Mechanical properties of materials are crucial to their suitability and potential for functional ... more Mechanical properties of materials are crucial to their suitability and potential for functional uses. A proposed method for the mechanical testing of orientated plastic bottle recovered PET material is outlined with a view to enable their assessment for additional uses as products or materials. Our method is presented, tested and discussed below. Our results indicate a potential for consistent mechanical testing of varied sample preparation and degradation methods.
Feed trials were carried out to assess the influence of crude protein content in finishing pig di... more Feed trials were carried out to assess the influence of crude protein content in finishing pig diets on odour and ammonia emissions. Eight pigs (4 boars and 4 gilts), average initial weight 70.8 kg (s.e. 3.167) were housed in two pens that were isolated from the rest of a pig house at University College Dublin Research Farm, Newcastle, Dublin, Ireland. Four diets containing 130, 160, 190 and 220 g kg À1 crude protein were fed during six four-week feeding periods (one treatment per room). The first week of the feeding periods served to allow odour build up in the pens and as a dietary adjustment period. The pens had partially slatted floors that were cleaned and had all the manure removed after each four-week period. Odour and ammonia concentrations were measured on days 9, 14, 16, 21 and 23 of each trial period. Odour samples were collected in Nalophan bags and analysed for odour concentration using an ECOMA Yes/No olfactometer. The odour threshold concentration was calculated according to the response of the olfactometry panel members and was displayed in Ou E m À3 , which referred to the physiological response from the panel equivalent to that elicited by 40 ppb v À1 n-butanol evaporated in 1 m 3 of neutral gas. Ammonia concentrations in the ventilation air were measured using Dr€ a ager tubes. The odour emission rates per animal for the 130, 160, 190 and 220 g kg À1 crude protein diets were 12.1, 13.2, 19.6 and 17.6 Ou E s À1 animal À1 , respectively (P < 0:01). The odour emission rate per livestock unit (500 kg) for the 130, 160, 190 and 220 gkg À1 crude protein diets were 77.6, 80.0, 115.8 and 102.9 Ou E s À1 LU À1 , respectively (P < 0:01). The ammonia emission rates per animal for the 130, 160, 190 and 220 g kg À1 crude protein diets were 3.11, 3.89, 5.89 and 8.27 g d À1 animal À1 , respectively (P 6 0:001). There was no significant difference in the average daily intake and the average daily gain for the four diets (P > 0:05). Manipulation of dietary crude protein levels would appear to offer a low cost alternative, in relation to end-of-pipe treatments, for the abatement of odour and ammonia emissions from finishing pig houses.
An investigation was conducted into the influence of manure composition on the odour emission rat... more An investigation was conducted into the influence of manure composition on the odour emission rate (OER) and the emission rate of ammonia (NH 3 ), when diets containing 130, 160, 190 and 210 g kg À1 crude protein (CP) were fed to finishing pigs. A group of four boars and four gilts, housed in environmentally sealed pens, were assigned to each diet for a 23-day experimental period which was replicated three times (n = 3). Ventilation air from each pen was sampled for NH 3 and odour, by olfactometry, on four days during the trial period. Simultaneous collections of manure were taken from the surface and base of each pit. The pH and the concentrations of dry matter, total Kjeldahl nitrogen (TKN), total ammoniacal nitrogen (TAN) and volatile fatty acids in the manure were measured. Manure composition differed between samples from the surface and base of the pit (P < 0.05). Reducing dietary CP concentration decreased the emission of NH 3 (linear, P < 0.001). The acetic acid:propionic acid ratio in manure samples was correlated to OER (r = 0.79, P < 0.001). There was a quadratic relationship between dietary CP concentration and OER (P < 0.05). OER decreased between 210 g kg À1 and 160 g kg À1 CP and increased between 160 g kg À1 and 130 g kg À1 CP. In conclusion, reducing dietary crude protein levels could be used effectively to reduce ammonia emissions and OER, although no significant advantage was to be gained in OER from reducing crude protein level below 160 g kg À1 .
