[Investigation of enhanced low carbon wastewater denitrification by catalytic iron].

The nitrogen removal efficiency and N2O production during the process of coupling catalytic iron and biological denitrification for low C/N ratio wastewater were studied. The results showed that biological denitrification coupled with catalytic iron could significantly improve nitrate transforming efficiency, but led to nitrite accumulation, resulting in little difference in total nitrogen removal efficiency, compared with traditional biological denitrification. N2O production from the catalytic iron group was obviously higher than the traditional control group, among which chemical reaction between ferrous oxide and nitrite had great contribution. However, the highest amount of accumulated N2O was less than 8% of the removed nitrate, and N2O was further reduced to N2 by microorganisms. Furthermore, catalytic iron group could eliminate dissolved oxygen and lower the oxidation reduction potential, which is beneficial for keeping anoxic conditions during denitrification.