SK288077B6 - Sewage water treatment plant - Google Patents

Abstract

The sewage treatment plant includes two wall version of the vertical cylindrical activated sludge tank (1), which is characterized by the fact that the two parallel dividing walls (4) are situated in the central part of the this tank (1), which determinate the central part (5) of the sewage treatment plant for the aerobic stabilization of the activated sludge, and simultaneously, within the space between them and the outer wall (3), create two functional symmetrically arranged areas for the sewage water and treating cultures. The separate sedimentation tanks (6) of downward tapered section are situated in these two areas. A hollow cylinder (20) is vertically situated in the axis of each sedimentation tank (6). These hollow cylinders are connected by the cross intake ducting (19) to inner area of the activated sludge tank as well as to inner area of the sedimentation tank (6) so that their outer side is adjoined by the bio-filter unit (7). Perforated piping (13) of the pressure air distribution system is situated on the bottom of the activated sludge tank. The central part (5) of the sewage treatment plant tank is vertically divided into several interconnected chambers creating a selector (9) which is connect with its inlet to the outlet of the rough contamination separator (10) or to the outlet of the drum separator (11) situated outside the sewage treatment plant tank (1), and with its outlet to the round denitrification area (16) inside the tank (1) which is arranged between the both walls (2, 3) of the sewage treatment plant tank (1) into which blenders (18) are situated to ensure the movement of the water and sludge mixture throughout the whole capacity of the denitrification area (16). This denitrification area (16) is connected by means of the through holes to the part of the activated sludge tank (1) in the area of the bio-filter units (7) into which the connection to the sedimentation lank (6) I is "issued by the cross duct (19) while the bottom area of the sedimentation tank (6) is connected to the central part (5) of the sewage treatment plant.

Description

Technical field

It is an object of the invention to provide a sewage treatment plant.

BACKGROUND OF THE INVENTION

Current technical solutions for larger wastewater treatment plants include a number of separate construction and technological objects and nodes that are interconnected by piping, pumping equipment and fittings. The disadvantage is the increased need for land take and repetition of construction activities, eg. excavation, reinforcing, formwork, concrete, etc., all increase investment costs and extend construction time. From the technological point of view, the repeated phenomenon of such atomization is incomplete, respectively. partial biological treatment resulting in increased energy intensity due to multiple pumping, mixing and more complicated technological processes. The accompanying phenomenon of waste treatment is then odor, occurrence of insect, or heavy traffic noise.

Of the known purification processes, virtually everyone has some major drawbacks. E.g. called. The “SBR” process - while seemingly integrating multiple processes in a single tank, it encounters problems associated with varying levels, sludge leaching and low-energy energy loss and accompanying aeration. Other known processes are often carried out on large building plots with a range of communication routes, which leads, among other things, to a complex process of operation and technology management, including sampling.

It is known to provide a sewage treatment plant according to CZ patent 293174, wherein the activating sewage treatment reactor consists of a double-shell tank of circular plan, containing a circular anoxic space, which is arranged along the entire inner surface of the tank shell and completely surrounds the oxic space. The source of the activation mixture drive in the circular anoxic space is a mechanical stirrer. Separation spaces in the form of widening truncated cones are located inside the oxic space, in the upper part there are drainage troughs of purified water and in the lower part the sludge with part of the activation mixture is sucked into the circular anoxic space.

The disadvantage of this solution is the fact that the overflow edge, i. j. the inner partition walls of the circular oxic and anoxic reactor are terminated below the surface of the waste water. Obviously, due to the oxygen concentration gradient of the oxic and anoxic spaces, it is not possible to separate the purification conditions in this solution. In other words, the water in both spaces communicates and the purification conditions interact with each other as a result of the gradient in the 02 concentrations.

The arrangement of a sewage treatment plant according to SK patent 283582 is also known. It has some disadvantages, e.g. there is no mechanical pre-treatment, which reduces the load on the biological reactor; it further does not include a multi-stage selector to prevent the growth of microorganisms forming unwanted long chains, so-called " fibrous being. Other disadvantages are the lack of active sludge regeneration, aerobic stabilization and thickening of the excess sludge to reduce the volume requirements of the balanced excess sludge and finally tertiary treatment. Similar disadvantages have the sewage treatment plant according to the SK utility model 3251, where the possibility of operation with aerobic sludge stabilization is mentioned, but the technical solution does not contain it.

