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- Effects of the Addition of Different Additives before Mechanical Separation of Pig Slurry on Composition and Gaseous EmissionsPublication . Pereira, José L.S.; Perdigão, Adelaide; Tavares, Ana; Silva, Maria E. F.; Brás, Isabel; Ferreira Wessel, DulcineiaThe treatment of animal slurry is used to improve management on a farm scale. The aim of this laboratory study was to assess the effects of the addition of the additives biochar, alum and clinoptilolite before the mechanical separation of whole pig slurry (WS) on the characteristics and emission of NH3 , N2O, CO2 and CH4 from solid (SF) and liquid fractions (LF). The additives were mixed with WS (5% w/w), followed by separation, in a total of 12 treatments with 3 replicates, including the controls and WS with additives. Gaseous emissions were measured for 30 d by a photoacoustic multigas monitor, and initial characteristics of the slurries were assessed. The results indicated that the separation of the WS modified the initial physicochemical characteristics and increased the GWP emissions of the SF and LF, but not the NH3 losses. However, the addition of additives before separation increased the nutrient value and reduced the GWP emissions from the SF and LF. Additionally, just the additive alum was effective in the reduction of E. coli. The additives led to significant reductions in NH3 and N2O emissions, with higher reductions in NH3 losses for alum (51% for NH3 ) and similar N2O losses for all additives (70% for N2O) observed, whereas the CO2 and CH4 emissions were reduced by biochar (25% for CO2 and 50% for CH4 ) and alum (33% for CO2 and 30% for CH4 ) but not by clinoptilolite. Although the additives had a positive effect on slurry management, it can be concluded that the addition of alum before mechanical separation has the potential to be the best mitigation measure because it improves the nutrient content and sanitation and decreases gaseous losses from slurry management.
- Review of Measures to Control Airborne Pollutants in Broiler HousingPublication . Pereira, José L.S.; Garcia, Carla; Trindade, HenriqueBroiler housing is a significant source of airborne pollutants from animal production, which lead to degradation of indoor air quality and outdoor emissions, particularly ammonia, nitrous oxide, carbon dioxide, methane, hydrogen sulphide, odours and particulate matter. In this chapter, we first analyse the current state of the art on the consequences of these pollutants on broiler farming, farm workers, and the environment. This includes the factors affecting pollutants generation, quantification, and mitigation measures suppressing airborne pollutants. Next, we describe different best available techniques for environmental protection and sustainability of broiler production, namely feeds and feeding management, feed supplements, bedding management and treatment of exhaust air. Thus, broiler farms should select mitigation strategies based on several considerations, such as location, climate conditions, environmental policies and financial resources
- Biochar as an Alternative Litter Additive to Mitigate Gaseous Emissions from Broiler Housing and Subsequent StoragePublication . Pereira, José L.S.; Martins, Filipa; Bonifácio, Gabriel; Garcia, Carla; Teixeira, José; Trindade, HenriqueBroiler farming is a significant source of gaseous emissions. The aim of this study was to assess the effects of different litter additives on the emission of NH3, N2O, CO2, and CH4 during broiler housing and subsequent manure storage. The gaseous emissions from the housing facilities were evaluated during one fattening cycle in environmentally controlled rooms with three different additives applied to the litter material (10% w/w aluminum sulphate or biochar and 2.50 mg m−2 urease inhibitor), as well as a control. A storage experiment was conducted under laboratory conditions for 90 days to evaluate the influence of these three additives on gaseous losses. During broiler housing, the results indicated that NH3 emissions were reduced significantly (40–60%) by litter additives, while global warming potential (GWP) emissions were reduced significantly (31%) by Alum. The addition of Biochar (a 58% reduction) had the same significant effect as Alum (a 60% reduction) to mitigate these losses. The re-application of Urease (a 41% reduction) may be required to reach an equal or higher reduction. During storage, NH3 and GWP emissions were not significantly affected by the litter additives. During broiler housing and subsequent manure storage, NH3 emissions were reduced significantly (22–41%) by litter additives, whereas GWP emissions did not decrease significantly. Globally, it can be concluded that Biochar appears to be a good alternative to Alum due to its equal effectiveness in mitigating NH3 losses, without increasing the GWP potential in the housing and avoiding pollution swapping.