A sustainable approach to combat industrial air pollution using commercially available and engineered gas-phase adsorbents

The occurrence of benzene, toluene, ethylbenzene, and xylene (BTEX) in the environment has human health and ecological consequences; hence, it is essential to remediate the gas-phase industrial plume before its release. A laboratory-scale experimental apparatus was designed to investigate single-component gas-phase adsorption of BTEX compounds on commercially available granular activated carbon (CGAC) and laboratory-developed Mesquite-derived granular activated carbon (MDAC). The physical properties of CGAC and MDAC show that these adsorbents have a high N₂ BET surface area, with CGAC exhibiting microporosity features. The single-component adsorption of BTEX was modeled by considering the transport of BTEX by axial dispersion, convective transport, and accumulation in the adsorbent bed at isothermal conditions. A linear driving force model was used to examine the mass transfer process. The experimental breakthrough curves showed good agreement with the modeled breakthrough curves. The modeling parameters demonstrated the dominance of intraparticle diffusion with a negligible external diffusion of BTEX onto CGAC and MDAC. The analysis of experimental data validated the modeled dynamic behavior of BTEX adsorption onto CGAC and MDAC. Overall, BTEX compounds followed Langmuir isotherms for both adsorbents, with intra-particle diffusion as a dominant gas phase adsorption mechanism.