It is an object of the present invention to provide an integrated construction technology plant for a sewage treatment plant which removes a number of the above drawbacks. In contrast to CZ patent 293174 it strictly defines an oxic and anoxic reactor.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a sewage treatment plant comprising a vertical cylindrical activation tank in a dual-shell embodiment, wherein the inner shell is concentrically disposed opposite the outer shell and wherein the inner shell defines a space in which the sedimentation tanks are arranged. SUMMARY OF THE INVENTION In the central region of the activation tank there are two mutually parallel dividing walls which define between each other a central part of the sewage treatment plant for the aerobic stabilization of activated sludge and two symmetrically arranged waste water and purification cultures. In the axis of each sedimentation tank, a hollow cylinder is connected along its height, connected both with the inner space of the activation tank through a transverse supply line and with the inner space of the sedimentation tank to which the biofiltration block adjoins on the outside. On the bottom of the activation tank there is a perforated compressed air distribution pipe. The central part of the sewage plant is vertically divided into several chambers interconnected by openings and these chambers form a selector connected by its inlet to the outlet of the coarse dirt separator or drum separator outside the sewage tank and its outlet to the circular de2

A nitrification space in the tank, arranged between the two shells of the sewage treatment tank, in which the agitators are provided to move the mixture of waste water and sludge throughout the volume of the denitrification space. This denitrification space is through through openings connected to a part of the activation tank space in the area of biofiltration blocks, into which the connection with the sedimentation tank is connected through a transverse supply line, while the bottom space of the sedimentation tank is connected with the central part of the treatment plant. The walls of the purifier tank are of a material selected from the group consisting of concrete, metal and plastic.

An advantage of the present invention is that the entire plant system is a compact unit, arranged in a single tank (single building). Multiple foundation of buildings is not necessary. This represents an advantageous spatial application with increased cleaning effect and reduced energy consumption of wastewater treatment. In a single compact unit there is a mechanical pre-treatment of sludge (which reduces the load on the biological reactor), there is a multi-stage selector (prevents the growth of microorganisms creating unwanted long chains, so called filamentation), active sludge regeneration, aerobic stabilization of excess sludge tertiary cleaning. The biological reactor has at least two separate parts that can be operated separately, independently of each other. The main advantage is to increase the efficiency of the biological degradation of organic substances from the waste water and also to reduce the sensitivity to the uneven load of the plant over time. This is due to the combination of active sludge in the float (activation tank) and solid biomass carrier (biofiltration blocks). In addition, the clogging of the filter blocks with excess sludge is eliminated by a scrubbing system using compressed air from a uniform distribution system.

The sedimentation tanks may preferably be conical in shape with a gradient of 60 °. Alternatively, they may have a flat bottom with oblique wall bodies disposed thereon, in the form selected from the group consisting of a pyramid, a cone, a truncated pyramid and a truncated cone, wherein the inclined walls have a slope of 60 °. The shape of the sloping inclined surfaces (at an angle of approximately 60 °) of the sedimentation tanks is advantageously used to create a velocity flow of the activation mixture (water and activated sludge) that occurs when microbubbles are released from the bottom via diffusers to the outer inclined walls of the sedimentation tanks. thoroughly mixing the activation mixture and forming a homogeneous mixture of sludge and water.

The bottom of the sedimentation tanks can be connected via a recovery tank in the central part of the sewage plant to one of the selector chambers. Thus, recirculated activated sludge from the bottom of the sedimentation tanks can be fed to the selector. The sewage treatment plant preferably comprises an even number of sedimentation tanks, at least two, usually four, and may also be eight. The sedimentation tanks are individually equipped in their upper part with a drainage trough of clarified water, which can be further connected to the water purification block.

The bottom space of the sedimentation tanks may also be connected to the denitrification space. The withdrawal of activated oxygen-free sludge from the bottom of the sedimentation tanks to the denitrification chamber, which occurs by the action of a stirrer in this denitrification chamber, increases the efficiency of denitrification. At the bottom of the denitrification chamber, an additional oxygenation system pipe may be provided. At lower ambient temperatures, below 6 ° C, when the anoxic denitrification processes are virtually non-existent, the denitrification process is strongly suppressed, and therefore the denitrification area of the sewage treatment plant can advantageously be equipped with an additional oxygenation system to ensure conventional biological water purification. denitrification space is a perforated pipe of an additional oxygenation system).

