TY - JOUR
T1 - Designing novel magnesium oxysulfate cement for stabilization/solidification of municipal solid waste incineration fly ash
AU - Wang, Lei
AU - Zhang, Yuying
AU - Chen, Liang
AU - Guo, Binglin
AU - Tan, Yongshan
AU - Sasaki, Keiko
AU - Tsang, Daniel C.W.
N1 - Funding Information:
The authors appreciate the financial support from the Japan Society for the Promotion of Science (JSPS) KAKENHI (A) (No. JP19H00883 ), KAKENHI Early Career Scientists (No. 21K14574 ), QR Program (Qdai-jump Research Program) (No. HA61050072 ) and the Alexander von Humboldt Foundation for this study. The authors also acknowledge the support of the Kyushu University Beamline ( SAGA-LS /BL06 ) for the EXAFS experiment (No. 2019IIIK001 ).
Publisher Copyright:
© 2021 Elsevier B.V.
PY - 2022/2/5
Y1 - 2022/2/5
N2 - Municipal solid waste incineration (MSWI) fly ash is a typical hazardous waste worldwide. In this study, an innovative magnesium oxysulfate cement (MOSC) binder was designed for stabilization/solidification (S/S) of MSWI fly ash, focusing on the interactions between MOSC binder and typical metallic cations (Pb2+)/oxyanions (AsO33-). Experimental results showed that Pb and As slightly inhibited the reaction of high-sulfate 5MS system but significantly suppressed the reaction process of low-sulfate 10MS system. The 5MS binder system exhibited excellent immobilization efficiencies (99.8%) for both Pb and As. The extended X-ray absorption fine structure spectra suggested that Pb2+ coordinated with SO42-/OH- in the MOSC system and substituted Mg2+ ion sites in the internal structure of 5Mg(OH)2·MgSO4.7H2O (5−1−7) phase. In contrast, the AsO33- substituted SO42- sites with the formation of inner-sphere complexes with Mg2+ in the large interlayer space of the 5–1–7 structure. Subsequent MSWI fly ash S/S experiments showed that a small amount of reactive Si in MSWI fly ash interfered with the MOSC reaction and adversely influenced the immobilization efficiencies of Pb, As, and other elements. Through the use of 33 wt% tailored MOSC binder for MSWI fly ash treatment, a satisfying S/S performance could be achieved.
AB - Municipal solid waste incineration (MSWI) fly ash is a typical hazardous waste worldwide. In this study, an innovative magnesium oxysulfate cement (MOSC) binder was designed for stabilization/solidification (S/S) of MSWI fly ash, focusing on the interactions between MOSC binder and typical metallic cations (Pb2+)/oxyanions (AsO33-). Experimental results showed that Pb and As slightly inhibited the reaction of high-sulfate 5MS system but significantly suppressed the reaction process of low-sulfate 10MS system. The 5MS binder system exhibited excellent immobilization efficiencies (99.8%) for both Pb and As. The extended X-ray absorption fine structure spectra suggested that Pb2+ coordinated with SO42-/OH- in the MOSC system and substituted Mg2+ ion sites in the internal structure of 5Mg(OH)2·MgSO4.7H2O (5−1−7) phase. In contrast, the AsO33- substituted SO42- sites with the formation of inner-sphere complexes with Mg2+ in the large interlayer space of the 5–1–7 structure. Subsequent MSWI fly ash S/S experiments showed that a small amount of reactive Si in MSWI fly ash interfered with the MOSC reaction and adversely influenced the immobilization efficiencies of Pb, As, and other elements. Through the use of 33 wt% tailored MOSC binder for MSWI fly ash treatment, a satisfying S/S performance could be achieved.
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U2 - 10.1016/j.jhazmat.2021.127025
DO - 10.1016/j.jhazmat.2021.127025
M3 - Article
C2 - 34481391
AN - SCOPUS:85113984401
VL - 423
JO - Journal of Hazardous Materials
JF - Journal of Hazardous Materials
SN - 0304-3894
M1 - 127025
ER -