SU977405A1 - Apparatus for purifying effluents with active silt - Google Patents

Description

(54) DEVICE FOR CLEANING WASTE WATERS BY ACTIVE SILM

This invention relates to the biological treatment of domestic and industrial wastewater with activated sludge.

Sewage treatment plants with activated sludge are known that contain an aeration tank. with ejector aerators installed in it, connected to the discharge port of the circulation pump, the suction pipe of which is introduced into the lower part of the receiving tank, equipped with the pipeline of raw sewage and connected to the aeration tank by the overflow pipe. At the same time, the ejection injection of air is carried out by a working stream consisting of untreated sewage and sludge mixture G1. The disadvantage of the device is a decrease in the efficiency and effectiveness of the cleaning process caused by the introduction of return sludge from the secondary settling tank into the aeration tank, and the ejector, the contents of rotenum a are relatively slow, resulting in the contact of active microorganisms performing purification with incoming contaminants and oxygen dissolved in water not fully baked. In addition, the return of activated sludge from secondary sedimentation tanks requires the use of additional pumping means, which causes an increase in energy consumption.

It is also known a device for purifying wastewater with activated sludge, containing an aerotank with 10 ejector aerators installed in it, connected to the discharge port of a circulation pump, the suction pipe of which is introduced into the lower part of the receiving tank, provided with 5 pipelines of untreated waste water and connected to aerotank overflow pipeline, as well as a secondary settling tank and return sludge pipeline. In this case, the ejection inlet of air is carried out by a working stream consisting of untreated sewage water, sludge mixture and return sludge C23.

The drawback of the device is

25 in reducing the efficiency of the cleaning process caused by the deterioration of the sedimentation properties of return sludge due to the crushing of sludge cotton first in the cochlea of the pump, and behind the 30 in a single-stage ejector, which entails the need for a coagulator to restore the sludge structure. In addition, increasing the concentration of contaminants in wastewater requires a significant increase in the volume of the aeration tank, which significantly reduces the economic use of this device. The purpose of the invention is to increase the efficiency of the cleaning process and improve economic performance. The goal is achieved by the fact that the ejector aerators are two-stage with connecting the second stages to the return sludge pipeline, in addition, the device is equipped with a flow stabilizer installed coaxially in a cylindrical receiving tank, which is located below the aerotank, while the overflow pipe is coaxially aligned flow regulator and with a gap between them, and the raw sewage piping and suction pipe are tangentially connected to the stub or to the flow dispenser and receiving tank. FIG. 1 shows the proposed device, a general view; in fig. 2 ejector aerator. The device includes pipeline 1 of untreated waste water, flow stabilizer 2, receiving tank 3, aeration tank 4, overflow pipe 5, pump b, ejector aerators 7, inlet pipes 8 and 9, working flow of the first and second stages, air pipes 10, inlet Returning sludge nozzles 11, first and second stage nozzles 12 and 13, first and second diffusers 14 and 15, connecting pipes 16 and 17, sockets 18, return sludge pipeline 1, secondary clarifier 2 O. The device works as follows. Sewage water through pipeline 1 of untreated sewage tangentially attached to the upper part of the flow stabilizer 2, is fed into the receiving tank 3. During the minimum inflow hours when the level B is lowered in the receiving tank, or erotank 4 through the overflow pipe 5 through the flow stabilizer by gravity flow enters the silt mixture, thus ejecting atmospheric air. The air mixture, after passing through the constriction of the flow stabilizer, enters its lower expanding part, where the separation of the liquid and air bubbles begins. Bubbles of air, which rises upward, meet in the constricted part of the flow stabilizer a downward flow of liquid, which breaks them up and prevents them from reaching the surface, due to which additional aeration of the liquid takes place. In the receiving tank, stirring of the activated sludge and wastewater coming out of the flow stabilizer is achieved by air bubbles enveloping the lower edge of the flow stabilizer and rushing up, as well as by creating a rotational motion of the liquid in the cylindrical receiving tank as a result of tangential flow and drainage fluid. Thus, already in the receiving tank, an initial decrease in organic pollution of sewage occurs. Next, the pump 6, the suction pipe of which is tangentially attached to the receiving tank, the sludge mixture is fed to the first stages of two-stage ejector aerators 7, consisting of supply pipes of the first and second stages, air pipes 10, supply pipes of return sludge , nozzles 12 and 13 of the first and second stages, diffusers 14 and 15 of the first and second stages, connecting pipes 15 and 17, and sockets 18. The working flow, having passed the first stages of ejector aerators and carrying out a tray of atmospheric air ha, through the air nozzle 10 enters into the second stage. Due to the vacuum created by the residual kinetic energy of the working stream, return sludge is drawn through the return sludge conduit 19 from the secondary settling tank 20 via the return sludge nozzle 11. This makes it possible to preserve the sludge structure and at the same time, using the kinetic energy of the flow, to achieve the elimination of the cost of forcibly feeding return sludge from the secondary settling tank to the aeration tank. The possibility of preserving the silt structure is illustrated as follows. Since the degree of sludge crushing is proportional to the kinetic energy of the working stream, it is technologically feasible to eject return sludge at the minimum flow rates of the working stream. At fluid flow rates through the first stage nozzle of the order of 15 m / s (12-18 m / s) and the flow rate of the second stage through the second stage nozzle of the order of 5 m / s (5-6 m / s), the kinetic energy proportional to the square of the speeds decreases by 9 times, which is quite enough to preserve the sludge structure. The present invention allows, on the one hand, to reduce ne

Claims (1)

• Claim A device for treating wastewater with activated sludge, comprising a receiving tank with an untreated water pipe, an overflow pipe and a circulation pump, an aeration tank with ejector aerators and a sump with a return sludge pipe, which is different. 20 in that, in order to increase the efficiency of the cleaning process and improve its economic indicators, the ejector aerators are made two-stage with the second stages connected to the return sludge pipe, the receiving tank is installed below the aeration tank and equipped with a flow stabilizer, at. this overflow pipe is located above the stabilizer and coaxially with it and the receiving tank, the raw water pipe is connected tangentially to the flow stabilizer, and the suction pipe of the circulation pump is connected tangentially to the receiving tank.