The advantages of the present invention over SK patent 283582 and SK utility model 3251 are as follows. In the compact unit there is a mechanical pre-treatment, which reduces the load on the biological reactor, furthermore a multi-stage selector prevents the growth of microorganisms forming unwanted long chains, the so-called. fibrous being. The solution according to the invention further comprises the recovery of the active sludge, aerobic stabilization and the thickening of the excess sludge to reduce the volume requirements of the balanced excess sludge and finally tertiary purification. The biological reactor uses a combination of active sludge in the float (activation tank) and a solid biomass carrier (biofiltration blocks). This increases the efficiency of biodegradation of organic matter from the waste water and, in particular, reduces the sensitivity to the uneven load of the plant over time. This is a major advantage over other systems that use only active sludge in hover. In addition, clogging of the filter blocks with excess sludge is eliminated by a pressurized air system from a uniform distribution system. The plant operates at a constant level in all chambers except the aerobic sludge stabilization tank. Sensitivity to unevenness of hydraulic and biological load over time is suppressed by the combination of active sludge and solid biomass carrier. A decrease in dissolved oxygen concentration after passing through a solid biomass carrier is also utilized to increase the oxygen transfer from air to water. The plant has a biological reactor divided into at least two separate parts that can be operated separately (eg one completely shut down).

In the separation space, the plant is equipped with a cylinder which directs the flow of water and, moreover, allows at least partial entrapment of floating substances or floating substances from the entire volume of water entering the separation space. In the separation space, it may be provided with conical, truncated, truncated, pyramidal, truncated interposed bodies which reduce the bottom area and allow settling of the activated sludge. The purifier also uses the exterior parts of the sloping walls of the sedimentation tanks to direct the flow and

The mixing of the activation mixture without the necessity of using a mechanical mixing device is therefore possible.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings, an example of an arrangement of a waste water treatment plant according to the invention is shown. In FIG. 1 and 2 is a schematic plan view of the plant arrangement; FIG. 2 is also a vertical cross-section of the purifier.

DETAILED DESCRIPTION OF THE INVENTION

The sewage treatment plant comprises a vertical cylindrical double-shell tank 1 made of concrete, plastic or metal, which comprises an outer shell 2 and a concentrically arranged inner shell 3 of smaller diameter opposite it. The diameter of the outer shell 2 of the tank I can be in a wide range, from two meters to several tens of meters. The width of the space between the inner shell 3 and the outer shell 2 ranges from one to about five meters, depending on the particular application. The height of the two walls of the tanks 2, 3 of the tank 1 is approximately the same, it may be from two to ten meters. Their thickness depends on the chosen construction material and ranges from a few millimeters (in the case of steel) or centimeters (in the case of construction plastic, for example polypropylene it is six to twelve centimeters), up to several tens of centimeters (concrete up to fifty centimeters) ). Inside the inner tank, so-called. In the activation tank defined by the inner jacket 3 and the bottom, the individual technological components of the sewage plant are incorporated, including the sedimentation tanks 6, the stabilization tank, the recovery tank 15 and other components, which will be described in more detail below.

In the inner tank there are built in its central part two mutually parallel vertical dividing walls 4 with a height corresponding to the height of the inner shell 3, which form between them the central part 5 of the sewage treatment plant for aerobic stabilization of activated sludge. At the same time, it divides the inner space of the sewage plant into two symmetrical halves in such a way as to prevent the free passage of the waste water and the purification culture between the two halves of the inner concentric tank. The sedimentation tanks 6, of which there are an even number (at least two, usually four, but may be eight), may be symmetrically inserted into the space of the inner concentric tank. They can be supported on the vertical partition walls 4 and can also be connected to them. The lower part of each of these sedimentation tanks 6 has a conical shape with an inclination of approximately 60 °, its cross section tapering downwards. It may have the shape of a pyramid or a cone. The bottom of the sedimentation tanks 6 can be opened or closed. Alternatively, the sedimentation tanks 6 may have a flat bottom with a solid or cone-shaped plastic or metal body or a cone-shaped body or a cone-shaped body, respectively. of a trim pyramid or cone with a wall inclination of approximately 60 °, which provides for settling of activated sludge particles. Advantageously, a vertical plastic hollow cylinder 20, the bottom of which is open, may be arranged in the central part of each segment of the sedimentation tank 6. An inlet duct 19 is connected to this column, the opposite end of which flows into the activation space of the sewage plant between the inner surface of the inner concentric tank jacket 3 and the outer walls of the sedimentation tanks 6. Aeration elements are formed at the bottom of the inner concentric tank. . silicone perforated hoses into which compressed air from blowers 12 (low-pressure compressors) is blown through the compressed air distribution line 13. The compressed air is then fed to the central part 5 of the purifier, to the selector chambers 9 and the recovery tank 15, further to the bottom of the denitrification space 16, which is part of the dual-shell activation tank 1, and finally to the biofiltration blocks 2 as described in more detail below. The compressed air manifold 13 is equipped with fine-bubble diffusers 14 which are situated in the activation tanks and extend below the inclined walls of the sedimentation tanks 6, further located at the bottom of the selector chamber 9, recovery tank 15 and in the central part 5 of the sewage treatment plant.

