SEM-EDX Chemistry of Coal Ash versus WTE Ash · SEM-EDX Chemistry of Coal Ash versus WTE Ash ......
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SEM-EDX Chemistry of Coal Ash versus WTE Ash Saugata Datta 1,2 and Nada Assaf-Anid 1,3 1 Columbia Earth Institute, 2 Barnard College, 3 Manhattan College Presentation at: Ash Consortium, WTERT, Nov 13, 2003 Columbia University -5.0 0.0 5.0 10.0 15.0 Energy (keV) 0 5 10 15 20 25 30 35 40 EDS spectra of the whole area observed Fe Ca Al Si 0.0 5.0 10.0 15.0 Energy (keV) 0 10 21 31 41 51 62 72 82 Si Si Si Si Si Al Si Fe Ca EDS spectra of large smooth spheres seen in Fig A and B. These spheres tend to be rich in Si and Al, with varying amounts of Ca, K and Fe. Coal Fly Ash from India A B
Transcript of SEM-EDX Chemistry of Coal Ash versus WTE Ash · SEM-EDX Chemistry of Coal Ash versus WTE Ash ......
SEM-EDX Chemistry of Coal Ash versus WTE Ash
Saugata Datta 1,2 and Nada Assaf-Anid 1,3
1Columbia Earth Institute, 2Barnard College, 3Manhattan College
Presentation at: Ash Consortium, WTERT, Nov 13, 2003
Columbia University
-5.0 0.0 5.0 10.0 15.0Energy (keV)
0
5
10
15
20
25
30
35
40
EDS spectra of the whole area observed
Fe
Ca
Al
Si
0.0 5.0 10.0 15.0Energy (keV)
0
10
21
31
41
51
62
72
82
Si
Si
SiSiSi
Al
Si
FeCa
EDS spectra of largesmooth spheres seenin Fig A and B. These spheres tend to be rich in Si and Al, with varying amounts of Ca, K and Fe.
Coal Fly Ash from India
A
B
Coal Fly Ash and Bottom Ash Morphology: Thailand
SEMASS Fly Ash
SEMASS Bottom Ash:highly porous particles1A: bright patch
Analysis: Pb, Cl
Hempsted Combined Ash: sieve-16
Hempsted Combined Ash: sieve -16
Unburnt wood material
ESSEX CombinedAsh: Boiler-1: sieve-16
Bright white patch analysis
ESSEX Combined Ash: Boiler-1: sieve-16
Back in WTERT June 2003-meeting we proposed:
• Characterize Bottom Ash (BA) and Fly Ash (FA) from several WTE plants both chemically and by SEM : Do different combustion processes generate different ashes? Does extent of combustion generate different ashes with different organic carbon content (need for COD analysis)? How does ash chemistry correlate with solid waste composition (i.e., plastics content, original MSW composition)?
• Compare bioavailability from leaching results of different mixture ratios of BA and FA: Is dilution beneficial?
• Find the optimum pH conditions of the BA/FA mixture: What is the optimum application scenario?
To Summarize the Main Research Questions Are
• Further leaching experiments of both fly ashes and potential ash-receiving matrices (i.e. soil; dredged sediments; landfilling materials)
• Understanding the toxic potential of leachate metals and chlorinated organics in relation to ash beneficial end-use and matrix-ash mixtures
• Unburnt carbon in fly ash: Is it beneficial because it has a binding (stabilizing) effect on low MW organics?
• Accounting for the impact of environmental stressors (i.e., variation of pCO2 => alkalinity, pH, aging, temp, redox, rainfall)
• Making sound and profitable WTE waste management decisions
• Assisting the EPA in designing new ash-specific leaching tests
