两种水系覆盖对富硫煤矸石的原位污染控制效果

In situ control of two water covers on sulfur-rich coal gangue contamination

为评价水系覆盖对富硫煤矸石污染物质溶出的控制效果,采用天然水、粉煤灰浆液、垃圾渗滤液设置对照、碱性水系覆盖、有机水系覆盖3种方式对富硫煤矸石进行浸没处理,处理周期1.5年。结果表明:对照处理上覆水样中有较低的p H(2.5~4.0)、较高的EC、Eh,同时富含Fe、Mn、Cu、Zn等金属离子及SO^(2-)_4和F^-等阴离子,呈现出矿山酸性废水的一般特征。相对比于对照处理,结合统计数据表明,碱性水系覆盖和有机水系覆盖处理上覆水样中有较高的p H(中性偏碱)和相对较低的Eh,能极显著降低上覆水样中的Fe、Mn、Zn、Cu的溶出,同时对SO^(2-)_4和F^-也有明显的抑制效果。两种水系覆盖上覆水样中的溶出离子并没有显著性差异,但碱性水系覆盖对于金属离子的溶出表现出更好的控制效果。因此,碱性水系覆盖和有机水系覆盖等水系覆盖处理技术是一种可用于富硫煤矸石污染原位控制的有效途径。

the control effectiveness of water covers on coal gangue contamination were evaluated in the test. Sulfur- rich coal gangue was treated with three immersion approaches： mixing tap water,fly ash slurry and landfill leachate as control,alkaline water cover and organic water cover. The results suggest that the lying water in control group has lower p H,higher EC and Eh and is of rich in metal ions such as Fe,Mn,Cu and Zn,anions like SO^2-_4and F^-,showing general characteristics of acid mine drainage. Compared to the control group,the lying water samples of alkaline water cover and organic water cover show higher p H and lower Eh after one and half years. The release of Fe,Mn,Zn and Cu are reduced significantly,SO^2-_4and F^-are also restrained obviously in the meantime.The leaching ions in lying water of these two water covers have no significant difference,but alkaline water cover displays better control effect on the release of metal ions. Hence water cover technique of alkaline water cover and organic water cover is an effective way of in situ control for sulfur- rich coal gangue contamination.