Source: https://www.vera-verification.eu/vera-glossary/ (2022-01-15)
|Belonging to the category of chemical air cleaners, this is a trickling filter in which the pH of the washing liquid is kept at low levels (pH < 5) through the addition of acid (usually sulphuric acid) in order to remove ammonia from the contaminated air. The ammonium ions produced by
the chemical reaction between NH3 and the acid is removed from the system with the discharge water. Due to the low pH-value, microbial degradation does not take place. Therefore, odour reduction is relatively insignificant and subject to considerable fluctuations.
|Additive (directly added)||A product or substance, manufactured or naturally occurring, that is added to manures with the purpose of modifying their biological, chemi-
cal, or physical properties. Examples: Acids and acidifying compounds, Adsorbents, Bacterial enzyme preparations, Disinfectants, Masking agents, Oxidising agents, Plant extracts, Polymers, Urease inhibitors
|Air cleaner||An end-of-pipe installation for cleaning the exhaust air of forced-ventilated animal housing systems from specified contaminants, such as
odour, ammonia, and dust.
|The volume flow of exhaust air in m3 h-1 can be given for the entire animal house or per animal (place).
If the system is based on partial air cleaning, the total airflow is split into two airflows: an airflow going through the air cleaner and an un- treated airflow blown directly out into the surroundings. When the external dimensions of a filter are evaluated, or when the air filter is subse- quently up/downscaled on another farm, the air flow per area of front filter in m3 h-1 m-2 is a basic parameter. The air flow can also be given per filter volume in m3 h-1 m-3, which is the reciprocal value of the retention time.
|Air purifier||See ‘air cleaner’.|
|Ammonia (NH3)||A gas derived from livestock manure by the transformation of urea excreted by livestock or uric acid excreted by poultry; it is implicated in the
acidification and nitrogen enrichment of sensitive ecosystems.
|Ammonia emission||The process by which ammonia gas (NH3) is released from a solution.|
|Animal category||The type of animal according to their species (pigs, cattle, chicken, ducks, turkeys, etc.), sex, age, and scope of production (e.g. breeding, rear-
ing, growing, and finishing for meat; and milk or egg production).
|See ‘livestock housing system’|
|Application rate||This refers to the mass (tons or Mg) or volume (m3) of manure applied per unit area of land (ha).|
|The concentration of aerial pollutants in the incoming air.|
|Installation in which the exhaust air is led through a filter bed, usually consisting of organic material such as root wood or wood chips. The filter material has to be kept moist so that gaseous contaminants are absorbed by the moisture film of the biofilter material and generally oxidised or degraded by microorganisms living on the filter material. In order to compensate for evaporation losses, and to guarantee proper function- ing, the exhaust air has either to be pre-humidified, e.g. by a washer, and/or the filter has to be moistened by controlled intermittent irrigation. Biofilters are mainly used to eliminate odours in housings with no bedding material. They can also be used for dust separation if coarsely struc- tured filter material, which does not tend to clog, is used, at least on the crude gas side. Biofilters, as a sole process stage, are not suitable for
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|Biotrickling filter||A trickling filter for the removal of dust, ammonia, and odour by means of absorption of the contaminants in the liquid phase and degradation by microorganisms settling on the filter elements as a bio film. Ammonia is degraded by a bacterial conversion to nitrite and nitrate, a process called nitrification. The accumulated nitrate, especially nitrites that may be toxic to microorganisms, has to be removed with the discharged water.|
|Broadcasting||A type of manure spreader that spreads the manure over the whole surface of an area of land.|
|Chemical scrubber||A trickling filter that removes pollutants by means of absorption of the contaminants in a liquid phase with specific chemical properties. In the case of using pH to facilitate pollution removal, the pH value could be obtained by the addition of an acid, e.g. sulphuric acid (see acid scrub-ber), or by the addition of a base.|
|Compartment||The separate part of an animal house with its own ventilation and manure system.|
|Cover technology||Cover systems for manure storage facilities can be divided into cover systems that float on the manure surface - floating covers - and roof sys-tems covering the manure storage facility - roof systems. See below.|
|(Deep) injection in uncropped land||The application of liquid manure by direct incorporation into the soil. This can be achieved by vertical slots, typically about 150 mm deep, cut into the soil by specially designed tines.
