Transcript SLAUGHTERHOUSES - IQ

SLAUGHTERHOUSES
Patricia García García de Pereda
Sonia García Redondo
Beatriz Gómez Fernández
Irene Huerta Illera
1. General information
1.1 The slaughtering industry in the European
Union
18%
17%
14%
1.2 Trends which may influence future
resources in the slaughtering industry
Larger installations: lower consumption per unit
easier tocontaminants
solve environmental problems
Food safety: Microbiological
BSE crisisReduction in the use of animal byAnimal welfare/ethics:
Increase
requirements
Higher intensity of
products
in chilling
animal processes
feed
Eating quality:
Controlhygiene
of carcase
cleaning and sterilisationIncreased consumption of
Working environment: health employeesnot repetitive operation
water and energy
Automation
 requirement
forprepared
energy
Processing: Increase
due
to the demand
of products
Packaging
Improved
lighting
and ventilation
quickly and
simply
Other considerations:
Not
to clean
intestines
if a reduction of
water usage or pollution of the waste
water is required
Cooling of blood requires considerable
amount of energy but provides better
products and less pollution
Capital availabilityproduction
improvements
1.3 Technical characteristics of slaughterhouses
Classification: those who carries out slaugtherhouse operations
only
those that also operates cutting plants to produce
specific meat cuts and portions. Most poultry processors
These are then packed as chilled or frozen meat for sale.
Concentration of the industry into fewer larger units downstream
activities and/or disposal or recycling of animal by-products take
place on the same premises as slaughtering reduce
consumption and emission levels on the integrated site as a
whole
Process lines automated Peak periods
Lifetime: 25-40 years
1.5 Key environmental issues
Air: Water vapour from boilers
Refrigerant gases
Water: high water consumption (EU & MS meat legislation)
high BOD, COD and TSS concentrationsblood treated at
WWTP or pretreatment
proportional to floor area used, method of slaughter,
carcase dressing & cooling and degree of automation
Energy: Refrigeration plant 45-90% electrical energy
Heat water oil and/or natural gas
Odour: blood storage and handling, slurry, occupied lairages and
inedible offal storage
Noise: animal noises during unloading and marshalling, vehicle
movements, compressors…
1.6 Economic overview
Diseases: Meat consumption grows (developing world) transport
and risk of spread diseases
Hidden costs in animal disease epidemics: price paid
to farmers for these animals
Keep costs to a minimum: contracts with larger companies
fierce competition bankrupt
Costs: provision and maintenance of abatement equipment
cleaning up and repairing damage to plant and environment
studies to avoid pollution
changing technological and operational techniques…
Have increased for the treatment and disposal of animal
by-products
Each MS has its own financial arrangements for paying for rendering
and for the subsequent disposal of animal meal: costs are passed
to the costumer, imposed a costumer tax on meat sales…
1.7 Food and veterinary legislation influences
Directive: set out the main hygiene requirements
for slaughterhouses.
some have significant environmental
consequences (water & energy consumption)
Other food, veterinary and animal welfare
legislation influences the applied processes
and techniques.
ABP Regulation: prevent animal by-products
derived from animals not fit for human
consumption, following health inspection, from
entering the feed chain and presenting a risk to
animal or public health.
2 Applied processes and techniques
-
Vary depending on the type of animal
Machinery is being developed to mechanise carcase dressing
and this tends to incorporate automatic carcase washing at
every stage
 Animal reception and lairage: animals are unloaded via ramps
Animals arrive cleanwet hides and skins can
deteriorate more quickly
Animals are held in the lairage recover from the
stress of the journey.
 Slaughter: Animals are moved along a walled passageway
Animals are stunned using a captive bolt pistol
The traditional stunning method for pigs involves
applying scissor
For pigs is also used CO2 baths.
Animals could be killed by electrocution
After stunning, animals are hung on an overhead rail
 Bleeding: starts just after stunning and is carried out rapidly,
profusely and completely
Is carried out according to certain religious rites.
Consists on incising the carotid arteries
Blood is pumped to a refrigerated and agitated tank 
additives to prevent coagulation.
Environmental controls
 Hide and skin removal: pull the hide/skin from the carcase.
Sometimes are salted to improve preservation
 Head and hoof removal for cattle and sheep
 Pig scalding: remove bristles, toenails and hair.
 Pig hair and toenail removal: By an automatic de-hairing machine
which brush or scrape the surface of the carcase.
