摘要 |
<p>A process and an apparatus for biological purification of waste water by the activated sludge method, wherein the waste water is continuously passed through one or more treatment zones and a clarification zone in the same tank under such conditions that an accumulation of sludge occurs in the treatment zone from which the treated waste water is withdrawn, and wherein the direction of flow through the tank is reversed, so that the non-treated waste water, after accumulation of sludge has occured at the outlet end of the tank, in a succeeding period, is introduced at this end, and treated waste water is withdrawn at the opposite end.</p> |