title: Fenton oxidation to remediate PAHs in contaminated soils: A critical review of major limitations and counter-strategies.
abstract: Fenton oxidation constitutes a viable remediation strategy to remove polycyclic aromatic hydrocarbons (PAHs) in contaminated soils. This review is intended to illustrate major limitations associated with this process like acidification, PAH unavailability, and deterioration of soil quality along with associated factors, followed by a critical description of various developments to overcome these constraints. Considering the limitation that its optimal pH is around 3, traditional Fenton treatment could be costly, impractical in soil due to the high buffering capacity of soils and associated hazardous effects. Use of various chelating agents (organic or inorganic) allowed oxidation at circumneutral pH but factors like higher oxidant demand, cost and toxicity should be considered. Another alternative is the use of iron minerals that can catalyze Fenton-like oxidation over a wide range of pH, but mobility of these particles in soils (i.e. saturated and unsaturated zones) should be investigated prior to in-situ applications. The PAH-unavailability is the crucial limitation hindering their effective degradation. Research data is compiled describing various strategies to address this issue like the use of availability enhancement agents, extraction or thermal pretreatment. Last section of this review is devoted to describe the effects of various developments in Fenton treatment onto soil quality and native microbiota. Finally, research gaps are discussed to suggest future directions in context of applying Fenton oxidation to remediate contaminated soils.
authors.affiliation: Department of Geosciences, Center for Applied Geosciences, University of Tübingen, 72074 Tübingen, Germany; Institute of Soil and Environmental Sciences, University of Agriculture, Faisalabad 38040, Pakistan. Electronic address: muhammad.usman@uaf.edu.pk.
authors.forename: M
authors.initials: M
authors.lastname: Usman
authors.affiliation: Ecole Nationale Supérieure de Chimie de Rennes, UMR CNRS 6226, 11 Allée de Beaulieu, 35708 Rennes Cedex 7, France.
authors.forename: K
authors.initials: K
authors.lastname: Hanna
authors.affiliation: Department of Geosciences, Center for Applied Geosciences, University of Tübingen, 72074 Tübingen, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Haderlein
mesh_terms: D052918:Environmental Restoration and Remediation / Q000379:methods*; D010084:Oxidation-Reduction; D011084:Polycyclic Aromatic Hydrocarbons / Q000737:chemistry*; D012989:Soil Pollutants / Q000737:chemistry*
chemical_list: D011084:Polycyclic Aromatic Hydrocarbons; D012989:Soil Pollutants
keywords: Fenton oxidation; PAH remediation; PAH unavailability; Soil quality; pH