title: Application of a magnesium/co-solvent system for the degradation of polycyclic aromatic hydrocarbons and their oxygenated derivatives in a spiked soil.
abstract: This study evaluates the capability, efficacy and practicality of a combined approach based on solvent extraction and chemical reduction to simultaneously degrade polycyclic aromatic hydrocarbons (PAHs) and their oxygenated derivatives (OPAHs) in spiked soil. The spiked soil was washed using a composite organic solvent consisting of ethanol and ethyl lactate (1:1, v/v) and then degradation of the extracted contaminants using zero-valent magnesium. The extraction conditions were optimized at 25 °C with solvent-soil ratio of 2:1 (v/w) and the ensuing degradation efficiency ranged from 79% to 88% for the OPAHs, and 66% to 87% for the PAHs after 24 h of reaction at pH of 6.1. The reductive degradation of the spiked contaminants followed pseudo-first-order kinetics; however, comparing the kinetic results of this study to soil-free studies, the degradation rates are significantly reduced. It can be inferred that extracted organic or inorganic components from the soil medium hinder the degradation process, possibly by reducing the reactivity of the activated metal. Furthermore, to our understanding, this study is the first report on the simultaneous degradation of these priority pollutants and their oxygenated derivatives. The experimental results encourage the application of this magnesium/co-solvent system for future pilot-scale remediation studies.
authors.affiliation: Environmental Chemistry Laboratory, University of Central Florida, 4000 Central Florida Blvd., Orlando, FL 32816, United States. eliem@onid.oregonstate.edu
authors.forename: Marc R
authors.initials: MR
authors.lastname: Elie
authors.forename: Robert E
authors.initials: RE
authors.lastname: Williamson
authors.forename: Christian A
authors.initials: CA
authors.lastname: Clausen
authors.forename: Cherie L
authors.initials: CL
authors.lastname: Yestrebsky
mesh_terms: D004787:Environmental Pollution / Q000517:prevention & control*; D052918:Environmental Restoration and Remediation / Q000379:methods*; D000431:Ethanol / Q000737:chemistry; D007773:Lactates / Q000737:chemistry; D008274:Magnesium / Q000737:chemistry*; D011084:Polycyclic Aromatic Hydrocarbons / Q000737:chemistry* / Q000378:metabolism; D012989:Soil Pollutants / Q000737:chemistry* / Q000378:metabolism; D012997:Solvents / Q000737:chemistry*
chemical_list: D007773:Lactates; D011084:Polycyclic Aromatic Hydrocarbons; D012989:Soil Pollutants; D012997:Solvents; D000431:Ethanol; C015866:ethyl lactate; D008274:Magnesium