A whole latte promise for old coffee grounds

Talk about black gold: City College of New York scientists say they’ve discovered that carbonized coffee grounds can be a cost-effective tool for the elimination of sewer gas.

It turns out that the caffeine in coffee also contains nitrogen, an ingredient that helps rev up its effectiveness when it’s used in filters that scrub toxins from the air. Normally, the nitrogen would have to be added during the carbon-making process, an expensive proposition.

In an article on the college’s Web site, Dr. Teresa Bandosz says research into finding materials that can be used to create activated charcoal — the main ingredient in many types of filtration systems — led to the discovery.

When a sewage treatment plant is functioning properly, odors outside the boundaries of the plant should be minimal. Most treatment plants, including those used by LCA, employ a biological process that relies on a mixture of bacteria and oxygen to break down the waste. A foul-smelling plant is usually indicative of a problem, which could have been triggered by toxic waste that killed the bacteria, or a problem with the blower system that prevents the waste and bacteria from getting enough air and movement.

At LCA, we’ve taken several additional steps to minimize the sewer odors that might be noticeable in the communities surrounding our treatment plants. At our industrial pre-treatment plant in Fogelsville, we use covered tanks to reduce wind-borne odors. At some other smaller plants, we introduce oxidizing agents, such as hydrogen peroxide, to neutralize odors. Perhaps in the future we’ll examine the viability of Dr. Bandosz’s filtration methods.

While not everyone can make active charcoal from their coffee leftovers, there’s still ways to put them to good use. They make excellent compost (paper filters and all), and if you don’t have a compost pile, never fear: they can be sprinkled directly around the base of acid loving plants such as evergreens (including azaleas, rhododendron, and junipers), tomatoes, garlic, blueberries and more. Not a gardener? Not a problem: You can always run the grounds through a garbage disposal. Studies show that sending table scraps to the waste treatment plant beats sending them to the landfill.

To read more about the use of coffee grounds to make activated charcoal filters, click here.