Harnessing the potential of Epipremnum aureum (Pothos) for indoor air purification in botanical filters

Abstract

Air pollution and human exposure to poor air quality rank nowadays as the most serious environmental threats to public health worldwide. Botanical biofiltration using active green walls based on air-purifying plants can support an effective control of indoor air pollution. This study focuses on the design and evaluation of the performance of an active botanical filter for the removal of acetone, toluene and α-pinene at low concentrations using the houseplant Epipremnum aureum (commonly known as golden Pothos). The botanical filter was constructed with a vertical polyurethane foam wall supporting Pothos, and internal mineral salt medium and air recirculation. Maximum steady state removal efficiencies of 99.8 ± 0.8 %, 83.6 ± 7.3 % and 71.1 ± 5.2 % were recorded for acetone, α-pinene and toluene, respectively. The reduction in the gas recirculation flow rate through the wall from 36 to 0 L min-1 decreased the removal efficiency of α-pinene to 70.37 ± 1.72 %, while acetone and toluene maintained their removal efficiency under these conditions. Reducing the internal recirculation rate of the nutrient medium from 1.50 to 0.95 L min-1 and the absence of Photos in the polyurethane wall of the biofilter also decreased the pollutant abatement efficiency of the botanical filter. In addition, the analysis of the microbial community composition revealed significant differences in microbial composition and differences in the relative abundances between liquid samples of the medium in which the plant species grew and the mineral salt medium recirculated across the biofilter, which might contribute to the pollutant removal mechanisms.