Is our landfills enough?

Organic materials 'biodegrade' as they are broken down into their constituent parts by other living organisms (such as fungi, bacteria, or other microbes), which are in turn recycled as the building blocks for new life by design. The process can occur aerobically (using oxygen) or anaerobically (using oxygen) (without oxygen). Under aerobic conditions, compounds break down even quicker, as oxygen helps break the molecules apart, a process called oxidation.

Landfills are too overcrowded for waste to biodegrade

Since they are too densely compacted, most landfills are inherently anaerobic and thus do not allow much air in. As such, any biodegradation that happens does this quite slowly.

"Typically, there is not much dirt, very little oxygen, and few if any microorganisms in landfills," says Debra Lynn Dadd, a green consumer advocate and author. She cites a landfill report performed by researchers from the University of Arizona that discovered still-recognizable 25-year-old hot dogs, corncobs, and grapes in landfills, as well as still-readable 50-year-old newspapers.

Processing May Inhibit Biodegradation

Biodegradable materials can also not break down in landfills if they have been transformed into forms unrecognizable by the microbes and enzymes that promote biodegradation by the industrial processing they experienced until their useful days. Petroleum, which biodegrades easily and quickly in its original form: crude oil, is a typical example. But it is no longer biodegradable when petroleum is refined into plastic, and can permanently clog up landfills as such.

Some manufacturers say that their goods are photodegradable, which means that, when exposed to sunlight, they can biodegrade. The plastic "polybag" in which several magazines now arrive covered in the mail is a common instance. But there is little or no risk that such objects would be exposed to sunlight when buried in a landfill hundreds of feet deep. And if they do photodegrade at all, they are only likely to be smaller bits of plastic, leading to the growing issue of microplastics and adding to our oceans' enormous quantity of plastic.

Landfill Design and Technology May Enhance Biodegradation

Via the injection of water, oxygen and even microbes, some landfills are now being planned to facilitate biodegradation. But it is expensive to build these types of facilities and, as a result, they have not caught on. Landfills that have different parts for compostable items, such as food scraps and yard waste, are another recent trend. Some researchers estimate that 65% of the waste currently sent to landfills in North America consists of such "biomass" that rapidly biodegrades and could create a new source of income for landfills: marketable soil.

Reduce, Reuse, Recycle Is Best Solution for Landfills

But having people to sort their garbage correctly is completely another matter. In fact, paying attention to the meaning of the "three Rs" of the environmental movement (reduce, reuse, recycle) is probably the best solution to addressing the problems created by our ever-growing piles of garbage. With landfills exceeding capacity all over the world, technical solutions are not likely to make our issues with waste disposal go away.