Yifan Wang1, Lixin Qian1, Zhengwei Yu This email address is being protected from spambots. You need JavaScript enabled to view it.1, Tiejun Chun This email address is being protected from spambots. You need JavaScript enabled to view it.1, Hongming Long1,2, Xuejian Wu1, Jiaxin Li1

1 School of Metallurgical Engineering, Anhui University of Technology, Ma’anshan, Anhui 243002, China
2 Anhui Province Key Laboratory of Metallurgy Engineering & Resources Recycling, Anhui University of Technology, Ma’anshan 243002, China


 

Received: February 3, 2020
Revised: May 13, 2020
Accepted: May 15, 2020
Download Citation: ||https://doi.org/10.4209/aaqr.2019.12.0660  

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Cite this article:

Wang, Y., Qian, L., Yu, Z., Chun, T., Long, H., Wu, X. and Li, J. (2020). Inhibition Behavior of PCDD/Fs Congeners by Addition of N-containing Compound in the Iron Ore Sintering. Aerosol Air Qual. Res. https://doi.org/10.4209/aaqr.2019.12.0660


HIGHLIGHTS

  • Urea can inhibit the emission of total PCDD/Fs.
  • Urea promotes the formation of TeCDF and TeCDD in the iron ore sintering.
  • The NH2· and H· can be formed in the pyrolysis process of urea.
  • The C-O bond of PCDD/Fs molecules can be attacked and broken by the H·.
  • The H· attacked the C-Cl bonds to promotes the hydrodechlorination reaction.
 

ABSTRACT


PCDD/Fs are typical toxic persistent aromatic compounds that greatly reduce air quality and harm human health. In this study, urea’s suppressive effect on PCDD/Fs and their congener emissions was investigated via sintering pot tests, and the inhibition mechanisms were studied. The results showed that the I-TEQ values for the total PCDD/Fs decreased from 0.50 to 0.20, 0.12 and 0.20 ng I-TEQ Nm3 after adding solid 0.02, 0.035 and 0.05 wt.% urea particles, respectively, to the iron ore sintering mixture, but these values increased for the low-chlorinated TeCDFs (from 0.003 to 0.009, 0.006 and 0.006 ng I-TEQ Nm3) and TeCDDs (from 0.014 to 0.020, 0.018 and 0.020 ng I-TEQ Nm3). Moreover, the average I-TEQ values for the chlorine substituents in the PCDFs and PCDDs decreased, indicating that urea inhibited chlorination or enhanced dechlorination. The potential mechanisms by which urea suppresses the total PCDD/Fs and hydrodechlorinates the high-chlorinated PCDD/Fs are discussed.


Keywords: PCDD/Fs; Congeners; Urea; Active radical; Iron ore sintering.



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