 Pig singeing: to remove residual hair, to provide a firmer skin
texture and to eliminate micro-organisms.
This unit consist on gas burners firing intermittently
 Rind treatment: to polish the skin and remove singe hair
and other debris.
 Evisceration: manual removal of the respiratory,
pulmonary and digestive organs
 Splitting: split the carcases along the spine using a saw
 Chilling: Carcases are chilled to reduce microbiological
growth
The refrigeration systems use a refrigerant to
transfer heat from the carcases to be cooled to
ambient air
 Associated downstream activities:
 Viscera treatment: use of casings for example for
sausage casings
 Hide and skin treatment: the best option is salting
trimming reduces the amount of salt consumption as
salt in waste water is difficult to treat
2.2 Waste water treatments
•
Types: treatment on-site
discharge directly to local water course
•
Best ways of minimising:
– preventing animal material entering the waste water stream
– avoiding the spillage of high strength organic liquids
•
The sludge produced may be used or disposed of in a variety of ways
•
The main uses of water and the waste water pretreatments are:
2.2 Waste water treatments
•
Primary: screening to remove organics debris and avoid blockages in
the WWTP
DAF treatment plant: use of very fine air bubbles to remove
suspended solids
•
Secondary: biological treatment which converts soluble and colloidal
materials into biosolids
– Aerobic digestion (activated sludge): remove inorganic nutrients.
– Anaerobic digestion: for water which has high organic load  reduction of
the concentration of impurities, low excess sludge production and
biologically stable sludge.
sludge used to be incinerated limitations on land spreading
storage, handling and spreadingodour problems
•
Removal of nitrogen and phosphorus: combine the carbon oxidation,
nitrification and denitrification steps in a single process  reducing the
volume of air needed, elimination of the need for intermediate clarifiers
and return-sludge systems
•
Tertiary: filtration, coagulation and precipitation as final cleaning step
to reduce the BOD and suspended solids
EMERGING TECHNIQUES
Bio-refining of animal by-products to produce soil
improvers and fertilisers
• bio-refining treatment of Animal carcases and parts of carcases which
sterilises pathogenic agents.
organic waste material +
finely divided organic fibrous material +
Reaction mixture
Ammonium nitrate
• heated in a hyperbaric reactor vessel at 180 - 200 ºC and 1000 – 1380
kPa for 20 – 40 minutes.
• to create saturated steam, to hydrolyse and to inactivat pathogenic
agents
• Environmental benefits: inactivate pathogens, including TSE prions.
• Applicability: this technique is not permitted in the EU.
Biotechnological treatment of animal by-products in
order to increase energetic valorisation
• Animal meal is sorted by grain size,
• Then treated with active microorganisms ability to degrade animal
and vegetable fat, proteins and starch.
• An enzymatic reaction is activated by the micro-organisms. This
substantially reduces the fat content and causes the calorific value
of the material to increase.
• The time needed for the process is 15 – 20 days.
• The reaction conditions are between 20 - 27 ºC in semi-darkness.
• Applicability: At the time of writing, this technique is not permitted in
the EU,
CURRENT CONSUMPTION AND EMISSION
LEVELS
• Air: Reported emissions of CO2, SO2 and NOX are shown in the
next table.
• Water:
All slaughterhouses must have a pressurised supply of potable
water within the meaning of Directive 80/778/EEC. This requirement
for potable water to be used limits the opportunities for re-use of
water.
A non-potable water supply is authorised in exceptional cases for
steam production, fire fighting and the cooling of refrigeration
equipment,
CURRENT CONSUMPTION AND EMISSION LEVELS
• Energy:
Slaughterhouses have an energy consumption even when no
production takes place (heating and operation of the refrigeration
system)range of 36 - 154 kWh/t carcase
CURRENT CONSUMPTION AND EMISSION LEVELS
• Solid waste:
include lairage and vehicle wash solids; animal by-products; sludge, clean
and contaminated packaging; protective clothing and equipment.
In the UK, solid wastes are commonly sent to landfill, but in Denmark, they
are used in biogas production.
• Noise and vibration: Typical noise levels found measured at the
perimeter fence of a slaughterhouse or at the nearest buildings are:
– 55 - 65 dB(A) during working hours
– 40 - 50 dB(A) in the evening
– 35 - 45 dB(A) at night,
The main sources of noise and vibration are: animal noises during unloading
and marshalling to the slaughter-line; vehicle movements; compressors;
air conditioners; ventilation fans and carcase splitting.
