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- Evaluation of Tomato-Based Packing Material for Retention of Ammonia, Nitrous Oxide, Carbon Dioxide and Methane in Gas Phase Biofilters: A Laboratory StudyPublication . Pereira, José L.S.; Perdigão, Adelaide; Marques, Francisco; Coelho, Catarina; Mota, Mariana; Fangueiro, DavidBiofilters are an effective air pollution control technology to break down gaseous contaminants and produce innocuous end products. This laboratory study aimed to evaluate a biofilter media, mainly composed by tomato waste, as packing material to reduce NH3, N2O, CO2 and CH4 losses from stored pig slurry. Three mixtures of packing materials, with and without oxalic acid, were arranged in treatments, namely: mixture of tomato waste, pine bark and agricultural compost; mixture of tomato waste and rice husk; tomato waste only. A control treatment (no biofilter) was also included. The experiments were conducted using a system of laboratory scale biofilters connected to jars filled with pig slurry and under a constant airflow rate. The gas concentrations were measured for 14 days and the physicochemical of the packing materials were assessed. Results showed that biofilter media mixtures had a potential for NH3 retention ranging from 51 to 77% and the addition of oxalic acid to these biofilters increased NH3 retention to 72–79%. Additionally, the biofilter media mixtures with and without oxalic acid showed a potential retention for CH4 (29–69%) but not for N2O, yet with no impact on the global warming potential. It can be concluded that tomato based biofilters had the potential to reduce gaseous emissions from slurry.
- Evaluation of a Tomato Waste Biofilter for the Retention of Gaseous Losses from Pig Slurry Hygienization by pH ModificationPublication . Pereira, José L.S.; Perdigão, Adelaide; Fangueiro, DavidThe use of pig slurry as organic fertilizer in intensive horticulture could be possible after hygienization to avoid contamination of products. This research aimed to evaluate a mixture of a tomato waste and rice husk as biofilter media to reduce NH3, N2O, CO2, and CH4 losses from a simple and low-cost solution for slurry hygienization by pH modification. The experiment was made in a system of laboratory scale biofilters connected to jars filled with raw slurry as control and three treatment methods: acidified slurry, alkalinized slurry, and neutralized slurry. The gas concentrations were measured for 35 days, and the composition of slurries and biofilters were determined. The results of this study showed that the mixture of biofiltering media, composed of tomato waste and rice husk, has the potential to retain NH3 and greenhouse gases (GHG) from a simple and low-cost solution for slurry hygienization by pH modification. Compared to the treatment raw slurry biofilter, the treatment neutralized slurry biofilter, subjected to a combined treatment by alkalinization/neutralization, retained 19% NH3, 4% CO2, and 83% CH4 losses and had no impact on N2O and global warming potential. Thus, the use of tomato waste biofilter during alkalinization did not increase the loss of NH3 and reduced GHG compared to raw slurry, avoiding the subsequent neutralization of slurry for environmental reasons, and could be used as an organic fertilizer in horticulture. However, using the combined alkalinization/neutralization treatment will improve the fertilizer value of the slurry by adjusting the pH from 9.5 to 7.5.
