The evolution of botanical biofilters: Developing practical phytoremediation of air pollution for the built environment

Abstract

Indoor air quality is of emerging importance due to the rapid growth of urban populations that spend the majority of their time indoors. Amongst the public, there is a common perception that potted-plants can clean the air of pollutants. Many laboratory-based studies have demonstrated air pollution phytoremediation with potted-plants. It has, however, been difficult to extrapolate these removal efficiencies to the built environment and, contrary to popular belief, it is likely that potted-plants could make a negligible contribution to built environment air quality. To overcome this problem, active green walls have been developed which use plants aligned vertically and the addition of active airflow to process a greater volume of air. Although a variety of designs have been devised, this technology is generally capable of cleaning a variety of air pollutants to the extent where comparisons against conventional air filtration technology can be made. The current work discusses the history and evolution of air phytoremediation systems from potted-plants through to practical botanical air filtration.