Now showing 1 - 10 of 66
  • Publication
    Der er noget om ammoniak
    This is a comic aimed at children from the age of eight upwards. It highlights impacts from ammonia in agriculture, plus sources and solutions to the problem.
      146
  • Publication
    Coś niecoś o Amoniaku
    This is a comic aimed at children from the age of eight upwards. It highlights impacts from ammonia in agriculture, plus sources and solutions to the problem.
      143
  • Publication
    अमोनिया के बारे में कुछ है
    This is a comic aimed at children from the age of eight upwards. It highlights impacts from ammonia in agriculture, plus sources and solutions to the problem.
      87
  • Publication
    Catechin-based extract optimization obtained from Arbutus unedo L. fruits using maceration/microwave/ultrasound extraction techniques
    This study compares three extraction techniques (maceration, microwave and ultrasound) for catechin recovery from Arbutus unedo fruit extracts. To obtain the conditions that maximize catechin extraction yield, a response surface methodology was applied using a 3-level full factorial Box-Behnken design in which the processing time (t), temperature (T), ultrasonic power (W) and ethanol percentage (Et%) were the relevant independent variables with the response (catechin content, mg/g dw) measured by HPLC-PDA. A fixed solid/solvent ratio of 50 g/L was used in all techniques. Maceration and microwave extractions were found to be the most effective methods, capable of yielding 1.38 ± 0.1 and 1.70 ± 0.3 mg/g dw of catechin, respectively at the optimal extraction conditions. The optimal conditions for maceration were 93.2 ± 3.7 min, 79.6 ± 5.2 °C and 23.1 ± 3.7% of ethanol, while for the microwave extraction were 42.2 ± 4.1 min, 137.1 ± 8.1 °C and 12.1 ± 1.1% of ethanol. Comparatively with maceration, the microwave system was a faster solution, conducting to slightly higher catechin yields, but using higher temperatures to reach similar values. The ultrasound method was the least effective solution, yielding 0.71 ± 0.1 mg/g dw of catechin at 42.4 ± 3.6 min, 314.9 ± 21.2 W and 40.3 ± 3.8% ethanol. The results highlight the potential of using A. unedo fruits bio-residues as a productive source of catechin.
      653Scopus© Citations 95
  • Publication
    Atmospheric ammonia and nitrogen deposition on Irish Natura 2000 sites: Implications for Irish agriculture
    With growing global demand for food, the agriculture sector worldwide is under pressure to intensify and expand, risking acceleration of existing negative biodiversity impacts. Agriculture is the dominant source of ammonia (NH3) emissions, which can impact biodiversity directly through dry deposition as NH3 and by wet deposition following conversion to ammonium (NH4) in the atmosphere. Nitrogen deposition is one of the leading causes of global decline in biodiversity alongside changing land use and climate. Natura 2000 sites which are intended to protect important habitats and species across Europe, require strict levels of protection to ensure designated features achieve favourable conservation status. Many of these sites are nitrogen-limited, and/or contain sensitive species such as lichens or mosses. This project carried out ambient NH3 monitoring on selected Irish Natura 2000 sites, in order to establish potential impacts from agricultural NH3. Monitoring on twelve Natura 2000 sites observed concentrations ranging from 0.47 to 4.59 μg NH3 m−3, from which dry deposition was calculated to be 1.22–11.92 kg N ha−1 yr−1. European Monitoring and Evaluation Programme (EMEP) was used to quantify wet deposited NH4 and nitrogen oxides (NOx), in addition to dry deposited NOx on monitored sites. Estimated total nitrogen deposition ranged between 5.93 and 17.78 kg N ha−1 yr−1. On average across all monitored sites, deposition was comprised of 50.4%, 31.7%, 7.5%, and 10.3% dry NH3, wet NH4, dry NOx and wet NOx respectively. Implications for Irish agriculture are discussed in the light of both this monitoring and the European Commission Dutch Nitrogen Case (C 293/17 & C 294/17), highlighting a number of recommendations to aid compliance with the EU Habitats Directive (92/43/EEC).
