Methods
for Disposal or Processing of Waste
Streams from Intensive Livestock Production in Scotland and Northern
Ireland
UKPIR01
Background
to research
The
Integrated Pollution Prevention and Control Directive requires that
operators
must:
The
Directive covers a range of activities but most numerous in Northern
Ireland
are those for the intensive rearing of pigs and poultry. The greatest
number of
intensive livestock installations in Northern Ireland are involved in
broiler
production but there are also IPPC installations for egg production and
pig
rearing. A similar
situation exists in
Scotland.
In
general land spreading has been used as a key disposal route for
livestock
manures from these installations, although in Scotland most broiler
litter is
burned for energy production. In
Northern Ireland large quantities of broiler litter have been utilised
in the
production of mushroom compost.
Many
freshwaters in Northern Ireland and some in Scotland are highly
eutrophic and
soils in many areas have high phosphate levels.
Producers will in some cases be constrained by the amount
of land
available for spreading and alternative techniques for dealing with
livestock
manures will need to be employed.
Objectives
of research
Four
key tasks/objectives were identified:
Task
1: To characterise
and quantify manure
waste streams from intensive pig and poultry installations. In order to define the
extent of the
problem, reliable information of the quantity and nutrient content of
broiler
litter, layer manure and pig slurry had to be established, and where
appropriate recommendations for revision of standard figures made.
Task
2: To review the
environmental impact
of current disposal practices, involving the identification of the key
environmental issues and activity data for each current practice,
including
products arising from any down stream processing.
Task
3: Prepare an
inventory of past and
current research and techniques employed in other countries in Europe
and
further afield, with a focus on successful techniques.
Task 4: Identify
alternative treatment method options with the greatest
potential for Northern Ireland and Scotland, taking into account the
structure
of the sectors and environmental constraints in Northern Ireland
and
Scotland. Include
economic and
environmental aspects in the evaluation as well as the potential for
disease
dispersion.
Key
findings and recommendations
Broiler
litter
There
was good evidence from the study that figures for nutrient output and
quantity
of broiler litter should be updated and a recommendation was made based
of the
data obtained from the study. In
Northern Ireland there is a real possibility that combustion as a
biomass fuel
can deal with surpluses in the medium term with appropriate investment
in
either a number of small combustion plants or a large centralised power
generation plant. A
recommendation was
made that combustion of broiler litter is adopted as an alternative
utilisation
for almost all surplus litter produced in Northern Ireland, as is
currently the
case in Scotland. Mushroom compost manufacture was also an important
alternative utilisation route.
Layer
manure
Clear
differences from previous standard figures for nutrient content and
quantity
were not apparent, and no recommendation for change has been made. Management options aimed
at producing drier
manure should be implemented, as this would permit a greater range of
alternative uses. Opportunities
for
composting should be actively pursued, but establishing markets for
compost
taking into account any legal constraints on the end use of the product
would
be a key element of this strategy.
A
recommendation was also made that opportunities for development of
manure into
a more saleable product are pursued, e.g. by pelletising and selling
into value
added markets outwith traditional agriculture.
Pig
manure and slurry
There
was significant variation in nutrient content of pig manure and no
recommendation was made for changes to standard figures. As a result of IPPC,
changes are currently
being made to pig diets to reduce the nitrogen and phosphorus content
of manures
and slurry. A
recommendation was made
that more detailed studies of this aspect be undertaken in two or three
years
time to evaluate this benefit. A
recommendation was made that best management practice and techniques
such as
solids liquid separation of slurries be implemented.
Further reductions in phosphorus are possible as shown by
the
results from multi-stage processes, and more novel processing
techniques such
as phosphorus removal by precipitation should be further examined.
Key
words: Integrated pollution prevention and control;
IPPC;
pig; poultry; manure; broiler litter; slurry; disposal; alternative;
utilisation; combustion; composting; biofuel; environmental; aspect;
impact;
intensive livestock production; land spreading; land bank; nitrogen;
phosphorus; nutrients; eutrophication
Copies of the two reports are available
in hard copy:
Technical Report
UKPIR01/TR at £25.00
Summary Report
UKPIR01/SR at £10.00
Each
report is available separately in electronic format at £20.00
+ VAT.
All prices less 20% to FWR members.
N.B. The report is available for download
from the SNIFFER
Website