Please use this identifier to cite or link to this item: https://hdl.handle.net/1959.11/56546
Title: Mechanisms for the Production and Amelioration of Ammonia (NH3) from Cattle Manure Using in vitro Methods
Contributor(s): Creevey, Skye Caitlin  (author); Wilkes, Janelle  (supervisor)orcid ; Tait, Louise Amy  (supervisor)orcid ; Cowley, Frances  (supervisor)orcid 
Conferred Date: 2023-07-12
Copyright Date: 2022-11
Handle Link: https://hdl.handle.net/1959.11/56546
Related Research Outputs: https://hdl.handle.net/1959.11/56547
Abstract: 

Ammonia (NH3) is a nitrogenous environmental pollutant that is associated with eutrophication and contamination of terrestrial ecosystems and can have detrimental impacts on human and livestock health. Livestock production is a significant contributor to global NH3 emissions largely as a result of nitrogen losses from the breakdown of manure. Intensively housed livestock situations, such as exporting live animals, lead to increased concentration of manure and development of the manure pad through accumulation of faeces and urine. This increase in higher concentrations of NH3 may also lead to health and welfare concerns of both humans and animals. Due to the complex interactions of factors contributing to the volatilsation of NH3 from manure, NH3 production in livestock operations is difficult to accurately predict with the various methods and modelling approaches currently utilised. Live export is an example of an intensively housed livestock industry where NH3 production has the potential to impact health and welfare of humans and animals on board. Quantification of NH3 using current methods is difficult in this industry due to highly variable conditions and limited understanding of how voyage conditions may affect NH3 production. Methods to quantify NH3 emissions from manure have some limitations in adoption and understanding of manure pad variables introduced directly by animals, such as disturbance. Use of in vitro methods rather than large scale animal experiments allows understanding of ammonia and testing of dose rates of ameliorates and also aligns with the animal ethics replace, reduce and refine.

The primary objectives of the current thesis were to develop an inexpensive, high throughput method of quantifying NH3 in solution, and an in vitro method of quantifying NH3 production from manure that would (1) evaluate the optimal microchamber design to quantify NH3 production rates from manure; (2) quantify the effect of disturbance of manure on NH3 production rates; (3) succeed as an alternative method of testing NH3 production to reduce the need for, or better inform, large-scale animal experiments (4) successfully evaluate the effectiveness of mitigation techniques.

This thesis includes a review of the available literature and three experimental chapters addressing the development and use of the in vitro method and assessment of an available NH3 mitigation technique. Findings and implications of this thesis include:

Development of a novel high-throughput plate-based analysis with a high degree of accuracy adapting the Berthelot method of quantifying NH3-N in solution. Boric acid solution was shown to be an effective eluent for gas trap sampling of NH3;

Successful development of a novel microchamber system. The microchamber design was evaluated and a standard size chosen for the following experiments. It is hypothesised interactions with pad surface areas and depth were dependent on variables facilitating mass transfer such as air flow and headspace. Microchamber results did not meet hypotheses, as (i) increasing microchamber manure surface area did not result in constant rates of NH3/m2 production, and (ii) increasing manure depth resulted in lower rates of NH3/m2 as opposed to a consistent production relative to surface area. The standard size chosen for the experiment on clinoptilolite (zeolite) was a surface area of 90mm diameter (SA90) and manure depth of 30mm (D30), based on less variation in results and ease of use;

Simulated animal movement through four repeated disturbances of cattle manure in micro-chambers every 90 minutes, resulted in increasing rates of NH3 production (slope coefficients) with each disturbance over 480 min for all treatments. This suggests cattle movement may generate continual fluxes of NH3 production from the manure over time;

The application of zeolite was successful in reducing NH3 production from cattle manure. All treatments achieved an immediate and sustained reduction in NH3 production over 21 hours. The minimum (1%) and maximum (10%) in-pad application rates resulted in a 32% to 70% reduction in NH3 emissions over 21 hours, respectively.

Application of zeolite suspended in the microchamber headspace reduced the presence of gaseous NH3 contamination in the air by 37% over 21 hours, similar to 1% zeolite applied in-pad over 21 hours.

Overall, the high-throughput plate-based methodology and microchamber system provided valuable insight into increasing fluxes of NH3 volatilsation with disturbance and optimal application rates of zeolite to reduce NH3 production. The aim of the microchamber design was to standardise headspace and air exchange rates in order to quantify the effect of increasing manure surface area and depth. The results demonstrated air flow dynamics are important and challenging factors when comparing these variables, however a standardised microchamber was successfully deployed to compare and determine an optimal application rate of zeolite for NH3 reduction.

Publication Type: Thesis Masters Research
Fields of Research (FoR) 2020: 300302 Animal management
300307 Environmental studies in animal production
310101 Analytical biochemistry
Socio-Economic Objective (SEO) 2020: 100101 Management of gaseous waste from animal production (excl. greenhouse gases)
100103 Management of solid waste from animal production
100401 Beef cattle
HERDC Category Description: T1 Thesis - Masters Degree by Research
Description: Please contact rune@une.edu.au if you require access to this thesis for the purpose of research or study.
Appears in Collections:School of Environmental and Rural Science
Thesis Masters Research

Files in This Item:
2 files
File Description SizeFormat 
Show full item record

Page view(s)

588
checked on Jul 7, 2024

Download(s)

8
checked on Jul 7, 2024
Google Media

Google ScholarTM

Check


Items in Research UNE are protected by copyright, with all rights reserved, unless otherwise indicated.