Page 1. The authors are solely responsible for the content of this technical presentation. The te... more Page 1. The authors are solely responsible for the content of this technical presentation. The technical presentation does not necessarily reflect the official position of the American Society of Agricultural Engineers (ASAE), and ...
Sludge dewatering is a key concern of sludge disposal field because it can decrease the quantity ... more Sludge dewatering is a key concern of sludge disposal field because it can decrease the quantity of sludge and consequently, reduce their environmental impact and minimize the costs of sludge treatment, transportation and disposing. Researches have developed the wastewater treatment processes to a more advance and environmentally friendly way. The global population growth in the last 60 years, has produced a dramatic increase of excess sludge, becoming not only a significant threat to the ecological system, if not properly disposed, but also an expensive treatment for the disposal of sludge (up to 60% of the total operation costs of a treatment plant). The enzymatic hydrolysis and its ability to dewater the sludge has been investigated for the last three decades. A number of enzymes and treatment processes have been reported to improve treatment plant applications and to reduce the cost of excess sludge disposal. In this paper, more efficient management tool to improve the dewaterab...
are part of a Trans-Atlantic Biosystems Engineering Network (TABE.NET), that has been established... more are part of a Trans-Atlantic Biosystems Engineering Network (TABE.NET), that has been established with the overall goal to advance internationalization of Biosystems Engineering (BSEN) curricula and develop a global awareness within the discipline.
A working group within the Trans-Atlantic Biosystems Engineering Network (TABE.NET) analyzed the ... more A working group within the Trans-Atlantic Biosystems Engineering Network (TABE.NET) analyzed the idea of the development of an international collaborative design project for undergraduate students in the participating institutions. Aims of this action were to get a change in the students' outlook to utilize in their remaining years within the university and a more internationalized resume before they finish. Further outcomes desired by the team were a second or third language acquisition and an appropriate peer assessment across cultures. Following a review of ways to collaborate, it was decided that the most feasible method to implement in the short term was a video podcast. This paper reports on the learning experience of students who took part in this collaboration across the network in the 2013/14 academic year. They were asked to create a video with technical content for an international peer audience and to assess and provide feedback for videos created by international peers. A total of 74 videos were compiled by student groups in six modules/courses/classes across a range of topics in five partner institutions. Videos were uploaded to YouTube and peer assessment was provided in the comments section under each clip. Students indicated that the video podcast collaboration was a positive experience and the vast majority felt they had improved their communication skills. The activity also led to a slight increase in the percentage of people who wanted to develop their language skills further. The students found it interesting but challenging to evaluate other students' work.
A model was developed to simulate domestic water flow> The model was applied to analyze selected ... more A model was developed to simulate domestic water flow> The model was applied to analyze selected domestic areas in Sligo, Ireland> Reliable parameters are generated allowing the analysis of water consumption> The results confirmed the capabilities of this approach identifying water trends> The study provides rigorous criteria to compare and predict water usage.
2011 Louisville, Kentucky, August 7 - August 10, 2011, 2011
A Trans-Atlantic Biosystems Engineering Network (TABE.NET) has been established with the overall ... more A Trans-Atlantic Biosystems Engineering Network (TABE.NET) has been established with the overall goal to advance internationalization of Biosystems Engineering (BSEN) curricula and develop a global awareness within the discipline. The participating institutions are Virginia A working group is exploring the potential to develop an international collaborative design project for undergraduate students in the participating institutions. This paper summarizes the first step in the process by examining current course structures and design experiences across the network.
2013 Kansas City, Missouri, July 21 - July 24, 2013, 2013
The available data about the interference of oxidation compounds in the oxidation kinetics of pro... more The available data about the interference of oxidation compounds in the oxidation kinetics of process such as lipid oxidation chain reactions, the resistance of pharmaceutical drugs, the effects of free radical agents in cell tissue, the damage caused in DNA, etc, are examples of the many applications for in vivo and in vitro assays. However, often in these bio-assays, only semi-quantitative conclusions can be obtained, due to the use of quantification procedures disregarding kinetic considerations.
