High-efficiency and low-carbon remediation of zinc contaminated sludge by magnesium oxysulfate cement
Research output: Contribution to journal › Research article › Contributed › peer-review
Contributors
Abstract
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.
Details
Original language | English |
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Article number | 124486 |
Journal | Journal of hazardous materials |
Volume | 408 |
Publication status | Published - 15 Apr 2021 |
Peer-reviewed | Yes |
External IDs
PubMed | 33243654 |
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Keywords
Sustainable Development Goals
ASJC Scopus subject areas
Keywords
- Electroplating sludge, Green and sustainable remediation, Hazardous waste immobilisation, Magnesium oxysulfate cement, Metal leachability, Stabilisation/solidification