Sunhee Kim  Younghee Kim

Vol. 31,  No. 4, pp. 363-369, Dec.  2025
10.7464/ksct.2025.31.4.363

Prussian blue analogue (PBA) Activated carbon Ammonia Hydrogen sulfide Adsorption

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Activated carbon has been widely used to control odorous gases due to its high surface area and microporous structure. However, adsorption efficiency for polar ammonia and reactive hydrogen sulfide is limited because of its nonpolar and hydrophobic surface characteristics. In this study, the feasibility of simultaneous removal of ammonia and hydrogen sulfide was evaluated by depositing a Prussian blue analogue (PBA) onto the surface of activated carbon. Palm-based activated carbon and coalbased activated carbon coated with PBA exhibited similar characteristics in ammonia adsorption. When mixed-gas adsorption tests for ammonia and hydrogen sulfide were conducted using PBA-impregnated palm-based activated carbon and ion exchange resin, the activated carbon showed relatively better removal efficiency for both gases than the ion exchange resin. In ammonia adsorption experiments in which the immersion time of K4Fe(CN)6 used in PBA synthesis was varied between 90 and 180 minutes, a slight improvement in adsorption capacity was observed with increasing immersion duration. Since K+ ions can occupy the interstitial sites within the PBA lattice and exchange with NH4 +, the sample with a single K+ post-treatment exhibited an adsorption capacity of 3.18 mg g–1 at 50% breakthrough point. However, additional immersion cycles resulted in decreased adsorption capacity. Under humid conditions, ammonia adsorption performance improved for both PBA-AC and PBA-IER. This enhancement is attributed to the conversion of NH3 into NH4 +, which activates ion-exchange-driven adsorption, as supported by the significantly delayed breakthrough observed for PBA-IER.