Nitrate removal from water by means of carbon adsorbents derived from spent coffee grounds

BACKGROUND

High levels of nitrate ions in drinking water can pose health risks to humans and livestock. These nitrates can infiltrate drinking water by means of agricultural activities and wastewater. Fertilizers used in agriculture can be carried away by rainwater into nearby lakes and rivers. Wastewater from failed septic systems can also find its way into nearby water sources. When these nitrate ions contaminate drinking water, it becomes critical that we have a way to effectively remove them. There are several solutions that exist, such as reverse osmosis and distillation, but these strategies are only effective on small-scale water purification. A solution that is cost-effective and scalable to industrial scale could be crucial in removing nitrate ions from drinking water effectively.

SUMMARY OF TECHNOLOGY

Researchers at Oklahoma State University have developed a strategy to remove nitrate ions in water using carbon adsorbents from spent coffee grounds. This carbon is prepared by pyrolysis of spent coffee grounds with metal chlorides such as Iron Chloride, Magnesium Chloride, Zinc Chloride, and Calcium Chloride. After the metal chloride is added to the spent coffee grounds, it goes through pyrolysis at 700ºC for one hour. After the pyrolysis process, the result will be porous carbon. The derived carbon containing metal oxides can effectively remove nitrate ions from water via an adsorption process. The porous carbon is added to the nitrate contaminated water and left for 2 to 24 hours at room temperature. The result is porous carbon (FeNO3) and filtered water. This removal process can take place in both closed and open systems, allowing for scalability to industrial scale applications. With this nitrate removal strategy, any companies interested in sustainable waste and nitrate treatment of water can effectively scale this solution to any desired application or system.

POTENTIAL AREAS OF APPLICATION

• Large-scale filtration used in waste treatment facilities.
• Small-scale carbon-filtration systems, such as a Brita water filter.
• Agricultural Runoff Treatment

MAIN ADVANTAGES

• Cost-effective: Freely available Spent Coffee Ground waste.
• Scalable: Easy carbon preparation makes scaling to industrial scale applications straightforward.
• Future-Oriented: Waste and nitrate treatment in water promotes sustainability.

STAGE OF DEVELOPMENT

• Proof of Concept