Drew Meyers Paracoccus denitrificans
Agriculture: 73%, 17% from Nitrate runoff Wastewater: 3% UNEP 2013 N2O Report
Labile Carbon and NO 3 - from treated wastewater
Labile Carbon and NO 3 - from treated wastewater NO 3 - from agricultural runoff
Labile Carbon and NO 3 - from treated wastewater NO 3 - from agricultural runoff Aerobic Respiration: Labile Carbon + Oxygen CO 2 +H 2 O + energy
Labile Carbon and NO 3 - from treated wastewater NO 3 - from agricultural runoff Aerobic Respiration: Labile Carbon + Oxygen CO 2 +H 2 O + energy Anaerobic Respiration: Some bacteria use Nitrate as an electron acceptor. This is the process of Denitrification.
Labile Carbon and NO 3 - from treated wastewater NO 3 - from agricultural runoff Complete Denitrification Process, <0.5mg Oxygen/L: NO 3 - NO 2 - NO + N 2 O N 2 Redox Rxn: 2 NO 3 − + 10 e − + 12 H + → N H 2 O
Labile Carbon and NO 3 - from treated wastewater NO 3 - from agricultural runoff Incomplete Denitrification Process: Conditions are not completely anoxic NO 3 - NO 2 - N 2 O
Labile Carbon and NO 3 - from treated wastewater NO 3 - from agricultural runoff Incomplete Denitrification Process: Conditions are not completely anoxic NO 3 - NO 2 - N 2 O N 2 O leaves water, enters atmosphere
O 3 +hv O 2 + O( 1 D) N 2 O + hv N 2 + O( 1 D) N 2 O + O( 1 D) N 2 + O 2 or 2 NO 3 – 4% of N2O loss in stratosphere results in Nitric Oxide (NO)
O 3 +hv O 2 + O( 1 D) N 2 O + hv N 2 + O( 1 D) N 2 O + O( 1 D) N 2 + O 2 or 2 NO NO + O 3 NO 2 + O 2 NO 2 + O NO +O 2 3 – 4% of N2O loss in stratosphere results in Nitric Oxide (NO)
O 3 +hv O 2 + O( 1 D) N 2 O + hv N 2 + O( 1 D) N 2 O + O( 1 D) N 2 + O 2 or 2 NO NO + O 3 NO 2 + O 2 NO 2 + O NO +O 2 Net Rxn: O 3 + O 2 O 2