β-carotene and crocin bleaching reactions are the basis of two methods extensively used to quanti... more β-carotene and crocin bleaching reactions are the basis of two methods extensively used to quantify antioxidant and pro-oxidant activities. They are appropriate for lipophilic and hydrophilic matrices, respectively, and can provide useful complementary information in the study of complex natural extracts containing components with variable degrees of polarity. In this regard, a microplate procedure (Carotene Combined Bleaching) is proposed that enables the combination of both methods in a single, informative and less expensive method which is also faster to carry out. As an illustrative model, the method was applied to test a set of commercial lipophilic and hydrophilic antioxidants and some predictable pro-oxidant agents.
Odour and ammonia emissions were measured at four intensive pig units in Ireland. Odour samples w... more Odour and ammonia emissions were measured at four intensive pig units in Ireland. Odour samples were collected on-site and analysed for odour concentration using an olfactometer. Ammonia concentrations in the exhaust ventilation air were measured using a portable sensor.
Feed trials were carried out to assess the influence of crude protein content in finishing pig di... more Feed trials were carried out to assess the influence of crude protein content in finishing pig diets on odour and ammonia emissions. Eight pigs (4 boars and 4 gilts), average initial weight 70.8 kg (s.e. 3.167) were housed in two pens that were isolated from the rest of a pig house at University College Dublin Research Farm, Newcastle, Dublin, Ireland. Four diets containing 130, 160, 190 and 220 g kg À1 crude protein were fed during six four-week feeding periods (one treatment per room). The first week of the feeding periods served to allow odour build up in the pens and as a dietary adjustment period. The pens had partially slatted floors that were cleaned and had all the manure removed after each four-week period. Odour and ammonia concentrations were measured on days 9, 14, 16, 21 and 23 of each trial period. Odour samples were collected in Nalophan bags and analysed for odour concentration using an ECOMA Yes/No olfactometer. The odour threshold concentration was calculated according to the response of the olfactometry panel members and was displayed in Ou E m À3 , which referred to the physiological response from the panel equivalent to that elicited by 40 ppb v À1 n-butanol evaporated in 1 m 3 of neutral gas. Ammonia concentrations in the ventilation air were measured using Dr€ a ager tubes. The odour emission rates per animal for the 130, 160, 190 and 220 g kg À1 crude protein diets were 12.1, 13.2, 19.6 and 17.6 Ou E s À1 animal À1 , respectively (P < 0:01). The odour emission rate per livestock unit (500 kg) for the 130, 160, 190 and 220 g kg À1 crude protein diets were 77.6, 80.0, 115.8 and 102.9 Ou E s À1 LU À1 , respectively (P < 0:01). The ammonia emission rates per animal for the 130, 160, 190 and 220 g kg À1 crude protein diets were 3.11, 3.89, 5.89 and 8.27 g d À1 animal À1 , respectively (P 6 0:001). There was no significant difference in the average daily intake and the average daily gain for the four diets (P > 0:05). Manipulation of dietary crude protein levels would appear to offer a low cost alternative, in relation to end-of-pipe treatments, for the abatement of odour and ammonia emissions from finishing pig houses.
An investigation was conducted into the influence of manure composition on the odour emission rat... more An investigation was conducted into the influence of manure composition on the odour emission rate (OER) and the emission rate of ammonia (NH 3 ), when diets containing 130, 160, 190 and 210 g kg À1 crude protein (CP) were fed to finishing pigs. A group of four boars and four gilts, housed in environmentally sealed pens, were assigned to each diet for a 23-day experimental period which was replicated three times (n = 3). Ventilation air from each pen was sampled for NH 3 and odour, by olfactometry, on four days during the trial period. Simultaneous collections of manure were taken from the surface and base of each pit. The pH and the concentrations of dry matter, total Kjeldahl nitrogen (TKN), total ammoniacal nitrogen (TAN) and volatile fatty acids in the manure were measured. Manure composition differed between samples from the surface and base of the pit (P < 0.05). Reducing dietary CP concentration decreased the emission of NH 3 (linear, P < 0.001). The acetic acid:propionic acid ratio in manure samples was correlated to OER (r = 0.79, P < 0.001). There was a quadratic relationship between dietary CP concentration and OER (P < 0.05). OER decreased between 210 g kg À1 and 160 g kg À1 CP and increased between 160 g kg À1 and 130 g kg À1 CP. In conclusion, reducing dietary crude protein levels could be used effectively to reduce ammonia emissions and OER, although no significant advantage was to be gained in OER from reducing crude protein level below 160 g kg À1 .
