| Author: | Mak, Cheuk-man |
| Title: | Efficiency of activated charcoal to remove indoor radon |
| Degree: | M.Sc. |
| Year: | 1998 |
| Subject: | Radon -- Safety measures Carbon, Activated Indoor air pollution Radon Hong Kong Polytechnic University -- Dissertations |
| Department: | Multi-disciplinary Studies Department of Building Services Engineering |
| Pages: | vii, 162 leaves : ill. ; 31 cm |
| Language: | English |
| Abstract: | Long exposure to environment with high indoor radon level might cause lung cancer of the occupants. Adsorption by activated charcoal as a way to reduce indoor radon was studied. Three types of activated charcoal purchased from the aqua and chemical shops were tested. They were spherical, cylindrical and irregular in shape. Several tests were performed on the activated charcoal. It included moisture adsorption test, pilot chamber test and a full scale test conducted in an emission free chamber located in laboratory F002 of the department. Special design filter racks with two different sizes were made. One could hold about 100g activated charcoal while the other could hold about 800g activated charcoal. Cylindrical type activated charcoal had the highest water and radon adsorption capacity in the moisture adsorption test and pilot chamber test respectively. It was reasonable to believe that there were more activated sites in the 'cylinder' type charcoal so it had the highest adsorption capacity among the other samples. In the full scale test done inside the emission free chamber, both the spherical and irregular type activated charcoal had little effect to reducing radon level. For the cylindrical type activated charcoal, radon concentration inside the chamber was reduced from 55 Bq/m3 to 35 Bq/m3 after 24 hour test, while the relative humidity was reduced from 80% to 60% inside. It is concluded that the practical application of activated charcoal to adsorb indoor radon in high relative humidity was limited. A mathematics model developed by other was verified. For the small filter pilot test, the actual performance was about 50% that predicted by the model. For the large filter rack at 0.2 m/s and 0.3 m/s bed facing velocity, the actual performance were about 50% and 20% that of predicted values respectively. No comparison was made for large filter rack in full scale test held inside the emission free chamber. |
| Rights: | All rights reserved |
| Access: | restricted access |
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| File | Description | Size | Format | |
|---|---|---|---|---|
| b14418757.pdf | For All Users (off-campus access for PolyU Staff & Students only) | 5.47 MB | Adobe PDF | View/Open |
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