Patent ID: 6238562
Filing Date: 2001-05-29
Classification: C02F,Y02W

Abstract:
A process 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 under such conditions that an accumulation of sludge takes place in the treatment zone from which the treated waste water is withdrawn, characterized in that the treatment is carried out in the same undivided tank, and that the non-treated waste water is introduced into one end of the tank for a period which is sufficiently long for an accumulation of sludge to occur at the outlet end of the tank, whereafter the direction of flow is reversed, so that the non-treated waste water in a succeeding period is introduced at this end for a period which is sufficiently long for an accumulation of sludge to occur at the opposite end of the tank, at which end treated waste water is withdrawn.