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 with great harm to the air quality and human health. In this study, the suppression effects of urea on total PCDD/Fs and their congeners emission were investigated via the sintering pot tests, and the inhibition mechanisms were studied. The results showed that the I-TEQ values of total PCDD/Fs decreased from 0.50 (non-urea) to 0.20, 0.12 and 0.20 ng I-TEQ Nm-3 with the addition of 0.02, 0.035 and 0.05 wt.% urea solid particles into the iron ore sintering mixture. However, the use of urea increased the low-chlorinated values from 0.003 to 0.009, 0.006 and 0.006 ng I-TEQ Nm-3, and from 0.014 to 0.020, 0.018 and 0.020 ng I-TEQ Nm-3, respectively for TeCDF and TeCDD. Moreover, the average I-TEQ number of chlorine substituents of PCDFs and PCDDs also decreased after adding urea, indicating that urea can inhibit the chlorination process of PCDD/Fs or promote the dechlorination reaction. The possible suppression mechanism and the high-chlorinated PCDD/Fs hydrodechlorination mechanism by urea were proposed and discussed.


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




Impact Factor: 2.735

5-Year Impact Factor: 2.827


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