BEST AVAILABLE TECHNIQUES
• This chapter are a reference point against
which to judge the current performance of
an existing installation or to judge a
proposal for a new installation.
• The BAT conclusions are presented in this
Figure:
Slaughterhouses and animal by-products
installations
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•
•
•
General processes and operations
BAT for environmental management
Integration of same site activities
Collaboration with upstream and
downstream activities
• Installation and equipment cleaning
• Treatment of waste water
General processes and operations
• A system of environmental management
• The formation(training)
• The utilization of a program of planned
maintenance
• The system application of management of the
energy, the refrigeration, the light and the noises
• The management and minimization of the water
quantities and emaciated detergents
BAT for environmental management
• Definition of an environmental policy for
the installation by top management
• Checking performance and taking
corrective action,
• Review by top management.
• Giving consideration to the development of
cleaner technologies
Integration of same site activities
• For slaughterhouses and/or animal byproducts installations, operating on the
same site,BAT is to do the following:
– re-use heat and/or power produced in one
activity in other activities
– share abatement techniques, where these are
required,
Installation and equipment cleaning
• Manage and minimise the quantities of
water and detergents consumed
• Select those detergents which cause
minimum impact on the environment
• Where the equipment is suitable, operate
a cleaning-in-place system
Treatment of waste water
Some examples of reached BAT:
• To avoid the stagnation of the waste water
• To apply leaked(filtered) initial of solid by means
of sieves
• To eliminate the fat of the residual water by
means of a grid of fats
• To use a plant(floor) of flotation to eliminate solid
additional
• To submit the effluent one to a process of
biological treatment
• To eliminate the produced mires
Additional BAT for the slaughter of large
animals
• To stop the nourishment of the animals 12 hours before
the slaughter
• To use a system of control of the water of drink
according to the demand
• To douche the porks with atomizers temporized of water
saving
• To re-use the cold water in the machines of depilated of
porks;
• To empty the stomaches and the intestines in I dry;
• To regulate and to minimize the water used to displace
the intestines
7.1. General techniques applicable in
slaughterhouses
• This techniques consider the possible routes for recovery
and recycling of by-products and waste to minimize the
impact on the environment.
– Emissions from by-products can be prevented by storing, handling,
processing and transferring materials within a suitable building.
– Storing animal by-products over prolonged periods at ambient
temperature in the open air increases the risk of direct pollution 
Necessary to use freezers (energy, refrigerant leaks…).
– It is necessary for all staff to be committed to its successful operation:
information and training about the use of the techniques.
7.2 Slaughterhouses: general techniques
applicable at installation level
•
Delivery:
–
–
•
Slaughter:
–
–
•
Vehicles are scraped before being cleaned to remove manure and to reduce the pollution burden in
the waste water.
At cleaning time, it is used a high-pressure trigger-operated adjustable water jet in order to reduce
water consumption.
Process automation to avoid and minimise carcase rinsing, combined with clean slaughter
techniques, that improve products quality and reduce the use of energy.
Reduction of odours by the refrigeration of blood.
Cleaning: They are based on the minimisation in the use of water and, therefore, on the minimisation
of the energy necessary to pump it:
– Dry collection of floor waste.
•
Maintenance: techniques in order to avoid the waste of energy.
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Monitoring of compressed air use.
Monitoring of ventilation use: cleaning of filters, use of backward bowed centrifugal fans.
Monitoring of hot water use. Reduce temperature in some applications.
Groundwater can be used to cool refrigerant gases.
7.2 Slaughterhouses: Slaughter of large
animals
• Animal reception and lairage:
– Techniques to reduce BOD contents in wastewater and odours:
• Cessation of feeding of animals 12 hours prior to slaughter  (+) hygiene.
• Minimise animals’ time in the slaughterhouse to reduce manure production.
• Addition of dry bedding to existing bedding, to soak up manure  (-) odours.
– Techniques to reduce the use of water:
• Demand-controlled drinking water: teats instead of water troughs  (+) cleanliness.
• Showering of pigs, using water saving, timer controlled nozzles  (+) less dust.
• Dry cleaning of the lairage floor and periodically cleaning it with water 
(-) odours, (+) less pollution of waste water.
7.2 Slaughterhouses: Slaughter of large
animals
• Bleeding:
– Optimisation of bleeding and blood collection:
• The maximum quantity of blood is collected and contained at the bleed area. This
reduces the requirement to manage dripping blood along the length of the
slaughter-line.
