| 摘要 |
<p>The biological filter (8) comprises a granular bed including a layer (17) based on active carbon in which the material satisfies the following conditions:… - density of between 0.18 and 0.32 g/cm<3>,… - carbon tetrachloride adsorption capacity of between 60% and 120% bypweight,… - carbon tetrachloride retention lower than 25% by weight of the adsorbed mass of carbon tetrachloride,… - methylene blue: between 5 and 30 ml,… - particle size range: between 0.5 and 1.5 mm of effective size with a uniformity coefficient lower than 2. …<??>A washing cycle (21, 24) (air alone; air + water; water alone) of this filter is triggered (38) when a value (36, 37) which is representative of the algal population of this layer reaches a predetermined set threshold. …<IMAGE>… </p> |
