Biological Removal of Dibenzothiophene from Soil and Changes to soil Sulfate by White-Rot Fungus Phanerochaete chrysosporium

Abstract

This study investigated biodegradation of dibenzothiophene (DBT) in marsh soil spiked by<br />white-rot fungus Phanerochaete chrysosporium. Soil samples were spiked with 100 ppm DBT<br />and incubated at 30°C in a dark chamber for 30 days. Samples were evaluated for pH, Mnperoxidase<br />activity, sulfate ion concentration and growth during the tests. Results showed<br />maximum levels of pH, Mn-peroxidase and sulfate concentrations at 8.19, 66 U L-1 and 31.21<br />mg kg-1 respectively. Colony forming unit assay determinations for contaminated soil samples<br />showed that the fungus was able to grow and use dibenzothiophene as a source of carbon and<br />energy. GC analysis of contaminated samples compared to control samples, demonstrated<br />degradation of DBT by Phanerochaete chrysosporium. There was no significantly improved<br />effect on degradation when the treatment was performed in presence of soil micro flora. The<br />system attained a high rate of DBT degradation at approximately 83.34%, the 30 day test<br />operation under optimal conditions. After 20 days, the sulfate ion concentration in soil samples<br />had almost doubled.