The invention relates to a short-
cut denitrification process adopting catalytic iron and biological
coupling. The
denitrification process comprises a catalytic iron biological
denitrification section and a biological
nitrosation section. In the catalytic iron biological denitrification section,
wastewater enters the catalytic iron biological denitrification section, and the
hydraulic retention time is controlled to be 20 minutes to 2 hours; the
reflux ratio of mixed liquor is 100-300%; catalytic iron stuffing is arranged internally and the stacking density is 50-200 kg / M<3>. In the biological
nitrosation section, when the number of structural-state
ferrous iron Fe (II) formed by catalytic iron in the denitrification section is sufficient, the
oxidation reduction potential (OPR) in the
nitrosation section is controlled to be 40-100 mV; the
hydraulic retention time in the nitrosation section is controlled to be 6-10 hours; when the number of structural-state
ferrous iron Fe (II) formed by catalytic iron in the denitrification section is insufficient for producing a
nitrite reduction reaction, the catalytic iron stuffing can be put at the front end of the nitrosation section at the same time, the generation of structural-state
ferrous iron Fe (II) is accelerated by dissolved
oxygen in the nitrosation section, a catalytic iron stuffing arrangement region is positioned at the front section of the biological nitrosation section, the
hydraulic retention time is 1.0 hour, and the stacking density is 50-200 kg / M<3>. The short-
cut denitrification process greatly reduces organic carbon sources required by denitrification and greatly shortens
nitrification and denitrification processes.