Reduction of benzo[a]pyrene with acid-activated magnesium metal in ethanol: A possible application for environmental remediation

Persistent organic pollutants (POPs) are a well-known threat to the environment. Substances such as polycyclic aromatic hydrocarbons (PAHs) in contaminated soils and sediments can have severe and long-term effects on human and environmental health. There is an urgent need for the development of safe technologies for their effective degradation. Here we present a new technique using ball-milled magnesium powder and ethanol solvent as a convenient electron transfer/proton source for the partial reduction of PAHs under ambient conditions. The rates of degradation were determined while evaluating the influences of acetic acid and type of ball-milled magnesium added to the reaction mixture. The results of these triplicate studies indicate that with the use of acetic acid as an activator and ball-milled magnesium carbon (Mg/C), this reducing system (Mg-EtOH) is able to achieve a 94% conversion of 250 mu g/mL of toxic benzo[a]pyrene into a mixture of less toxic and partially hydrogenated polycyclic compounds within 24 h. This methodology can be used as a combined process involving ethanol washing followed by reduction reaction and it can also be considered as an easy handling and efficient alternative process to the catalytic hydrogenation of PAHs. (C) 2011 Elsevier B.V. All rights reserved.