Comparing metal leaching and toxicity from high pH, low pH, and high ammonia fly ash

Journal Article · Sun Jul 01 04:00:00 EDT 2007 · Fuel, 86(10-11):1623-1630

DOI:https://doi.org/10.1016/j.fuel.2006.11.018· OSTI ID:909997

Palumbo, Anthony V; Tarver, Jana R; Fagan, Lisa A; McNeilly, Meghan S; Ruther, Rose; Fisher, L S; Amonette, James E

Previous work with both class F and class C fly ash indicated minimal leaching from most fly ashes tested. However, the addition of NOx removal equipment might result in higher levels of ammonia in the fly ash. We have recently been testing fly ash with a wide range of pH (3.7–12.4) originating from systems with NOx removal equipment. Leaching experiments were done using dilute CaCl2 solutions in batch and columns and a batch nitric acid method. All methods indicated that the leaching of heavy metals was different in the highest ammonia sample tested and the high pH sample. However, toxicity testing with the Microtox* system has indicated little potential toxicity in leachates except for the fly ash at the highest pH (12.4). When the leachate from the high pH fly ash was neutralized, toxicity was eliminated.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 909997
• Report Number(s): PNNL-SA-55295; 4298; AA3010000
• Journal Information: Fuel, 86(10-11):1623-1630, Journal Name: Fuel, 86(10-11):1623-1630 Journal Issue: 10-11 Vol. 86; ISSN FUELAC; ISSN 0016-2361
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
54 ENVIRONMENTAL SCIENCES
AMMONIA
Carbon sequestration
Environmental Molecular Sciences Laboratory
FLY ASH
Fly ash
HEAVY METALS
LEACHATES
LEACHING
MATERIALS TESTING
Metals
PH VALUE
TOXICITY