| 摘要 |
Waste water treatment appts. comprises a filter bed planted with nitrophilic aquatic plants. The filter bed comprises (a) an upper layer comprising coarse particulates (ranging from sand to gravel) and iron scrap, penetrated by inlet pipes; (b) an intermediate gravel layer; and (c) a lower layer of fine loamy soil provided with drainage pipes. The appts. also includes means for controlling the water level in the bed. ADVANTAGE - N cpds. in the waste water are nitrified in the aerobic upper layer and denitrified (with release of N2) in the anaerobic lower layer. These actions are promoted by the 'Rhizosphere effect' of the plant roots. The iron scrap promotes pptn. of phosphates and the bed also has a mechanical filtering action.
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