Metal leaching from MSW fly ash before and after chemical and thermal treatments

Journal Article · · Environmental Progress

DOI:https://doi.org/10.1002/ep.670180219· OSTI ID:6178762

Iretskaya, S ^[1]; Nzihou, A ^[2]; Zahraoui, C; Sharrock, P ^[3]

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1. Inst. of Technology, Saint-Petersburg (Russian Federation)
2. Ecole des Mines d'Albi-Carmaux, Albi (France). Centre Energetique et Environnement
3. Univ. Paul Sabatier, Toulouse (France). Lab. de Chimie Inorganique

Municipal Solid Waste (MSW) incineration fly ash was collected in the industrial facilities in the city of Toulouse, equipped with recent gas scrubbing equipment which collects daily 15 t of lime treated fly ash. The fly ash contains a large proportion of water soluble chlorides, besides trace elements such as iron, zinc, titanium and copper. Presently, the fly ash is landfilled after a cement solidification process. Matrix stability and leaching behavior of heavy metals (Cd, Cu) from samples of doped MSW fly ash were examined before and after chemical and thermal treatments. A new phosphate process leading to hydroxylapatite formation is described. To evaluate its performance as a stabilization process, cupric and cadmium ions were added as typical pollutant tracers and their distribution was studied as a function of different treatment parameters. The hydroxylapatite process used effectively removes chloride ions in the water extract and retains most of the added metal ions in the solid residues. Evaluation of this procedure as a cold process shows 50% reduction in leachable metal ions. Calcination of the solid residues at 900 C results in agglomerated particles with increased resistance to metal ion dissolution. This is attributed to heavy metal incorporation in the hydroxylapatite matrix formed during the thermal treatment. Thus, combined chemical and thermal treatments are efficient for heavy metal stabilization in MSW fly ash.

• OSTI ID: 6178762
• Journal Information: Environmental Progress, Journal Name: Environmental Progress Vol. 18:2; ISSN 0278-4491; ISSN ENVPDI
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
320604* -- Energy Conservation
Consumption
& Utilization-- Municipalities & Community Systems-- Municipal Waste Management-- (1980-)
AEROSOL WASTES
AIR POLLUTION ABATEMENT
ASHES
CHLORIDES
CHLORINE COMPOUNDS
COMBUSTION PRODUCTS
COPPER
DISSOLUTION
ELEMENTS
FLY ASH
HALIDES
HALOGEN COMPOUNDS
INCINERATORS
IRON
LEACHING
MANAGEMENT
METALS
MUNICIPAL WASTES
PERFORMANCE TESTING
POLLUTION ABATEMENT
PROCESSING
RESIDUES
SEPARATION PROCESSES
TESTING
TITANIUM
TRANSITION ELEMENTS
WASTE MANAGEMENT
WASTE PROCESSING
WASTES
ZINC