Odour and ammonia emissions were measured at four intensive pig units in Ireland. Odour samples w... more Odour and ammonia emissions were measured at four intensive pig units in Ireland. Odour samples were collected on-site and analysed for odour concentration using an olfactometer. Ammonia concentrations in the exhaust ventilation air were measured using a portable sensor.
The use of atmospheric dispersion modelling has become more common for the determination of odour... more 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 (C(98,1-h)6.0 ou(E) m(-3)) and a new odour annoyance criterion (C(98,1-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 m were calculated for 40,000 broilers, 40,000 layers and 10,000 turkeys respectively at the current limit (C(98,1-h) 6.0 ou(E) m(-3)). However, if the suggested odour impact criterion (C(98,1-h) 9.7 ou(E) m(-3)) is implemented, the maximum setback distances decrease to 460, 500 and 785 m for broilers, layers and turkeys, respectively.
It is becoming more common now to use atmospheric dispersion models to predict where odour nuisan... more It is becoming more common now to use atmospheric dispersion models to predict where odour nuisance is likely to occur near pig units. An odour threshold concentration of 1 Ou E m À3 is the level at which an odour is detectable by 50% of screened panellists. A new odour annoyance criterion (C 98;1-h (98%-ile, 1-h average odour concentration) 6 4.3 Ou E m À3 ) was developed in this study and compared to the Environmental Protection Agency (EPA) (Ireland) recommendation (C 98;1-h 6 6 Ou E m À3 ) using the ISCST3 model with data from three meteorological stations. Abatement techniques such as exhaust vent modification, feed manipulation, and biofiltration were assessed. Based on current limits (C 98;1-h 6 6 Ou E m À3 ) for existing facilities, predicted setback distances can be up to 780 m for a 1000-sow unit, depending on which meteorological data set is used. However, if using the suggested odour impact criterion in this research (C 98;1-h 6 4:3 Ou E m À3 ), setback distances could reach a maximum of 1000 m. Biofilters on second stage weaning and finishing pig buildings offer the greatest single reduction (up to 650 m) in odour impact. When combined with feed manipulation and increased exhaust air velocity, the figure can be as high as 920 m. Due to the critical requirement for local meteorological data, it is recommended that a meteorological station be installed on large pig units to facilitate more accurate predictions. Site measurements of odour emissions should be made in each case because emissions are influenced by a range of local factors including feed, manure management, building design and operation.
Microalgae cultivation in photobioreactors has many advantages such as reduced risk of contaminat... more Microalgae cultivation in photobioreactors has many advantages such as reduced risk of contamination; more controlled cultivation and increased illuminated area to volume ratio. However, due to the adhesive nature of microalgae, fouling of the light transmitting surfaces can be problematic. Traditional methods of sterilising photobioreactors between batches involve ultrasound, autoclaving or as seen in recent times, the photobioreactor incorporates a cleaning system. The objective of this research was to look at an alternative method of sterilisation. The efficacy of ozone was investigated to treat the algae strain Dunaliella tertiolecta (Butcher). Algae cultures at 10 4 cells CFU mL -1 were exposed to 3-29 μg mL -1 of ozone at varying time periods (0-80 sec) and constant gas flow rates of 0.125 and 0.25 L min -1 . Inactivation rates for total reduction of D. tertiolecta were found to increase significantly with an increase in ozone concentration and treatment time. The effectiveness of ozone treatment is dependent on various factors such as contact time, ozone concentration and the ozone demand of the algae.
