[Enhanced Short-cut Denitrification by Fe-activated Carbon and Its Influencing Factors].

In order to reduce the carbon source for biological short-cut denitrification, Fe-activated carbon was used to enhance nitrogen removal in the absence of organic carbon, and the influences of the Fe/C mass ratio and initial pH value on the nitrogen removal efficiency were explored. The results showed that the nitrite removal efficiency increased from 7.4% to 31.1% when the Fe-activated carbon was used to enhance short-cut denitrification. When the Fe/C mass ratio was reduced from 2:1 to 1:1 and 1:2, both the denitrification rate and nitrite removal efficiency first increased and then decreased. At a Fe/C mass ratio of 1:1, a maximum denitrification rate of 5.58 mg·(g·h) and a maximum nitrite removal efficiency of 41.1% were achieved, respectively, and 0.1 mg of nitrous oxide was emitted. When the pH value was increased from 6.0 to 9.0, the denitrification rate decreased from 7.39 to 5.96 mg·(g·h), and the nitrous oxide emission decreased from 0.19 to 0.12 mg. Therefore, a higher nitrogen removal efficiency could be achieved by Fe-activated at a Fe/C mass ratio of 1:1 and pH value of 6.0. However, more nitrous oxide would be emitted at a low pH value.