Comparing Metal Leaching and Toxicity from High pH, Low pH, and High Ammonia Fly Ash

Journal Article · Mon Jan 01 00:00:00 EST 2007 · Fuel

DOI:https://doi.org/10.1016/j.fuel.2006.11.018· OSTI ID:931710

Palumbo, Anthony Vito ^[1]; Phillips, Jana Randolph ^[1]; Fagan, Lisa Anne ^[1]; Drake, Meghan M ^[1]; Ruther, Rose Emily ^[2]; Fisher, L. Suzanne ^[3]; Amonette, J. E. ^[4]

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1. ORNL
2. New College of Florida, Sarasota, FL
3. Tennessee Valley Authority (TVA)
4. Pacific Northwest National Laboratory (PNNL)

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: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: FE USDOE - Office of Fossil Energy (FE)
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 931710
• Journal Information: Fuel, Vol. 86, Issue 10-11
• Country of Publication: United States
• Language: English

Related Subjects

Fly Ash
Leaching