Investigations on Chlorophytum comosum ability to remove toluene from air in a closed environment

Abstract

Plants play a major role in bioregenerative systems for air and water
supplies. They may also contribute to the removal of volatile organic
compounds (VOC) from the air in a closed environment, based on the
ability to absorb toxic compounds and to detoxify them. The aim of our
work was to study the capabilities of Chlorophytum comosum for toluene
removal and to identify the main parts of the plants which are
responsible for the elimination. A 1-m3 sealed chamber was
designed and built in 8-mm window glass assembled with UV-polymerized
glue. It was equipped with one internal fan for air mixing. The other
materials (low-emitting and low-adsorptive) were aluminium and PTFE. A
cooling system was also used to regulate humidity content which was
monitored continuously as well as temperature and carbon dioxide
concentration. Experiments were carried out in this chamber with
Chlorophytum comosum plants exposed to an initial concentration of
11.5x103 μg toluene m-3. Pollutant
concentration was measured every five minutes during several days.
Toluene removal was studied in various configurations (potting media,
hydroponic conditions{ldots}) in order to document the level of
contribution of each component (leaves, roots, microorganisms and soil)
of the potted plants. Results show that 54 % of toluene was removed in
72 h with the whole potted plant. A large participation of the soil in
the purification process was noticed whereas foliage seemed to have
little effect at the light intensity used in the experiments. Moreover,
the tests realized with both natural and sterilized soils suggest that
soil bacteria (in potting media) play a significant role in the removal
process showing that soil and its microorganisms may have complementary
roles in the elimination phenomena. Detoxifying function of potted
plants could find current applications in improving air quality, in
particular indoor air from domestic buildings.