- Effect of Biochar on Emission of Greenhouse Gases and Productivity of Cardoon Crop (Cynara cardunculus L.)Publication . Barracosa, Paulo; Cardoso, Isabel; Marques, Francisco; Pinto, António; Oliveira, Jorge; Trindade, Henrique; Rodrigues, P.; Pereira, José L.S.Cardoon could be cropped for agro-environmental, industrial, and pharmaceutical purposes. The aim of this study was to assess the effects of biochar on emissions of nitrous oxide (N2O), carbon dioxide (CO2), and methane (CH4), and productivity of cardoon crop. A pot experiment was run outdoors from April to August 2018, with a cardoon plant per pot. The following four treatments, with four replicates each, were applied: control, soil only; mineral, soil amended with mineral fertilizer (2.5 g N m−2); biochar, soil amended with biochar (1 kg m−2); and mineral+biochar, soil amended with mineral fertilizer (2.5 g N m−2) and biochar (1 kg m−2). The morphological characteristics and biomass production of cardoon plants were evaluated, and the fluxes of N2O, CO2 and CH4 were measured by using the closed chamber technique. The application of biochar combined with mineral reduced N2O emissions by 36% and global warming potential (GWP) by 26% relative to mineral. However, the cumulative CO2 and CH4 emissions as well as yield-scaled GWP were not significantly different among amended soil treatments. Furthermore, the biomass production was increased by 50% by the application of biochar combined with mineral fertilizer relative to mineral. It was concluded that biochar combined with mineral fertilizer is recommended as a pathway mitigation for agro-environmental purposes, because it reduces the global warming potential and could increase the biomass production of cardoon plants.
- Mitigating Ammonia and Greenhouse Gas Emissions from Stored Pig Slurry Using Chemical Additives and BiocharsPublication . Pereira, José L.S.; Perdigão, Adelaide; Marques, Francisco; Ferreira Wessel, Dulcineia; Trindade, Henrique; Fangueiro, DavidSlurry storage is a significant source of NH3 and greenhouse gas (GHG) emissions. The aim of this laboratory study was to assess the effects of different chemical additives and biochars on the emissions of NH3, N2O, CO2, and CH4 during the short-term storage of pig slurry. The experiment was performed using Kilner jars filled with raw slurry as control and six treatment additives (5% w/w): acidified slurry, alkalinized slurry, neutralized slurry, agroforestry biochar, cardoon biochar, and elderberry biochar. The gas emissions were measured for 30 days, and the composition of the slurries was determined. During short-term storage, the results of this laboratory study indicated that the NH3 emissions were reduced by 58% by acidification and by 20% by the biochars (Agroforestry, Cardoon, and Elderberry treatments), while neutralization reduced this loss by only 12%. Nitrous oxide emissions were not reduced by the chemical additives (Acidified, Alkalinized, and Neutralized treatments), while this loss was increased by 12% by the biochars. Carbon dioxide, CH4, and global warming potential emissions were not affected by the chemical additives and biochars. Furthermore, the absence of differences between the biochars may be related to their similar composition. Regarding the influence of the studied additives on NH3 losses, it can be concluded that acidification was the best mitigation measure and the biochars were quite similar due to their composition. Furthermore, neutralization had the advantage of sanitizing the slurry, but only had a mild impact on NH3 preservation.
- Effects of Biochar in Soil and Water Remediation: A ReviewPublication . Perdigão, Adelaide; Pereira, José L.S.In the last decades increased global environmental concerns to water and soils pollution. The main concerns are related to the contamination of the ecosystem, food security, and human health since many of the contaminants present in soil and water (residues of pesticides and antibiotics, genes of resistance to antibiotics, and heavy metals) are absorbed by plants and enter the food chain. Remediation of the contaminated water and soil to ensure sustainable water supply and food production is urgently needed. The use of biochar can have a positive effect on this remediation process. There are several studies that demonstrate the biochar’s ability to block/reduce the contaminating effect of pesticides, antibiotic residues, antibiotic resistance genes, and heavy metals. The objective of this chapter is to carry out a comprehensive review of the effect of using biochar on the availability/transmission of these contaminants to the soil and food supply chain.
- 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.
