Livestock emissions

Question 1

1. Define the terms “emission”, “transmission” and “immission”.

Answer 1

Emission: Release of pollutants from the source to the environment

Transmission: Distribution and conversion of pollutants during the atmospheric transport

Immission: Concentration and deposition of pollutants with impact on the places and creatures exposed

Question 2

2. Sketch/explain the influences on and processes of the formation and release of ammonia, nitrous oxide, methane

Answer 2

Ammonia formation:
(1)
Formation of ammonia is induced by catalytic breakdown of urea (urease)
–> CO(NH2)2 + H20 —> (urease) 2 NH3 + CO2

(2): Ammonia-Ammounium-Equilibrium in liquid
NH3+H2O –> (T,pH) NH4+ + OH-
The lower the temperature and pH the less solved as NH3 and the mote dissociated as NH4+

(3) : release: convection mass transfer from liquid to gasous phase–> Main promoting factors: high temperature, high air velocity, high turbulence of the air stream, size of the emitting surface, replenishment of potential NH3 pool

Nitrous oxide (N20) formation:
- Can be formed due to incomplete oxidation process (02 deficiency) by chemical decomposition of the intermediate hydroxylamine NH2OH within the nitrification process
- N20 is an obligate intermediate within the denitrification process
- also anamox reaction
Influences on Nitrous oxide formation:
- semi-optimal-oxy-conditions (straw cover on manure storage), slurry injections, in case of suboptimal process control and conditions, housing systems based on composting

Methane formation: manure from ruminants
Hydrolysis: Complex compounds (proteins, carbohydrates, lipids) are broken down into simpler compounds like amino acids, sugars, fatty acids by bacterial enzymes
Acidogenesis: The solutes are broken down into organic acids (butyric, propionic, acetic acids), lower alcohols, hydrogen etc. (stopped at low pH)
Acetogenesis: substances are further converted into acetic acid by acetogenic bacteria
Methanogenesis: acetic acids are split into methane, carbon dioxide and water. Hydrogen and carbon dioxide are reduced to methane and water.
Influences on methane formation:
Share of ruminants in livestock production.

Question 3

3. Give examples for main mitigation strategies to reduce emissions (formation and release; feeding; housing; ventilation; storage, application) or sketch the five major emission mitigation steps

Answer 3

Formation and release:
* inhibit the urease activity (ammonia formation)
* avoid suboptimal conditions for the conversion of N-bonds (nitrous oxide)
* reduce extensive cattle feeding (roughage) (methane)

feeding: low protein diets (ammonia), feed additives, dietary improvements, improving forage quality –> avoid N-surplus which can not be metabolized and will be excreted; adjusted rations to species and production stage, reduce extensive cattle feeding (roughage-methane)

housing: Air scrubbers, manure removal (avoid dirty surfaces), Güllekanalverengung, Kühlung, Cow-toilets

Velocity:
* reduce air velocity and temperature near emitting surfaces
* optimization of the balance between air flow rate, necessary air exchange, temperature needs
manure treatment: Anaerobic digesters, acidification
manure storage: storage covers
manure application: shallow injection , lower temperatures ad pH, fast incorporation into soil after application

Question 4

4. List six out of 11 measures investigated by the FAO report on the low emission pathways to 2050. Which measure seems to be the most “powerful”?

Answer 4

1. Productivity increase (30 % emission reduction in livestock)
2. selective Breeding
3. improved animal health and welfare (higher productivity, growth rates)
4. Carbon sequestration in grasslands (integration of trees
5. Feed and nutrition improvements
6. reducing food loss and waste

Question 5

5. What is the guiding idea of the environmental protection laws (e.g. BImSchG German federal pollution control bill).

Answer 5

• Protection against harmful effects on the environment or other hazards, considerable disadvantages and considerable nuisance to the general neighbourhood.
• Precautions to prevent harmful effects, in particular by such emission control measures as are appropriate according to the state of the art.

Question 6

6. Explain the term “Best available technique”, what is meant behind?

Answer 6

• “Best”: most effective protection of the environment as a whole (Best Techniques: Low emissions air, soil, water and efficiently use of energy and raw materials; Amount & quality of manure and waste; animal welfare)
• “Available”: possible/viable implementation in relevant sector, taking into consideration the costs and advantages (technical & economical application possible)
• “Techniques”: Technology itself & it’s application (Design, construction, maintenance, operation)