为评价微生物在不同氧化还原环境下对含硫煤矸石中污染物释放的作用,通过设置氧化处理、氧化灭菌处理、还原处理和还原灭菌处理4组处理方式对煤矸石进行连续浸提实验,并测定0、1、3、6、9d后各处理煤矸石浸出液的pH、电导率(EC)、氧化还原电位(Eh)、总溶解性固体(TDS)、金属离子(Fe^3+、Mn^2+、Cu^2+、Zn^2+)和阴离子(SO4^2-、F^-)等特征污染指标。结果表明:氧化环境下,灭菌处理能抑制煤矸石氧化酸化,提高煤矸石浸出液的pH,降低浸出液EC、TDS,并明显降低煤矸石浸出液中Fe^3+的溶出浓度,对Mn^2+、Cu^2+、F^-和SO4^2-等特征污染离子的溶出也有一定的抑制效果,且随着浸提时间的延长。这种抑制效应日趋加强;而还原环境下,灭菌处理却在一定程度上减弱了还原环境对煤矸石中污染物释放的抑制作用。综上表明,灭菌与否对不同氧化还原环境下含硫煤矸石污染物的释放有重要影响。因此,可以通过工程手段调控矿山环境中微生物活性或类群,对含硫煤矸石污染进行有效的原位控制或治理。
The batch leaching tests were conducted under different redox environments to investigate the effects of microbial on the release of the contaminants from coal gangue. These tests were conducted for 9 days in the sealed containers with four different treatments, which were the simulated oxidation condition, oxidation and sterilization condition, reduction condition, reduction and sterilization condition, respectively. During the leaching tests, the leachates were collected and analyzed for pH, electrical conductivity (EC), redox potential (Eh), total dissolved solids (TDS), and Fe^3+,Mn^2+,Cu^2+,Zn^2+,SO4^2- and F^- concentrations every 0,1,3,6,9 d. The results showed that,under the oxidation condition,the sterilization could reduce the acid formation and increase the pH of leachate; EC and TDS value was reduced and the Fe^3+ leaching concentration was decreased significantly; the leaching of Mn^2+ , F^- , Cu^2+ and SO4^2- were also inhibited,and this inhibitory effect was increasing with test time. However,to some extent,the sterilization could weaken the inhibitory effect under reduction condition. Above all, under different redox environments,microbial effect could have a meaningful impact on the release of the contaminants from coal gangue. It suggested that using engineering method to change or control the microbial activity or community in mine could be a suitable method for the coal gangue pollution abatement and on-site immobilization.