Quantification of pentachlorophenol transformation product distribution in the presence of Phanerochaete chrysosporium

Abstract

Experiments were carried out to quantify the mineralization and distribution of pentachlorophenol (PCP) by the white rot fungus Phanerochaete chrysosporium, and distribution of its transformation products into water-soluble, solvent-soluble, sorbed, and volatile fractions in liquid cultures. Water-soluble and solvent-soluble products from ¹⁴C-PCP transformation were first measured under oxygen limited conditions. Results indicated that after 12 days, 15% of ¹⁴C was recovered in methylene chloride, and less than 1% was water soluble. Sorption to the fungal mat reached a maximum of 16% ¹⁴C after 9 days incubation and declined to 5% at day 12. However, recovery of ¹⁴C within the system was only 30% at day 12. To improve the mass balance of the system, polyurethane foam was placed inside the culture flask to trap volatile products of PCP transformation. Results showed that after 12 days incubation of ¹⁴C-PCP with the fungus, 82% of the ¹⁴C added was volatilized. GC/MS analysis demonstrated that pentachloroanisole (PCA) was the only volatile product of PCP transformation. Sorption of ¹⁴C to the fungal mat was reversible to some extent. Chemical mass balance results in this experiment were near 100%. In the final experiment, the polyurethane volatile trap was placed outside the culture flask to assess the impact of the continuous removal of volatiles from the flask head space on mineralization. Increased ¹⁴CO₂ production was observed when the polyurethane volatile trap was placed outside the culture flask compared with placement inside the flask.