The reuse of disposable COVID-19 surgical masks as a nitrogen-enrichment agent and structure promotor for a wild plant-derived sorbent

In this work, disposable surgical face masks (SFMs) have been utilized as nitrogen (N)-doping agents for carbon (C) adsorbents through thermal carbonization using K₂CO₃ as activators. A readily available wild-plant biomass (Cyperus papyrus, CP) was chosen as the raw material for manufacturing the adsorbent. A “green-etching” process was employed to synthesize adsorbents with significant modifications and without using of any chemicals. As observed via characterization analysis, upon mixing SFMs with CP at a 1:1 weight ratio, there were considerable developments in the specific surface area (S_BET = 830 m²/g) for both micro- (0.333 cm³/g) and mesopores (0.053 cm³/g) as well as diversified functional groups (e.g., amino and carbonyl) on the sorbent that was produced. This is a key for the adsorbent's ability in order to remove a variety of pollutants from aqueous solutions. The heavy metal (Cr(VI)) ion adsorption capacity was used to identify the optimum adsorption parameters. Significantly lower amounts of Cr(VI) residues were achieved at a concentration of 2 mg/L from an initial Cr(VI) concentration of 30 mg/L by applying an SFM-modified sorbent dose of 10 g/L. The outcomes of this research could be advantageous for decision making in plastic waste management that surged during the COVID-19 pandemic.