Earth Air Purification (EAP)

As traffic volumes increase, so urban air quaility deteriorates - particularly along main roads and highways, and at busy intersections. Although the long-term solution is reduction of traffic levels through improved public transportation, in the short term the most pressing need is to reduce levels of atmospheric pollutants. In this case, Fujita's Earth Air Purifiers (EAPs) provide a new and innovative solution.

the technology

EAPs are an environmentally-friendly way of improving urban air quality by taking advantage of naturally-occuring biological and biochemical processes. EAPs pump polluted air into a wind tunnel under specially-designed 'gardens'. As the air passes through the soil (and through the root-zone of the plants in the bed) physical, biochemical and biological processes combine to remove pollutants from the air stream.

EAP schematic

EAPs are suitable for installation in many urban environments, including at busy road intersections, above underground car parks and road tunnels, and at airports. In addition to improvements in local air quality, such installations also replace urban 'dead space' with visually-attractive greenery.

The performance of our EAPs have so far been very encouraging. On an annual basis Fujita's eight Japanese pilot plants have been shown to remove more than 80% of nitrogen oxides from polluted air. They also remove more than 90% of carbon monoxide, sulfur dioxide and suspended particulate matter, and more than 75% of non-methyl hydrocarbons.

current EAP projects

Project Type* Date Area (m2) Purified Air (m3/h)
1. Fujita Corporation HQ
U
12/1992
8
55
2. Higashiosaka City
R
10/1994
75
5,400
3. Higashiosaka City
R
10/1995
50
3,600
4. Adachi Govt Office
U
05/1996
110
8,000
5. Ashiya City
U
10/1996
80
5,760
6. Seishin New Town
U
03/1997
200
14,400
7. Suita City
R
03/1997
500
36,000
8. Hanna Tunnel
T
04/1997
400
28,800
9. Itabashi Govt. Office
R
07/1998
40
2,880 - 5,760
10. Kawasaki City
R
11/1999
500*
36,000 -72,000
11. Fujisawa City
P
10/2000
280*
20,600

*Type U= underground parking lot; Type R= roadside installation; Type T= road tunnel HVAC

more information

For more information about EAP, please contact us or download a brochure (1.2 MB, pdf format).

tried and tested

The success of Fujita's EAP technology in the field was not unexpected. Prior to deployment of EAP pilot plants, rigorous testing wascarried out at Fujita's Technical Institute.

laboratory set up
laboratory testing

Artificially polluted air passes through the soil layer, from the bottom to the surface at the speed of 10-30mm/sec and total flow volume is 60-180 l/min.

The figure below shows the monitoring apparatus used in the laboratory testing of the EAP process and in assessing the effectiveness of different soil mixes.

schematic of the system
Schematic of laboratory system