      289Scopus© Citations 13
  • Publication
    A dispersion modelling approach to determine the odour impact of intensive poultry production units in Ireland
    The use of atmospheric dispersion modelling has become more common for the determination of odour impacts from existing poultry production facilities and the assessment of setback distances for new facilities. Setback distances for broiler, layer and turkey units were determined using the atmospheric dispersion model ISCST3 and the Environmental Protection Agency (EPA, Ireland) recommended criterion (C98.1-h <= 6.0 ou(E) m(-3)) and a new odour annoyance criterion (C-98,C-1-h <= 9.7 ou(E) m(-3)) developed in this study. For a typical size unit in Ireland, maximum setback distances of 660, 665 and 1035 in were calculated for 40,000 broilers, 40,000 layers and 10,000 turkeys respectively at the current limit (C-98,C-1-h <= 6.0 ou(E) m(-3)). However, if the suggested odour impact criterion (C-98,C-1-h <= 9.7 ou(E) m(-3)) is implemented, the maximum setback distances decrease to 460, 500 and 785 in for broilers, layers and turkeys, respectively. 
      1384Scopus© Citations 42
  • Publication
    SE—Structures and Environment: Biofiltration of Odour and Ammonia from a Pig Unit—Biofiltration of Odour and Ammonia from a Pig Unit—a pilot-scale Study
    A pilot-scale biofiltration unit was constructed at a pig finishing building on the University College Dublin research farm. The biofiltration system was investigated over three trial periods. Exhaust air from a single pen was extracted by a variable speed centrifugal fan and passed through a humidifier and biofilter. A 0·5 m depth of woodchips of over 20 mm screen size was used as the biofilter medium. The moisture content of the medium was maintained at 64±4% (wet weight basis) for trial one and 69±4% (wet weight basis) for trials two and three using a load cell method. The volumetric loading rate varied from 769 to 1898 m3 [air] m−3 [medium] h−1 during the three trial periods. Odour and ammonia removal efficiencies ranged from 77 to 95% and 54 to 93%, respectively. The pH of the biofilter leachate remained between 6 and 8 throughout the experimental periods. The pressure drop across the biofilter ranged from 14 to 64 Pa. It is concluded that a wood chip media particle size >20 mm is suitable for use in biofiltration systems on intensive pig production facilities. This will minimize the pressure drop on the system fans to reduce overall operation costs. It is recommended that a filter bed moisture content (wet weight basis) of greater than 63% be used to maintain overall efficiency. An efficient air moisturizing system (humidification and bed sprinkling) along with a properly designed air distribution system must be incorporated in the overall design when operating at such high volumetric loading rates.
      1068Scopus© Citations 51
  • Publication
    Analytical criteria to quantify and compare the antioxidant and pro-oxidant capacity in competition assays: The bell protection function
    The development of a convenient mathematical application for testing the antioxidant and pro-oxidant potential of standard and novel therapeutic agents is essential for the research community and food industry in order to perform more precise evaluations of products and processes. In this work, a simple non-linear dose–time tool to test the effectiveness of compounds for competitive assays is presented. The model helps to describe accurately the antioxidant and pro-oxidant response as a function of time and dose by two criteria values and allows one to perform easily comparisons of both capacities from different compounds. The quantification procedure developed was applied to two well known in vitro competition assays, the β-carotene and crocin bleaching asymptotic reactions. The dose–time dependency of the response of commercial antioxidants and some expected pro-oxidant compounds was evaluated in this study and the results showed low experimental error. In addition, as an illustrative example of the capabilities of the criteria proposed, the quantification of the combined effect of an antioxidant and a pro-oxidant was analyzed. Afterwards, the model was verified for other relevant competitive methods, using available experimental data from the bibliography. Its application is simple, it provides parametric estimates which characterize the response, and it facilitates rigorous comparisons among the effects of different compounds and experimental approaches. In all experimental data tested, the calculated parameters were always statistically significant (Student's t-test, α = 0.05), the equations were consistent (Fisher's F-test) and the goodness of fit coefficient of determination was higher than 0.98.
