TY - JOUR
T1 - Electrodialytic remediation of municipal solid waste incineration fly ash as pre-treatment before geopolymerisation with coal fly ash
AU - Zhan, Xinyuan
AU - Kirkelund, Gunvor Marie
PY - 2021
Y1 - 2021
N2 - Municipal solid waste incineration (MSWI) fly ash is classified as hazardous waste and needs to be disposed of according to strict regulations. By disposal, valuable resources in the MSWI fly ash is lost, and other solutions are sought for. The effect of electrodialytic remediation (ED) as a pre-treatment for removing heavy metals from MSWI fly ash before using the treated ash in geopolymerization with coal fly ash was explored. ED pre-treatment for MSWI fly ash increased the Si reactivity and the Si/Al ratio. The mixture of 80% coal fly ash and 20% ED treated fly ash with 8 M NaOH (L/S 0.37 mL/g) was found optimal, with a resulting compressive strength of 15.3 MPa, which was higher than the reference coal fly ash geopolymer. The leaching concentrations of Pb, Zn, Cr, Cu and Ni were below 0.02 mg/L with Mn and Cd at 0.023 and 0.027 mg/L, respectively. The enhanced mechanism for ED treated MSWI fly ash in geopolymer was confirmed by FTIR analysis and SEM images. The resistance against extreme leaching environments for treated fly ash geopolymer was stronger than raw fly ash geopolymer, and physical encapsulation of geopolymeric gels contributed to the heavy metal immobilization.
AB - Municipal solid waste incineration (MSWI) fly ash is classified as hazardous waste and needs to be disposed of according to strict regulations. By disposal, valuable resources in the MSWI fly ash is lost, and other solutions are sought for. The effect of electrodialytic remediation (ED) as a pre-treatment for removing heavy metals from MSWI fly ash before using the treated ash in geopolymerization with coal fly ash was explored. ED pre-treatment for MSWI fly ash increased the Si reactivity and the Si/Al ratio. The mixture of 80% coal fly ash and 20% ED treated fly ash with 8 M NaOH (L/S 0.37 mL/g) was found optimal, with a resulting compressive strength of 15.3 MPa, which was higher than the reference coal fly ash geopolymer. The leaching concentrations of Pb, Zn, Cr, Cu and Ni were below 0.02 mg/L with Mn and Cd at 0.023 and 0.027 mg/L, respectively. The enhanced mechanism for ED treated MSWI fly ash in geopolymer was confirmed by FTIR analysis and SEM images. The resistance against extreme leaching environments for treated fly ash geopolymer was stronger than raw fly ash geopolymer, and physical encapsulation of geopolymeric gels contributed to the heavy metal immobilization.
KW - Electrodialytic remediation
KW - Geopolymers
KW - Heavy metals
KW - Immobilization
KW - MSWI fly ash
U2 - 10.1016/j.jhazmat.2021.125220
DO - 10.1016/j.jhazmat.2021.125220
M3 - Journal article
C2 - 33951862
AN - SCOPUS:85100426215
SN - 0304-3894
VL - 412
JO - Journal of Hazardous Materials
JF - Journal of Hazardous Materials
M1 - 125220
ER -