BG66054B1 - Sewage treatment plant - Google Patents

Abstract

The sewage treatment plant comprises a two-wall version of a vertical cylindrical activated sludge tank (1), the two parallel dividing walls (4) of which are located in its central part and define the central part (5) of the sewage treatment plant for the aerobic stabilization of the activated sludge and, along with that, in the space between them and the outer wall (3) they create two functionalsymmetrically arranged areas for the sewage water and the treating cultures. Separate sedimentation tanks (6) of downward tapered section are situated in those two areas. A hollow cylinder (20) is located vertically along the axis of each sedimentation tanks (6). The hollow cylinders are connected through a cross intake duct (19) to the inner area of the activated sludge tank (1) as well as to the inner area of the sedimentation tanks (6), thus a biofilter unit (7) is adjoined to their outer side. A perforated pipe (13) of a pressure air distribution system is situated on the bottom of the activated sludge tank (1). The central part (5) of the sewage treatment plant is vertically divided into several interconnected chambers forming a selector (9), the inlet of which is connected to the outlet of a rough contamination separator (10) or to the outlet of a drum separator (11) situated outside the tank (1) of the sewage treatment plant, while its outlet is connected to the round denitrification area (16) inside the tank (1), which is located between the two walls (2, 3) of the tank (1) of the sewage treatment plant, in which blenders (18) are placed. The area (16) is connected by the through holes to the part of the activated sludge tank (1) in the area of the biofilter units (7), into which the connection to the sedimentation tanks (6) is issued by means of the cross intake duct (19), while the bottom area of the sedimentation tanks (6) is connected to the central part (5) of the sewage treatment plant.

Description

Technical field

The invention relates to a wastewater treatment reactor for use in treatment plants.

BACKGROUND OF THE INVENTION

Known engineering solutions for larger wastewater treatment plants include a number of separate construction and technological structures and units that are interconnected with pipelines, pumping systems and pipe fittings. The disadvantage of these solutions is the increased need for the acquisition of terrains and repetitive construction operations such as excavation, reinforcement, formwork, concrete pouring and more. All this increases investment costs and extends the construction period. From a technological point of view, such "atomization" leads to imperfect and therefore only partial biological treatment, which further increases the energy requirements resulting from repeated pumping, mixing and, in general, the more complicated technological process. Unpleasant odors, massive insect infestation and high noise are the side effects of such decisions.

Almost every known treatment process has its fundamental disadvantages. For example, the so-called "SBR" process (cyclically discontinuous aerobic reactor) - although it apparently integrates several processes into a single reactor tank for wastewater treatment - faces problems related to variable water levels, washing of sediment and energy losses in low water conditions and associated aeration. Other known processes are often implemented on objects with large structures with multiple communications. These shortcomings predetermine complex technological management systems, including sampling.

From WO 2002/085800 Ale, a known wastewater treatment reactor consisting of a vertical cylindrical activated sludge tank having an outer and an inner wall, concentrically arranged relative to one another, and in the space formed on the inner side, parallel to the settling tanks with tapered, tapering down, cross section. The known solution does not efficiently purify waste water.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a structurally and technologically integrated reactor for a wastewater treatment plant, with improved design and providing more efficient wastewater treatment.

This task is accomplished by creating a wastewater treatment reactor that includes a double-walled vertical cylindrical tank for activated sludge, with outer and inner walls, between which is a denitrification zone in which mixers are arranged to allow the movement of the mixture of water and sludge throughout the volume of the denitrification zone. In the inner space of the tank, bounded by the inner wall, there are sludge tanks with a tapered, tapering cross-section. The principle of the invention is that two parallel dividing walls are located in the central part of the tank, defining a central part of the wastewater treatment reactor for aerobic stabilization of the activated sludge. In the space between the dividing walls and the inner wall, two functional, symmetrically arranged waste water zones and cultivation zones are created, in which the separate sedimentation tanks are located. A vertically hollow cylinder is mounted on the axis of each sludge tank. Said hollow cylinders are connected via a transverse inlet pipeline to the inner area of the activated sludge tank as well as to the inner area of the sedimentation tank. A biofilter block is attached to the outside of the sedimentation tank. The perforated pipe of the pressure air distribution system is located at the bottom of the asset tank

66054 Bl early sludge. The central part of the wastewater treatment reactor tank is divided into several vertical interconnected chambers that form a selector connected to its inlet to the outlet of the coarse separator or to the outlet of the drum separator located outside the reactor reservoir. sewage treatment 1 and, with its outlet, to the circular denitrification zone, which is connected by means of apertures to the part of the activated sludge tank in the biofilm zone Lateral blocks in which the connection to the sludge tank via the transverse piping is discharged. The bottom area of the sludge tank is connected to the central part of the reactor for wastewater treatment.

