Photo: Jesper Rais.
Better indoor air quality for employees on pig farms, a large reduction in emissions from livestock housing and the development of an effective biological air purification system with a large national and international market potential. These are the great and promising ambitions of a new research project involving scientists from Aarhus University who will be working on the biological air purification of livestock housing combined with a relatively new ventilation principle called partial point extraction— the ventilation of the polluted air from the manure channel under the pig house.
The combination of local exhaust ventilation and new knowledge on biological purification means that it could become possible to eliminate large amounts of ammonia and odours from the housing in an affordable way. Compared to biological purification of the entire air volume from an animal house, an integrated solution consisting of biological air purification and point extraction has the potential to significantly reduce costs, achieve a more effective cleaning process and reduce waste volumes, says project manager Anders Feilberg from Aarhus University, and continues:.
The effect of the combination of the two known technologies is not precisely known, but the people behind the project expect that there is great potential and need for a future product, not least in light of the ever-stricter regulations on livestock production in a growing number of countries.
The German state of North Rhine-Westphalia has just introduced a requirement for mandatory air filter purification for all new pig finishing units with a capacity for more than pigs.
Flushing slurry from under slatted piggeries has proved effective in neutralising odour from slurry deposits. In poultry houses the manure should be removed daily from beneath cages to a store or spreader. The addition of water to poultry manure invariably induces reactions which produce strong, unpleasant smells. Where droppings are collected under cages for storage, drying by blowing ventilated air over them will minimise odour and ammonia emissions. Keep areas around stock buildings clean.
Stocking densities should comply with the recommendations set out in the appropriate Codes of Recommendations for the Welfare of Livestock.
Animals should be kept in a clean and healthy condition. Bedding materials should always be stored in a dry form and where possible be free of moulds and dust. Livestock buildings should be regularly and thoroughly cleaned.
The ventilation meets the thermal and hygienic requirements differently. Frank and Swensson In: Anonymous Ed. Where, ER is the rate of ammonia emission g NH3 bird -1 d -1 ,. The difference between cattle and pigs are significant for all levels of final CP when CP reductions are greater than 3.
Disinfect them after the removal of each batch of stock. Dairy and parlour buildings require frequent washing. Use the correct type and quantity of disinfectant and volumes of wash water. Buildings should be properly ventilated to control temperature, humidity and the concentration of gases, and to provide a stable distribution pattern of clean air under a wide variety of external weather conditions. Ventilators should be thoroughly cleaned between batches of stock and maintained to ensure operation at the correct airflow for the stock requirements.
and control of ammonia and odours emissions from livestock production. Odour Prevention and Control of Organic Sludge and Livestock Farming: Nielsen V C. Odour and Ammonia Emissions from Livestock Farming. Front Cover. V. C. Nielsen, J. H. Voorburg, Pierre L'Hermite. Elsevier Applied Science, Dec 31,
The removal of dust will help to reduce the level of odour. Humid conditions caused by poor ventilation result in smells and the build up of high levels of ammonia. Professional advice should be sought on the positioning of ventilator outlets. The higher the outlet the greater the dilution factor from air movement.
Ventilation outlets positioned along the sides of buildings, below slatted floors and immediately over the slurry collection channels can exaggerate odour. The use of bloscrubbers and biofilters in exhaust ventilators are developing technologies, but a relatively low cost solution has yet to be achieved. Maintain or replace drinking systems to avoid overflow and spillage which lead to wet, smelly areas, increased levels of waste production, slurry dilution or wet poultry litter or bedding. Open concrete areas used for livestock should drain to the slurry storage system and not be allowed to run off on to roads where evaporation will increase smells, in addition to posing a road safety risk.
Drainage from food stores and feed preparation areas should be collected by the foul-drainage system. Waste foods such as milk products whey, skimmed milk , draff and molasses must be kept in properly constructed containers which are easy to fill and empty to avoid spillage. The collectioi-l and treatment of swill is controlled by the Diseases of Animals Waste Food Order The installation of temperature-controlled systems can reduce complaints about smells from boiling the swill. The swill should be allowed to cool before delivery to the feed troughs.
From Slurry and Manure Stores Offensive smells from slurry stores are produced by: long periods of storage under warm conditions the addition of waste foods, milk products or silage effluent as these provide readily available sources of nutrients for micro-organism activity. From Land Application The following guidance should be adhered to: obtain a weather forecast and select suitable conditions for spreading. The following such measures are available for all production phases and processes and classes of animals:.
Moreover, good agricultural practices should be implemented, i. Optimized nitrogen emission management should take into account ecological parameters low NH3 emissions as well as economic and social parameters. Further efforts should be made to optimize chemical-fertilizer nitrogen efficiency higher plant nitrogen absorption per fertilizer application and to minimize nitrogen surpluses nitrogen input minus plant nitrogen uptake.
The impact of climate change will be felt more strongly in the future — and in Germany too. This is the conclusion reached in what is called the vulnerability analysis, a comprehensive study on Germany's vulnerability to climate change.
This limit is currently being exceeded or is not being reliably met. Such facilities must be constructed and operated in accordance with the state of the art. Abatement measures Nitrogen emission abatement measures need to be implemented at ammonia emission point sources. The following such measures are available for all production phases and processes and classes of animals: Measures in cow-sheds and pigsties, and for storage: waste air cleaning; low-emission loose-housing systems for pigs and cattle; covering storage facilities; hygienic measures.