Element composition and mineralogical characterisation of air pollution control residue from UK energy-from-waste facilities

Journal Article · Sun Feb 15 00:00:00 EST 2015 · Waste Management

DOI:https://doi.org/10.1016/J.WASMAN.2014.11.017· OSTI ID:22475999

Bogush, Anna ^[1]; Wood, Ian ^[2]; Roy, Amitava ^[3]

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1. Centre for Resource Efficiency & the Environment (CREE), Department of Civil, Environmental & Geomatic Engineering (CEGE), University College London UCL, Chadwick Building, Gower Street, London WC1E 6BT (United Kingdom)
2. Department of Earth Sciences, University College London UCL, Gower Street, London WC1E 6BT (United Kingdom)
3. J. Bennett Johnston, Sr., Center for Advanced Microstructures & Devices, Louisiana State University, 6980 Jefferson Hwy, Baton Rouge, LA 70806 (United States)

Highlights: • 66 elements, including “critical strategic elements” were determined in UK EfW APC residues. • Metal pollutants (Zn, Pb, As, Cd, Cu, Mo, Sb, Sn, Se, Ag and In) are enriched in APC residues. • Metal pollutants were widely associated with fine deposits of highly soluble CaCl{sub x}OH{sub 2−x}. • Specific metal (Zn, Pb, Cu)-bearing minerals were also detected in APC residues. - Abstract: Air pollution control (APC) residues from energy-from-waste (EfW) are alkaline (corrosive) and contain high concentrations of metals, such as zinc and lead, and soluble salts, such as chlorides and sulphates. The EPA 3050B-extractable concentrations of 66 elements, including critical elements of strategic importance for advanced electronics and energy technologies, were determined in eight APC residues from six UK EfW facilities. The concentrations of Ag (6–15 mg/kg) and In (1–13 mg/kg), as well as potential pollutants, especially Zn (0.26–0.73 wt.%), Pb (0.05–0.2 wt.%), As, Cd, Cu, Mo, Sb, Sn and Se were found to be enriched in all APC residues compared to average crustal abundances. Results from a combination of scanning electron microscopy with energy dispersive X-ray spectroscopy and also powder X-ray diffraction, thermal analysis and Fourier transform infrared spectroscopy give an exceptionally full understanding of the mineralogy of these residues, which is discussed in the context of other results in the literature. The present work has shown that the bulk of the crystalline phases present in the investigated APC residues include Ca-based phases, such as CaCl{sub x}OH{sub 2−x}, CaCO{sub 3}, Ca(OH){sub 2}, CaSO{sub 4}, and CaO, as well as soluble salts, such as NaCl and KCl. Poorly-crystalline aragonite was identified by FTIR. Sulphur appears to have complex redox speciation, presenting as both anhydrite and hannebachite in some UK EfW APC residues. Hazardous elements (Zn and Pb) were widely associated with soluble Ca- and Cl-bearing phases (e.g. CaCl{sub x}OH{sub 2−x} and sylvite), as well as unburnt organic matter and aluminosilicates. Specific metal-bearing minerals were also detected in some samples: e.g., Pb present as cerussite; Zn in gahnite, zincowoodwardite and copper nickel zinc oxide; Cu in tenorite, copper nickel zinc oxide and fedotovite. Aluminium foil pieces were present and abundantly covered by fine phases, particularly in any cracks, probably in the form of Friedel’s salt.

• OSTI ID: 22475999
• Journal Information: Waste Management, Vol. 36; Other Information: Copyright (c) 2014 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0956-053X
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ALUMINIUM
ARAGONITE
CALCIUM COMPOUNDS
COPPER
FOURIER TRANSFORM SPECTROMETERS
INFRARED SPECTRA
LEAD
NICKEL
POLLUTANTS
POTASSIUM CHLORIDES
SCANNING ELECTRON MICROSCOPY
SODIUM CHLORIDES
THERMAL ANALYSIS
WASTES
X-RAY DIFFRACTION
X-RAY SPECTROSCOPY
ZINC
ZINC OXIDES