两种水系覆盖对富硫煤矸石的原位污染控制效果研究

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、垃圾渗滤液分别设置为对照、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 a。结果表明：天然水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SO2-4和F-等阴离子,呈现出矿山酸性废水的一般特征。相对对照处理,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SO2-4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 gangues were treated with three immersion approaches ： mixing tap water, fly ash slurry and landfill leachate as control, alkaline water cover and organic water cover. The re- suits suggested that the lying water in control group had lower pH, higher EC and Eh and was rich in metal ions such as Fe, Mn, Cu and Zn, anions like SO24- and F-, presenting general characteristics of acid mine drainage. Compared to the control group, the lying water samples of alkaline water cover and organic water cover showed higher pH and lower Eh after one and half years. The release of Fe, Mn, Zn and Cu were reduced significantly, SO24- and F- were also restrained obviously in the mean- time. The leaching ions in lying water of these two water covers had no significant difference, but al- kaline water cover displayed better control effect on the release of metal ions. Hence water cover technique of alkaline water cover and organic water cover is an effective ways of situ control on sulfur-rich coal gangue contamination.