某硫酸盐还原菌株的分离及其在煤矸石山酸化污染修复中的应用

Isolation of an SRB Strain and It′s Application in Remediation of Coal Gangue Acidification Pollution

煤矸石堆场氧化导致的高盐酸性废水是严重危害煤矿区环境质量的污染源之一。利用硫酸盐还原菌进行生物固硫,能够有效控制煤矸石氧化产酸及其造成的污染。针对已知的硫酸盐还原菌多为严格厌氧菌、依赖外加碳源、难以应用于露天煤矸石山的问题,从酸性煤矸石堆场周边土壤中分离、筛选出一株兼性厌氧硫酸盐还原菌,分析菌株的16S r RNA基因序列、形态和生理生化特性,并利用柱状淋溶实验测定该菌株对煤矸石酸化污染的修复效果。结果表明:该菌株与Bacillus subtilis具有99.93%同源性,外形为杆状,大小(0.4~0.6)μm×0.2μm,最适生长温度范围为25~35℃,在p H为4~8的环境中均生长良好。该菌株对外加碳源的依赖性低,在无任何外加碳源的好氧条件下,接种该菌株18 d后,可将已酸化煤矸石的p H由3.09提升至4.62,同时去除48.25%的硫酸盐离子和88.40%以上的重金属离子,有效控制煤矸石堆场高盐酸性废水的产生。

The high salinity acid drainage caused by the oxidation of coal gangue are one of the pollution sources that seriously harm the environmental quality of coal mine area.The use of sulfate-reducing bacteria for biological sulfur fixation can effectively control the acid production and pollution caused by the oxidation of coal gangue.In view of the problem that most of the known sulfate reducing bacteria are strict anaerobic bacteria,depending on external carbon source,and difficult to be applied to open coal gangue mountain,a facultative anaerobic sulfate reducing bacteria was isolated and screened from the soil around the acid coal gangue yard.The 16S rDNA gene sequence,morphology,physiological and biochemical characteristics of isolated strain were investigated,and the column leaching experiments was used to analyze the repair effect of the strain on coal gangue acidification pollution.The results showed that the strain had 99.93%homology with Bacillus subtilis,and its shape was rod-shaped,with size(0.4~0.6)μm×0.2μm.The optimal growth temperature range of the strain was 25~35℃,and it grew well with pH of 4~8.In the absence of any additional carbon source,the pH value of the acidified coal gangue was raised from 3.09 to 4.62 after inoculation of the strain for 18 days,and 48.25%sulfate ions and more than 88.40%heavy metal were removed,effectively controlling the generation of high-salt acidic wastewater in the coal gangue yard.