Removal of Bound PAH Residues in Contaminated Soils by Fenton Oxidation

Abstract

The availability of bound residues of polycyclic aromatic hydrocarbons (PAHs), in reference to their parent compounds, can be enhanced by microbial activity and chemical reactions, which pose severe risks for the ecosystems encompassing contaminated soils. Considerable attention has been raised on how to remove these bound residues from PAH-contaminated soils. This paper provides a novel application of Fenton oxidation in the removal of bound residues of model PAHs, such as naphthalene (NAP), acenaphthene (ACP), fluorene (FLU) and anthracene (ANT), from naturally contaminated soils. The citric acid-enhanced Fenton treatment resulted in the degradation of bound PAH residues that followed pseudo-first-order kinetics, with rate constants within 4.22 × 10−2, 1.25 × 10−1 and 2.72 × 10−1 h−1 for NAP, FLU, and ANT, respectively. The reactivity of bound PAH residues showed a correlation with their ionization potential (IP) values. Moreover, the degradation rate of bound PAH residues was significantly correlated with H2O2-Fe2+ ratio (m/m) and H2O2 concentrations. The highest removal efficiencies of bound PAH residues was up to 89.5% with the treatment of chelating agent oxalic acid, which was demonstrated to be superior to other acids, such as citric acid and hydrochloric acid. This study provides valuable insight into the feasibility of citric acid-Fenton and oxalic acid-Fenton treatments in rehabilitating bound PAH residues in contaminated soils.

Biochar-Supported FeS/Fe3O4 Composite for Catalyzed Fenton-Type Degradation of Ciprofloxacin

“…Previous studies have shown that the biochar prepared at lower temperatures (<400 • C) has more un-carbonized organic residues such as polycyclic aromatic hydrocarbons [52]. These organic residues might compete with the target pollutant (ciprofloxacin) for the consumption of reactive species [53]. The BC600 biochar alone can remove more ciprofloxacin, according to the results in Figure 8a.…”

Fenton oxidation for soil remediation: A critical review of observations in historically contaminated soils

“…The CAs have a strong chelation ability for metal ions to keep them in solution even at higher pH values which extends the optimum range of reaction pH. As illustrated in Table 2, chelating agents have been used in Fenton oxidation of various pollutants such PAHs (Laurent et al, 2012;Lemaire et al, 2019;Liao et al, 2019;Zhao et al, 2019), TPHs (Chunyang et al, 2019;Liu et al, 2019;Martínez-Pascual et al, 2015;Sutton et al, 2014b;2014a;Wang et al, 2015;Xu et al, 2011a;2011b;2017a; or polychlorinated biphenyls (PCBs) (Ma et al, 2018). The use of CAs with soluble Fe(II) exhibited significant enhancement in oxidation efficiency.…”

Fuzzy Coordination Control Strategy and Thermohydraulic Dynamics Modeling of a Natural Gas Heating System for In Situ Soil Thermal Remediation

“…7The compressive work and viscous dissipation effects of liquid are negligible. (8) The effects of contaminants are ignored.…”

“…A cornucopia of remediation technologies has been developed to treat contaminated soils [5][6][7][8]. Among these technologies, in situ soil thermal remediation holds an important niche role due to its ability to clean pollutants quickly and reliably [9].…”