Thomas P. Curran

The influence of diet crude protein level on odour and ammonia emissions from finishing pig houses

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 x kg(-1) 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(-3), which referred to the physiological response from the panel equivalent to that elicited by 40 ppbv(-1) n-butanol evaporated in 1 m(3) of neutral gas. Ammonia concentrations in the ventilation air were measured using Dräger tubes. The odour emission rates per animal for the 130, 160, 190 and 220 g x kg(-1) crude protein diets were 12.1, 13.2, 19.6 and 17.6 Ou(E)s(-1)animal(-1), respectively (P<0.01). The odour emission rate per livestock unit (500 kg) for the 130, 160, 190 and 220 g x kg(-1) crude protein diets were 77.6, 80.0, 115.8 and 102.9 Ou(E)s(-1)LU(-1), respectively (P<0.01). The ammonia emission rates per animal for the 130, 160, 190 and 220 g x kg(-1) crude protein diets were 3.11, 3.89, 5.89 and 8.27 g x d(-1)animal(-1), respectively (P<or=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.

Biofiltration of n-butyric acid for the control of odour

Odour control from pig production facilities is a significant concern due to increased public awareness and the development of more stringent legislation to control production. Although many technologies exist, biofiltration is still the most attractive due to its low maintenance and operating costs. One of the key odour components, n-butyric acid, was selected for a laboratory scale biofilter study. It was examined as a sole carbon substrate in order to investigate the effectiveness of biofiltration in reducing n-butyric acid concentration under different operating conditions using a moist enriched woodchip medium. Three superficial gas velocities; 38.2, 76.4, and 114.6 m x h(-1) were tested for n-butyric acid concentrations ranging from 0.13 to 3.1 g [n-butyric acid] m(-3) [air]. For superficial gas velocities 38.2, 76.4, and 114.6 m x h(-1), maximum elimination capacities (100% removal) of 148, 113 and 34.4 g x m(3) x h(-1), respectively, were achieved. Upon investigation of effective bed height, true elimination capacities (100% removal) of 230, 233 and 103 g x m(-3) x h(-1), respectively, were achieved at these superficial gas velocities. Averaged pressure drops for superficial gas velocities 38.2, 76.4, and 114.6 m x h(-1) were 30, 78 and 120 Pa, respectively. It was concluded that biofiltration is a viable technology for the removal of n-butyric acid from waste exhaust air, but near 100% removal efficiency is required due to the low odour detection threshold for this gaseous compound.

Evaluation of the odour reduction potential of alternative cover materials at a commercial landfill

The availability of virgin soils and traditional landfill covers are not only costly and increasingly becoming scarce, but they also reduce the storage capacity of landfill. The problem can be overcome by the utilisation of certain suitable waste streams as alternative landfill covers. The objective of this study was to assess the suitability of Construction & Demolition fines (C&D), Commercial & Industrial fines (C&I) and woodchip (WC) as potential landfill cover materials in terms of odour control. Background odour analysis was conducted to determine if any residual odour was emitted from the cover types. It was deemed negligible for the three materials. The odour reduction performance of each of the materials was also examined on an area of an active landfill site. A range of intermediate cover compositions were also studied to assess their performance. Odour emissions were sampled using a Jiang hood and analysed. Results indicate that the 200 mm deep combination layer of C&D and wood chip used on-site is adequate for odour abatement. The application of daily cover was found to result in effective reduction allowing for the background odour of woodchip.

Odour and ammonia emissions from pig and poultry units

Odour and ammonia emission rates were measured at three pig units, three broiler units and one layer unit. The ventilation rates in the pig and poultry houses were calculated using readings from an anemometer and a CO2 sensor. Ammonia concentrations were measured using Draeger tubes and an electrochemical sensor. Air samples were collected in exhaust ventilation air on site and odour concentrations in the samples were determined using an ECOMA T07 olfactometer. Mean odour and ammonia emission rates for finishing pigs ranged from 6.0-10.7 OuE s-1 pig-1 and 8.4-10.0 g day-1 pig-1, respectively. The minimum odour emission rate in pig housing was 4.6 OuE s-1 pig-1 for 1st stage weaners and the maximum was 66.4 OuE s-1 pig-1 for farrowing houses. Mean odour and ammonia emission rates for broilers ranged from 0.45-0.55 OuE s-1 bird-1 and 0.14-0.42 g day-1 bird-1, respectively. The layer unit had a low odour concentration but a similar odour emission rate of 0.43 OuE s-1 bird-1. Most of the emission rates were comparable to those found by other researchers. However, there is a lack of unanimity in the literature and a scarcity of published data, particularly for poultry units. The variability in the figures highlights the need for individual site assessment. The emission rates are useful as inputs to atmospheric dispersion models to determine appropriate ‘setback’ distances. Further research is being carried out on other pig and poultry units to assess the influence of factors such as building design, manure management, unit operation and diet.