Mechanical properties of materials are crucial to their suitability and potential for functional ... more Mechanical properties of materials are crucial to their suitability and potential for functional uses. A proposed method for the mechanical testing of orientated plastic bottle recovered PET material is outlined with a view to enable their assessment for additional uses as products or materials. Our method is presented, tested and discussed below. Our results indicate a potential for consistent mechanical testing of varied sample preparation and degradation methods.
Feed trials were carried out to assess the influence of crude protein content in finishing pig di... more Feed trials were carried out to assess the influence of crude protein content in finishing pig diets on odour and ammonia emissions. Eight pigs (4 boars and 4 gilts), average initial weight 70.8 kg (s.e. 3.167) were housed in two pens that were isolated from the rest of a pig house at University College Dublin Research Farm, Newcastle, Dublin, Ireland. Four diets containing 130, 160, 190 and 220 g kg À1 crude protein were fed during six four-week feeding periods (one treatment per room). The first week of the feeding periods served to allow odour build up in the pens and as a dietary adjustment period. The pens had partially slatted floors that were cleaned and had all the manure removed after each four-week period. Odour and ammonia concentrations were measured on days 9, 14, 16, 21 and 23 of each trial period. Odour samples were collected in Nalophan bags and analysed for odour concentration using an ECOMA Yes/No olfactometer. The odour threshold concentration was calculated according to the response of the olfactometry panel members and was displayed in Ou E m À3 , which referred to the physiological response from the panel equivalent to that elicited by 40 ppb v À1 n-butanol evaporated in 1 m 3 of neutral gas. Ammonia concentrations in the ventilation air were measured using Dr€ a ager tubes. The odour emission rates per animal for the 130, 160, 190 and 220 g kg À1 crude protein diets were 12.1, 13.2, 19.6 and 17.6 Ou E s À1 animal À1 , respectively (P < 0:01). The odour emission rate per livestock unit (500 kg) for the 130, 160, 190 and 220 gkg À1 crude protein diets were 77.6, 80.0, 115.8 and 102.9 Ou E s À1 LU À1 , respectively (P < 0:01). The ammonia emission rates per animal for the 130, 160, 190 and 220 g kg À1 crude protein diets were 3.11, 3.89, 5.89 and 8.27 g d À1 animal À1 , respectively (P 6 0:001). There was no significant difference in the average daily intake and the average daily gain for the four diets (P > 0:05). Manipulation of dietary crude protein levels would appear to offer a low cost alternative, in relation to end-of-pipe treatments, for the abatement of odour and ammonia emissions from finishing pig houses.
An investigation was conducted into the influence of manure composition on the odour emission rat... more An investigation was conducted into the influence of manure composition on the odour emission rate (OER) and the emission rate of ammonia (NH 3 ), when diets containing 130, 160, 190 and 210 g kg À1 crude protein (CP) were fed to finishing pigs. A group of four boars and four gilts, housed in environmentally sealed pens, were assigned to each diet for a 23-day experimental period which was replicated three times (n = 3). Ventilation air from each pen was sampled for NH 3 and odour, by olfactometry, on four days during the trial period. Simultaneous collections of manure were taken from the surface and base of each pit. The pH and the concentrations of dry matter, total Kjeldahl nitrogen (TKN), total ammoniacal nitrogen (TAN) and volatile fatty acids in the manure were measured. Manure composition differed between samples from the surface and base of the pit (P < 0.05). Reducing dietary CP concentration decreased the emission of NH 3 (linear, P < 0.001). The acetic acid:propionic acid ratio in manure samples was correlated to OER (r = 0.79, P < 0.001). There was a quadratic relationship between dietary CP concentration and OER (P < 0.05). OER decreased between 210 g kg À1 and 160 g kg À1 CP and increased between 160 g kg À1 and 130 g kg À1 CP. In conclusion, reducing dietary crude protein levels could be used effectively to reduce ammonia emissions and OER, although no significant advantage was to be gained in OER from reducing crude protein level below 160 g kg À1 .