In addition to the sedimentation tanks 6, biofiltration blocks 7 are built in the space of the activation tank on the supporting structure, below which the perforated duct 13 of the compressed air distribution is connected. Compressed air is supplied at regular preset intervals below the bodies of the biofiltration blocks 7, in which sludge deposits are entrained from the plastic surface of the biofilters. This maintains the optimum concentration of the biological culture on the surface of the biofilters and at the same time throughout the activation tank.

The central part 5 of the treatment plant, in the space between the two parallel partition walls 4 of the activation tank, is divided by vertical compartments arranged from the bottom over the entire height of the partition walls 4 into several chambers which can be mutually equipped with intersections allowing water to circulate therebetween. The bottom of the central part 5 is provided with a system of compressed air distribution pipe 13 into which the aeration elements, e.g. silicone, finely perforated hoses, which are threaded onto plastic (polypropylene, polyvinyl chloride, etc.) tubes with larger through holes in their sheathing, screwed into pipe 13. Other technological components of the plant are described in the description of the plant's function.

SK 288077 Β6

The contaminated waste water flows through a coarse dirt separator 10 containing e.g. mechanical rakes where solid mechanical particles are separated from the waste water. In the event of shutdowns of the separator JO, e.g. in the event of failure or maintenance, the waste water flows to the drum impurity separator 11, which serves as a replacement by-pass for solids separation. From the separator 10 the wastewater flows through a selector 9 which is formed by at least two (preferably three or more) side-by-side chambers with vertical compartments 8 interconnected through openings in their vertical walls which are arranged in the central part 5 of the treatment plant between parallel partition walls 4 of the activation. tank. At the bottom of the two chambers there is a compressed air distribution line 13 with fine-bubble diffusers 14. At the same time, recirculated activated sludge from the bottom of the sedimentation tanks 6 is fed into one of these chambers via a regeneration tank 15 connected to it. The bottom of the recovery tank 15 is also provided with a compressed air distribution line 13 with fine-bubble diffusers 14. The mixture of waste water and activated sludge from the selector 9 flows into the denitrification space 16 between the inner jacket 3 and the outer jacket 2 of the tank 1. In this denitrification space 16, in which there is a lack of free dissolved oxygen, the sludge microorganisms begin to collect chemically bound oxygen. in nitrates in water, thereby reducing their water content. This process is functional at temperatures above about 6 ° C. In the case of lower ambient temperatures, the denitrification process is strongly suppressed, and therefore the denitrification chamber 16 of the purifier J. is preferably equipped with an additional oxygenation system that ensures the conventional biological water purification process in this area. ).

Furthermore, stirrers 18 are incorporated in the denitrification chamber 16 of the purifier 1 to move the mixture of water and sludge throughout the volume of the denitrification chamber 16 to prevent sludge settling. The geometry of the cylindrical annular denitrification space 16 is very advantageous over conventional tanks of another plan, since it has a low hydraulic flow resistance of the water / sludge mixture, thereby reducing the mixer ' water and sludge.

The denitrification space 16 communicates through the through holes with the activation tank space in the area of the biofiltration blocks 7. The mixture of water and sludge flows vertically through the biological filter bodies, oxygenated at the bottom of the activation tank and thoroughly mixed by bubbles of compressed air. The shape of the inclined inclined surfaces (at an angle of approximately 60 °) of the sedimentation tanks 6 is advantageously used to generate a velocity flow of the activation mixture (water and activated sludge) which occurs when microbubbles are released from the bottom via diffusers 14 on the outer inclined walls of the sedimentation tanks 6. thereby perfectly mixing the activation mixture and forming a homogeneous mixture of sludge and water. There is a strong flow of the escaping air-water mixture and a velocity gradient, a dense flow of the water-air mixture from the bottom, which is further guided to the top of the biological filters. This homogeneous mixture, which is a prerequisite for the optimal course of biological wastewater treatment processes, then enters through the supply line 19 into the vertical hollow cylinder 20 in the axis of the sedimentation tank 6, from where it flows down to the bottom of the sedimentation space. Here, the purified water is separated from the heavier activated sludge particles. The clarified water then flows through the toothed edge of the drainage trough 21 (to ensure even water drainage along its length) to the collecting duct and further to the water purification block 22 which may be part of the water treatment plant L The water purification block 22 may include drum microsites , microfilters, sand filters 23 or combinations thereof. Excess sludge from the bottom of the sedimentation tanks 6 is pumped into the central part 5 of the activated sludge treatment plant, which is equipped with oxygenation diffusers 14, loses odor and reduces its volume by autolysis. Upon stopping the oxidation process, the stabilized sludge sedimentes and is pumped from the bottom by sludge pumps 24 to the centrifuge 25, where it is concentrated and the sludge water is returned to the selector 9 via the mechanical separator 10 to the selector 9. The dry sludge is collected into containers and exported.