The walls of the wastewater treatment reactor are made of a material selected from the group of materials including concrete, metal and plastic.

An advantage of the present invention is that the wastewater treatment reactor is compact and has an enhanced treatment effect, while reducing the energy requirement for wastewater treatment.

Sedimentary tanks may have a conical shape with a bevel of less than 60 °. Alternatively, they may have a flat bottom with beveled elements laid thereon; the shape of these elements can be selected from a group of shapes comprising a pyramid, a cone, a truncated pyramid, or a truncated cone, with the sides slanting at an angle of 60 °. The use of sloping sides (approximately at an angle of 60 °) of the settling tanks is preferred because of the advantage that the flow of the activating mixture (from water and activated sludge) is accelerated, which is generated by the action of bubbles coming from the bottom through the diffusers on the slanted sides. of the sedimentation tanks, thereby perfectly mixing the activating mixture and creating a uniform mixture of sediment and water.

The bottom areas of the sludge tanks can be connected through a regeneration tank located in the central part of the wastewater treatment reactor to one of the chambers of the selector. In this way, the recycled and activated sludge can be introduced into the selector from the bottom of the settling tanks. It is preferred that the sewage treatment reactor includes an even number of sedimentation tanks - at least two, usually four, but the number can reach eight. Separately, the sludge tanks may be equipped at their upper end with a drainage pipe for the discharge of clear water, which can be connected to the apparatus for the final treatment of water.

The bottom area of the sedimentation tanks may also be connected to the denitrification zone. The activated sludge, which does not have dissolved oxygen, is drawn from the bottom of the sedimentation tanks, which is triggered by the action of the mixers within the denitrification zone, thereby enhancing the denitrification effect.

At the bottom of the denitrification zone, a pipeline of an additional oxidation system may be fitted. The denitrification process can be delayed if the ambient temperature drops. Therefore, the denitrification zone may be equipped with a suitable additional oxidation system that provides conventional biological treatment of the water in that zone (the perforated pipeline of the additional oxidation system is placed near the bottom of the denitrification zone).

Explanation of the annexed figures

The accompanying figures provide an example of a configuration of a wastewater treatment reactor according to the present invention, of which:

Figure 1 is a top plan view of a partial sectional view of the reactor according to the invention;

Figure 2 is a top plan view of the reactor according to the invention;

Figure 3 is a cross-sectional view through the reactor.

An example of implementation and operation of the invention

Wastewater treatment reactor

66054 Bl of water includes a vertical cylindrical double wall tank 1 made of concrete, plastic or metal; it has an outer wall 2 and a concentrically arranged inner wall 3 of smaller diameter. The diameter of the outer wall 2 of tank 1 can vary widely, from two meters to several tens of meters. The width range of the space between the outer wall 2 and the inner wall 3 may be from one meter to about five meters, depending on the particular application. The heights of both walls 2 and 3 of tank 1 are approximately the same; they can be two to ten meters high. The thickness of the walls depends on the material from which they are made and can range from a few millimeters (if steel is used) or a few centimeters (if using technical plastic; for example, it is six to fifteen centimeters in polypropylene) and to reaches several tens of centimeters (up to fifty centimeters in concrete). Certain components of the reactor, including sludge tanks 6, stabilization tank, regeneration tank 15, and other components are integrated into the interior of the inner tank, the so-called activated sludge tank, which is defined by the inner wall 3 and the bottom of the tank. These components are described below.

Two parallel, vertically spaced, dividing walls 4 of the same height as the inner wall 3 are constructed in the inner tank and create with each other the central part 5 of the wastewater treatment reactor intended for aerobic stabilization of the activated sludge. At the same time, they separate the inner zone of the wastewater treatment reactor into two symmetrical halves, thus preventing the free passage of wastewater and the cultivation crop between the two halves of the inner concentric tank. Sedimentary tanks 6, whose number is an even number (at least two, usually four but their number may reach eight), can be introduced symmetrically inside the concentric inner tank. They may be supported by vertical dividing walls 4 but may also be connected to them. The bottom of each of these sedimentary tanks 6 has a conical shape with a bevel at an angle of 60 ° and its cross section is reduced in a downward direction. The bottom of the sludge tanks may be open or closed. Alternatively, the sludge tanks 6 may have a flat bottom with bevelled plastic or metal elements mounted thereon; these elements may be in the form of a pyramid, a cone, a truncated pyramid or a truncated cone, with their sides beveled at an angle of approximately 60 °; they provide the sedimentation of the activated sludge particles. A hollow plastic cylinder without bottom 20 can be conveniently placed in the central part of each segment of the settling tank 6. The inlet conduit 19 is discharged into this hollow cylinder, its opposite end being discharged into the area of the activated sludge of the purification reactor. of wastewater between the inner side of the inner concentric wall 3 and the outer sides of the settling tanks 6. Aeration elements created, for example, by means of perforated silicone hoses, are located at the bottom inside nal concentric tank (activated sludge tank). The aerating elements are supplied with pressurized air via a pressure distribution line 13 from the pressure fans 12 (low pressure compressors).

