Characterization of fly ash from municipal waste incineration and study of the leaching in view of metal removal

Book · Tue Dec 31 04:00:00 EST 1996

OSTI ID:495366

Herck, P van; Vandecasteele, C; Wilms, D ^[1]

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1. Katholieke Univ., Leuven (Netherlands). Dept. of Chemical Engineering

Combustion residues in general and fly ash in particular form a major environmental problem. Due to the fact that the legal standards for the emission of contaminants are getting more stringent the air pollution control system of the incinerators must be improved, resulting in an increase of the amount of residues of the control system which must be regarded as hazardous waste. Fly ash from a municipal waste incinerator contains several heavy metals. The heavy metals can be removed from the fly ash by leaching with the acid waste water obtained in the wet scrubber of the air pollution control system. Afterwards the fly ash can e.g. be valorized as a construction material. An understanding of the factors that influence leaching is very important for the treatment of the fly ash. Therefore, the composition and the particle size distribution of the fly ash were determined and a sequential extraction procedure was used to obtain information on the chemical form of the metals on the fly ash. Study of the influence of pH and Liquid/Solid-ratio indicated that solubility limitation is one of the most important aspects governing the process. Calculations were made and compared to the experimental results in order to determine which insoluble compounds limit the solubility of the heavy metals. Possible solutions for this solubility limitation are increasing the amount of acid and increasing the Liquid/Solid-ratio. Also the addition of complexing reagents like EDTA and the use of a two stage process were investigated.

• OSTI ID: 495366
• Report Number(s): CONF-9504119--
• Country of Publication: United States
• Language: English

Related Subjects

09 BIOMASS FUELS
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
54 ENVIRONMENTAL SCIENCES
CHEMICAL COMPOSITION
DEMETALLIZATION
EXPERIMENTAL DATA
FLY ASH
INCINERATORS
MUNICIPAL WASTES
PARTICLE SIZE
SOLID WASTES
WASTE MANAGEMENT