Table 4.
A summary of active biofiltration studies that detail the removal of various VOCs from static chambers
| Study | Year | Pollutants | Starting concentrations | Plant species | Substrate information | Chamber volume | Removal rate/efficiency | Removal mechanism |
|---|---|---|---|---|---|---|---|---|
| (Wang and Zhang) | 2011 | Formaldehyde and toluene |
17 ppb formaldehyde and 2 ppb toluene |
E.aureum | 1.08 m2 | 54,400 L | 50.1–98.7% | Activated carbon and porous shale pebbles |
| (Wang et al.) | 2014 | Formaldehyde | 7.5–10 ppm; and 250 ppm | E.aureum | 1.08 m2 | 5,100 L | 39.5% (biofilter) | Activated carbon pellets and pebbles |
| (Lee et al.) | 2015 | PM, formaldehyde, o – xylene, xylene, ethylbenzene, toluene, benzene | Undisclosed | D. amoena | N/A | Undisclosed |
40% (PM10) 4% (PM2.5) 72% (xylene, ethylbenzene, toluene, and TVOC) ≥ 39% (benzene and HCHO) |
Soil |
| (Irga, Paull, et al.) | 2017 | Particulate matter | ~ 700; g.m−3 (TSP) | C. comosum | 0.25 m2 | 216 L |
53.5% (TSP) 53.51% (PM10) 48.21% (PM2.5) |
Coconut husk |
| (Pettit et al.) | 2017 | PM |
19.86 µg/m3 (PM0.3–0.5) 8.09 µg/m3 (PM5-10) 142.23 µg/m3 (TSP) |
C. orchidastrum, N. glabra, F. lyrata, N.bostoniensis, N.duffii, S.amate, S.arboricola | 0.25 m2 | 216 L |
Max removal; 45.78% (PM0.3 – 0.5) 92.46% (PM5-10) |
Coconut husk |
| (Ibrahim et al.) | 2018 | PM2.5, PM10 | Undisclosed | E. aureum | 0.14 m2 | 216 L |
Removal efficiency: 85% (TSP), 75.2% (PM2.5) and 71.9% PM10 CADR: 123 L.s−1 (TSP), 112.80 L. s−1 (PM2.5), 107.88 L. s−1 (PM10) |
Kenaf fibre |
| (Torpy et al.) | 2018 | Methyl ethyl ketone | 30 ppbv |
P.scandens, P.’brazil’ scandens, A.antiquum, and S.podophyllum |
1.5 m2 | 30,000 L | 56.60% | Inorganic growing media |
| (Pettit et al.) | 2018a | PM, VOCs |
~ 500 – 600 ppb (VOCs) N/A (PM) |
N.bostoniensis | 0.25 m2 | 216 L |
25.66% higher removal than soil treatment for benzene ~ 78% SPRE (ethyl acetate) |
50:50 (coconut husk to granular activated carbon) |
| (Hung et al.) | 2019 | CO2, formaldehyde, PM10 | Undisclosed | N. exaltata | 0.38 m2 | 1400 L |
Removal capacity: 88.2% (PM10), 62.2% (PM2.5), 13.9% (CO2), 60.4% (formaldehyde) |
Undisclosed |
| (Paull et al.) | 2019 | PM, VOCs, CO2 | Undisclosed | 6 Australian native species | 0.25 m2 | 216 L |
SPRE: 59.04% (Benzene), Australian native plants are less effective for PM and CO2 removal, compared to common ornamental indoor plants |
Coconut fibre-based substrate |
| (T Pettit et al.) | 2019 | PM, VOCs (from lavender oil) |
300 ppbv (TVOC) 101.18 µg m−3 (TSP) |
N.exaltata, P.obtusifolia, S.arborcola, S.wallisii | 9m2 | 120,200 L |
~ 28% over 20 min (TVOC) 42.6% over 20 min (TSP) |
Coconut husk |
| (Thomas Pettit et al.) | 2019 | Nitrogen dioxide, ozone |
6.656 ppm (NO2) 7.280 ppm (O3) |
S.wallisii S.podophyllum |
1.06 cm2 0.901 cm3 |
900 L (flow reactor internal volume) |
CADR (m3 ·h −1 ·m−3 of biofilter substrate) 661.32 and 95.04 (S.wallisii) 550 and 23 (S.podophyllum) for NO2 and O3 |
