Investigating the Effect of KOH-Modification on “AR-A” Activated Carbon: Implications for Isopropanol and n-Hexane Adsorption Capacity, Kinetics and Mechanism

This study examines the impact of potassium hydroxide (KOH) modification on the adsorption performance of AR-A activated carbon for the removal of isopropanol and n-hexane. Modified AR-A activated carbon samples were prepared with varying volumes of KOH solution-to-mass of AC ratios. The adsorption capacity was evaluated through gravimetric analysis, and the experimental data were further analyzed using the Lagergren equation of pseudo-first-order (PFO), Ho-Mackay pseudo-second-order (PSO), Elovich, and Morris-Weber intraparticle diffusion models. Results show that KOH modification significantly enhances the surface area and microporosity of the carbon, leading to improved adsorption capacity, particularly for isopropanol. The modified activated carbon demonstrates high affinity and increased uptake for both volatile organic compounds, with the adsorption mechanisms influenced by physical interactions and surface functional groups. These findings highlight the potential of KOH-modified AR-A activated carbon as an efficient adsorbent for VOC removal applications.