• Use of hollow knives and blood recovering orifices under the animal
(+) more hygiene, less recovering time, more capacity, less pollution in wastewater.
(-) high consumption of energy.
– Use of a squeegee for initial cleaning of the blood collection trough:
• (+) Reduction of water consumption, waste water production and waste water
contamination (less COD and BOD). Increased potential for waste minimisation.
Increased potential for recovery or recycling of blood.
7.2 Slaughterhouses: Slaughter of large
animals
• Pig scalding:
– Insulation and covering of pig scalding tanks  (+) Less consumption of energy and
water. Less ventilation needs. Less production of odours (reduced evaporation).
– Water level control on pig scalding tanks  (+) Energy and water saving, by
preventing the loss and need for replacement of water heated to approximately 60 °C.
– Condensation/steam scalding of pigs (vertical scalding) 
(+) Reduced water and energy consumption. The lungs can be used.
(-) The carcases will have to be washed prior to scalding. If there is any dirt on the
skin, this will prevent the steam from contacting the skin. Expensive.
7.2 Slaughterhouses: Slaughter of large
animals
• Pig hair and toenail removal:
– Recirculation of water within pig de-hairing machines  (+) Reduced water
consumption and energy use.
– Replace irrigation pipes at the top of de-hairing machines, with nozzles  (+) the spray
to transport the hair away can be moved over and beneath the pig. Reduced water
consumption.
7.2 Slaughterhouses: Slaughter of large
animals
• Pig singeing:
– Re-use of cooling water from the singeing kiln and use of nozzles fitted directed to the
pigs  (+) Reduced consumption of water.
– Heat recovery from pig singeing exhaust gases to preheat water  (+) less energy, less
odour.
– Post singeing showering with flat jet nozzles instead of shower heads  The water
supply can be arranged so that water only flows when a carcase is present (less
consumption of water).
7.2 Slaughterhouses: Slaughter of large
animals
• Rind treatment:
– Replace irrigation pipes with flat jet nozzles  (+) Less consumption of water.
• Evisceration:
– Saw sterilisation in a cabinet with automated hot water nozzles 
• (+) Reduced water consumption and energy too.
– Regulation and minimisation of water use for moving intestines 
• (+) Reduced water consumption and reduced water entrainment of high BOD
material, especially intestine contents.
• (+) The intestines can be used for sausage casings or pet food.
7.2 Slaughterhouses: Slaughter of large
animals
• Chilling:
– Blast-chilling/shock-cooling tunnel 
• (+) Low shrinkage and small tunnel dimensions.
• (+) Low process temperatures cause surface freezing, which kills all non-cold
tolerant bacteria and improves food safety.
• (-) The low chilling temperature, increases the energy consumption.
– Water-spraying/mist-cooling as a method of cooling pigs 
• (+) Reduction in energy consumption for cooling and ventilation.
• (+) Low carcase shrinkage and high process temperature (avoid surface freezing).
• (-) High water consumption.
– NOT showering carcases before they are chilled in a chilling tunnel 
• (+) Reduced water consumption.
7.2 Slaughterhouses: Slaughter of large
animals
• Associated downstream activities - viscera and hide and skin treatments:
– Removal of chopping blades from a by-product washer 
• (+) Further recovery and recycling of substances.
• (+) Reduction in BOD, suspended solids, and other pollutants in wastewater.
– Dry emptying of stomachs 
• (+) For for use in biogas production or composting.
• (+) Reduced water consumption and consequently a reduced volume and BOD
loading of wastewater.
• (+) The stomachs can be used as human food, e.g. ox tripe, or for pet food.
– “Dry” collection of the contents of small intestines
• (+) Reduced water consumption. Reduced volume and BOD loading of wastewater.
• (+) The intestines can be used for sausage casings or pet food.
7.2 Slaughterhouses: Slaughter of large
animals
• Associated downstream activities - viscera and hide and skin treatments:
– “Dry” emptying of pig intestines, which are not to be used for casings
• (+) Reduced water consumption and consequently a reduced volume and BOD
loading of wastewater. The water used is warm so there are also energy savings.
• (+) The reduced water content of the condemned intestines also reduces the energy
costs associated with driving off the water at the rendering plant.
• (+) The manure can be used as fertiliser, after gas production in a biogas plant.