Coconut husk |
| (Elkamhawy and Jang) | 2020 | PM10, PM2.5 | undisclosed | Vegetation (grass or moss), engineering soil and porous material | 7 m in height |
In-situ outdoor |
78.5% reduction for PM2.5, 47% reduction for PM10 |
Vegetation soil, engineered soil, porous material |
| (Pettit et al.) | 2020 | NO2, O3 and PM2.5 | 5-min ambient averages of 178.6 ppb, 59.4 ppb and 774.7 µg/m3 (NO2, O3, and PM2.5 |
W.fruticosa, M.parvifolium, S.anisophyllus and N.domestica |
5 × 20 m2 | in-situ outdoor |
SPRE (average); 63.17%, 38.79% and 24.84% (for NO2, O3, PM2.5 |
Coconut husk |
| (Siswanto et al.) | 2020 | Formaldehyde, acetone, benzene and xylene |
120–150 ppm (formaldehyde) 127–145 ppm (acetone) 15–35 ppb |
S.trifasciata C.comosum |
500 cm2 | 24 m3 | 80–90% (TVOC) | 1:1 mix of soil (40:50% clay, 25–30% silt and 25–30% sand) and coconut coir |
| (Ibrahim et al.) | 2021 | PM2.5, PM10 and TVOC | ~ 18–25 mg.m−3 | E.aureum | 0.05 m3 | 240 L |
Removal efficiencies: 54.5 ± 6.04% (PM2.5) 65.42 ± 9.27% (PM10) 46 ± 4.02% (VOC) |
Kenaf fibre |
| (Suárez-Cáceres et al.) | 2021 | TVOC and n- hexane | 5.69–7.51 mg.m−3 | N.exaltata L | 2 X 0.18 m2 | 128 L |
Reduction rate: 0.17 and 0.1 mg.m−3 h |
Mixture of coconut fibre and peat |
| (Pettit et al.) | 2021 | NO2, O3 and PM2.5 | N/A | M.parvifolium, S.anisophyllus and N.domestica | 5 × 20 m2 | in-situ outdoor |
SPRE (average); 71.5%, 28.1%, 22.1% (NO2, O3, PM2.5) |
Coconut husk |
| (Abedi et al.) | 2022 | Formaldehyde | 0.3 – 2 ppm |
Epipremnum aureum (4 per modules), Syngonium podophyllum (4 per modules), Chlorophytum comosum (4 per modules), Peperomia obtusifolia (2 per modules), Pilea cadierei (1 per modules), and Aglaonema treubii (1 per modules) |
0.25 m2 | 50 L |
SPRE range 47.05—99.99% in all systems CADR 17.6 m3/h |
Granular activated carbon, leca and commercial pot soil |
| (Morgan et al.) | 2022 | Environmental tobacco smoke (ETS), all size fractions of PM | Full cigarette over 8 min (35 mL puff volume with 1 puff per min) | S.wallisii | 0.25 m2 | 216 L |
SPRE; 43.26% TVOC 34.37% TSP |
Coconut husk |
| (Permana et al.) | 2022 | PM1, PM2.5, PM10, formaldehyde and acetone from tobacco smoke |
2.9–3.0 mg.m−3 (PM1 and PM2.5) 3.6–3.7 mg.m−3 (PM10) 123–148 mg.m−3 (Formaldehyde) 9.5–12 mg.m−3 (acetone) |
S. trifasciata | 0.05 cm3 |
24,000 L (Testing room) |
Removal of PMx over 8 h; 140–250 µg m−3 (PM1) 147–257 µg m−3 (PM2.5) 212–455 µg m−3 (PM10) Removal efficiency over 24 h; 45–69% (formaldehyde) 31–61% (acetone) 40–65% (TVOC) |
1:1 mix of soil and coconut coir |
Table includes pollutant type, starting concentration, plant species used, size of the active botanical biofilter, room or chamber volume study was conducted in, the efficiency of the system for each pollutant and substrate information
TVOC total volatile organic compounds; CADR clean air delivery rate; SPRE single pass removal efficiency