Geoenvironmental weathering/deterioration of landfilled MSWI-BA glass

Yunmei Wei; Amirhomayoun Saffarzadeh; Takayuki Shimaoka; Chun Zhao; Xuya Peng; Junmin Gao

doi:10.1016/j.jhazmat.2014.05.093

Geoenvironmental weathering/deterioration of landfilled MSWI-BA glass

J Hazard Mater. 2014 Aug 15:278:610-9. doi: 10.1016/j.jhazmat.2014.05.093. Epub 2014 Jun 8.

Authors

Yunmei Wei¹, Amirhomayoun Saffarzadeh², Takayuki Shimaoka², Chun Zhao³, Xuya Peng¹, Junmin Gao¹

Affiliations

¹ Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, 174th, Shapingba Zhengjie Street, Shapingba District, Chongqing 400 045, PR China; National Center for International Research of Low-carbon and Green Buildings, Chongqing University, 174th, Shapingba Zhengjie Street,Shapingba District, Chongqing 400 045, PR China.
² Department of Urban and Environmental Engineering, Graduate School of Engineering, Kyushu University, 744, Motooka, Nishi-ku, Fukuoka 819 0395, Japan.
³ Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, 174th, Shapingba Zhengjie Street, Shapingba District, Chongqing 400 045, PR China; National Center for International Research of Low-carbon and Green Buildings, Chongqing University, 174th, Shapingba Zhengjie Street,Shapingba District, Chongqing 400 045, PR China. Electronic address: wym_1982@cqu.edu.cn.

PMID: 25043593
DOI: 10.1016/j.jhazmat.2014.05.093

Abstract

Municipal solid waste incineration bottom ash (MSWI-BA) glass serves as a matrix of assorted bottom ash (BA) compounds. Deterioration of the BA glass phases is quite important as they regulate the distribution of a series of toxic elements. This paper studied landfilled MSWI-BA samples from the mineralogical and geochemical viewpoint to understand the deterioration behavior of the BA glass phases as well as mechanisms involved. Bulk analysis by PXRD as well as micro-scale analysis by optical microscopy and SEM/EDX was conducted for such purposes. The results revealed that dissolution of the BA glass phases has resulted in a deterioration layer of 10(0)-10(2)μm thickness after years of disposal. This rapid weathering process is highly relevant to the specific glass characteristics and solution pH. The BA glass phases with more embedded compounds and cracks/fissures tend to be more vulnerable. Moreover, the generally alkaline pH in ash deposit favors a rapid disruption of the glass phase. The weathering products are mainly gel phases (including Al-Si gel, Ca-Al-Si gel, Fe-Al-Si gel etc.) with iron oxide/hydroxide as accessory products. Breakdown of the BA glass phases triggers chemical evolution of the embedded compounds. Based on all the findings above, a model is proposed to illustrate a general evolution trend for the landfilled MSWI-BA glass phases.

Keywords: Gel; Glass; Landfill; MSWI bottom ash; Toxic elements; Weathering.

Publication types

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

MeSH terms

Glass / analysis
Glass / chemistry*
Incineration*
Industrial Waste* / analysis
Waste Disposal Facilities

Substances

Industrial Waste