doi: 10.18178/ijesd.2025.16.5.1547
Preparation of Low-Cost Activated Carbon from Spent Coffee Grounds for Rhodamine B Removal
Kanchalar Keeratirawee1,*
,
Orasa Choola-aied2 ,
Pornprapa Kongtragoul3
- 1Department of General Sciences, King Mongkut’s Institute of Technology Ladkrabang, Prince of Chumphon Campus, Thailand
- 2Laboratory Services, King Mongkut’s Institute of Technology Ladkrabang, Prince of Chumphon Campus, Thailand
- 3Department of Agricultural Technology, King Mongkut’s Institute of Technology Ladkrabang, Prince of Chumphon Campus, Thailand
- Manuscript receivedMarch 2, 2025
- revisedApril 16, 2025
- acceptedApril 28, 2025
- publishedOctober 13, 2025
Abstract
A low-cost coffee-based activated carbon forRhodamine B (RhB) removal was investigated. Spent coffeegrounds obtained from a local coffee shop in Pathio, Chumphon,Thailand, were utilized as the raw material to produce biochar.The coffee grounds were pre-treated by washing with 1M H2<sub>S</sub>O<sub>4</sub>before carbonization at 600 ºC for 2 h under a limit-oxygenatmosphere. The acid washing process was found to be apromising method for preparing activated carbon withoutrequiring an inert gas flow during the carbonization. Thisapproach resulted in activated carbon free of ash aftercarbonization. The carbonized coffee grounds were activatedusing a microwave-assisted process with KOH as the activatingagent. The performance of the prepared activated carbon forRhodamine B adsorption was evaluated using the batch method.Key parameters, including initial concentration of RhodamineB (3–11 mg/L), pH (3–11), and contact time (15–150 min), wereoptimized. The maximum adsorption capacity was 16 mg/g ofadsorbents. The optimal pH for Rhodamine B adsorption wasfound to be 7. The adsorption of Rhodamine B onto theadsorbent fits a Langmuir isotherm and a pseudo-second-orderkinetic model. The study revealed that the prepared activatedcarbon from waste coffee grounds is an efficient and affordablesolution for removing Rhodamine B contaminants from thewater system.
Keywords
- activated carbon
- Rhodamine B
- KOH
- limitoxygen carbonization
- microwave activation
- acid washing
How to Cite
Kanchalar Keeratirawee, Orasa Choola-aied, and Pornprapa Kongtragoul, "Preparation of Low-Cost Activated Carbon from Spent Coffee Grounds for Rhodamine B Removal," International Journal of Environmental Science and Development, vol. 16, no. 5, pp. 386-392, 2025. https://doi.org/10.18178/ijesd.2025.16.5.1547
Copyright & License
Copyright © 2025 by the authors. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).