeks at ambient temperature, resulted in the following removal: 86% of total 16 PAHs, 89% of 3-ring PAHs, 87% of 4-ring PAHs and 48% of 5-ring PAHs.