Mobilization of Metals from Indian Coal Fly Ash under Dynamic Conditions

The toxic metals leaching through coal fly ash has environmental concern. The dynamic ageing study was carried out to understand the behavior of the elements during leaching from coal fly ash. The 48 hours experiments, simulating fly ash under the rain water condition, for determining the metal leaching were performed. The leachates were analyzed through the inductively coupled plasma atomic emission spectroscopy (ICP-AES) for elements Arsenic, Chromium, Copper,Selenium, Nickel, Barium, Vanadium and Lithium. It was found that although variable but significant amount of As, Cr, Se,Ni, Ba, V, and Li leached from nine fly ash samples studied. The amount of as leached ranged from 450-680 ppb. Similarly for Cr, Se, Ni, Ba, V, and Li the amount of metal leached ranged from 10-220 ppb, 2-24 ppb, 10-240 ppb, 20-120 ppb, 10-1100 ppb and 20-750 ppb respectively. The concentration of all the metals leached with copper being an exception, were found to be higher than WHO recommended values for drinking water.