Nitrogen Oxides. O = Lachgas =Stickoxydul =Distickstoffoxid = Nitrous Oxide N 2. Nitrogen oxides

Transkript

1 Nitrogen Oxides N 2 O = Lachgas =Stickoxydul =Distickstoffoxid = Nitrous Oxide

2 Structure of this lecture Introduction Ecology of the nitrogen cycle Processes of nitrification, denitrification, NH 3 emission Sources of N 2 O The global nitrogen cycle

3 Important Atmospheric nitrogen oxides Nitrogen Oxide English Deutsch Oxidation State of Nitrogen N 2 O Nitrous oxide Distickstoffoxid +1 NO Nitric oxide Stickstoffmonoxid +2 NO x NO 2 Nitrogen dioxide Stickstoffdioxid +4 HNO 3, N 2 O 5 Nitric acid, Salpetersäure +5 Dinitrogen Pentoxide NO 3 Nitrate Nitrat +6

4 Nitrogen Cycle in Agriculture

5 Entstehung von Stickstoffoxiden in Böden ( Hole in the Pipe Modell)

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7 Nitrification depends on 1. Ammonia availability 2. Oxygen (texture:sand) 3. Neural ph 4. Temperature 5. Medium soil moisture Nitrosomonas sp.

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9 N-Cycle in Forests

10 Hot spots of denitrification

11 Denitrifying Bacteria

12 Denitrification depends on 1. Nitrate availability 2. Temporary anaerobic conditions (soil moisture, texture: clay) 3. Organic substrate (energy) 4. Temperature 5. ph 6. Plants

13 N 2 O to N 2 ratio depends on 1. Nitrate availability 2. Acidity (ph) 3. Anaerobic conditions 4. Pollutants ph and nutrient availability

14 Emission of NO and N 2 O depending on soil moisture

15 Zusammenfassung 1 Der N-Kreislauf in natürlichen Ökossystemen ist geschlossener als der in landwirtschaftlichen Ökosystemen Lachgas kann während der Nitrifikation unter warmen Bedingungen und bei guter Durchlüftung entstehen Lachgas entsteht vor allem während der Denitrifikation unter temporär anaeroben Bedingungen; dabei ist auch das N 2 O zu N 2 Verhältnis besonders ungünstig

16 NH 3 emission depends on Alkalinity (ph) Water (weather conditions) Temperature NH 4 availability Manure treatment Application

17 Global increase of N 2 O

18 Lachgas N 2 O Anstieg von 270 ppb auf 319 ppb Lachgas ist 296 mal strahlungswirksamer als CO 2 Verweildauer in der Atmosphäre: 120 Jahre Mehr als ein Drittel aller Lachgasemissionen sind anthropogen und primär durch die Landwirtschaft verursacht

19 Loss of biodiversity due to N inputs

20 Atmospheric chemistry of nitrogen oxides

21 NO x and Ozone

22 Sources of N 2 O

23 N 2 O from Waste Water

24 N 2 O and NH 3 from Manure

25 The volume emitted varies according to the type of fuel, technology, or pollution control device used, as well as maintenance and operation practices. N 2 O from traffic

26 N 2 O from adipic acid production The vast majority of all adipic acid produced is used to manufacture nylon. N 2 O control in the process is possible.

27 N 2 O from nitric acid production Nitric acid production is used primarily to make synthetic commercial fertilizer, this raw material is also a major component in the production of adipic acid and explosives. It is produced by the oxidation of ammonia, during which N 2 O is formed and emitted to the atmosphere.

28 Other Sources of N 2 O Other N 2 O-emitting activities include the burning of agricultural crop residues and changes in land use.

29 Global Nitrogen Cycle

30 Summary Human activity has lead to a acceleration of the Nitrogen Cycle N 2 O emissions come mainly from soils (Ninput, anaerobic conditions) NO emissions come mainly from combustion processes Agriculture (fertilization, animals) is a major driver in the Nitrogen Cycle