Meat and Poultry Wastes

Feed lot, stockyard, and poultry receiving area wastes consist primarily of manure, unconsumed feed, feathers, and straw, together with common dirt and drain water. Pollution can be reduced if solid wastes are not diluted by water.

In killing operations blood must be collected separately and prevented from entering sewer or waste treatment systems, since blood has an extremely high waste strength of about 100,000 ppm BOD. In poultry plants, various processes must be isolated to avoid cross-contamination from live birds or wastes of previous operations. As the bird goes through the plant on shackles, feathers are removed and flumed away. A major incision is made, entrails and major organs are pulled out, and inedible viscera are discarded in a flowaway flume system. The lungs and other material remaining in the carcass are removed by vacuum suction.

Flowaway systems (for feathers, entrails and offal) create an increased organic load, and it is desirable to use a dry conveying system. Most plants use the flowaway system as a more convenient and nuisance-free operation. After the offal flowaway leaves the area, it must be screened in order to remove solids. These solids and wastes from other operations are then sent to a rendering plant where they are utilized in making chicken feed.

Meat packing houses generate a strong waste. These wastes are amenable to treatment, as are poultry wastes. Before releasing processing wastewaters into city sewers or private waste treatment systems, screening and grease removal should be provided to recover solids for by-product use. Removal of large solids and free floating grease is also important to avoid clogging sewer lines and fouling biological treatment systems.

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