Management of surgical mask waste to activated carbons for CO₂ capture

The worldwide COVID-19 pandemic has resulted in a huge amount of face masks being used up and thrown away, resulting in increased environmental pollution and infection risks. In our work, we have developed a highly efficient process of neutralizing face mask waste into a useful carbon material. Then, the prepared activated carbon was used for CO₂ adsorption studies. A series of activated carbons from face masks used as a precursor were synthesized using KOH and the activation temperature was in the range of 600-800 °C. All materials were characterized by well-developed porosity. The influence of activation temperature on the textural properties of prepared activated carbons and their adsorption abilities were investigated. The highest CO₂ adsorption was received for the M_800 carbon and it was 3.91 mmol/g at the temperature of 0 °C and the pressure of 1 bar. M_800 carbon exhibited also high selectivity of CO₂ over N₂. Seven equilibrium isotherms were applied to the experimental data to find out the best fit (Langmuir, Freundlich, Sips, Toth, Unilan, Fritz-Schlunder and Radke-Prausnitz isotherms). The presented research provides an environmentally friendly and cost-effective method of recycling waste masks into a valuable product in the form of carbon and its potential use in the absorption of harmful CO₂ influencing the greenhouse effect.