Phytoremediation of benzene vapors from indoor air by Schefflera arboricola and Spathiphyllum wallisii plants

Pettit

et al. 2019

Environ Sci Pollut Res

Volatile organic compounds (VOCs) are of public concern due to their adverse health effects. Botanical air filtration is a promising technology for reducing indoor air contaminants, but the underlying mechanisms are not fully understood. This study assessed active botanical biofilters for their single-pass removal efficiency (SPRE) for benzene, ethyl acetate and ambient total volatile organic compounds (TVOC)s, at concentrations of in situ relevance. Biofilters containing four plant species (Chlorophytum orchidastrum, Nematanthus glabra, Nephrolepis cordifolia 'duffii' and Schefflera arboricola) were compared to discern whether plant selection influenced VOC SPRE. Amongst all tested plant species, benzene SPREs were between 45.54-59.50%, with N. glabra the most efficient. The botanical biofilters removed 32.36-91.19% of ethyl acetate, with C. orchidastrum and S. arboricola recording significantly higher ethyl acetate SPREs than N. glabra and N. cordifolia. These findings thus indicate that plant type influences botanical biofilter VOC removal. It is proposed that ethyl acetate SPREs were dependent on hydrophilic adsorbent sites, with increasing root surface area, root diameter and root mass all associated with increasing ethyl acetate SPRE. The high benzene SPRE of N. glabra is likely due to the high wax content in its leaf cuticles. The SPREs for the relatively low levels of ambient TVOCs were consistent amongst plant species, providing no evidence to suggest that in situ TVOC removal is influenced by plant choice. Nonetheless, as inter-species differences do exist for some VOCs, botanical biofilters using a mixture of plants is proposed. Keywords Air pollution; botanical biofilters; phytoremediation; green walls; VOCs 'active green walls', which utilise mechanical assistance to funnel air into the biofilter substrate, improves their bioremediation efficiency to the extent that functional air remediation is probable (Torpy et al. 2015). These systems may also be practical for large infrastructure use, given that they are accessible, robust, cost-effective and have a low-energy footprint. Although the available types of botanical biofiltration systems differ in design, they all use active airflow facilitated with devices such as impellers that increase the airflow across or through the systems and therefore allow larger volumes of air to be processed by the biofilter. Whilst there is a growing body of literature that demonstrates the air pollutant remediation capabilities of this technology (Pettit et al. 2019), to date, the potential for plant selection to enhance botanical biofilters ability to filter some of the more dangerous air pollutants is required. Plant selection is known to have an influence on VOC removal efficiency for static, potted-plant systems (e.g. Kim et al. 2010). Whilst the nature of the plant characteristics that determine these effects have yet to be resolved, there may be phylogenetic associations where certain groups of plants are more effective for the removal of certain forms of VOC (Ki...

“…Alternatively, S. arboricola has been shown to have high benzene removal efficiency, which has been previously attributed to its relatively large leaf area (Parseh et al 2018),…”

Section: Discussionmentioning

confidence: 99%

Does plant species selection in functional active green walls influence VOC phytoremediation efficiency?

Pettit

et al. 2019

Environ Sci Pollut Res

“…VOCs from chambers over several hours (Liang et al 2018;Parseh et al 2018;Su et al 2018), the relatively short trial time in this experiment suggests that VOCs were most likely removed through adsorption processes as opposed to microbial degradation. Orwell et al (2004) found that the substrate microbial community's VOC removal efficiency improves with repeated exposure to multiple doses, and it is possible that considerably lengthening the experimental trial period, or testing the VOC removal of repeated VOC doses, may have provided improved removal rates.…”

Section: Discussionmentioning

confidence: 92%

The in situ pilot-scale phytoremediation of airborne VOCs and particulate matter with an active green wall

Pettit

Torpy

2018

Air Qual Atmos Health

Atmospheric pollutant phytoremediation technologies, such as potted-plants and green walls, have been thoroughly tested in lab-scale experiments for their potential to remove air pollutants. The functional value of these technologies, however, is yet to be adequately assessed in situ, in 'high value' environments, where pollutant removal will provide the greatest occupant health benefits. Air pollution in countries such as China is a significant public health issue, and efficient air pollution control technologies are needed. This work used pilot-scale trials to test the capacity of potted-plants, a passive green wall and an active green wall (AGW) to remove particulate matter (PM) and total volatile organic compounds (TVOCs) from a room in a suburban residential house in Sydney, Australia, followed by an assessment of the AGW's potential to remove these pollutants from a classroom in Beijing. In the residential room; compared to potted-plants and the passive green wall, the AGW maintained TVOCs at significantly lower concentrations throughout the experimental period (average TVOC concentration 72.5% lower than the control), with a similar trend observed for PM. In the classroom, the AGW reduced the average TVOC concentration by ~28% over a 20 min testing period compared to levels with no green wall and a filtered HVAC system in operation. The average ambient PM concentration in the classroom with the HVAC system operating was 101.18 µg/m 3 , which was reduced by 42.6% by the AGW. With further empirical validation, AGWs may be implemented to efficiently clean indoor air through functional reductions in PM and TVOC concentrations.

“…has been used in various studies for purifying indoor air by removing gaseous pollutants, such as volatile organic compounds, and particulate pollutants, such as PM 10 and PM 2.5 . It has also been studied for improving indoor temperature and humidity (Hörmann et al, 2018;Kwon and Park, 2018;Parseh et al, 2018).…”

Section: Methodsmentioning

confidence: 99%

Efficiency of Spathiphyllum spp. as a plant-microbial fuel cell

Kwon

Park

2021

Ornam. Hortic.

The purpose of this study was to investigate the utility of an ornamental plant, Spathiphyllum spp., as a plant-microbial fuel cell (Plant MFC) to produce voltage and current. This study also evaluated the effect of the Plant MFC on water use efficiency and plant growth. The experiment used four experimental groups: used MFC without plant (Soil MFC), used MFC with plant (Plant MFC), unused MFC without plant (Soil Pot), and unused MFC with plant (Plant Pot). Plant MFC generated higher voltage and current levels than Soil MFC. The average voltage of Plant MFC and Soil MFC was 0.475 V and 0.375 V, respectively, and the average current was 0.110 mA and 0.030 mA, respectively. Plant MFC using Spathiphyllum spp. produced a constant voltage output, with a deviation of 0.027 V during the four-month indoor experiment. The difference between the maximum and minimum voltage during the day was as small as 0.015 V, which supports the utility of Plant MFC as a stable power source. Volumetric soil moisture content, chlorophyll fluorescence (Fv/Fm), photosynthesis rate, leaf area, fresh weight, and dry weight of Plant MFC and Plant Pot were measured. There was no significant difference in any values, and volumetric soil moisture and plant growth were not affected by the utilization of Plant MFC. Thus, a Plant-MFC using Spathiphyllum spp. can play the same ornamental role as conventional plants and at the same time be used as a sustainable bioelectricity source.