Recycling of air pollution control residues from municipal solid waste incineration into lightweight aggregates.
This work focuses on the assessment of technological properties and on the leaching behavior of lightweight aggregates (LWA) produced by incorporating different quantities of air pollution control (APC) residues from municipal solid waste (MSW) incineration. Currently this hazardous waste has been mostly landfilled after stabilization/solidification. The LWA were produced by pelletizing natural clay, APC residues as-received from incineration plant, or after a washing treatment, a small amount of oil and water. The pellets were fired in a laboratory chamber furnace over calcium carbonate. The main technological properties of the LWA were evaluated, mainly concerning morphology, bulk and particle densities, compressive strength, bloating index, water adsorption and porosity. Given that APC residues do not own expansive (bloating) properties, the incorporation into LWA is only possible in moderate quantities, such as 3% as received or 5% after pre-washing treatment. The leaching behavior of heavy metals from sintered LWA using water or acid solutions was investigated, and despite the low acid neutralization capacity of the synthetic aggregates, the released quantities were low over a wide pH range. In conclusion, after a washing pre-treatment and if the percentage of incorporation is low, these residues may be incorporated into LWA. However, the recycling of APC residues from MSW incineration into LWA does not revealed any technical advantage.
CIEPQPF - Research Centre on Chemical Processes Engineering and Forest Products, Department of Chemical Engineering, University of Coimbra, Rua Sílvio Lima, 3030-790 Coimbra, Portugal. Electronic address: guida@eq.uc.pt.
Margarida J
MJ
Quina
Associate Laboratory IBB, Department of Chemical Engineering, Instituto Superior Técnico, Av. Rovisco Pais, 1049-001 Lisboa, Portugal.
João M
JM
Bordado
CIEPQPF - Research Centre on Chemical Processes Engineering and Forest Products, Department of Chemical Engineering, University of Coimbra, Rua Sílvio Lima, 3030-790 Coimbra, Portugal.
Rosa M
RM
Quinta-Ferreira
D000397:Air Pollution / Q000517:prevention & control*; D002947:Cities; D006256:Hazardous Waste / Q000032:analysis*; D017745:Incineration / Q000379:methods*; D019216:Metals, Heavy / Q000032:analysis; D012037:Refuse Disposal / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000032:analysis*
D006256:Hazardous Waste; D019216:Metals, Heavy; D014874:Water Pollutants, Chemical
APC residues; Lightweight aggregates; MSW incineration; Recycling