Next to the settling tanks 6 in the area of the activated sludge tank, on the supporting structure are integrated biofilter blocks 7, under which is located the perforated pipeline for distribution of pressurized air 13. The pressurized air is supplied through the pipeline for distribution of pressurized air, pre-set intervals, under the housings of the biofilter blocks 7, to remove sediment from the plastic surface of the biofilters. In this way, the optimal concentration of biological culture is maintained both on the surface of the biofilters and throughout the activated sludge tank.

The central section 5 of the wastewater treatment reactor, in the space between the two parallel separating walls 4 of the activated sludge tank, is separated by vertical barriers starting from the

66054 Bloth and extending over the entire height of the dividing walls 4, several chambers that can be connected to each other by pipelines to allow water to circulate between them. The bottom of the central part 5 is provided with a pipeline of the pressure distribution system 13, which ends with aeration parts; these details may represent; for example, finely perforated silicone hoses that are flush with plastic (polypropylene, polyvinyl chloride, etc.) hoses with larger openings in their surface connected to the pipeline 13. Other technological components of the wastewater treatment reactor are described in the head that deals with the operation of the wastewater treatment reactor.

Contaminated waste water flows through the coarse pollutant separator 10, which includes, for example, waste shelves where solids are separated from the waste water. When the separator 10 is closed, for example due to failure or maintenance operation, the wastewater flows into the pollutant drum separator 11, which serves as an emergency bypass separator for the solid pollutants. From the separator 10, the wastewater flows through the selector 9, which is formed by two (preferably three or more) vertical barriers 8 which are connected to each other by the openings in their vertical walls; the chambers are located in the central zone 5 of the wastewater treatment reactor between the separation walls 4 of the activated sludge tank. The air distribution pipeline 13 together with the fine bubble diffusers 14 are located at the bottom of these chambers. At the same time, the recirculated activated sludge from the bottom of the sludge tank 6 is fed through the associated regeneration tank 15, which is located in the central part of the wastewater treatment reactor 5, thus being connected to the selector 9 in. one of these cameras. The bottom of the regeneration tank 15 is also equipped with a pressure distribution line 13 and a fine bubble diffuser 14. A mixture of wastewater and activated sludge flows from the selector 9 into the denitrification zone 16 between the inner wall 3 and the outer wall 2. reservoir 1. In this denitrification zone 16, in which free oxygen is dissolved, the germs from the precipitate begin to extract chemically bound oxygen, for example from nitrates in water, thereby reducing their content in water. ata. This process operates at temperatures above approximately 6 ° C. The denitrification process is reduced at lower ambient temperatures; therefore, the denitrification zone 16 of the wastewater treatment reactor 1 is equipped with an additional oxidation system that provides conventional biological treatment in that zone (the perforated tube 17 of the additional oxidation system is located at the bottom of the denitrification zone 16). In this denitrification zone 16 of the wastewater treatment reactor 1, mixers 18 are also installed, which allow the mixture of water and sludge to move throughout the volume of the denitrification zone 16 to prevent sediment deposition. The annular geometric shape of the denitrification zone 16 is much more appropriate than conventional tanks with different foundation layouts, as it is characterized by low hydraulic resistance to the flow of water and sediment. In this way, the energy consumption required for mixing in a unit volume of the tank, respectively, and the number of mixers 18, is reduced, while ensuring perfect mixing in the mixture of water and sludge.

The denitrification zone is connected through openings to the activated sludge zone at the location of the biofilter blocks 7. The mixture of water and sludge flows vertically through the biofilter blocks and is oxidized and mixed perfectly at the bottom of the activated sludge reservoir under the action of bubbles. . The shape of the tapered sides (at an angle of approximately 60 °) of the settling tanks 6 is used to accelerate the flow of the activating mixture (from water and activated sludge) generated by the action of the bubbles coming from the bottom through the diffusers 14 on the outer bevels sides of the sediment reserve

66054 Bl variants 6, thereby achieving perfect mixing of the activating mixture and creating a homogeneous mixture of sediment and water. This homogeneous mixture, which is a prerequisite for the optimal biological wastewater treatment process, then passes through the inlet duct 19 into the vertical hollow drum 20, which is located along the axis of the sedimentation tank 6, from where it flows down to the bottom of the sedimentation zone. Here, the treated water is separated from the heavier particles that form the activated sludge. Thereafter, clear water flows through the notched crown of the exhaust pipe 21 (to ensure a constant flow along the entire length of that pipe) into the collector duct and further into the final water treatment unit 22, which may be part of 1. A final water treatment plant 22 may include drum micro-screens, sand filters 23, or a combination of these devices. The excess sludge is pumped from the bottom of the sludge tanks 6 into the central portion 5 of the wastewater treatment reactor equipped with oxidizing diffusers 14. Here, aerobic stabilization of the activated sludge takes place and it loses its unpleasant odor and volume it is reduced by autolysis. After the oxidation process is complete, the stabilized activated sludge is precipitated and then pumped with wastewater pumps 24 from the bottom and fed into the centrifuge 25, where it is sealed and the water from the sludge is returned through the separator 10 at the start 9. the purification process. The dry part of the sludge is collected in containers and transported.

