PowerPoint Presentation

Denitrification as a Source of Nitrous Oxide

Drew MeyersParacoccus denitrificans

Nitrous Oxide (N2O), Why Does it Matter?N2O is now the most significant ozone-depleting substance emission and 3rd most important greenhouse gas released into the atmosphere. United Nations Environment Program (UNEP), N2O Report 2013

Emissions of N2OHow much do we emit?5.3 Teragrams of N2O N per yearWhat are the sources of N2O emission?

Agriculture: 73%, 17% from Nitrate runoff

Wastewater: 3%UNEP 2013 N2O Report

Denvers Largest Wastewater Treatment Site

Labile Carbon and NO3-from treated wastewater

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Labile Carbon and NO3-from treated wastewaterNO3- from agricultural runoff

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Labile Carbon and NO3-from treated wastewaterNO3- from agricultural runoffAerobic Respiration:Labile Carbon + Oxygen CO2 +H2O + energy

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Labile Carbon and NO3-from treated wastewaterNO3- from agricultural runoffAerobic Respiration:Labile Carbon + Oxygen CO2 +H2O + energyAnaerobic Respiration:Some bacteria use Nitrate as an electron acceptor.This is the process of Denitrification.

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Labile Carbon and NO3-from treated wastewaterNO3- from agricultural runoffComplete Denitrification Process,