| The effects of humic acid on the fate of two PAHs, phenanthrene and pyrene, were studied. The enhancements on the apparent solubility and adsorption partition coefficient were related mathematically to the humic acid concentration showing a Langmuir type partition and logarithmic relationships, respectively. Two species of PAH degrading bacteria were isolated and identified to be Pseudomonas sp. and Xanthomonas sp. Both bacteria could utilize PYR as a sole source of carbon and energy. The mineralization of the humic acid-PHE complex by Pseudomonas sp. was stimulated by the presence of humic acid to a same magnitude as in the sorption effects. Meanwhile, the magnitude of enhancement in PYR mineralization by Xanthomonas sp. was lower compared to the desorption enhancement. |
