What to do with our food wastes including packaging material is a big challenge for the environment. The National Resources Defense Council (2013) estimates that 40% of all edible food is wasted by consumers, restaurants and grocery stores in the US. They further estimate that $750 million is spent each year in the US to dispose food wastes. Food wastes may take the form of, solid waste (including food solids and packaging), liquid waste, gaseous waste (air pollution). Solid wastes are typically managed by one of the following ways:
Landfill: Landfills are constructed by digging a large basin in the ground and covering the bottom surface with layers of material that will prevent/minimize the possibility of the collection area leaching into ground water to cause contamination. The basin is then filled with garbage where they are compacted and allowed to remain until they break down. For packaging material in the landfill, this could take hundreds or thousands of years. During breakdown, landfills give off harmful gases such as methane which is harmful to the earth’s atmosphere. In some landfill operations, methane (some) may be trapped and utilized as fuel
Composting: Instead of sending to landfills, food material can be separated and composted. This involves the breakdown of organic material by microorganisms to produce mulch which can be used as fertilizer. Food companies may sell their organic waste to organic farmers to be used for composting
Animal Feed: Bone, blood, unwanted meat scraps and spent hens can be rendered and converted to high-protein animal feed. Organic plant material may be converted to animal feed instead of composting. For example, distillers dried grain with solubles (DDGS) is a co-product of ethanol production from corn. It is used as a high-protein ration for livestock and poultry
Recycling Packaging: Packaging material such as plastics, metal cans, and glass can be melted and reused
Recycling or Treating Food Waste: Food waste to be recycled may be in liquid form, or solids incorporated in waste water. Waste water is treated at a waste water treatment plant where large solids are separated and smaller solids are degraded by microorganisms and further treated to remove pathogens, leaving potable (drinkable) water that can be sent back for use in the food plant. Food companies may send their waste water to the city treatment facility or may choose to treat their own waste to reduce high cost due to surcharge caused by large concentration of solids in the waste water. The level of contamination of waste water is measured by its biological or (biochemical) oxygen demand (BOD) or its chemical oxygen demand (COD). The higher the BOD or COD, the higher the level of contamination. High contamination of solids means high levels of nutrients available for algae and bacteria growth. As algae and bacteria grows, they use up the oxygen in the water, making little available for other aquatic life. As a result aquatic species such as fish dies.
Food companies can take several steps to manage water and solid wastes by doing the following:
- Install water meters and monitor use
- Train employees how to use water efficiently
- Use automatic shut-off nozzles on all water hoses
- Use high pressure-low volume cleaning systems
- Recycle water where possible
- Minimize spills of ingredients
- Using trays beneath machines to catch spillage
- Placing screens over drains
- Don’t use hose as a broom
