Physiological Investigations of the Plants Involved in Air Biofiltration: Study Case

In this study, the behavior of an aerial plant (Tillandsia xerographica) during air biofiltration was investigated by monitoring the trend of the CO2 concentration in the processed air as a response to a change in the environmental conditions. In this regard, a botanical biofilter equipped with T. xerographica was continuously operated with ambient air for about three weeks under different light intensity, air flow rate, ambient temperature, and relative humidity. The plant was able to decrease the CO2 concentration in the processed gas in both the presence/absence of light, as long as a regular alternate day/night regime was kept, this behavior being attributed to its specific plant metabolism. Overall, plant physiology under the influence of the above mentioned factors is pointed out, which in turn reveals the plant potential in urban air biofiltration, with the possibility to further address not only the carbon dioxide removal but also other trace gaseous contaminants in ambient air as well, improving the air quality and reducing the health risks associated with exposure to polluted air. Therefore, further modeling and optimization of this process, along with the investigation of the plant's response under different contaminated environments, is expected to significantly contribute to the development of new such versatile biofilters for air treatment.