Page 1. The authors are solely responsible for the content of this technical presentation. The te... more Page 1. The authors are solely responsible for the content of this technical presentation. The technical presentation does not necessarily reflect the official position of the American Society of Agricultural Engineers (ASAE), and ...
Sludge dewatering is a key concern of sludge disposal field because it can decrease the quantity ... more Sludge dewatering is a key concern of sludge disposal field because it can decrease the quantity of sludge and consequently, reduce their environmental impact and minimize the costs of sludge treatment, transportation and disposing. Researches have developed the wastewater treatment processes to a more advance and environmentally friendly way. The global population growth in the last 60 years, has produced a dramatic increase of excess sludge, becoming not only a significant threat to the ecological system, if not properly disposed, but also an expensive treatment for the disposal of sludge (up to 60% of the total operation costs of a treatment plant). The enzymatic hydrolysis and its ability to dewater the sludge has been investigated for the last three decades. A number of enzymes and treatment processes have been reported to improve treatment plant applications and to reduce the cost of excess sludge disposal. In this paper, more efficient management tool to improve the dewaterab...
are part of a Trans-Atlantic Biosystems Engineering Network (TABE.NET), that has been established... more are part of a Trans-Atlantic Biosystems Engineering Network (TABE.NET), that has been established with the overall goal to advance internationalization of Biosystems Engineering (BSEN) curricula and develop a global awareness within the discipline.
A working group within the Trans-Atlantic Biosystems Engineering Network (TABE.NET) analyzed the ... more A working group within the Trans-Atlantic Biosystems Engineering Network (TABE.NET) analyzed the idea of the development of an international collaborative design project for undergraduate students in the participating institutions. Aims of this action were to get a change in the students' outlook to utilize in their remaining years within the university and a more internationalized resume before they finish. Further outcomes desired by the team were a second or third language acquisition and an appropriate peer assessment across cultures. Following a review of ways to collaborate, it was decided that the most feasible method to implement in the short term was a video podcast. This paper reports on the learning experience of students who took part in this collaboration across the network in the 2013/14 academic year. They were asked to create a video with technical content for an international peer audience and to assess and provide feedback for videos created by international peers. A total of 74 videos were compiled by student groups in six modules/courses/classes across a range of topics in five partner institutions. Videos were uploaded to YouTube and peer assessment was provided in the comments section under each clip. Students indicated that the video podcast collaboration was a positive experience and the vast majority felt they had improved their communication skills. The activity also led to a slight increase in the percentage of people who wanted to develop their language skills further. The students found it interesting but challenging to evaluate other students' work.
A model was developed to simulate domestic water flow> The model was applied to analyze selected ... more A model was developed to simulate domestic water flow> The model was applied to analyze selected domestic areas in Sligo, Ireland> Reliable parameters are generated allowing the analysis of water consumption> The results confirmed the capabilities of this approach identifying water trends> The study provides rigorous criteria to compare and predict water usage.
2011 Louisville, Kentucky, August 7 - August 10, 2011, 2011
A Trans-Atlantic Biosystems Engineering Network (TABE.NET) has been established with the overall ... more A Trans-Atlantic Biosystems Engineering Network (TABE.NET) has been established with the overall goal to advance internationalization of Biosystems Engineering (BSEN) curricula and develop a global awareness within the discipline. The participating institutions are Virginia A working group is exploring the potential to develop an international collaborative design project for undergraduate students in the participating institutions. This paper summarizes the first step in the process by examining current course structures and design experiences across the network.
2013 Kansas City, Missouri, July 21 - July 24, 2013, 2013
The available data about the interference of oxidation compounds in the oxidation kinetics of pro... more The available data about the interference of oxidation compounds in the oxidation kinetics of process such as lipid oxidation chain reactions, the resistance of pharmaceutical drugs, the effects of free radical agents in cell tissue, the damage caused in DNA, etc, are examples of the many applications for in vivo and in vitro assays. However, often in these bio-assays, only semi-quantitative conclusions can be obtained, due to the use of quantification procedures disregarding kinetic considerations.
