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Ammonia emissions and pathogen inactivation during controlled composting of pig manure

Cronjé, Angela Leigh (2004)
Ph.D. thesis, University of Birmingham.

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The effects of adjusting the initial carbon to nitrogen (C:N) ration and pH of pig manure and straw mixes on ammonia emissions and pathogen marker inactivation during composting were investigated by experimentation and modelling.

Three, 210-litre reactors were designed and built to control conditions, such as the maximum operating temperature, minimise temperature gradients and enable analysis of the off-gas for ammonia, water, oxygen and carbon dioxide.

Respirometry showed that the optimal temperature for composting pig manure was about 60°C.

A simulation model suggested that ammonia emissions could be reduced by lowering the initial pH and increasing the initial C:N ratio of the organic material. Experimentally, lowering the initial pH significantly reduced ammonia emissions. The effect of the initial C:N ratio on ammonia emissions was not significant because of variations in the pig manure.

Pathogen markers were sometimes detected after composting from experiments with low ammonia emissions, so questioning the established criteria for pathogen inactivation.

Experimental data validated the model, which simulated organic material decomposition using first order reaction rate kinetics and predicted the temperature and ammonia emissions profiles from initial conditions.

Type of Work:Ph.D. thesis.
Supervisor(s):Barker, Andrew (1943-) and Guy, Stuart
School/Faculty:Schools (1998 to 2008) > School of Engineering
Department:Department of Chemical Engineering
Keywords:Composting, pathogens, ammonia emissions, process model
Subjects:GE Environmental Sciences
TP Chemical technology
Institution:University of Birmingham
Library Catalogue:Check for printed version of this thesis
ID Code:155
This unpublished thesis/dissertation is copyright of the author and/or third parties. The intellectual property rights of the author or third parties in respect of this work are as defined by The Copyright Designs and Patents Act 1988 or as modified by any successor legislation. Any use made of information contained in this thesis/dissertation must be in accordance with that legislation and must be properly acknowledged. Further distribution or reproduction in any format is prohibited without the permission of the copyright holder.
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