A strain of aerobic denitrifying bacteria was isolated from mine water and further investigated for its characteristics of growth and denitrification. As both of optimal C/N ratio and rotational speed were determined through static-sample experiments, batch-fermentor experiments were subsequently conducted respectively with one-time addition and continuous equivalent additions of nitrate nitrogen (NO3--N). A phase of exuberant metabolism and rapid denitrification was noted after 20 h of cultivation, the logarithmic growth phase was observed at the 25th hour, and the duration of the entire lifecycle was determined to be 120 h as a whole. The most effective denitrification was achieved during static-sample experiments under such conditions as nitrate concentration of 360 mg/L, 10% bacterial inoculum, initial pH of 7.5, C/N ratio of 10: 1, and rotational speed of 100 rpm, as compared to that of batch-fermentor experiments conducted under similar conditions, but only with lower nitrogen gas production. Although the addition of 10% bacterial inoculum led to the highest NO3--N removal rate, the addition of 15% bacterial inoculum accomplished an increased NO3--N removal rate after pH adjustment. Continuous equivalent additions of NO3--N in the denitrification experiments resulted in a more complete use of carbon sources, more stable pH changes, and more effective denitrification, comparing with one-time NO3--N addition. The achieved results provide a critical experimental and industrial reference for the bio-removal of nitrate nitrogen in groundwater.

In adoption of plate isolation, anaerobic culture and PCR amplification techniques, a methanogens-culture experiment was conducted for investigating the mechanisms of generation of biogenic methane, during which coals of Shaqu colliery were used as substrates and mine water collected from Zhongtai and Shaqu collieries, respectively. The white-rot fungi preserved in laboratory were utilized as strain sources. Methane production was fully examined with the addition of disodium EDTA under various concentration gradients. The results show that there are methanogens present in mine water of Zhongtai, while the growth of methanogens in mine water of Shaqu is possibly discouraged due to the tested existence of denitrifying bacteria and overhigh pH. Hence, there is no methane being produced from coals of Shaqu as compared to the occurrence of gaseous production from that of Zhongtai under the same conditions. Meanwhile, when disodium EDTA is added at 1 g/L can the CH4 production reach a peak of 10 mL/g after a period of increase and the pH value can also see a notable rise after reaction.

Nowadays, carbon dioxide is the main cause of global warming, coal mining and its utilization is a major source of greenhouse gas emission, based on the theory of biogenic coalbed methane, this paper puts forward three models to achieve energy saving and emission reduction by using microbes, respectively they are the biological residual coal mining, the coalbed methane development and the carbon dioxide coalbed sequestration and transformation. And this paper analyses the utilization prospects from the aspects of the research status and technical procedures. Microbial technology has a great potential significance for energy saving and emission reduction and environment protection in coal mine.