Environmental concerns regarding the potential contamination of soil, surface and
ground water due to the presence of soluble metal species in the ash pond leachate
is of great importance. Serial batch leaching was carried out simulating the rainwater
condition of the study area to understand the behaviour of elements during leaching.
The leachates were analysed for the elements Al, Ca, K, Mg, Na, P, S, Si, As, Ba,
Fe, Mn, Mo, Ti, V, Pb, Zn, Co, Cr, Cu, Ni and Cd by inductively coupled plasma optical
emission spectrometer (ICP-OES). It was found that Cd, Co, Cr and Ni did not leach
from the ash while Cu and Pb concentrations were insignificant in the leachate regardless
of liquid to solid (L/S) ratio. Most of the elements showed maximum concentrations
at lower L/S ratio and then decreased with increasing L/S. The total cumulative concentrations
of As, Mn and Mo were found to be higher than the World Health Organization (WHO)
recommended values for drinking water while the concentrations of Fe, Mn and As exceeded
the maximum allowable concentrations prescribed by the United States Environmental
Protection Agency (USEPA). The pre and the post leached ash samples were analysed
for morphology, specific surface area and mineralogical changes. Analysis of post-leached
fly ash indicated changes in the specific surface area and morphology but no change
in mineralogy.