Analysis of Leachate Characteristics to Study Coal Ash Usability - Management of Natural Resources in a Changing Environment - page 231

shows it can be utilized as a construction material, in waste treatment, soil stabilization,
stowing material, liner for landfi lls, embankments, etc. which may allow it to be used
for environmental benefi t rather than being disposed of as a waste.
Ashes contain various potential hazardous chemical compounds. Therefore pre-
cautions must be taken to avoid leaching of harmful substances both in its disposal
and its utilization. Major problem among these coal ashes are of pond ash and fl y
ash, therefore in this paper mixture of fl y ash and pond ash have been taken and its
leachate properties are studied. The leaching tests performed in this study indicate
that the major environmental challenge for the management of coal fl y. This paper
focuses on some chemical properties and leachability of various coal ash samples
collected from fi ve different thermal power plants across India. Extraction and
leaching of various metals like Fe, Pb, Cu, Ni, Cd and Cr, and soluble salts like
potassium, calcium, sodium and phosphate and sulphate ions were studied.

Materials and Methods

Coal Ash Samples

Coal ash samples were collected from fi ve different thermal power plants shown in
Table 1 . Fly ash was collected from the silos and pond ash was collected from the
ash disposal pond. Fly ash and pond ash were mixed together. Coal ash (fl y ash and
pond ash mixture) samples were oven dried for 24 h. to carry out the experiments.

Coal Ash Characterization and Chemical Compositions

The chemical composition of coal ash samples were determined by IS 1355-1984
method. Loss on ignition was carried by ASTM D7348-08 method to know the
amount of unburnt carbon. SEM and EDXA analysis was done to understand its
particles in closer view and to fi nd the presence of various elements respectively.

Table 1 Sa mple names and location

Sample
No.

Sample
names Power plants Location

1 Bokaro Thermal Power Station BTPS Bokaro district, Jharkhand

2 Chandrapura Thermal Power

Station

CTPS Bokaro district, Jharkhand

3 Durgapur Thermal Power Station DTPS Durluvpur, Mejia, Bankura, West

Bengal

4 Mejia Thermal Power Station MTPS Durluvpur, Mejia, Bankura, West

Bengal

5 Maithon Power Limited MPL Dhanbad, Jharkhand