title: Bioaugmentation and biostimulation as strategies for the bioremediation of a burned woodland soil contaminated by toxic hydrocarbons: a comparative study.
abstract: In this work, the natural attenuation strategy (no soil amendments done) was compared with two different bioremediation approaches, namely bioaugmentation through soil inoculation with a suspension of Trichoderma sp. mycelium and biostimulation by soil addition with a microbial growth promoting formulation, in order to verify the effectiveness of these methods in terms of degradation efficiency towards toxic hydrocarbons, with particular attention to the high molecular weight (HMW) fraction, in a forest area impacted by recent wildfire in Northern Italy. The area under investigation, divided into three parcels, was monitored to figure out the dynamics of decay in soil concentration of C₁₂₋₄₀ hydrocarbons (including isoalkanes, cycloalkanes, alkyl-benzenes and alkyl-naphthalenes besides PAHs) and low molecular weight (LMW) PAHs, following the adoption of the foregoing different remediation strategies. Soil hydrocarbonoclastic potential was even checked by characterizing the autochthonous microbial cenoses. Field experiments proved that the best performance in the abatement of HMW hydrocarbons was reached 60 days after soil treatment through the biostimulation protocol, when about 70% of the initial concentration of HMW hydrocarbons was depleted. Within the same time, about 55% degradation was obtained with the bioaugmentation protocol, whilst natural attenuation allowed only a 45% removal of the starting C12-40 hydrocarbon fraction. Therefore, biostimulation seems to significantly reduce the time required for the remediation, most likely because of the enhancement of microbial degradation through the improvement of nutrient balance in the burned soil.
authors: Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy.
authors: Marco
authors: M
authors: Andreolli
authors: Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy. Electronic address: silvia.lampis@univr.it.
authors: Silvia
authors: S
authors: Lampis
authors: Eurovix SpA, Viale Europa 10, 25046 Cazzago San Martino, BS, Italy.
authors: Pierlorenzo
authors: P
authors: Brignoli
authors: Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy. Electronic address: giovanni.vallini@univr.it.
authors: Giovanni
authors: G
authors: Vallini
mesh_terms: D001673:Biodegradation, Environmental; D052918:Environmental Restoration and Remediation / Q000379:methods*; D065928:Forests; D006838:Hydrocarbons / Q000378:metabolism*; D007558:Italy; D012621:Seasons; D012987:Soil / Q000737:chemistry*; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000378:metabolism*; D014242:Trichoderma / Q000378:metabolism
chemical_list: D006838:Hydrocarbons; D012987:Soil; D012989:Soil Pollutants
keywords: Bioaugmentation; Bioremediation; Biostimulation; Natural attenuation; Toxic hydrocarbons; Trichoderma sp.; Wildfire-impacted forest soil