Tailoring of activated carbon with ammonia for enhanced anaesthetic sevoflurane adsorption

摘要

Activated carbon (AC) has been reported to be useful for removing waste volatile anaesthetics that are highly potent greenhouse gases. Surface functionalities play essential roles in sevoflurane adsorption. However, the relationship between surface nitrogen functionalities and sevoflurane adsorption has not been investigated. In this study, both single-and two-step nitrogenation of a granular AC were conducted to examine the effect of surface nitrogen functionality on sevoflurane adsorptivity under otherwise fixed experimental conditions (bed depth: 10 cm, inlet concentration: 528 mg/L, and flow rate: 3 L/min). The potential interaction between sevoflurane molecules and surface nitrogen functionality were examined using the conductor-like screening model for real solvents (COMOS-RS). COSMO-RS prediction suggested that the nitrogen groups containing C-N-C structures had a higher tendency for sevoflurane to adsorb to activated carbon. The findings agreed with the experimental adsorption results, where the pyrrolic or pyridonic groups showed an enhancing effect on sevoflurane adsorption. These findings are a useful foundation for future tailoring of activated carbon adsorbents for selective enrichment of beneficial surface functionality to remove sevoflurane before emission of anaesthetic gases.