Evaluation of a dry filter for dust removal under laboratory conditions in comparison to practical use at a laying hen barn.

The high amount of particulate matter from poultry houses in the exhaust air, especially at different types of laying hen barns, is the main challenge farmers are faced with concerning emissions. As a possibility for the mitigation of particulate matter in the outgoing air, a dry filter based on the principle of centrifugal force was investigated under laboratory and field conditions. Aerosol spectrometers were used for continuous measurements in raw and clean gas. Field experiments took place under summer and winter conditions, so that filter efficiency under different climate conditions could be compared and measurement values at the barn were continuously collected over 24-h periods. Data collected under laboratory conditions showed a high efficiency of the dry filter, whereas results of the field experiments differed in each size fraction of the particulate matter. These differences may be explained by the fact that under laboratory conditions, better circumstances for correct measuring were created, e.g., laminar flow of the air.

Analysis of the dust emissions from a naturally ventilated turkey house using tracer gas method.

Particulate matter (PM) emissions are becoming increasingly important in licensing procedures for the construction of new livestock houses or for the modernization of existing ones. Emission predictions require reliable data about emission rates. On this account, it is necessary to obtain information about the emission development and the relevant influencing factors in naturally ventilated turkey houses. The primary objective of the present research was to describe different aspects of PM emissions from a naturally ventilated turkey house. This includes the quantification of PM emissions and descriptions of the relevant influencing factors. Moreover, the tracer gas decay (TGD) method for ventilation rate estimation had to be used. To determine the emission mass flow from livestock buildings, it was necessary to measure the concentration of the target substance in the exhaust air and the airflow volume. The PM concentration measurements were carried out with a light scattering aerosol spectrometer in the exhaust air. The airflow volume was determined using the TGD method. To this purpose, tracer gas was injected into the supply air before the concentration decay was measured in the exhaust air of the building. The main influences on the PM concentration and the PM size distribution were shown to be animal activity and air volume flow. For the turkey barn, the PM emission factor averaged 0.027 g h(-1) animal(-1) over the entire year. If service times were to be included in the calculation, the emission factor 0.021 g h(-1) animal(-1), again averaged over the entire year, is well below the regulatory limit.

Physical properties of particulate matter from animal houses-empirical studies to improve emission modelling.

Maintaining and preserving the environment from pollutants are of utmost importance. Particulate matter (PM) is considered one of the main air pollutants. In addition to the harmful effects of PM in the environment, it has also a negative indoor impact on human and animal health. The specific forms of damage of particulate emission from livestock buildings depend on its physical properties. The physical properties of particulates from livestock facilities are largely unknown. Most studies assume the livestock particles to be spherical with a constant density which can result in biased estimations, leading to inaccurate results and errors in the calculation of particle mass concentration in livestock buildings. The physical properties of PM, including difference in density as a function of particle size and shape, can have a significant impact on the predictions of particles' behaviour. The aim of this research was to characterize the physical properties of PM from different animal houses and consequently determine PM mass concentration. The mean densities of collected PM from laying hens, dairy cows and pig barns were 1450, 1520 and 2030 kg m(-3), respectively, whilst the mass factors were 2.17 × 10(-3), 2.18 × 10(-3) and 5.36 × 10(-3) µm, respectively. The highest mass concentration was observed in pig barns generally followed by laying hen barns, and the lowest concentration was in dairy cow buildings. Results are presented in such a way that they can be used in subsequent research for simulation purposes and to form the basis for a data set of PM physical properties.