Multivariate evaluation and optimization of an activated-magnesium/co-solvent system for the reductive degradation of polycyclic aromatic hydrocarbons.

The present study evaluates the capability of an activated-magnesium metal and protic co-solvents to promote the reductive degradation of three different polycyclic aromatic hydrocarbons, specifically pyrene, benzo[k]fluoranthene and benzo[g,h,i]perylene. Multivariate analyses demonstrated that the kinetics of degradation was affected by several experimental factors such as magnesium loading, acid addition and solubility of the compounds. It was determined that an acid activator is needed for the degradation reaction to proceed and it is also noted that the use of a 1:1 ethanol/ethyl lactate co-solvent is ideal for the complete dissolution of all three compounds with concentrations varying from 200 to 275mgL(-1). The experimental results also indicate that, at room temperature conditions, only 0.05-0.1g of magnesium is required in order to achieve greater than 93% degradation efficiency after 24h of reaction. This methodology is attractive and may allow for the development of an economic and environmentally friendly field application for the remediation of other polycyclic aromatic hydrocarbons.