Biological composting of petroleum waste organics using the white rot fungus Phanerochaete chrysosporium

Environmental enrichment of the white rot fungus Phanerochaete chrysosporium in biological compost soil reactors was effective in enhancing the rates of Benzo(a)pyrene removal over that observed under natural soil conditions. In contaminated soil compost systems amended with fungal inoculum and primary substrate, maximum Benzo(a)pyrene removal rates of 0.31 mg B(a)p/kg compost material-day (0.25 mgB(a)p/kg soil-day) were observed while in unamended soil conditions, maximum removal rates of 0.13 mg B(a)p/kg soil-day were recorded. Additions of primary substrate without any fungal inoculum gave compound removal rates similar to soil only conditions (i.e., 14 mg B(a)p/kg soil-day). Differences in contaminant and radioactivity (14C) removal rates indicated that Benzo(a)pyrene derived carbon was being incorporated into nonvolatile materials within the compost environment. Contaminated soil pH had a significant effect on Benzo(a)pyrene removal rates during composting treatment. With acid soils (pH-4.8), a maximum Benzo(a)pyrene removal rate of 0.11 mg B(a)p/kg compost material-day was determined compared to 0.31 mg B(a)p/kg compost material-day in alkaline (pH-8.0) soil. Oxygen availability appeared to be one of the most important process variables influencing both fungal growth and Benzo(a)pyrene removal. Periodic pulses of oxygen equivalent to a three volume turnover of reactor headspace every three days resulted in increasing the Benzo(a)pyrene removal rate from 0.31 mg B(a)p/kg compost material-day to 0.85 mg B(a)p/kg compost material day