For coffee lovers, the first cup of the morning is one of life's best aromas. But did you know that the leftover grounds could eliminate one of the worst smells around sewer gas?
In research to develop a novel, eco-friendly filter to remove toxic gases from the air, scientists at The City College of New York (CCNY) found that a material made from used coffee grounds can sop up hydrogen sulfide gas, the chemical that makes raw sewage stinky.
Dr. Teresa Bandosz, CCNY professor of chemistry and chemical engineering develops and tests materials that scrub toxic gases like hydrogen sulfide from air in industrial facilities and pollution control plants. Much like the grains of charcoal packed into the filter of a tabletop water pitcher, her filters use a form of charcoal called "activated carbon."
Carbon producers already use materials like coal, wood, peat, fruit pits, and coconut shells to make filters. Professor Bandosz realized that our modern coffee culture could supply an abundant source of eco-friendly organic waste. But coffee grounds also come equipped with a special ingredient that boosts their smell-fighting power.
Caffeine, the stimulant that gives coffee its energy jolt, contains nitrogen. This element cranks up carbon's ability to clean sulfur from the air, a process called adsorption. "We should not neglect the natural biomass that is rich in this element," she and colleagues assert in the January 30 issue of the Journal of Hazardous Materials. The National Science Foundation (NSF) and the Army Research Office funded the research.
Usually, making carbon adsorbents more reactive to toxins requires treating the original with a nitrogen-rich chemical such as ammonia, melamine, or urea, the main nitrogen-containing substance in mammal urine. "All of these," the researchers note, "significantly increase the cost of adsorbents."
To make their new filter, Professor Bandosz and her colleagues carbo
|Contact: Jessa Netting|
City College of New York