Synthesis of geopolymer using municipal solid waste incineration fly ash and steel slag: Hydration properties and immobilization of heavy metals

Jun Liu; Guangming Xie; Zhengdong Wang; Zhenlin Li; Xu Fan; Hesong Jin; Weizhuo Zhang; Feng Xing; Luping Tang

doi:10.1016/j.jenvman.2023.118053

Synthesis of geopolymer using municipal solid waste incineration fly ash and steel slag: Hydration properties and immobilization of heavy metals

J Environ Manage. 2023 Sep 1:341:118053. doi: 10.1016/j.jenvman.2023.118053. Epub 2023 May 9.

Authors

Jun Liu¹, Guangming Xie¹, Zhengdong Wang¹, Zhenlin Li¹, Xu Fan¹, Hesong Jin¹, Weizhuo Zhang², Feng Xing¹, Luping Tang³

Affiliations

¹ Guangdong Provincial Key Laboratory of Durability for Marine Civil Engineering, College of Civil and Transportation Engineering, Shenzhen University, Shenzhen, 518060, PR China.
² Guangdong Provincial Key Laboratory of Durability for Marine Civil Engineering, College of Civil and Transportation Engineering, Shenzhen University, Shenzhen, 518060, PR China. Electronic address: 2060471065@email.szu.edu.cn.
³ Department of Architecture and Civil Engineering, Division of Building Technology, Chalmers University of Technology, 41296, Gothenburg, Sweden.

PMID: 37167697
DOI: 10.1016/j.jenvman.2023.118053

Abstract

In this study, a novel method for the disposal of municipal solid waste incineration fly ash (MSWIFA) was proposed. By applying geopolymer technology, steel slag (SS) and MSWIFA were used together as precursors to synthesize a cementitious material with sufficient strength that is useable in construction. The effects of the dosages of SS and alkaline activator on the properties of the geopolymer were investigated. Compressive testing was used to characterize the mechanical properties of the geopolymer. X-ray diffraction (XRD), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) were used for microscopic analysis. Leaching tests were performed to assess the immobilization effect of the geopolymer on heavy metals. The results showed that the compressive strength of the geopolymer reached 23.03 MPa at 56 d with 20% SS and 11% Na₂O admixture. Highly polymerized hydration products, such as C-(A)-S-H gels and N-A-S-H gels, contributed to the compact microstructure, which provided mechanical strength and limited the migration and leaching of heavy metals in the geopolymer matrix. In terms of the results, this work is significant for the development of MSWIFA management.

Keywords: Hazardous waste; Leaching risk; MSWI fly ash-based geopolymer material; Mechanical strength; Solidification/stabilization.

MeSH terms

Carbon / chemistry
Coal Ash / chemistry
Incineration / methods
Metals, Heavy* / analysis
Particulate Matter
Refuse Disposal* / methods
Solid Waste / analysis
X-Ray Diffraction

Substances

Coal Ash
Solid Waste
Metals, Heavy
Carbon
Particulate Matter