A Polar−Nonpolar, Acetic Acid/Heptane, Solvent Medium for Degradation of Pyrene by Ozone

Abstract

Pyrene of natural and anthropogenic sources is one of the toxic, mutagenic polycyclic aromatic hydrocarbons (PAHs) listed as priority pollutants. The recalcitrant nature of pyrene and other PAHs lies in part in their low solubility in water, rendering them less susceptible to chemical or biological degradation. This work investigates the use of a polar−nonpolar (PNP) solvent system, in conjunction with ozonation, to overcome this remediation obstacle. The PNP solvent system consists of equal portions of polar acetic acid and nonpolar heptane. The heptane component enables high concentrations of pyrene to be dissolved, while the acetic acid keeps subsequently formed polar intermediates and byproducts in solution. This PNP solvent system maintains effective exposure of all compounds to aqueous ozone throughout the course of reaction and prevents the formation of solid precipitation. Following ozonation, the solvent system is added with a small amount of water that results in the formation of two distinct ph...