Characterization and phosphate stabilization of dusts from the vitrification of MSW combustion residues

Journal Article · Thu Dec 31 04:00:00 EST 1998 · Waste Management

DOI:https://doi.org/10.1016/S0956-053X(98)00139-1· OSTI ID:347640

Eighmy, T T; Crannell, B S; Krzanowski, J E ^[1]; Butler, L G; Cartledge, F K; Emery, E F ^[2]; Eusden, Jr, J D ^[3]; Shaw, E L ^[4]; Francis, C A ^[5]

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1. Univ. of New Hampshire, Durham, NH (United States)
2. Louisiana State Univ., Baton Rouge, LA (United States). Chemistry Dept.
3. Bates Coll., Lewiston, ME (United States). Geology Dept.
4. Massachusetts Inst. of Tech., Cambridge, MA (United States)
5. Harvard Univ., Cambridge, MA (United States)

The use of soluble PO{sub 4}{sup 3{minus}} as a heavy metal chemical stabilization agent was evaluated for a dust generated from melting or vitrification of municipal solid waste combustion residues. Vitrification dusts contain high concentrations of volatile elements such as Cl, Na, K, S, Pb, and Zn. These elements are present in the dusts largely as simple salts which are highly leachable. At an experimental dose of 0.4 moles of soluble PO{sub 4}{sup 3{minus}} per kg of residue, the pH-dependent leaching showed that the treatment was able to reduce equilibrium concentrations by factors of 3 to 100 for many metals, particularly Cd, Cu, pb and Zn. Bulk and surface spectroscopies showed that the insoluble reaction products are tertiary metal phosphate and apatite family minerals. Geochemical thermodynamic equilibrium modeling showed that apatite family and tertiary metal phosphate phases act as controlling solids for the equilibrium concentrations of Ca{sup 2+}, Zn{sup 2+}, Pb{sup 2+}, Cu{sup 2+}, and Cd{sup 2+} in the leachates during pH-dependent leaching. Both end members and ideal solid solutions were seen to be controlling solids. Soluble phosphate effectively converted soluble metal salts into insoluble metal phosphate phases despite the relatively low doses and dry mixing conditions that were used. Soluble phosphate is an effective stabilization agent for divalent heavy metals in melting dusts where leachable metals are present in high concentrations.

• Sponsoring Organization: USDOE
• OSTI ID: 347640
• Report Number(s): CONF-980513--
• Journal Information: Waste Management, Journal Name: Waste Management Journal Issue: 6-8 Vol. 18; ISSN WAMAE2; ISSN 0956-053X
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
AIR POLLUTION ABATEMENT
CADMIUM
CHLORIDES
COMBUSTION PRODUCTS
COPPER
DUSTS
LEAD
MUNICIPAL WASTES
PHOSPHATES
POTASSIUM
SODIUM
SOLID WASTES
STABILIZATION
SULFIDES
WASTE PROCESSING
ZINC