TY - JOUR
T1 - Enhancing phase identification in waste-to-energy fly ashes
T2 - Role of Raman spectroscopy, background fluorescence, and photobleaching
AU - Samouh, Hamza
AU - Kumar, Vikram
AU - Santiago, Halle Mari
AU - Garg, Nishant
N1 - The information, data, or work presented herein was funded by the Advanced Research Projects Agency-Energy (ARPA-E), U.S. Department of Energy , under Award Number DE-AR0001401 . The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. The authors would like to acknowledge that a part of this research was carried out at the Materials Research Laboratory Central Research Facilities and Core Facilities at the Carl R. Woese Institute of Genomic Biology at the University of Illinois Urbana-Champaign. We thank Chirayu Kothari for his MATLAB code, enabling pixel assignment to different phases based on the signal-to-noise (S/N) ratio.
The information, data, or work presented herein was funded by the Advanced Research Projects Agency-Energy (ARPA-E), U.S. Department of Energy, under Award Number DE-AR0001401. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. The authors would like to acknowledge that a part of this research was carried out at the Materials Research Laboratory Central Research Facilities and Core Facilities at the Carl R. Woese Institute of Genomic Biology at the University of Illinois Urbana-Champaign. We thank Chirayu Kothari for his MATLAB code, enabling pixel assignment to different phases based on the signal-to-noise (S/N) ratio.
PY - 2023/10/15
Y1 - 2023/10/15
N2 - Waste-to-Energy (WTE) facilities incinerate ∼11% (∼ 222 Mt) of global solid waste, generating bottom and fly ashes. Landfilling these ashes is costly, and risks releasing contaminants into the environment. Instead, using WTE ashes in secondary industrial applications can circumvent such environmental risks. However, their secondary use is restricted by their inconsistent mineralogy, which may vary due to fluctuating waste composition and combustion conditions. Therefore, there is a need for rapid and reliable monitoring of WTE fly ash mineralogy. Here, we evaluate the employment of Raman spectroscopy for that purpose. Our initial investigation of 12 unique WTE fly ashes resulted in excessive fluorescence, rendering key Raman peaks obscure. To address this issue, we report that a mere 2 min of photobleaching can significantly reduce this fluorescence, facilitating the detection of calcite, calcium sulfate, zincite, and carbon – phases previously undetectable in original spectra. These results show the potential of Raman spectroscopy for rapid monitoring of WTE fly ash mineralogy, which could be beneficial in diverting these ashes from landfill.
AB - Waste-to-Energy (WTE) facilities incinerate ∼11% (∼ 222 Mt) of global solid waste, generating bottom and fly ashes. Landfilling these ashes is costly, and risks releasing contaminants into the environment. Instead, using WTE ashes in secondary industrial applications can circumvent such environmental risks. However, their secondary use is restricted by their inconsistent mineralogy, which may vary due to fluctuating waste composition and combustion conditions. Therefore, there is a need for rapid and reliable monitoring of WTE fly ash mineralogy. Here, we evaluate the employment of Raman spectroscopy for that purpose. Our initial investigation of 12 unique WTE fly ashes resulted in excessive fluorescence, rendering key Raman peaks obscure. To address this issue, we report that a mere 2 min of photobleaching can significantly reduce this fluorescence, facilitating the detection of calcite, calcium sulfate, zincite, and carbon – phases previously undetectable in original spectra. These results show the potential of Raman spectroscopy for rapid monitoring of WTE fly ash mineralogy, which could be beneficial in diverting these ashes from landfill.
KW - Photobleaching
KW - Photolysis
KW - Raman Spectroscopy
KW - WTE fly ash
KW - Waste-to-Energy
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U2 - 10.1016/j.jhazmat.2023.132462
DO - 10.1016/j.jhazmat.2023.132462
M3 - Article
C2 - 37683344
AN - SCOPUS:85171632782
SN - 0304-3894
VL - 460
JO - Journal of Hazardous Materials
JF - Journal of Hazardous Materials
M1 - 132462
ER -