Quirks & Quarks

Wouldn't our garbage break down faster if we kept our compost mixed in?

Can compost help break down garbage? Apparently not even the powerful microbes in our compost can help us break down garbage quicker.

Apparently not even the powerful microbes in our compost can help us break down garbage quicker

Workers sort recycling material at the Waste Management Material Recovery Facility in Elkridge, Maryland. (Saul Loeb/AFP/Getty Images)

Originally published on March 7, 2020.

This week's question comes from Terry Myland in Owen Sound, Ontario. He asks:  

So we separate our compost from our garbage. Wouldn't it be better to leave the compost mixed in with the garbage to help it all break down faster?

Dr. Grant Clark, an associate professor in bio resource engineering at McGill University explains that it wouldn't quite work. Compost is made when microbes break down organic material. They need things like heat, air, and moisture to do that. If our garbage was just made up of organic materials, like food waste, leaves, and even paper or cardboard, then yes, those microbes could get to work and break it all down. However, those microbes are generally unable to break down inorganic material like plastic, glass, and metal, so if those are mixed in, the compost is contaminated, the microbes can't do their job, and the end result wouldn't be useful in your garden.

Not only would those inorganic materials ruin the compost, but the compost would also ruin any potential recyclable materials. In order for things like plastic, glass, and metal to be recycled, they need to be clean and separated from each other. If we keep our compost and our garbage together, we don't end up with anything useful in the end. So, it's better to keep them separated.

Produced and written by Amanda Buckiewicz


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