利用粉煤灰及改性粉煤灰处理酸性矿井水研究

THE TREATMENT OF ACID MINE WASTEWATER BY COAL FLY ASH AND MODIFIED COAL FLY ASH

利用粉煤灰作为可渗透反应墙的反应介质处理酸性矿井废水进行研究,同时利用化学酸法对粉煤灰进行了改性,测试了它们对酸性矿井水的p H调节作用,对COD、SO42-及Cd2+、Cu2+、Zn2+3种重金属离子的处理效果。结果表明,粉煤灰对酸性矿井水有较好的处理效果,对COD和SO42-的去除率在反应12 h达到最好,分别为53.4%和60.4%,对Cd2+、Cu2+、Zn2+的最大去除率分别为42.9%、74.8%、26.7%。与原粉煤灰相比,经过改性的粉煤灰也有较好的处理效果,对重金属离子的去除率有较大提高,尤其是对Cu2+的去除率最高可达91.85%。

The feasibility of treating the acid mine drainage （AMD） by using a process of permeable reactive barrier （PRB） was studied, where coal fly ash （CFA） was used as the reaction medium. Meanwhile, the modification of CFA was conducted in chemical acid modification method. The adjustment of pH and the removal of COD, sulfate and three kinds of heavy metal ions including Cd^2＋, Cu^2＋ and 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% and 60.4%, respectively; the maximum removal efficiencies of Cd^2＋, Cu^2＋ and Zn^2＋ were 42.9%, 74.8% and 26.7%, respectively. In comparison with the original CFA, the modified coal fly ash displayed better treatment effect toward the acid mine wastewater. The removal rate of heavy metal ions was obviously improved by the modified CFA, and the highest removal rate of Cu^2＋ could reached 91.85%.