The effect of protease and nonstarch polysaccharide enzymes on manure odor and ammonia emissions from finisher pigs

A 2 × 2 factorial experiment was conducted to investigate the effect of dietary protease (0 and 200 mg/kg) and xylanase (0 and 200mg/kg) in reducing manure odor and NH(3) from finisher pigs. Sixteen pigs were assigned to 1 of 4 dietary treatments, (i) basal diet, (ii) basal diet + xylanase, (iii) basal diet + protease, or (iv) basal diet + xylanase + protease, for 24 d. The manure samples from pigs offered diets containing protease showed increased (P < 0.05) molar proportions of isobutyric acid, isovaleric acid, valeric acid, and branched-chain fatty acids in contrast to pigs offered diets without protease supplementation. The pigs offered diets with xylanase inclusion had reduced (P < 0.05) manure odor emissions compared to pigs offered diets without xylanase supplementation [598 vs. 1306 European odor units (OuE)/m(3)]. Pigs offered protease-supplemented diets alone had significantly higher NH(3) emissions compared to basal fed pigs. However, NH(3) emissions were reduced when protease was combined with xylanase. In summary, this study indicates that protease supplementation increased protein-derived VFA in manure and also increased manure NH(3) emissions when offered singularly. Consumption of diets containing xylanase reduced manure odor emissions.

Undergraduate Design Experiences in the Trans-Atlantic Biosystems Engineering Network (TABE.NET)

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 Polytechnic Institute and State University (VT), University of Illinois at Urbana-Champaign (UIUC), University College Dublin (UCD), Agricultural University of Athens (AUA), Universidad Politecnica de Madrid (UPM), and University of Bari (UniBar). 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.

Evaluation of ISC3 and CALPUFF Atmospheric Dispersion Models for Odor Nuisance Prediction

This paper presents an evaluation of a plume model (ISC3) and an advanced puff model (CALPUFF) for the prediction of odor concentrations at a commercial pig unit. Key parameters such as odor emission rate and meteorological conditions were measured at source. Downwind odor intensity was assessed by field panelists during 10-minute periods on three sampling days and converted to mean concentrations by equations developed from laboratory analysis of source odor samples. Emission characteristics and meteorological data were inputted to both ISC3 and the screening mode of CALPUFF. Both models produced similar predicted odor concentrations. The average predicted to measured mean concentration ratio on the sampling days varied from 1.40 to 9.37. Over 80% of the predictions were greater than the corresponding measured values, thus indicating that both models produce conservative estimates of downwind odor concentration.

Evaluation of Optimum Biofilter Performance at a Meat By-Products Rendering Plant

The operational characteristics of a light expanded clay aggregate (LECA) media biofilter treating the odorous off gases from the cooking process of a rendering facility were investigated. Over the course of a 20 month period odour removal efficiencies ranged from 63.2% to 98.2%. Lower efficiencies were observed when the media in the biofilter was changed. The new media was inadequate and had to be replaced again to achieve the desired odour removal efficiencies. When the biofilter media was adequate the odour removal efficiencies were generally above 90% and often above 95%. Inlet odour concentrations ranged from 7,100 ouE m-3 to 233,536 ouE m-3. The biofilter was capable of reducing high and low odour concentrations efficiently. The empty bed retention time of the biofilter varied between 25 and 47 seconds. It was desirable to achieve an EBRT close to 35 seconds during warmer periods of the year when odour concentrations were higher. The biofilter moisture content at 400 mm deep ranged from 33.4% to 59.6%. Deeper in the biofilter at 900 mm, moisture content ranged from 34.5% to 44.7%. It was desirable to keep the moisture content between 40% and 45% although during autumn test dates moisture content was lower than 40% and efficiency remained high. The pH of the biofilter ranged from 6.4 to 9.6 at 400 mm and 6.0 to 9.4 at 900 mm deep. Ideally, pH should be maintained between 7 and 8.

The biosystems engineering design challenge at University College Dublin

The Biosystems Engineering Design Challenge has recently become an academic module open to all undergraduate students at University College Dublin. The focus of the module is on designing and building a working, bench-scale device that solves a practical problem relevant to Biosystems Engineering. The module provides an opportunity for students to learn about engineering design, project management and teamwork. Enrolled students are split into teams of up to seven and meet an assigned mentor each week during a semester (12 weeks) to solve a specified problem. The objectives thus far have focused on water-driven electricity generation, treatment of greywater from domestic buildings,and biofiltration of malodors from food waste. The assessment criteria include teamwork, minimisation of expenditure, device design, innovation, operational safety, system performance, report writing and appropriate use of biological and recycled materials. External experts evaluate each entry and substantial cash prizes are awarded to the top teams. Students receive individual academic grades based on their contribution. Feedback on the module has been very positive from both inside and outside the University. The most recent developments have been the introduction of an online project journal for each student and the involvement of biosystems engineering graduate students as mentors.

An Accurate and Rapid System to Identify Play Patterns in Tennis Using Video Recording Material: Break Point Situations as a Case Study

Abstract The goal of this study was to present an accurate and rapid detection system to identify patterns in tennis, based on t-pattern analysis. As a case study, the break point situations in the final matches of the clay court tournaments played during the seasons 2011 and 2012 between the tennis players Novak Djokovic and Rafael Nadal were chosen. The results show that Nadal achieves a higher conversion rate with respect to Djokovic in the break point situations, independent of the outcome of the match. Some repetitive patterns of both players were revealed in break point circumstances. In long rally sequences (higher than seven hits), the Spanish player won more break points, both serving and receiving, as a result of unforced errors of his opponent’s backhand. In medium rally sequences (between four and seven hits), other factors such as the type, direction or serve location have shown to play an important role in the outcome of the point. The study also reveals that Djokovic frequently commits double faults in these critical situations of the match. This is the first time that t-patterns have been used to analyze the sport of tennis. The technique is based on computer vision algorithms and video recording material to detect particular relationships between events and helps to discover the hidden mechanistic sequences of tennis players.