β-carotene and crocin bleaching reactions are the basis of two methods extensively used to quanti... more β-carotene and crocin bleaching reactions are the basis of two methods extensively used to quantify antioxidant and pro-oxidant activities. They are appropriate for lipophilic and hydrophilic matrices, respectively, and can provide useful complementary information in the study of complex natural extracts containing components with variable degrees of polarity. In this regard, a microplate procedure (Carotene Combined Bleaching) is proposed that enables the combination of both methods in a single, informative and less expensive method which is also faster to carry out. As an illustrative model, the method was applied to test a set of commercial lipophilic and hydrophilic antioxidants and some predictable pro-oxidant agents.
Odour and ammonia emissions were measured at four intensive pig units in Ireland. Odour samples w... more Odour and ammonia emissions were measured at four intensive pig units in Ireland. Odour samples were collected on-site and analysed for odour concentration using an olfactometer. Ammonia concentrations in the exhaust ventilation air were measured using a portable sensor.
Feed trials were carried out to assess the influence of crude protein content in finishing pig di... more Feed trials were carried out to assess the influence of crude protein content in finishing pig diets on odour and ammonia emissions. Eight pigs (4 boars and 4 gilts), average initial weight 70.8 kg (s.e. 3.167) were housed in two pens that were isolated from the rest of a pig house at University College Dublin Research Farm, Newcastle, Dublin, Ireland. Four diets containing 130, 160, 190 and 220 g kg À1 crude protein were fed during six four-week feeding periods (one treatment per room). The first week of the feeding periods served to allow odour build up in the pens and as a dietary adjustment period. The pens had partially slatted floors that were cleaned and had all the manure removed after each four-week period. Odour and ammonia concentrations were measured on days 9, 14, 16, 21 and 23 of each trial period. Odour samples were collected in Nalophan bags and analysed for odour concentration using an ECOMA Yes/No olfactometer. The odour threshold concentration was calculated according to the response of the olfactometry panel members and was displayed in Ou E m À3 , which referred to the physiological response from the panel equivalent to that elicited by 40 ppb v À1 n-butanol evaporated in 1 m 3 of neutral gas. Ammonia concentrations in the ventilation air were measured using Dr€ a ager tubes. The odour emission rates per animal for the 130, 160, 190 and 220 g kg À1 crude protein diets were 12.1, 13.2, 19.6 and 17.6 Ou E s À1 animal À1 , respectively (P < 0:01). The odour emission rate per livestock unit (500 kg) for the 130, 160, 190 and 220 g kg À1 crude protein diets were 77.6, 80.0, 115.8 and 102.9 Ou E s À1 LU À1 , respectively (P < 0:01). The ammonia emission rates per animal for the 130, 160, 190 and 220 g kg À1 crude protein diets were 3.11, 3.89, 5.89 and 8.27 g d À1 animal À1 , respectively (P 6 0:001). There was no significant difference in the average daily intake and the average daily gain for the four diets (P > 0:05). Manipulation of dietary crude protein levels would appear to offer a low cost alternative, in relation to end-of-pipe treatments, for the abatement of odour and ammonia emissions from finishing pig houses.
An investigation was conducted into the influence of manure composition on the odour emission rat... more An investigation was conducted into the influence of manure composition on the odour emission rate (OER) and the emission rate of ammonia (NH 3 ), when diets containing 130, 160, 190 and 210 g kg À1 crude protein (CP) were fed to finishing pigs. A group of four boars and four gilts, housed in environmentally sealed pens, were assigned to each diet for a 23-day experimental period which was replicated three times (n = 3). Ventilation air from each pen was sampled for NH 3 and odour, by olfactometry, on four days during the trial period. Simultaneous collections of manure were taken from the surface and base of each pit. The pH and the concentrations of dry matter, total Kjeldahl nitrogen (TKN), total ammoniacal nitrogen (TAN) and volatile fatty acids in the manure were measured. Manure composition differed between samples from the surface and base of the pit (P < 0.05). Reducing dietary CP concentration decreased the emission of NH 3 (linear, P < 0.001). The acetic acid:propionic acid ratio in manure samples was correlated to OER (r = 0.79, P < 0.001). There was a quadratic relationship between dietary CP concentration and OER (P < 0.05). OER decreased between 210 g kg À1 and 160 g kg À1 CP and increased between 160 g kg À1 and 130 g kg À1 CP. In conclusion, reducing dietary crude protein levels could be used effectively to reduce ammonia emissions and OER, although no significant advantage was to be gained in OER from reducing crude protein level below 160 g kg À1 .
