DE1459453C - Sewage treatment plant - Google Patents

Description

at the central overflow to the secondary clarifier C or again, closing the circle, runs to the nozzles d .

The return sludge is pressed from the secondary clarification tank C by means of a pump e ' via a water jet suction device c and a distributor ring g to nozzles d'. In this way, the circulating flow caused by the nozzles d is further intensified. In particular, the air carried along with the flow is intensively mixed with the activated sludge. If strong foam formation occurs as a result of detergents, this can be kept down by spraying with raw water from sprinkler devices /. The nozzles d and d ' are arranged offset in such a way that a uniform bottom flow is formed radially from the center to the pool wall.

If the oxygen introduced in aeration basin B is not yet sufficient, additional air can be introduced into the water via aeration devices α , in a direction that deviates by about 30 to 45 ° from the horizontal and 40 to 90 ° from the radial. The ventilation devices α can consist of air blowers. However, it has also proven to be useful simply to stir additional air into the aeration basin B using stirrers. The special inclination of this

ίο stirrer or this air blower leads to a helical flow of the basin contents, making air, activated sludge and waste water particularly be mixed intensively.

The clarified and cleaned wastewater runs off at E , the excess sludge and the fresh sludge from primary clarification tank A, which are further treated in the usual way, at F.

1 sheet of drawings

Claims (2)

Patent claims: I. Sewage treatment plant with a round aeration basin, to which the sewage continuously is fed and in which a central overflow is arranged, from which the wastewater in a Secondary clarifier, which is connected to the aeration tank by a delivery line, increasing concentration equalization of the constituents of the wastewater on its way to the central drain achieved. The disadvantage of this known system is that by dividing the ventilation basin into different loading zones the volume load over the entire tank contents not evenly is distributed and the utilization of the oxygen introduced is not very good. The invention is therefore based on the object through which the return sludge under pressure in i ° a wastewater treatment plant of the type mentioned the aeration basin is introduced distributed, characterized in that "the wastewater is fed under pressure to the aeration basin (B) and in the pressure line of the wastewater feed and return sludge feed at least one water jet suction device (b, c) above the water level of the aeration basin (B) to suck in the for biodegradation air required, and in that for the discharge of the waste water and the return sludge in the bottom portion of the aeration basin (B) nozzles (d, d ') are arranged such that on the bottom of the aeration basin (B) has a radially against the pool wall directed ^ circulating flow arises. 2. Sewage treatment plant according to claim 1, characterized in that additionally ventilation devices (a) are arranged on the water level surface, the air in one direction to be designed in such a way that even space loading and ventilation of the entire pool contents of the aeration basin and the oxygen introduced is better used. This object is achieved according to the invention in that the wastewater under pressure the aeration basin is supplied and in the pressure line of the Wastewater feed and return sludge feed at least one water jet suction device above each the water level of the aeration basin to suck in the elements required for biodegradation Air is arranged and that for the exit of the sewage and the return sludge in the bottom area of the aeration basin nozzles are arranged such that above the bottom of the aeration basin a circulating flow directed radially against the pool wall is created. This has the advantage that as a result the even space load the ventilation about 30 "to 45 ° from the horizontal and 40 ^{; j} 30 basin deviates up to 90 ° from the radial for a given wastewater pollution load, into which smaller can be dimensioned and thus smaller poisoning basins (B) blow factory According to the state of the art. Due to the even ventilation of the entire pool contents, the Volume load capacity increased and through the ventilation already taking place in the pressure pipe system known water jet aspirators, the O., - Increased yield from the introduced air. As a result of the high The invention relates to a sewage treatment plant with load capacity of the aeration basin can not only a round aeration basin, which the wastewater 4c reduces the construction volume for the biological stage is continuously fed and in which a zen are; also for mechanical primary clarification Overflow is arranged, from which the wastewater generally suffice very short residence times enters a secondary clarifier, which takes 10 to 12 minutes with the aeration. processing basin is connected by a delivery line, In a further development of the invention are at the by means of which the return sludge under pressure into the 45 water level surface is additionally aeration pre-aeration basin is initiated distributed. arranged in one direction, the air in one direction, In a known sewage treatment plant of this type
The sewage and the return sludge are supplied in different zones of the aeration basin., The return sludge is thereby tangled
tially on the inside of the outer wall of the round aeration basin in an outer charging zone arranged concentrically to the drain. In this way, a circular flow component arises in the aeration basin, the aeration basins and secondary clarification basins and, with the radial FIG. 2 striving towards the central drain, a top view of the aeration basin Flow component a horizontal spiral according to Fig. I. flow causes. To the loading zone for the organically polluted, domestic or Return sludge closes in the direction of the industrial wastewater, the charging zone for the wastewater 60 in the primary clarification tank A enters through an inflow line D in the middle of the basin. From there it promotes a pump that is fed to aeration basin B above the water level surface of this zone, evenly distributed over the water. Above the professional ejector b , the wastewater is enriched with atmospheric oxygen, the aeration basin is air-enriched and distributed through nozzles d radially from the center, which cause the aeration basin B to circulate vertically against the basin wall. Through 65 pushes. A circulating flow is formed, which is the superposition of the horizontal spiral flow from the nozzles d over the bottom of the ventilation. With the vertical circulating flow, next to the basin B to the basin wall, there is deflected after aeration as a result of mixing a gradually flowing up and back on the surface, which deviates about 30 to 45 "from the horizontal and 40 to 90 ° from the radial, into the aeration basin blow in. An embodiment of the system according to the invention is explained in more detail with reference to the drawing. It shows Fig. 1 is an axial section through a sewage treatment plant according to the invention with primary clarifier,