Investigação espectrométrica da transferência gás-sólido envolvendo naftaleno, antraceno e criseno em XAD-2, EPU e sílica

Abstract

Polycyclic aromatics hydrocarbons (PAH) are an important class of pollutants ubiquitous in the environment, being spread from its source to different parts of the world, like Amazonia and Antartica, and has already been related to many health issues, such as cancer, behavior disorders in children and miscarriage. Its major font of production are on the burning or pyrolysis of fuels and during asphalt applications. Adsorption processes has been used on air samplers, sensors and poluted media remediation, being XAD-2, polyurethane foam (PUF) and silica commonly used for those purposes. Recent studies on liquid systems showed that silica may be used as good PAH adsorbent. Kinetik information is necessary for better results on PAH uptake processes. In this study, spectrometric studies were conducted and a system, composed by a glass tube, a 50 mL trap and a succion pump, was developed to monitor the gas  solid mass transfer. Naphthalene, anthracene and chrysene were the compounds used on the studies, being representants of two-, three- and four-ring compounds, respectively. The adsorption was studied on XAD-2, PUF as separated adsorbents (using 10 mg, 20 mg and 30 mg) and as mixtures of XAD-2/Silica (on a adsorbent’s total mass of 30 mg). A mixture of XAD- 2/Silica a proportion of 2:1 gave the best results in therms of mass uptake of PAH and preliminar process kinetics, but it is recommended to use it in a proportion of 1:1, as it give a better cost/benefit result. Improvements on the system’s temperature control are necessary for experiments with PAH with more than two rings. It is also necessary to improve the system to conduct experiments with higher mass of PUF, wich is promising for PAH uptake. Further studies have also to evalueate the influence of the air relative humidity on the adsorption’s processes.