HEAVY METALS LEACHING CHARACTERISTICS FROM COAL FLY ASH OF THREE THERMAL POWER PLANTS AND ITS ADVERSE EFFECTS ON ENVIRONMENT

Huge amount of coal fly ash, generated from power plants which contain trace toxic metals also like Pb, As, Hg, Ni, Cd and Ba etc., is considered as an environmental hazard worldwide. These toxic elements are leached into water, soil and ground water from coal fly ash and contaminate them. The leaching behaviour of trace toxic elements as a function of liquid/solid (L/S) ratio present in coal fly ash from three coal-fired power plants were studied by conducting US EPA leaching test methods (LEAF). The test has been conducted under a different range liquid to solid ratios. Most of trace elements show similar nature of liquid/solid partitioning (LSP) curve in the different coal fly ash samples in the leaching tests despite of elemental and mineralogical compositions and different ranks of coals fly ash. LSP curves of trace elements from fly ash samples in the L/S ratios tests (LEAF) shows some variations also. The present study is an assessment the leachability of trace elements in three coal fly ash samples collected from three power plants by LEAF at different L/S ratios.