SLAUGHTERHOUSES

1. SLAUGHTERHOUSES Patricia García García de Pereda Sonia García Redondo Beatriz Gómez Fernández Irene Huerta Illera

2. 1. General information 1.1 The slaughtering industry in the European Union 18% 17% 14%

3. 1.2 Trends which may influence future resources in the slaughtering industry Larger installations: lower consumption per unit easier to solve environmental problems Food safety: Microbiological contaminants BSE crisis Increase hygiene requirements Higher intensity of cleaning and sterilisationIncreased consumption of water and energy Packaging Animal welfare/ethics: Reduction in the use of animal by-products in animal feed Eating quality: Control of carcase chilling processes Working environment: health employeesnot repetitive operation Automation  requirement for energy Improved lighting and ventilation Processing: Increase due to the demand of products prepared 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

4. 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

5. 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…

6. 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…

7. 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.

8. 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

9. 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

10. 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

11. 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:

12. 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

13. organic waste material + finely divided organic fibrous material + Ammonium nitrate Reaction mixture EMERGING TECHNIQUESBio-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. • 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.

14. Biotechnological treatment of animal by-products inorder 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,

15. 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,

16. 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

17. 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.

18. 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:

20. Slaughterhouses and animal by-products installations • 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

21. 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

22. 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

23. Integration of same site activities • For slaughterhouses and/or animal by-products 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,

24. 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

25. 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

26. 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

27. 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.

28. 7.2 Slaughterhouses: general techniques applicable at installation level • Delivery: • 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. • Slaughter: • 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. • 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.

29. 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.

30. 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.

31. 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.

32. 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.

33. 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).

34. 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.

35. 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.

36. 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.

37. 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.

38. 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.

39. 7.2 Slaughterhouses: Slaughterhouse cleaning • Use of detergents using enzymes: • (+) 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.

40. 7.2 Slaughterhouses: Storage and handling of slaughterhouse by-products • Segregated storage and handling of different kinds of by-products: 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 by-products. • (+) 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.

41. 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: • (+) 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.

42. 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.