Impact of the Fenton-like treatment on the microbial community of a diesel-contaminated soil. (January 2018)

• Record Type: Journal Article
• Authors: Polli, Flavia; Zingaretti, Daniela; Crognale, Silvia; Pesciaroli, Lorena; D'Annibale, Alessandro; Petruccioli, Maurizio; Baciocchi, Renato
• Is Part Of: Chemosphere. Volume 191(2018)
• Page Start: 580
• Page End: 588
• Publication Date: 2018-01
• Subjects: Fenton -- Bioremediation -- Diesel contamination -- DGGE -- qPCR; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2017.10.081
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Fenton-like treatment (FLT) is an ISCO technique relying on the iron-induced H2 O2 activation in the presence of additives aimed at increasing the oxidant lifetime and maximizing iron solubility under natural soil pH conditions. The efficacy of FLT in the clean-up of hydrocarbon-contaminated soils is well established at the field-scale. However, a better assessment of the impact of the FLT on density, diversity and activity of the indigenous soil microbiota, might provide further insights into an optimal combination between FLT and in-situ bioremediation (ISB). The aim of this work was to assess the impacts of FLT on the microbial community of a diesel-contaminated soil collected nearby a gasoline station. Different FLT conditions were tested by varying either the H2 O2 concentrations (2 and 6%) or the oxidant application mode (single or double dosage). The impact of these treatments on the indigenous microbial community was assessed immediately after the Fenton-like treatment and after 30, 60 and 90 d and compared with enhanced natural attenuation (ENA). After FLT, a dramatic decrease in bacterial density, diversity and functionality was evident. Although in microcosms with double dosing at 2% H2 O2 a delayed recovery of the indigenous microbiota was observed as compared to those subjected to single oxidant dose, after 60 d incubation the respiration rate increased from 0.036 to 0.256 μg CCO2 g −1 soil h −1 . Irrespective of the oxidant dose, best degradation results after 90 d incubation (around 80%) were observed with combined FLT, relying on double oxidant addition, and bioremediation. Highlights: The effect of a Fenton-like treatment on the soil microbial community was assessed. Adding H2 O2 twice at lower amount is effective as adding it once at higher amount. Higher H2 O2 concentration entails more severe impact on microbial community. Bioattenuation occurred after Fenton-like step despite the observed negative impacts. Fenton-like treatment can significantly shorten the bioremediation process.