Manure management Flashcards
- Define “liquid manure” and “solid manure”
liquid manure:
liquid form of animal waste that is produced (urine and feces).contains high concentration of nutrients (nitrogen, phosphorus, and potassium)
solid manure: solid form of animal waste
- Manure mixed with bedding material (straw etc.)
what are the main potential pollutants coming out of liquid and solid manure (environmental relevance).
-not properly stored or applied –> contamination of water
-Too much liquid manure –> water and nutrient pollution (Run-off BOD, COD, NPK)
- pollution from unwanted matter (weed seeds, pathogens, heavy metals)
- eutrophication (harmful algal blooms, oxygen depletion)
- large piles can produce methane gas CH4 (or nitrous oxide) –> contributes to CC
- nutrient imbalances on the field
- Whats is a scraper system, where is it mainly used?
A scraper system is a type of mechanized equipment used for removing manure from the stable. There are different system variants: Folding scraper, flap scraper (liquid) and push rod conveyor, flat scraper
- How does a floating demanuring system work? mainly used for cattle housing
- continuous manure discharge into a storage tank is characterized.
- Manure and urine fall through a slatted floor into the liquid manure channel, at the end of hold-up nose. ( This keeps an absolutely necessary layer of liquid (water or slurry) on the bottom of the channel)
- The solid manure components build up on this sliding layer in such a way that its surface slopes from the beginning to the end of the channel. This builds up hydrostatic pressure and thus shear stress. As soon as this is high enough to overcome internal and external friction, the flow process begins.
- Discuss the environmental and hygienic aspects of an indoor liquid manure storage system compared to e.g. ponding systems.
indoor liquid manure storage system:
- accumulation of harmful gases in the barn during agitation (environment)
- bad in swine housing because of the lack of interruption of infection chain (rein- raus Verfahren nicht möglich)
Ponding systems: Ponding systems can be cleaned and disinfected and there is no accumulation of gases
- Describe different techniques to cover manure storages and their emission reduction potential
= covering to avoid gas (ammonia) emissions and odour emissions
liquid manure:
- Natural floating cover: Reduction gases ca. 70 % (cattle); 30 % (pig)
- Artificial floating cover →straw chaff 80 % reduction; Fixed cover (plastic, concrete)–> 90 % reduction; plastic granulates 85 %
solid manure: dung heap with drainage liquid pit ( to reduce emissions store compactly with a relative small emitting surface)
- Describe the structure of a biogas plant and the biogas process and its dependence on temperature
four-step degradation process:
Hydrolysis => Acidogenesis => Acetogenesis => Methanogenesis
- Needs: Wet material; Anaerobic milieu; Constant temperature and feeding; pH value 7
- The organic substances contained in the raw substrates, such as carbohydrates, fats and proteins, are broken down into their low-molecular-weight building blocks by enzymes and various microorganisms working hand in hand. The methane bacteria working at the end of the microbial decomposition chain produce combustible methane and carbon dioxide as well as other gases contained in small quantities. The most important of these is hydrogen sulfide.
dependence on temperature: dependence on temperature: Like all biological processes, this is also strongly temperature-dependent, so that organic matter is degraded more rapidly as the temperature rises. However, there are different strains of methane bacteria that have their optimum activity in different temperature ranges.
- How can we make energy out of biogas
- biogas as a fuel to generate heat or electricity by a CHP (combined heat and power facility)
- biogas collected and cleaned (sulfur compounds) and burned (CHP) –> mechanical energy –> electricity
- heat –> can be used for heating or other industrial processes
and what is the expected efficiency of biogas to energy process?
The expected efficiency of a biogas-to-energy system depends on several factors:
- composition of the biogas
- the design of the system
- and the type of equipment used.
In general, the efficiency of a biogas-to-energy system can range from 30% to 60% (highest in CHP up to 90 %)
- What are the advantages of a liquid-solid separation? “liquid phase”
liquid phase:
+ volume reduction (10-20%)
+ more homogenous
+ protection of technical installations against foreign matter
+ avoidance of plugging of tubes (slurry application)
+ exact analysis of nutrient composition possible
+ better soil infiltration
+ less nitrogen losses
+ less odour emission
+ less chemical burn of plants
+ more precise and specific fertilizing, longer application period
+ suitable for further treatment
- What are the advantages of a liquid-solid separation? “solid phase”
+ easy storage, no special precautions necessary
+ higher content of nutrients
+ less transport
+ compostable, production of a good for sale
+ specific application to improve the soil structure
+ allowed for use as fertilizer in water protection zones
- What are the aims and advantages of composting?
- Volume and mass reduction through the decomposition of OM
- Stabilization of organic waste (reduction of odors and ammonia during storage and application)
- inactivation of weed seeds and some pathogens
- Greater availability of nutrients from the waste for recycling to the crop production
- Mixing of organic material with fertilizer and other materials for soil improvement
- Improvement of the soil; additional income through sale
- Enabling transport of surplus nutrients (as dry and stabilized concentrate) to regions with poorer soils and need for organic material
- How does the aeration rate influence the ammonia emissions during composting?
aeration rate: The amount of oxygen available during composting affects the activity of microorganisms that decompose the organic matter. If the aeration rate is too low → the decomposition process slow down and result in incomplete decomposition → release of more ammonia. On the other hand, excessive aeration → loss of nitrogen through nitrification and denitrification → increase ammonia emissions.
- How does the aeration rate, dry matter content influence the ammonia emissions during composting.
dry matter: The dry matter content of the composting material influences the amount of moisture present, which can affect the activity of microorganisms. If the dry matter content is too low, the compost may become waterlogged→ anaerobic conditions that can increase the production of ammonia. Conversely, if the dry matter content is too high, the compost may become too dry → slowdown in microbial activity and incomplete decomposition.
How does C:N ratio influence the ammonia emissions during composting.
C/N ratio: The C:N ratio is the ratio of carbon to nitrogen in the composting material. A high C:N ratio can lead to a slower decomposition process, which can increase the production of ammonia. This is because the microorganisms responsible for decomposing the organic matter require nitrogen to grow and reproduce. If the C:N ratio is too low, there may not be enough carbon to support the microbial population, leading to incomplete decomposition and the release of more ammonia.
