Heavy metal leaching from hydroxide, sulphide and silicate stabilized/solidified wastes

Journal Article · Fri Jan 01 04:00:00 EST 1993 · Waste Management; (United States)

DOI:https://doi.org/10.1016/0956-053X(93)90015-O· OSTI ID:7309857

Cheeseman, C R; Butcher, E J; Sollars, C J; Perry, R ^[1]

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1. Imperial College of Science, Technology and Medicine, London (United Kingdom). Centre for Environmental Control and Waste Management

A synthetic, mixed-metal solution has been stabilized by treatment with sodium hydroxide, sodium sulphide, and sodium silicate, respectively. The three stabilized filter cakes have subsequently been solidified using additions of ordinary Portland cement and pulverized fuel ash (PFA) which are typically used in UK solidification operations. Both the stabilized filter cakes and the solidified wastes have been subjected to an equilibrium extraction test, a modified TCLP test, and a series of single-extraction, batch leach tests using an increasingly acidic leachant. Metal release was found to be primarily dependent on the pH of the leachate. Under mildly acidic conditions, the percentages leached from the stabilized and the stabilized/solidified wastes were comparable for most metals. A high-volume fraction of these solidified wastes is occupied by the stabilized filter cake. When they are broken up and tested in single-extraction leach tests, the primary effect of the cementitious additives is to increase the pH of the leachate so that most heavy metals remain insoluble. When tested under acidic leachate conditions, copper, lead, and mercury were found to be particularly well retained within sodium sulphide stabilized wastes. Under similar tests conditions, cadmium was leached at very low levels from the sodium silicate stabilized waste.

• OSTI ID: 7309857
• Journal Information: Waste Management; (United States), Journal Name: Waste Management; (United States) Vol. 13:8; ISSN WAMAE2; ISSN 0956-053X
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540220* -- Environment
Terrestrial-- Chemicals Monitoring & Transport-- (1990-)
CADMIUM
COPPER
DISSOLUTION
ELEMENTS
HAZARDOUS MATERIALS
LEACHING
LEAD
MANAGEMENT
MATERIALS
MERCURY
METALS
PROCESSING
SEPARATION PROCESSES
TRANSITION ELEMENTS
WASTE MANAGEMENT
WASTE PROCESSING