| A Study of Purification of NOx in Polluted Air
Using the Soil Filtering Method |
 |
| - The Experiments of Purification of Polluted Air at Osakabashi, Meguro Ward, Tokyo - |
| Satoshi OYANAGI *1, Yuichi HIGUCHI *1, Masako
ITO *1 and Takamichi SOEJIMA *2 |
| A study of purification of NOx in polluted air
using the soil filtering method, as the purification method of polluted air
in city areas in these years, has been examined. Nitrogen dioxide NO2 can be
removed by dissolving into soil moisture; however, nitrogen oxide NO is difficult
to be dissolved into soil moisture. Therefore, the activated carbon layer to
adsorb nitrogen oxide is set onto the soil layer. The latest results shows
the removal rate in NO2 is nearly 100% and that in NO is 60 to 70% respectively
at the flow rate of 100 m3/hr per unit area. SPM can be absorbed in soil and
the removal rate is 70 to 90%. In addition to that, special oxidizing materials
has been examined to maintain purification of NO for long period and the result
of the ability to oxidize NO was confirmed. Higher cost peformance will be
achieved in near future. The future study includes confirmation of purification
of NOx at the faster flow rate than the present method and confirmation of
the maximum flow rate while maintaining microbial decomposition. |
| keywords: |
nitrogen oxides, soil filtering,
activated carbon, microbial decomposition, oxidizing materials |