The present invention is based on a combination of its technical features, which in a compact unit include mechanical pre-treatment, multi-stage selector, active sludge regeneration, aerobic stabilization of excess sludge and further treatment. A preferred part of the purification process is the withdrawal of activated oxygen-free sludge from the bottom of the sedimentation tanks 6 to the denitrification space 16, this suction of the sludge from the minimum oxygen content (bottom of the sedimentation tanks 6) occurs by agitation 18 in the denitrification space 16. This increases the efficiency of denitrification.

In a single activation tank there is a combination of two bio-cultures with different physiological activity. As they grow rapidly, they contaminate the water and degrade organic pollution. One such bio-culture is fixed on the walls of the plastic carrier of the biological filters, the other is dispersed in the form of flakes in the sludge-water activation mixture. The combination of these bio-cultures accelerates the purification process and increases the sludge concentration in the system.

Claims (10)

PATENT CLAIMS A sewage treatment plant comprising a vertically cylindrical activation tank (1) in a double-shell design, wherein the inner shell (3) is concentrically arranged with respect to the outer shell (2) and wherein the inner shell (3) defines the space in which the sedimentation tanks are arranged (6), the cross-section of which is tapered downwards, characterized in that two mutually parallel dividing walls (4) are arranged in the central region of the activation tank (1) which define between them the central part (5) of the activated aerobic stabilizer sludge and, simultaneously with respect to the inner shell (3), two symmetrically arranged waste water and purification cultures in which the sedimentation tanks (6) are individually arranged, and in the axis of each sedimentation tank (6) there is a hollow cylinder (20) along its height connected to the interior of the activation tank (1) by means of a transverse supply line (19) and on the one hand, with the interior of the sedimentation tank (6) adjoining the biofiltration block (7) from the outside, on the bottom surface of the activation tank (1) there is a perforated duct (13) of compressed air distribution where the central part (5) divided into a plurality of chambers interconnected by apertures, and these chambers form a selector (9) connected by its inlet to the outlet of the coarse dirt separator (10) or the drum separator (11) outside the purifier tank (1) and its outlet to the circular denitrification space (16) ) in a tank (1) arranged between the two shells (2, 3) of the sewage treatment tank (1), in which the stirrers (18) are provided to move the waste water / sludge mixture throughout the volume of the denitrification space (16); the space (16) communicates through the through holes with a part of the space of the activation tank (1) in the area of the biofiltration blocks (7), into which it is connected to the sedimentation tank (6) by a transverse supply line (19), the lower space of the sedimentation tank (6) being connected to the central part (5) of the treatment plant. Waste water treatment plant according to claim 1, characterized in that the sedimentation tanks (6) are conical in shape with a gradient of 60 °. A sewage treatment plant according to claim 1, characterized in that the at least one sedimentation tank (6) has a flat bottom with oblique wall bodies disposed thereon, in the form selected from the group consisting of pyramid, cone, truncated pyramid and truncated cone, wherein the inclined walls have an inclination of 60 °. Waste water treatment plant according to claim 2 or 3, characterized in that the lower space of the sedimentation tanks (6) is connected via a recovery tank (15) in the central part (5) of the treatment plant to one of the selector chambers (9). Waste water treatment plant according to claim 4, characterized in that the lower space of the sedimentation tanks (6) is connected to the denitrification space (16). Waste water treatment plant according to claim 1, characterized in that the sedimentation tanks (6) are individually provided in their upper part with a drainage trough (21) of clarified water. A sewage treatment plant according to claim 6, characterized in that the drain channel (21) is connected to the water purification block (22). Waste water treatment plant according to claim 1, characterized in that its walls are of a material selected from the group consisting of concrete, metal and plastic. Wastewater treatment plant according to claim 1, characterized in that it comprises an even number of sedimentation tanks (6). Waste water treatment plant according to claim 1, characterized in that a conduit (17) of an additional oxidant system is arranged at the bottom of the denitrification space (16).