The principles of the invention relate to the configurations of the wastewater treatment reactor, in particular the geometric shape of its denitrification zone 16 and the sedimentation tanks 6. The step which determines the advantage of the treatment process is the extraction of activated sludge in which there is no dissolved oxygen from the bottom of the sedimentation tanks 6 in the denitrification zone 16; this leakage of the medium with a minimum oxygen content (the bottom of the sedimentation tanks 6) is caused by the action of the mixers 18 in the denitrification zone 16. This increases the efficiency of the denitrification process.

In one activated sludge tank, there is a combination of two biocultures with different physiological effects. During their rapid development, they metabolize water pollution and break down organic pollutants. One bioculture is attached to the walls of the carrier of the biofilters, while the other is dispersed in the form of floccules in the activated mixture of water and sludge. The combination of these biocultures accelerates the purification process and increases the concentration of sediment in the reactor.

Claims (10)

Claims 1. A wastewater treatment reactor comprising a double-walled vertical cylindrical tank for activated sludge (1), with an external (2) and an inner (3) wall, between which is a denitrification zone (16) housing mixers ( 18) to ensure the movement of the mixture of water and sludge throughout the volume of the denitrification zone (16), with sludge tanks (6) in the inner space of the reservoir delimited by the inner wall (3) with a conical narrowing down cross section, characterized in that is two parallel separation walls (4) are located in the central part of the tank (1), defining the central part (5) of the wastewater treatment reactor for aerobic stabilization of the activated sludge and, simultaneously, in the space between them and internal wall (3), they create two functional, symmetrically arranged zones for waste water and cultivation plants, in which zones are located the individual sedimentary tanks (6), and a vertically hollow cylinder (20) is placed on the axis of each sedimentary tank (6). ) as a memo the hollow cylinders (20) are connected via a transverse inlet conduit (19) to the inner zone of the activated sludge tank and to the inner zone of the sedimentation tank (6) to which the biofilter block (7) is attached to the outside perforated pipe (13) of the pressure distribution system is located on the bottom of the tank for 66054 Bl activated sludge, and the central part (5) of the wastewater treatment tank is divided into several vertical interconnected chambers that form a selector (9) connected to its inlet to the outlet of the coarse separator (10). ) or to the outlet opening of the drum separator (11) located outside the reservoir of the wastewater treatment reactor (1) and its outlet opening to the circular denitrification zone (16), which is connected by means of apertures to the tank part for activated sludge (1) in the area of the biofilter blocks (7), in which the connection to the sludge tank (6) is discharged via the transverse pipe (19), while the bottom area of the sludge tank (6) is connected to the central part (5) of the wastewater treatment reactor. Wastewater treatment reactor according to claim 1, characterized in that the sedimentation tanks (6) have a conical shape with a bevel of 60 °. Wastewater treatment reactor according to claim 1, characterized in that at least one of the settling tanks (6) has a flat bottom with beveled elements laid thereon, the form of which can be selected from the group shapes including a pyramid, a cone, a truncated pyramid or a truncated cone in which the sides are angled at 60 °. Wastewater treatment reactor according to Claims 2 or 3, characterized in that the bottom zone of the settling tanks (6) is connected through a regeneration tank (15) located in the central part (5) of the purification reactor. waste water to one of the selector chambers (9). 5. A wastewater treatment reactor according to claim 4, characterized in that the bottom zone of the settling tanks is connected to the denitrification zone (16). Wastewater treatment reactor according to claim 1, characterized in that the sludge tanks (6) are individually provided at their upper end with the outlet pipe for clear water (21). 7. Wastewater treatment reactor according to claim 6, characterized in that the outlet pipe for clear water discharge (21) is connected to the device for the final treatment of water (22). Wastewater treatment reactor according to claim 1, characterized in that its walls are made of materials selected from the group of materials including concrete, metal and plastic. Wastewater treatment reactor according to claim 1, characterized in that it comprises an even number of sedimentation tanks (6). Wastewater treatment reactor according to claim 1, characterized in that the additional pipeline of the oxidation system (17) is located at the bottom of the denitrification zone (16).