Odour and ammonia emissions were measured at four intensive pig units in Ireland. Odour samples w... more Odour and ammonia emissions were measured at four intensive pig units in Ireland. Odour samples were collected on-site and analysed for odour concentration using an olfactometer. Ammonia concentrations in the exhaust ventilation air were measured using a portable sensor.
The use of atmospheric dispersion modelling has become more common for the determination of odour... more 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 (C(98,1-h)6.0 ou(E) m(-3)) and a new odour annoyance criterion (C(98,1-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 m were calculated for 40,000 broilers, 40,000 layers and 10,000 turkeys respectively at the current limit (C(98,1-h) 6.0 ou(E) m(-3)). However, if the suggested odour impact criterion (C(98,1-h) 9.7 ou(E) m(-3)) is implemented, the maximum setback distances decrease to 460, 500 and 785 m for broilers, layers and turkeys, respectively.
It is becoming more common now to use atmospheric dispersion models to predict where odour nuisan... more It is becoming more common now to use atmospheric dispersion models to predict where odour nuisance is likely to occur near pig units. An odour threshold concentration of 1 Ou E m À3 is the level at which an odour is detectable by 50% of screened panellists. A new odour annoyance criterion (C 98;1-h (98%-ile, 1-h average odour concentration) 6 4.3 Ou E m À3 ) was developed in this study and compared to the Environmental Protection Agency (EPA) (Ireland) recommendation (C 98;1-h 6 6 Ou E m À3 ) using the ISCST3 model with data from three meteorological stations. Abatement techniques such as exhaust vent modification, feed manipulation, and biofiltration were assessed. Based on current limits (C 98;1-h 6 6 Ou E m À3 ) for existing facilities, predicted setback distances can be up to 780 m for a 1000-sow unit, depending on which meteorological data set is used. However, if using the suggested odour impact criterion in this research (C 98;1-h 6 4:3 Ou E m À3 ), setback distances could reach a maximum of 1000 m. Biofilters on second stage weaning and finishing pig buildings offer the greatest single reduction (up to 650 m) in odour impact. When combined with feed manipulation and increased exhaust air velocity, the figure can be as high as 920 m. Due to the critical requirement for local meteorological data, it is recommended that a meteorological station be installed on large pig units to facilitate more accurate predictions. Site measurements of odour emissions should be made in each case because emissions are influenced by a range of local factors including feed, manure management, building design and operation.
Microalgae cultivation in photobioreactors has many advantages such as reduced risk of contaminat... more Microalgae cultivation in photobioreactors has many advantages such as reduced risk of contamination; more controlled cultivation and increased illuminated area to volume ratio. However, due to the adhesive nature of microalgae, fouling of the light transmitting surfaces can be problematic. Traditional methods of sterilising photobioreactors between batches involve ultrasound, autoclaving or as seen in recent times, the photobioreactor incorporates a cleaning system. The objective of this research was to look at an alternative method of sterilisation. The efficacy of ozone was investigated to treat the algae strain Dunaliella tertiolecta (Butcher). Algae cultures at 10 4 cells CFU mL -1 were exposed to 3-29 μg mL -1 of ozone at varying time periods (0-80 sec) and constant gas flow rates of 0.125 and 0.25 L min -1 . Inactivation rates for total reduction of D. tertiolecta were found to increase significantly with an increase in ozone concentration and treatment time. The effectiveness of ozone treatment is dependent on various factors such as contact time, ozone concentration and the ozone demand of the algae.
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Papers by Thomas Curran
degradation methods.
degradation methods.