Degradation and enhanced biodegradability of polycyclic aromatic hydrocarbons by ozonation in a bipolar solvent system.

摘要

Polycyclic aromatic hydrocarbons (PAHs) are highly hazardous pollutants found in soil, sediments, and air; they are produced from heat and power generation, petroleum leakages and spills, shale oil, coal liquification processes, motor vehicle emissions, and cigarette smoke. Some of them are acutely toxic, mutagenic, or carcinogenic. The recalcitrant nature of pyrene and other PAHs in part lies in their low solubility in water, rendering them less susceptible to chemical or biological degradation. An ozone-bipolar solvent system was developed to overcome this remediation obstacle. The objectives of this study are to: (1) provide mechanistic details in the degradation of pyrene and benzo[a]pyrene under ozonation in the bipolar solvent system, (2) test the biodegradability of resultant intermediates from ozonation, (3) evaluate the potential of the ozone-bipolar solvent system for the treatment of PAHs, (4) and apply the ozone-bipolar system to remediate bulk petroleum residues. Samples containing reaction intermediates and byproducts from the ozone-bipolar solvent system at different ozonation stages were collected, identified, and further tested for their biodegradability. The results indicate that the innovative ozone-bipolar solvent system is feasible for degradation of recalcitrant pyrene, benzo[a]pyrene, and bulk petroleum residues into less toxic and more water soluble intermediates that are amenable to subsequent biological treatment processes.