Study on the Treatment of Acid Mine Wastewater by Coal Fly Ash

This paper studied the feasibility of treating the acid mine drainage (AMD) by using a process of permeable reactive barrier (PRB), in which coal fly ash(CFA) was used as the reaction medium. The adjustment of pH and the removal of COD, sulfate and three kinds of heavy metal ions (Cd 2+ , Cu 2+ , Zn 2+ ) were illustrated. The results showed that the coal fly ash was effective in treating AMD, and the highest removal rates for COD and sulfate could be obtained in 12 h with 53.4% and60.4%, respectively; the maximum removal efficiencies of Cd 2+ , Cu 2+ and Zn 2+ were 42.9%, 74.8% and 26.7%; Besides, in this work, the modification of CFA was conducted by using an acid modification method. In comparison to the original CFA, the modified coal fly ash presented not too bad and displayed a better treatment effect toward the acid mine wastewater. MCFA have higher removal rate of heavy metal ions (Cd 2+ , Cu 2+ and Zn 2+ ), the removal rate of Cu 2+ even reached 91.85%.