Potted-plant/growth media interactions and capacities for removal of volatiles from indoor air

Results are presented of an investigation into the capacity of the indoor potted-plant/growth medium microcosm to remove air-borne volatile organic compounds (VOCs) which contaminate the indoor environment, using three plant species, Howea forsteriana (Becc. (Kentia palm), Spathiphyllum wallisii Schott. 'Petite' (Peace Lily) and Dracaena deremensis Engl. 'Janet Craig'. The selected VOCs were benzene and n-hexane, both common contaminants of indoor air. The findings provide the first comprehensive demonstration of the ability of the potted-plant system to act as an integrated biofilter in removing these contaminants. Under the test conditions used, it was found that the microorganisms of the growth medium were the rapid-response agents of VOC removal, the role of the plants apparently being mainly in sustaining the root microorganisms. The use of potted-plants as a sustainable biofiltration system to help improve indoor air quality can now be confidently promoted. The results are a first step towards developing varieties of plants and associated microflora with enhanced air-cleaning capacities, while continuing to make an important contribution to the aesthetics and psychological comfort of the indoor environment.