COMBINED FILTRATION VOCs/PARTICLES ON FIBROUS FILTERING MEDIAS

摘要

Particles and VOCs (Volatile Organic Compounds) are two very common pollutants of citizens’ everyday life environment, which is mainly composed of indoors places such as cars, homes, offices, … And even if these two pollutants are known to have bad effects on health, nowadays, no really efficient filtration system is able to treat them simultaneously. rnThus, the final objective of this research is to develop and test innovative fibrous filtering medias as efficient for treating particles as for treating VOCs, and the study presented in this paper corresponds to the first step of this research. rnFor this study, commercial medias made of activated carbon fibers, either woven or nonwoven, are tested on two specific experimental set-ups (dedicated to adsorption and particulate filtration measurements), in order to determine their adsorption capacities, the minimum thickness needed for adsorption, their particulate filtration efficiencies and their pressure drop. rnAdsorption measurements are realized by using toluene as pollutant at an upstream concentration of 10 ppm and for a relative humidity rate of 14 %. Different numbers of layers of media are tested, for six different medias, at a frontal velocity of 0.5 m.s~-1. Particulate filtration measurements are performed on four different medias by using aluminum oxide particles of diameter ranging from 0.2 to 9 μm as pollutant. These particles are generated at a concentration of 2600 particles.cm~-3, for a frontal velocity of 0.5 m.s~-1 and a relative humidity rate of 45 %. rnFrom the results obtained, it appears that all the medias tested are good adsorbents, as their adsorption capacities (either at saturation or breakthrough time) are always higher than 200 mg.g-1. The minimum thickness of the woven medias tested (so that breakthrough is not immediate) is higher than the one of non-woven ones. Then, from particulate filtration measurements, it appears that the woven media tested is less efficient than non-woven medias, especially because of its ability to release particles. Non-woven medias present all similar good results, as their efficiency is about 80 % and their pressure drop is low. rnThus, in view of the results obtained both in adsorption and particulate filtration, it seems that non-woven medias are more interesting materials to be used in combined filtration, as they present good adsorption capacities and particulate filtration efficiencies for low minimum thickness and pressure drop.