TY - JOUR
T1 - High-efficiency and low-carbon remediation of zinc contaminated sludge by magnesium oxysulfate cement
AU - Guo, Binglin
AU - Tan, Yongshan
AU - Wang, Lei
AU - Chen, Liang
AU - Wu, Zuliang
AU - Sasaki, Keiko
AU - Mechtcherine, Viktor
AU - Tsang, Daniel C.W.
N1 - Funding Information:
The authors acknowledge with gratitude the financial support of the Japan Society for the Promotion of Science (JSPS) KAKENHI (A) (No. JP19H00883 ), the Alexander von Humboldt Foundation , and the Hong Kong Research Grants Council (PolyU 15223517 ) for this study. The EXAFS experiments were conducted at Kyushu University Beamline (SAGA-LS /BL06) under the proposal No. 2019IIIK001.
Publisher Copyright:
© 2020 Elsevier B.V.
PY - 2021/4/15
Y1 - 2021/4/15
N2 - Electroplating sludge is classified as a hazardous waste due to its extremely high leachability of potentially toxic elements. This study concerns the use of magnesium oxysulfate cement (MOSC) for the stabilisation/solidification (S/S) of Zn-rich electroplating sludge. According to X-ray diffraction and thermogravimetric analyses, Zn was mainly immobilised through both chemical interaction and physical encapsulation in the MOSC hydrates of 5Mg(OH)2·MgSO4.7H2O (5−1−7) phase. The crystal size analysis, elemental mapping, and extended X-ray absorption fine structure (EXAFS) analysis proved that the Zn2+ was also incorporated in the structure of 5–1–7 phase. Unlike Portland cement system, hydration kinetics, setting time, and compressive strength of the MOSC system were only negligibly modified by the presence of Zn, indicating its superior compatibility. Subsequent S/S experiments demonstrated that the MOSC binder exhibited an excellent performance on immobilisation efficiency of Zn (up to 99.9%), as well as satisfying the requirements of setting time and mechanical strength of sludge S/S products. Therefore, MOSC could be an effective and sustainable binder for the treatment of the Zn-rich industrial wastes.
AB - Electroplating sludge is classified as a hazardous waste due to its extremely high leachability of potentially toxic elements. This study concerns the use of magnesium oxysulfate cement (MOSC) for the stabilisation/solidification (S/S) of Zn-rich electroplating sludge. According to X-ray diffraction and thermogravimetric analyses, Zn was mainly immobilised through both chemical interaction and physical encapsulation in the MOSC hydrates of 5Mg(OH)2·MgSO4.7H2O (5−1−7) phase. The crystal size analysis, elemental mapping, and extended X-ray absorption fine structure (EXAFS) analysis proved that the Zn2+ was also incorporated in the structure of 5–1–7 phase. Unlike Portland cement system, hydration kinetics, setting time, and compressive strength of the MOSC system were only negligibly modified by the presence of Zn, indicating its superior compatibility. Subsequent S/S experiments demonstrated that the MOSC binder exhibited an excellent performance on immobilisation efficiency of Zn (up to 99.9%), as well as satisfying the requirements of setting time and mechanical strength of sludge S/S products. Therefore, MOSC could be an effective and sustainable binder for the treatment of the Zn-rich industrial wastes.
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U2 - 10.1016/j.jhazmat.2020.124486
DO - 10.1016/j.jhazmat.2020.124486
M3 - Article
C2 - 33243654
AN - SCOPUS:85097091182
VL - 408
JO - Journal of Hazardous Materials
JF - Journal of Hazardous Materials
SN - 0304-3894
M1 - 124486
ER -
