Research into acetone removal from air by biofiltration using a biofilter with straight structure plates

Figures & data

Figure 1. Chart of an air cleaning biofilter having a straight plate internal structure and capillary system for packing material humidification: side-view (a), view from above (b), view of biofilter cartridge (c), composition of the plate (d).

Note: 1 – polluted air duct; 2 – valve; 3 – ventilator; 4 – a thermal regulator; 5 – sensor; 6 – sampling holes; 7 – fixation elements; 8 – temperature sensor; 9 – tank; 10 – controllable valves; 11 – supply hose; 12 – controllable valves; 13 – clean air duct; 14 – biomedium heating element; 15 – perforated plate; 16 – biofilter cartridge; 17 – channel air heater; WL – water level, WB – wood fiber, NWCM – not-woven caulking material, LPP – linear polymer plate.

Table 1. Composition of aqueous biomedium.

Substance	Amount (g)
K2HPO4	1
KCl	0.5
MgSO4⋅7H2O	0.5
FeSO4⋅7H2O	0.1
NaNO3	0.9
Distilled water	1000

Table 2. Biofilter operating conditions.

Filtering medium	Wood fiber
Pollutant	Acetone
Cartridge dimensions	900 × 200 × 200 mm
Inlet concentration	0.025–0.997 g m^−3
Airflow rate	3.4 m^3 h^−1
Residence time	11.2 s

Table 3. Operating sections of the biofilter.

Section	Gas flow rate (m^3 h^−1)	Empty bed residence time EBRT (s)	Time (days)	Inlet concentration (g m^−3)
A	3.4	11.2	1–10	0.025–0.277
B			10–12	0.296–0.310
C			12–13	0.451
D			13–14	0.634
E			14–15	0.997

Figure 2. Structure of the birch fibre: 150 times magnification (a), 1000 times magnification (b).

Figure 3. Medium pH and temperature during the time of passage of air polluted with acetone vapour through the biological packing material composed of wood fibre.

Figure 4. The humidity and temperature of the airflow during the cleaning and the humidity of the biological packing material.

Figure 5. Relationships between the biofilter's air cleaning efficiency and concentration of the pollutant supplied to the biofilter when straight plates and packing material composed of wood fibre are used.

Figure 6. The amount of micromycetes, yeasts and bacteria (CFU g⁻¹) when using straight plates and packing material composed of wood fibre (treated pollutant – acetone).

Figure 7. Bacteria composition by species.

Note: 1 – bacteria of the species Bacillus subtilis, 2 – bacteria of the species Staphylococcus aureus, 3 – bacteria of the genus Rhodococcus sp.