Deep injection tines may be fitted with lateral wings in order to increase the lateral dispersion of slurry into the soil. To directly incorporate the manure, different kinds of tillage implements may be used. It is mainly used to reduce the emission of ammonia but it also reduces the emis-sion of odour.
|Denitrification unit||Biological denitrification units are used for removing oxidised nitrogen species originating from NH3 in polluted air. Denitrification is a biological process in which bacteria use one or more of the oxidised nitrogen species, i.e. nitrate NO3-, nitrite NO2-, nitric oxide NO, and nitrous oxide N2O, for respiration under anoxic conditions while degrading organic material. The ultimate end product of denitrification is atmospheric nitrogen, N2, which is harmless in the environment, and N2O which must be minimised through the controlled denitrification process.
Prior to denitrification, NH3 has to be oxidised within the air cleaner or in a separate unit external to the air cleaner. The growing of nitrifiers strictly depends on temperature. Therefore, it is recommendable to avoid energy losses as far as possible. Good operational results will be achieved at temperatures above 15°C, otherwise the growing of the nitrifying bacteria and nitrification rates are very low.
|Downtime||The period of time when the system tested is not operating as a result of malfunctions.|
|Dust||Also referred to as ‘particulate (or particular) matter’.|
|Emission value||The emission level of a given pollutant from an animal house into the atmosphere, which can be expressed as the integrated mass emitted per time interval and animal produced (e.g. kg year-1 animal-1), livestock unit (e.g. OUE s-1 LU-1), or per m² floor (e.g. kg year-1 m-2). It may also be expressed as a percentage (e.g. % total ammoniacal nitrogen or total nitrogen).|
|Enrichment factor||The ratio of the concentration of a compound in a specific output fraction to its concentration in the input fraction.|
|Feed composition||A description of the individual ingredients and their nutritional value that constitute a feed formula/diet.|
|Feeding technique||A description of the technical installations for mixing, transporting, and dispensing the feed to the animals, which can be applied in solid or liquid form.|
|Filter area||The front area of the filter where the air flows in is based on the external dimensions of the filter (m2).
The specific filter area is the area of the filter material per volume of filter element (e.g. m2 filter or m3 filter element).
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|Floating covers||Fabric membrane:
floats directly upon the slurry surface. Water collected on the membrane needs to be pumped away;
is suspended from the rim of the store and floats on the slurry surface. Water collected on the membrane needs to be pumped away.
natural crust, which may be formed by the content and residues of the slurry;
chopped straw, which is applied upon the surface of the slurry;
solid manure, which is applied upon the surface of the slurry;
LECA pebbles, which are applied upon the surface of the slurry;
granules or structures made of degradable or non-degradable floating elements, which are applied upon the surface of the slurry.
|Floor design||The floor type, e.g. a solid (concrete) floor, including the use of bedding material, or a slatted floor. The slats can be made of metal, concrete, or plastic.|
|Greenhouse gas (GHG)||Gases that contribute to the ‘greenhouse effect’ and global warming, primarily including carbon dioxide (CO2), methane (CH4), and nitrous ox-ide (N2O).|
|Heating system||An installation for the production, transportation, and distribution of heat in the housing system.|
|Incoming air||This is preferred to the term ‘background’ (air) to distinguish the effects of nearby emission sources from the ‘clean’ background.|
|Land application||The distribution of manure onto land by any method.|
|Liquid fraction||The liquid or thin fraction derived from the mechanical separation of slurry.|
|Livestock housing system||A unit with the primary function of providing housing for a specified animal category and with a specific design, equipment, and management that determines its environmental performance.
This includes the way that a certain animal category is stocked (e.g. floor and pen design), the manure storage and management system, the ventilation system installed to control the indoor climate in the building, and the type and regime used to provide feed and water to the ani-mals. In addition, it can be divided into separate compartments or different functional areas.
|Livestock unit (LU)||A unit used to compare or aggregate numbers of animals of different species or categories. Often 1 Livestock Unit = 500 kg live weight of an animal category. Other equivalences are defined on the feed requirements (or sometimes nutrient excretion).|
|Manure||A general term denoting any organic material containing excreta from the digestive system of livestock that supplies organic matter to soils and nutrients to plants, usually in lower concentrations when compared to inorganic fertilisers.|
|Manure system||The collection and removal of slurry or manure out of the housing system, e.g. by gutters, channels, and scrapers.|
|Multi-stage exhaust air cleaning systems, usually consisting of two or three stages, combine different cleaning principles and their advantages (see Table 1), e.g. an improved ammonia separation by an acid scrubber with an optimal odour degradation in a biofilter.|
|The description of an emission factor for a standard housing system, which is used as a reference standard factor in individual countries.|