Advancement in Fenton-like reactions using PVA coated calcium peroxide/FeS system: Pivotal role of sulfide ion in regenerating the Fe(II) ions and improving trichloroethylene degradation

Ali, M ; Sharif University of Technology | 2021

589 Viewed
  1. Type of Document: Article
  2. DOI: 10.1016/j.jece.2020.104591
  3. Publisher: Elsevier Ltd , 2021
  4. Abstract:
  5. This study demonstrated the prolonged benefits of polyvinyl-coated calcium peroxide (PVA@CP) in Fe(II)/nFeS mediated Fenton-like reaction. PVA@CP was prepared by a coating of PVA on calcium peroxide (CP) and synthesized nano-sized iron sulfide (nFeS) was characterized by scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM) with energy dispersive spectroscopy (EDS) elemental mapping, X-ray diffractometry (XRD), X-ray photoelectron spectroscopy (XPS), inductively coupled plasma optical emission spectroscopy (ICP-OES) and Fourier transmission infrared (FTIR) techniques. Trichloroethylene (TCE) degradation in various oxic environments (H2O2, CP, or PVA@CP) was investigated using Fe(II)/nFeS, and the slowest rate constant of 0.031 M-1 min-1 with 91 % TCE removal highlighted the long-lasting effects of PVA@CP. The effect of initial solution pH revealed that the acidic condition was most favorable. PVA@CP system accumulated the least amount (6.34 mg/L) of Fe(III) than H2O2 and CP systems. Electron paramagnetic resonance (EPR) and scavenging tests highlighted that free hydroxyl radicals (HOfree) contributed dominantly in H2O2 system while both free and surface-bound species participated well in CP and PVA@CP systems. Moreover, the insight mechanism of regenerated Fe(II) on the nFeS surface was explored by XPS. Both oxidation and reduction of sulfur were discussed and declared that S(-II) was responsible for regenerating Fe(II). The recycling sample checked the reusability of nFeS, and 98.8 % TCE removal in actual groundwater emphasized that PVA@CP/Fe(II)/nFeS is a viable technique. In conclusion, the PVA@CP/Fe(II)/nFeS system is highly recommended for long-lasting remediation of TCE contaminated groundwater. © 2020 Elsevier Ltd
  6. Keywords:
  7. Anesthetics ; Calcium compounds ; Electron spin resonance spectroscopy ; Energy dispersive spectroscopy ; Fourier transform infrared spectroscopy ; Groundwater ; Groundwater pollution ; High resolution transmission electron microscopy ; Hydrogen peroxide ; Inductively coupled plasma ; Optical emission spectroscopy ; Oxidation ; Paramagnetic resonance ; Peroxides ; Rate constants ; Remediation ; Reusability ; Scanning electron microscopy ; Sulfide minerals ; Sulfur compounds ; Transmissions ; Trichloroethylene ; X ray diffraction analysis ; X ray photoelectron spectroscopy ; Contaminated groundwater ; Electron paramagnetic resonances (EPR) ; Energy dispersive spectroscopies (EDS) ; Fenton-like reactions ; Free hydroxyl radicals ; Inductively coupled plasma-optical emission spectroscopy ; Oxidation and reduction ; Surface-bound species ; Iron metallography
  8. Source: Journal of Environmental Chemical Engineering ; Volume 9, Issue 1 , 2021 ; 22133437 (ISSN)
  9. URL: https://www.sciencedirect.com/science/article/abs/pii/S2213343720309404