Characterization and degradation mechanism of bimetallic iron-based/AC activated persulfate for PAHs-contaminated soil remediation. (March 2021)

• Record Type: Journal Article
• Authors: Tian, Huifang; Chen, Changzhi; Zhu, Tianle; Zhu, Bingjun; Sun, Yifei
• Is Part Of: Chemosphere. Volume 267(2021)
• Publication Date: 2021-03
• Subjects: Bimetals -- Activated persulfate -- PAHs -- Characterization -- Mechanism; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2020.128875
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: In this research, a novel iron based bimetallic nanoparticles (Fe–Ni) supported on activated carbon (AC) were synthesized and employed as an activator of persulfate in polycyclic aromatic hydrocarbons (PAHs) polluted sites remediation. AC-supported Fe–Ni activator was prepared according to two-step reduction method: the liquid phase reduction and H2 - reduction under high temperature (600 °C), which was defined as Fe–Ni/AC. Characterizations using micropore physisorption analyzer, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and high-resolution transmission electron microscopy (HR-TEM) showed that the synthetic material had large specific surface area, nano-size and carbon-encapsulated metal particles, moreover, the lattice fringes of metals were clearly defined. The PAH compound types and their concentrations were determined by gas chromatography mass spectrometry (GC-MS) with SIM mode, the method detection limit (MDL) was estimated to about 0.21 μg/kg for PAHs, and the average recovery of PAHs was 96.3%. Mechanisms of PAH oxidation degradation with the reaction system of Fe–Ni/AC activated persulfate were discussed, the results showed that short-life free radicals, such as SO4 − ·, OH·, and OOH· were generated simultaneously, which acted as strong oxidizing radicals, resulting in the oxidation and almost complete opening of the PAH rings. Graphical abstract: Image 1 Highlights: A novel bimetallic iron-based/AC was synthesized by two-step reduction method. The prepared Fe–Ni/AC belongs to carbon-encapsulated metal nanoscale particles. Quantification and quality control for 19 types of PAHs in soils was determined. OH·, OOH·, SO4 − · short-lived free radicals are responsible for PAHs degradation. Both heating and metals improved the generation of SO4 − · from persulfate.