wastage
- Cass Yang 14269495 -
In the past decades, meat industry has become one of the most essential industries in New Zealand. Meat industry brings a huge income for the country, however, the amount of waste has been increased as well. Most of the wastes are from the slaughterhouse, during the process of slaughtering, dressing, chilling, boning and packaging, there are large amount of organic solid waste being produced. Due to the nutrition resources from the wastes, people have also widely processed these wastes into new products.
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Types of Waste
solid wastes in slaughterhouse
There are few types of waste being produced during the processing of slaughtering. The blood would be one of the most valuable wastes, it contains large amounts of protein, it is used as a raw material for blood meal, fertiliser, animal feed and used in fibrin or blood serum (Anaerobic treatment of slaughterhouse waste and wastewater , 2001 ). Lamb contains on average 20% fat (USAD, 2016). However, lamb fat is highly saturated, which means that the fat would solidify at a relatively high temperature, and it has also been linked with raising cholesterol level and heart disease (Savell, 1988). Lamb fat is currently added to pet food or animal feed, as well as for other industrial purpose such as the soap industry (Gerpen, 2014). Furthermore, the lamb head, feet and viscera would be processed as animal feed or pet food. Other inedible wastes like trimmings from boning and the dead stock due to diseases would be discharged.
Wastage Treatment
Rendering: The heating process to separate the lamb fat from meat. The meat-bone meal produced from rendering would be used in animal feed or as fertiliser. The lamb fat from the process may be used for animal feed, chemical industry, or burned as fuel (Salminen, 2001).
Incineration: The waste treatment which destroys the potential infectious agents by the technology of thermal destructions. However, the process condition, the discharged solid waste and air emission need to be controlled strictly during incineration (Ritter and Chinside, 1995).
Composting: A common method to treat solid wastes with an aerobic biological process to decompose organic material. The organic materials like trimming, residues, manures and litter will be composed into soil conditioner or fertiliser (Senesi, 1989).
Anaerobic digestion: A biological process in which organic wastes are degraded to methane under anaerobic condition. Methane is an energy resource which can replace fossil fuel and reduce the emission of carbon dioxide(Braber, 1995).
Wastage treatment process
