摘要 |
<p>Sewage treatment apparatus comprising tank means (10), inlet means (25) of the tank means (10) to pass sewage into the tank means (10) and outlet means (27) thereof to pass effluent out of the tank means (10) on successive occasions. Aeration means (72) serve to aerate a biomass contained within the tank means (10) when the apparatus is in use. Economy mode switch means are connected to the aeration means (72) to switch operation of latter into an economy mode, in which the length of time of aeration of the biomass in the tank means (10) is reduced, in the event of a lack of flow of sewage into the tank means (10) through the inlet means (25). <IMAGE></p> |