Gas phase interactions of super activated carbon nanoparticles with benzene, o-xylene and water

摘要

Nanotechnology research in aerospace, medicine, science, automobile tires, cosmetics, energy and environmental technology promises exceptional advancements. Nano-technological advances also lead to an increased manufacture and use of Engineered Nanoparticles (ENPs) with a typical size of approximately 1-100 nm. ENPs have unique properties including surface area, conductivity and reactivity as compared to the larger particles of the same material. ENPs are eventually released in the environment at their different life cycle stages including raw material, manufacturing, transportation, consumer use and disposal. Nanoparticles that are released into the environment can interact with already present hazardous air pollutants (HAPs). Some HAPs found in the industrial workplace such as benzene and o-xylene are considered hazardous substances by the U.S. Environmental Protection Agency. Benzene and o-xylene are colorless volatile organic compounds (VOCs) that, once released into the air, can evaporate very quickly. This study investigated the adsorption competition of binary and ternary gas mixtures of benzene, o-xylene and water vapor on super activated carbon nanoarticles (NPs). There has been an extensive use of granular activated carbon to remove hazardous pollutants from gas stream and water streams. However, there is no research that studies the interaction of benzene, o-xylene, and water vapor using nanoscale activated particles. A bench-scale experimental setup was designed and set up to determine the competition of benzene, o-xylene and water vapor for adsorption sites of super activated carbon NPs. After completion of the bench-scale adsorption system, there were several experiments carried out to determine the generation of water vapor, benzene and o-xylene at different concentrations. Results showed that in binary adsorption between benzene and o-xylene, at higher o-xylene concentration caused a displacement of benzene from the super activated carbon NPs pore sites. However, in ternary adsorption the water vapor seems to be responsible for the decrease of the adsorption capacity of super activated carbon NPs for benzene.