- Assessment of Mineralized Nitrogen During Maize Growth Succeeding Different Winter Cover Crops in the Mediterranean EnvironmentPublication . Perdigão, Adelaide; Pereira, José L.S.; Moreira, Nuno; Trindade, Henrique; Coutinho, JoãoBackground: Understanding soil nitrogen (N) dynamics is essential to find alternative N sources and improve N use efficiency in agriculture. Objective: The aim of this study was to assess N mineralization rates from residues of winter cover crops, during maize crop season, under Mediterranean conditions. Methods: A field experiment was carried out from May to September in central Portugal, with four replications, two sowing dates of cover crops (15/10/2011 and 29/11/2011) and three cover crops residues (balansa clover, ryegrass and yellow lupine) that were incorporated in the soil. Plots were cropped with local maize and net N mineralization was measured during the crop cycle, using soil cylinders placed inside micro-perforated polyethylene bags. Results and Discussion: Early sowing of the cover crops residues increased the NH4+ and NO3- contents in the soil. Yellow lupine residue had the highest rate of daily N mineralization (0.71 mg N kg-1 day-1). For all treatments, the highest mineralization rate was found in the last incubation period, ranging between 0.78 mg N kg-1 day-1 and 1.84 mg N kg-1 day-1, both for balansa clover, from the second and the first sowing date, respectively. Conclusion: The present study suggests that, under Mediterranean field conditions, cover crops residue of Italian ryegrass, balansa clover and yellow lupin can be used as a nitrogen source namely for sustainable maize crops.
- A 3-year field study to assess winter cover crops as nitrogen sources for an organic maize crop in Mediterranean PortugalPublication . Perdigão, Adelaide; Pereira, José L.S.; Moreira, Nuno; Trindade, Henrique; Coutinho, JoãoCurrent environmental concerns, the rising economic and environmental costs of mineral fertilizers and the need to respond to the limitations of N fertilization in organic farming motivate the search for alternative sources of N in maize cropping. Forage legumes used as winter cover crops may improve soil N fertility and offer benefits to the environment. The aim of this study was to examine the effects, in a factorial field experiment, of two sowing dates (SD) and nine different cover crop treatments (balansa clover, crimson clover, gland clover, arrowleaf clover, French serradella, yellow lupin, Italian ryegrass, a cover mixture and a weedy fallow) as a potential alternative N source in an organically managed maize crop. The experiment was conducted at Viseu (Portugal) for three years (2007/2008, 2008/2009 and 2011/12), in the same field. Results showed that maize grain yield was not influenced by cover crop species but was affected by SD and the higher dry matter (DM) aboveground biomass production was observed in early SD (6.1 t ha 1). The cover crops revealed their importance in maize N uptake: yellow lupin of earlier SD had the highest N uptake (83.6 kg N ha 1), but this was not significantly different from balansa clover (83.2 kg N ha 1). Ryegrass was the most efficient in depleting soil mineral N but values were just significantly lower than yellow lupin. Lupin was the least efficient, leaving more mineral N in the soil than the others cover crops, immediately before the period when the risk of leaching is high. It was concluded that, under the edaphoclimatic conditions tested, most of the tested cover crops were efficient in supplying N to maize, and balansa clover had the best performance.
- 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
- Computational Fluid Dynamics Modeling of Ammonia Concentration in a Commercial Broiler BuildingPublication . Goncalves, J. C.; Lopes, António M. G.; Pereira, José L.S.In the present study, a numerical model was developed to predict the flow pattern inside a broiler building. The model intends to predict the velocities fields inside the domain and am-monia (NH3) emitted or released by litter from poultry housing. The numerical model developed in Computational Fluid Dynamics (CFD) commercial code, intends to represent a commercial broiler building, and intends to simulate the 3D and heat transfer, in steady state flow. The evaporative cooling pads were also included in the model. The validation of the model was based in experimental measurements obtained in previous studies. The simulations were fo-cused on Summer, Winter and also Mid-Season situation. The numerical results of NH3 concen-tration were compared with the experimental measurements, and a quite good agreement was verified. The numerical results allowed the characterization of: the inside flow pattern devel-oped for the summer and winter situation; the inside NH3 distribution, and the velocity field distribution inside the broiler building. It was found that NH3 concentration increases along the tunnel, especially in low flow rate imposed from the exhaust fan. Also, it was verified that the low velocities inside domain are no sufficient to remove the gaseous pollutants.