Leaching behaviour of elements from sub-bituminous coal fly ash

Abstract

The disposal or use of coal fly ash in ponds, landfills or in construction of roads is a great concern, because of its leaching behavior. It has problem especially when elements from fly ash get leached and contaminate or degrade the quality of drinking water. The aim of this study is to investigate leaching behavior of metals from northeastern coal fly ash. Serial batch leaching test for elements namely Fe, Mn, Zn, Cu and Pb has been carried out with liquid to solid (L/S) ratio at 4 and 12. The pH of the leachate was weekly alkaline in nature, ranging from 7.39 to 7.90. Concentration of Fe and Mn in the leachate is higher than the maximum contaminant level of drinking water. However, concentration of elements in the leachate from the northeastern fly ash is less than that of the Gondwana fly ash. This is possibly due to the different physico-chemical properties of the fly ash.