Remediation of phenanthrene-contaminated soil by simultaneous persulfate chemical oxidation and biodegradation processes

Abstract

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous compounds with carcinogenic and/or mutagenic potential. To address the limitations of individual remediation techniques and to achieve better PAH removal efficiencies, the combination of chemical and biological treatments can be used. The degradation of phenanthrene (chosen as a model of PAH) by persulfate in freshly contaminated soil microcosms was studied to assess its impact on the biodegradation process and on soil properties. Soil microcosms contaminated with 140 mg/kgDRY SOIL of phenanthrene were treated with different persulfate (PS) concentrations 0.86-41.7 g/kgDRY SOIL and incubated for 28 days. Analyses of phenanthrene and persulfate concentrations and soil pH were performed. Cultivable heterotrophic bacterial count was carried out after 28 days of treatment. Genetic diversity analysis of the soil microcosm bacterial community was performed by PCR amplification of bacterial 16S rDNA fragments followed by denaturing gradient gel electrophoresis (DGGE). The addition of PS in low concentrations could be an interesting biostimulatory strategy that managed to shorten the lag phase of the phenanthrene biological elimination, without negative effects on the physicochemical and biological soil properties, improving the remediation treatment.

Use of different kinds of persulfate activation with iron for the remediation of a PAH-contaminated soil

“…Its characterization procedure and a detailed description of the properties are found elsewhere (Pardo et al, 2014;Vicente et al, 2012). Procedure of soil spiking was performed as followed in literature (Kulik et al, 2006;Mora et al, 2014), where an acetone solution with ANT, PHE, PYR and BaP was distributed and mixed manually onto the soil with a spatula. Contaminant concentrations obtained were 97 ± 6 mg·kg −1 for ANT, 89 ± 2 mg·kg −1 for PHE, 93 ± 1 mg·kg − 1 for PYR and 102 ± 1 mg·kg − 1 for BaP, respectively.…”

“…ISCO has been increasingly regarded as a relevant alternative to conventional treatment technologies for remediation of groundwater and soils contaminated by recalcitrant organic contaminants (Watts and Teel, 2006), including PAHs (Rivas, 2006;Sirguey et al, 2008). The most commonly used oxidants include permanganate (MnO 4 ), Fenton's reagent (hydrogen peroxide and Fe 2+ ) (Ferrarese et al, 2008;Laurent et al, 2012;Pardo et al, 2014), ozone (Rivas et al, 2009), and sodium persulfate (PS) (Mora et al, 2014). These oxidants can effectively transform target contaminants in soil or water into harmless products, such as CO 2 and H 2 O (Chen et al, 2009).…”

Fate of iron and polycyclic aromatic hydrocarbons during the remediation of a contaminated soil using iron-activated persulfate: A column study

“…Soil properties and the characterization procedure, except the determination of the hydraulic conductivity, are detailed in previous works (Pardo et al, 2014;Vicente et al, 2012). Soil spiking was carried out as reported elsewhere (Kulik et al, 2006;Mora et al, 2014;Peluffo et al, 2015), spreading slowly an acetone stock solution of the contaminants to the clean soil, being mixed manually with a spatula simultaneously. After spiking, contaminated soil was kept at room temperature in the absence of light for three months in order to ensure a certain grade of aging.…”

Remediation of soil contaminated by PAHs and TPH using alkaline activated persulfate enhanced by surfactant addition at flow conditions

“…Property values such as pH = 7.22, total organic carbon = 0.196% and labile iron = 7235 mg kg −1 , dp < 2 mm and hydraulic conductivity = 14.1 cm day −1 , were characterized in previous work , . The spiking procedure was developed according to the literature , , . An acetone solution containing heating oil, ANT, PHE, PYR and BaP was applied to the soil and mixed manually with a spatula simultaneously.…”

“…48,49 The spiking procedure was developed according to the literature. 40,50,51 An acetone solution containing heating oil, ANT, PHE, PYR and BaP was applied to the soil and mixed manually with a spatula simultaneously. Once the spiking was completed, the contaminated soil was aged for three months at room temperature in the absence of light and for the following six months at 10 ∘ C. After this ageing, TPH and PAH concentration was measured in the spiked soil, with results: HHO 4820 mg kg -1 soil, PHE 101 mg kg -1 soil, ANT 31 mg kg -1 soil, ATQ 92 mg kg -1 soil, PYR 106 mg kg -1 soil, BaP 26 mg kg -1 soil.…”