      342Scopus© Citations 1
  • Publication
    Hydrogen sulfide gas emissions during disturbance and removal of stored spent mushroom compost
    (American Society of Agricultural and Biological Engineers, 2013-12) ; ;
     Spent mushroom compost (SMC) is a by-product of the mushroom industry that is used as an agricultural fertilizer. In Europe its storage and use are governed by the EU Nitrates Directive 91/676/EEC to protect waterways against pollution by nitrates. A health and safety risk was identified during the removal and spreading of stored SMC onto land whereby stored SMC released high levels of toxic H2S gas into the atmosphere when disturbed. Emissions of H2S were monitored at two outdoor and two indoor locations where stored SMC was being removed for spreading on land. A repeating peak-trough pattern of H2S emissions was detected at all sites with peaks corresponding to periods of active disturbance of SMC. The highest H2S concentrations (10 s average) detected at the SMC face were: 680 and 2083 ppm at outdoor Sites 1 and 2; and 687 and 89 ppm at indoor Sites 3 and 4, respectively. Higher concentrations of H2S were released from older SMC compared to younger material. Indoor-stored SMC had lower moisture content (53% to 65%) compared to outdoor-stored material (66% to 72%) while the temperature of indoor-stored SMC was higher (33 ºC to 51ºC) compared to outdoor-stored material (24ºC to 36ºC). The current Short Term Exposure Limit (STEL) of 10 ppm was exceeded at all sites except Site 4, which was smaller than the others, indicating a significant health and safety risk associated with working in the vicinity of stored SMC when it is being actively disturbed. Results suggest that SMC stored in small heaps (600 m3) under cover, emits less H2S during disturbance and removal compared to SMC stored in large heaps (>1500 m3) outdoors. This should be taken into consideration in the design, construction and management of SMC storage facilities. Health and safety protocols should be in place at SMC storage facilities to cover the risks of exposure to toxic H2S gas during disturbance of stored SMC.
      774Scopus© Citations 8
  • Publication
    Predicting atmospheric ammonia dispersion and potential ecological effects using monitored emission rates from an intensive laying hen facility in Ireland
    Agriculture is responsible for 98% of atmospheric ammonia (NH3) in Ireland, of which pigs and poultry produce 7%; with laying hens specifically contributing 0.6%. Though a small proportion of the national NH3 total emissions, the ecological impacts on sensitive sites attributed to laying hen farms can be substantial. NH3 emission monitoring was conducted in Spring (February to March) and Summer (July to August) 2016 to account for seasonal variation. The total average emission and ventilation rate was 0.25 g bird−1 day−1 and 931 cm3 s−1 bird−1. This is lower than the previously used emission factor for the Irish national inventory of 0.5 g bird−1 day−1, but broadly similar to factors reported in the United Kingdom (UK) and the European Union (EU). Dispersion modelling using monitored data indicated potentially acute effects within 84 m, critical level exceedance within 312 m and exceedance of 0.3 kg N ha−1 year−1 deposition within 2.9–5.2 km. The sensitivity of the model was tested using SCAIL-Agriculture emission and ventilation rates which showed P-values for one tailed critical level below 0.01 for all models, indicating that when normalised the maximum extents modelled by AERMOD were significantly different. This analysis showed emission rate having more influence than ventilation rate. Both parameters combined had the greatest increase in dispersion extent, on average 55.8% greater than the use of monitored rates. A deposition rate of 0.3 kg N ha−1 year−1 was modelled to occur within 5.1–7.7 km when using SCAIL-Agriculture rates. Indicating that the use of SCAIL-Agriculture recommended emission and ventilation rates would have been sufficiently precautionary to assess negative ecological effects on a Natura 2000 site under the Habitats Directive (92/43/EEC). In relation to Appropriate Assessment (AA) screening, the use of any contribution from a source within a set distance may be an appropriate full AA trigger.
      199Scopus© Citations 10