NY07018 - Towards Improving Indoor Air Quality with Pot -Plants — A Multifactorial

International research (including that at UTS) has shown indoor plants can reduce all types of urban air pollution. The aims of this project have been threefold:
-to investigate the effect of pot size on the capacity of pot-plants to reduce concentrations of volatile organic compounds (VOCs), a major class of outdoor and indoor air pollution;
-to characterise the potting mix bacteria which are the primary VOC removal agents (plants nourish their root-zone bacteria a mutualistic relationship at work); and
 to initiate testing of CO2 reduction by indoor plants.
Key outcomes:
-Our results, with three species, showed that for VOC reduction, three 125 mm pots are as effective as one 200 mm pot; and one 200 mm pot is as effective as a 300 mm pot.
- Applications: The results show the very high capacity for pot-plants to remove VOCs. The findings allow for more flexibility in interiorscapes, eg with towers or clusters of small plants interspersed among larger pots.
-Our tests on potting mix of Spathiphyllum have provided the first-ever community physiological profile of the VOC-removing bacterial consortium, and tracked changes in that community as the result of exposure to a VOC.
-Applications: The results confirm the mechanism by which VOCs are biodegraded, so the ability of indoor pot-plants to perform this role can be promoted with confidence.
-The preliminary studies on plant CO2 removal in the office habitat showed that they can adapt to the very low light levels for CO2 reductions, but respiration of roots and potting mix must be taken into account in assessing effectiveness.
- Applications: Indoor plants should be placed according to shade tolerance; they can acclimatise to prevailing lighting for CO2 reduction.
Much more research is needed in this area. It should also be directed to comparative studies of VOC and CO2 reductions of plants in hydroculture which is becoming more standard overseas and likely to become so in Australia. Indoor plants have the potential to reduce the energy consumption of air-conditioning and hence the C-imprint of the city, for sustainable urban living.