About Organics Management

With the exception of paper and cardboard, most of our recycling has been focused on managing inorganics – that is, the material that does not decompose. This includes glass and cans and plastic. As those materials are removed from the waste stream, organics become a larger component. Organic waste is the material that can readily be broken down or decomposed. In municipal solid waste, this includes yard waste, food waste, and paper. As organics are the largest component remaining in MSW, attention is increasingly focused on it as a target for reduction, diversion and composting.

According to the Environmental Protection Agency, the amount of food and yard waste discarded has changed significantly over the past 50 years. Yard waste used to make up nearly a quarter (22.7%) of the waste generated, but has dropped to 13.5% as a total percentage of waste. In addition, the amount recovered has increased from a negligible amount to more than half so that less total yard waste is being discarded today than a half-century ago despite total waste quantities nearly tripling.

Food waste’s percentage, on the other hand has remained steady – so its numbers HAVE nearly tripled over the past 50 years. Recovery of food waste has increased slightly, but according to the EPA food waste now makes up the largest category of all discards.

Waste generated: 1960 2012
Food waste 13.8% 14.5%
Yard waste 22.7% 13.5%
Waste recovered (recycling/composting): 1960 20112
Food waste Negligible 4.8%
Yard waste Negligible 57.3%
Waste discarded (waste-to-energy or landfilling) 1960 2012
Food Waste 14.8% 21.1%
Yard Waste 24.2% 8.8%

Source reduction

As can be seen with yard waste, source reduction can effectively reduce the material that is generated. Many homeowners now use “mulching mowers” that leave grass clippings on the lawn. Even leaves can be mulched! Alternatively, yard waste can be composted. Food waste can often be added to the compost as well depending on the type of food. Composting and mulching adds nutrients back to the soil reducing the need for additional fertilizers and pesticides.

Food waste reduction strategies include reducing over-purchasing of food, ensuring proper storage, and reducing the amount taken. According to a survey by Aramark Higher Education, trayless dining at college campus reduces the amount taken by approximately 2 ounces per person per meal. Given that 300 colleges and universities serviced by Aramark have gone trayless, they estimate that approximately 15 million pounds of food waste is saved.

Commercial or industrial organics management

Windrow composting

The organic waste is formed in long piles approximately eight feet high by about 14 feet wide. The long piles are called windrows. The piles are turned every so often to aerate the pile and speed decomposition.

Aerated static pile composting

The aerated static pile utilized blowers and a network of pipes beneath the pile to keep it aerated. This eliminates the need to turn the piles, thus providing more flexibility on pile dimensions.

In-vessel composting

This process moves the organic material into a vessel that could be anything from a concrete bunker to a plastic tank. By containing the material, the operator has greater control over the process.

Anaerobic digestion

Anaerobic digestion is done in-vessel but eliminates the aeration portion. Instead, the process relies on anaerobic microorganisms to degrade the material. This process results in the generation of methane which is then utilized as a fuel.

Continue reading here: Know Your Trash Facts

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