Waste management from the perspective of circularity of materials

The purpose of the study was to analyze the social phenomenon of collecting animal carcasses from rural properties using the perspective of the ecological modernization theory. The results show that the success of the Recolhe pilot project is associated with users’ engagement in environmental awareness, environmental regulations, sanitary and environmental risk management, minimization of labor in rural properties, and municipal legal pressures.     

Intra-cultivar variability of the soil-to-grain transfer of fallout 137Cs and 90Sr for winter wheat

Differences between the root uptake of fallout radionuclides by different cultivars ('inter-cultivar' variability) growing on the same field may be influenced not only by genetic differences of the cultivars, but also by the spatial variability of the soil-to-grain transfer within the cultivation area of each cultivar. This 'intra-cultivar' variability was investigated in 2001 and 2002 for 137Cs and 90Sr using three winter wheat cultivars with four replicates for each cultivar at three different sites in Bavaria, Germany. The intra-cultivar variability proved to be in the same range as the inter-cultivar variability which was determined earlier at the same sites for both radionuclides. An ANOVA of the 137Cs data set revealed that the variability of the 137Cs soil-to-grain transfer was caused by the soil and climate (year) at the field sites and the interaction of cultivar and field. A significant contribution of the factor 'cultivar' alone to the variability could not be detected. This may be due to the complex environmental conditions to which plants are exposed in field experiments. To find wheat cultivars with minimal uptake of fallout radionuclides it may be better to examine the molecular mechanisms of their root uptake in order to identify targets for breeding "safer" plants.     

A comprehensive model to estimate the simultaneous release of acidic and basic gaseous pollutants from swine slurry under different scenarios

Swine slurry is a source of atmospheric pollutants. Emissions of basic and acidic compounds from slurry are largely dependent on the surface pH. In a storage system, the pH at the surface layers changes over time due to the volatilisation of ammonia (NH₃), carbon dioxide (CO₂) and acetic acid (HAc). In this article, a comprehensive gas emission–pH (GE–pH) coupled model is proposed to describe the simultaneous release of acidic and basic gaseous pollutants from swine slurry. The model was applied to describe the release of NH₃, CO₂, HAc and hydrogen sulphide (H₂S) from standard slurries stored in animal houses, outside storage tanks and lagoons. The modelled results agreed well with values reported in the literature and could be reasonably interpreted. The key parameters affecting the release of gases were: initial pH, initial concentration of total ammonium nitrogen and inorganic carbon, slurry temperature and air velocity. This study suggests that future modelling studies on gas emissions from animal slurry should consider the concentration of inorganic carbon and the frequency in which the slurry surface is mixed or altered, because they affect the surface pH and the release of gaseous pollutants from slurry.     

Validation of model calculation of ammonia deposition in the neighbourhood of a poultry farm using measured NH3 concentrations and N deposition

Substantial emission of ammonia (NH₃) from animal houses and the related high local deposition of NH₃-N are a threat to semi-natural nitrogen-deficient ecosystems situated near the NH₃ source. In Denmark, there are regulations limiting the level of NH₃ emission from livestock houses near N-deficient ecosystems that are likely to change due to nitrogen (N) enrichment caused by NH₃ deposition. The models used for assessing NH₃ emission from livestock production, therefore, need to be precise, as the regulation will affect both the nature of the ecosystem and the economy of the farmer. Therefore a study was carried out with the objective of validating the Danish model used to monitor NH₃ transport, dispersion and deposition from and in the neighbourhood of a chicken farm. In the study we measured NH₃ emission with standard flux measuring methods, NH₃ concentrations at increasing distances from the chicken houses using passive diffusion samplers and deposition using ¹⁵N-enriched biomonitors and field plot studies. The dispersion and deposition of NH₃ were modelled using the Danish OML-DEP model. It was also shown that model calculations clearly reflect the measured NH₃ concentration and N deposition. Deposition of N measured by biomonitors clearly reflected the variation in NH₃ concentrations and showed that deposition was not significantly different from zero (P < 0.05) at distances greater than 150–200 m from these chicken houses. Calculations confirmed this, as calculated N deposition 320 m away from the chicken farm was only marginally affected by the NH₃ emission from the farm. There was agreement between calculated and measured deposition showing that the model gives true estimates of the deposition in the neighbourhood of a livestock house emitting NH₃.