Immobilization of hazardous municipal solid waste incineration fly ash by novel alternative binders derived from cementitious waste

Pei Tang; Wei Chen; Dongxing Xuan; Hiuwun Cheng; Chi Sun Poon; Daniel C W Tsang

doi:10.1016/j.jhazmat.2020.122386

Immobilization of hazardous municipal solid waste incineration fly ash by novel alternative binders derived from cementitious waste

J Hazard Mater. 2020 Jul 5:393:122386. doi: 10.1016/j.jhazmat.2020.122386. Epub 2020 Feb 24.

Authors

Pei Tang¹, Wei Chen², Dongxing Xuan³, Hiuwun Cheng³, Chi Sun Poon⁴, Daniel C W Tsang⁵

Affiliations

¹ State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan, 430070, PR China; Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong. Electronic address: pei-tang@whut.edu.cn.
² State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan, 430070, PR China. Electronic address: chen.wei@whut.edu.cn.
³ Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.
⁴ Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong. Electronic address: cecspoon@polyu.edu.hk.
⁵ Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong. Electronic address: dan.tsang@polyu.edu.hk.

PMID: 32114128
DOI: 10.1016/j.jhazmat.2020.122386

Abstract

This work aims to immobilize hazardous municipal solid waste incineration fly ash (IFA) using alternative binders recycled from cementitious waste (CW) that was dehydrated. The dehydration temperature of CW applied was 200 °C, 500 °C and 800 °C, and the resulted binder was labelled as DCW2, DCW5 and DCW8, respectively. Thermal treatment increased the rehydration capacity of DCWs. Higher temperatures at 500 °C) can increase the amount of dehydrated phases, and contribute to a higher 28-day strength of DCW pastes. The DCW5 paste had the highest 28-day strength which was 18.74 MPa. The dicalcium silicate phase can be formed in DCW8, which resulted in its slow strength development and a lower 28-day strength compared to the DCW5 paste (about 50 % lower). Chloride contained in IFA can take part in the DCW hydration and contribute to the strength development of the binder-IFA pastes. The use of DCWs as binders had better immobilization efficiency of Pb compared to OPC. Furthermore, the CO₂ emission for preparing DCW2, DCW5, and DCW8 was 94 %, 86 % and 65 % lower than that of OPC, respectively. The DCWs can be considered as alternative binders regarding the recycling and immobilization of IFA.

Keywords: CO(2) emission; Cementitious waste; Dehydration; Rehydration; Stabilization.

Publication types

Research Support, Non-U.S. Gov't