Degradation of High-Concentration Nitrate Nitrogen in Groundwater: A Laboratory Study

To investigate effective and reasonable methods for the remediation of nitrate nitrogen pollution in groundwater, two groups of laboratory denitrification experiments were conducted: one on the effect of native denitrifying microbes in groundwater and another on the effect of artificially added denitrifying microbes. The water used in the experiment was typical groundwater with a high concentration of nitrate nitrogen. The temperature was controlled at 15°C. Both groups of experiments established four types of culture environments: anaerobic, anaerobic with an added carbon source (glucose), aerobic, and aerobic with an added carbon source (glucose). The results indicated that native denitrifying microbes in the groundwater have almost no ability to remove high concentrations of nitrate nitrogen. However, artificially added denitrifying microbes can effectively promote denitrification. Artificially added denitrifying microbes had the highest activity in an anaerobic environment in which a carbon source had been added, and the rate removal of a high concentration of nitrate nitrogen in groundwater was the highest and reached as high as 89.52%.