– Use of nozzles instead of showers to flush out large intestines (pigs), control of water
consumption for small and large intestine washing, minimise water usage during rinsing
of tongues and hearts  (+) Reduced water consumption.
– Use of a mechanised fat trap for removing fat from water 
• (+) Preventing the fat from dissolving makes its collection easier.
• (+) Reduction of BOD and N in waste water.
• (+) The fat can be used for rendering.
7.2 Slaughterhouses: Slaughter of large
animals
• Associated downstream activities - viscera and hide and skin treatments:
– Collection of the mucosa from small intestines (pigs)
• (+) Reduction of organic matter (BOD) in the waste water.
• (+) Mucosa can be used by the pharmaceutical industry, for manufacturing
heparin or it can be rendered or used in biogas installations.
– Trimming of all hide/skin material not destined for tanning immediately after removal
from the animal, storage of hides/skins at 10 - 15 ºC, drum salting of hides and skins
(also with added boric acid), dry collection of salt residues from hide, skin or fur
preservation, preservation of hides and skins by refrigeration or by cooling with flaked
or crushed ice. 
• (+) Minimise the consumption of substances used in the preservation processes, of
process chemicals, of water and reduce odour problems.
• (+) Prevent the growth of some bacteria.
• (+) Energy is saved.
• (-) The contamination of water is involved.
• (-) Salt can reduce the efficiency of the wastewater treatment.
7.2 Slaughterhouses: Slaughterhouse
cleaning
• Use of detergents using enzymes:
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–
–
(+) Less harmful to the environment.
(+) Lower temperatures  energy savings.
(+) Lower COD than other chemicals.
(+) Non-corrosive.
• Pre-cleaning blood and meat juice contamination with cold water:
– (+)Reduced energy consumption (it can be carried out with cold water).
– (+) Reduced use of detergents and contamination of waste water by detergents.
• CIP (Cleaning-in-place):
– (+) Reduction in the consumption of water, detergents and the energy needed to heat the
water (the consumption levels are set).
– (-) High capital investment.
• Use of cyclonic vacuum cleaners:
– (+) Reduced water contamination.
– (-) Increased use of energy compared to simply hosing down, or using a squeegee.
7.2 Slaughterhouses: Storage and handling
of slaughterhouse by-products
• Segregated storage and handling of different kinds of byproducts:
By-products can be collected, handled and stored separately or in
categories, depending on their further use or disposal route and on the
potential environmental consequences of mixing them.
– (+) Reduced odour emissions associated with the storage of malodorous byproducts.
– (+) Reduced cross contamination between different by-products.
– (+) The refrigeration capacity required will be less.
– (+) Segregation enables individual by-products to be used instead of disposed
of.
– (+) Reduced waste disposal costs.
7.2 Slaughterhouses: Slaughterhouse
waste water treatment
• Moving bed trickling filter - for the treatment of air, water and air/water
mixtures:
– (+) Low energy consumption.
– (+) COD levels and nitrogen compounds are reduced by 90 % and 55 %, respectively.
• Treatment of slaughterhouse waste water at municipal WWTPs:
– (+) No need to reduce BOD levels.
– (-) Necessary to remove fats and gross solids before the treatment.
– (+) Waste water from slaughterhouses contains easily degradable organic matter with a
favourable C:N ratio: complete denitrification is obtained easily.
• Use of sequencing batch reactors (SBR) in slaughterhouse wastewater
treatment:
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–
–
(+) The system allows equalisation, COD removal, nutrient removal and clarification.
(+) The energy consumption is low (no need for recirculation between tanks).
(+) No requirement to use chemicals  No chemically contaminated sludge  Composting.
(-) CO2 and nitrates emissions  Global warming.
(+) Flexible technique. Not requiring much space and not requiring a clarification system.
7.2 Slaughterhouses: Slaughterhouse waste
treatment
• Microbiological treatment of slaughterhouse waste:
•
(+) Waste water treatment producing water and solids which can be used instead of needing to
be disposed of.
– The sludge produced by the digesters is dewatered to give a biomass with a commercial
value as a fertiliser.
– Liquid is used for land spreading, or used for belt washing.
– The final effluent is suitable for yard washing, after veterinary approval.
•
(+) Capable of treating high-strength wastes with a COD content of over 100 g/l and of adapting
to a wide range of pollutant loads.
•
(-) Some energy use for the operation of the process and odour from the biomass.