Co-combustion of Zn/Cd-hyperaccumulator and textile dyeing sludge: Heavy metal immobilizations, gas-to-ash behaviors, and their temperature and atmosphere dependencies
Yükleniyor...
Dosyalar
Tarih
2023
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Elsevier
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
This study quantified and revealed the temperature and atmosphere dependencies of the enrichment rates and speciation distributions of Zn and Cd and the behaviors of Cl and S for the co-combustion of a hyperaccumulator (SAH) of Zn and Cd and textile dyeing sludge (TDS) at a blend ratio of 3:1 (ST31). The addition of Al-rich TDS to SAH provided the chemisorption sites for Zn and Cd and generated stable Al/Si structures for their stabilization in the ST31 ash. The rising temperature and the atmosphere change from N-2/O-2 to CO2/O-2 transformed Zn and Cd into their oxidizable and residual fractions. Cl promoted the volatilizations of the heavy metals, with its content in the ST31 ash falling from 86.28% at 650 ? to 17.98% at 950 ?. The S content (31.08-33.86%) of the ST31 ash existed mainly as CaSO4 and was slightly higher in the CO2/O-2 than N-2/O-2 atmosphere (29.45%) since the high CO2 concentration adversely influenced the decomposition of CaCO3, while S indirectly affected the migrations of Zn and Cd. The combined results of the experiments, thermodynamic simulations, and multi-objective optimization pointed to 850 ? in the oxy-fuel atmosphere with 30% O-2 concentration as the optimal settings in order to stabilize Zn and Cd with an acceptable risk. The possible reaction pathways and immobilization mechanisms were also derived considering the interactions among minerals, Zn, Cd, Cl, and S.
Açıklama
This research was financially supported by the National Natural Science Foundation of China (No. 51978175) , the Scientific and Tech- nological Planning Project of Guangzhou, China (No. 202103000004) , and Natural Science Foundation of Guangdong Province, China (No. 2022A1515010825;2019A1515012131) . We would like to thank Miss. Yang and Mr. Yan at Analysis and Test Center of Guangdong University of Technology for their assistance with TG-FTIR-GC/MS and XPS analyses.
Anahtar Kelimeler
Hyperaccumulator, Sludge, Heavy Metal, Cl/S, Immobilization Mechanism, Oxy-fuel Combustion
Kaynak
Chemical Engineering Journal
WoS Q Değeri
Q4
Scopus Q Değeri
Q1
Cilt
451
Sayı
Künye
Wu, X., Chen, Z., Liu, J., Wei, Z., Chen, Z., Evrendilek, F., ... & Chen, Z. (2023). Co-combustion of Zn/Cd-hyperaccumulator and textile dyeing sludge: Heavy metal immobilizations, gas-to-ash behaviors, and their temperature and atmosphere dependencies. Chemical Engineering Journal, 451, 138683.
