SK8072001A3 - The method of waste water treatment and the aero-selector for the realisation of this method - Google Patents

Abstract

The waste water treatment is realised in such a way that the waste water after the optional removal of coarse materials and/or the waste water from the adjoined anaerobic area (17) is recycled in the activation tank (1) through the oxic and anoxic part of the activation by the means of escaping air bubbles created after the air loading into the aeration device (8). At the same time sediments are washed away from the sedimentation tank (2). By the means of the optional creation of the water jump (10) onto the slot (7) by the appropriate velocity of the recycled water and air escaping from the aeration device (8) the activation mixture is pumped into the sludge area or the anaerobic area in the case of phosphorus removal. The cleaned waste water is discharged via the collection channel (11) into recipient. The aero-selector for waste water treatment consists of cylindrical, horizontal activation tank (1) on which the sedimentation tank (2) is connected whose bottom part opens radially into the lower part of the activation tank (1) and this opening area is adapted for the sedimentation degassing. The activation tank (1) is inside equipped with the aeration device (8) for the recycling and aeration of the activation mixture and with an upper opening (5) created along the activation tank (1) in the highest point of its wall. The slot (7) created between the inner wall of the activation tank (1) and the plate-shaped part (6) can end in the opening (5). The activation tank (1) can be equipped with a sludge carrier (9) of cylindrical shape with at least one opening.

Description

A wastewater treatment method and an aero selector for carrying out the method.

RP m-zooi

Technical field

The invention relates to a process for the purification of municipal waste water by activation with partial stabilization of sludge, reduction of nitrogen contamination and phosphorus and an aero selector for carrying out the process.

BACKGROUND OF THE INVENTION

Technological requirements for waste water activation processes such as oxic and anoxic conditions for nitrogen pollution removal, anaerobic conditions for phosphorus removal, sludge removal, adherence to fabric, volume loading and sludge age impose considerable investment and operational requirements on the current purification process. Conventional activation systems for wastewater treatment require the forced removal of sludge from the sedimentation and its further redistribution by recirculation for technological treatment processes and sludge wiping is required for larger treatment plants. In forced sludge recirculation, the inflow of sedimentation in the vast majority of current technological treatment processes is increased over the effluent effluent by recirculated water with a negative impact on sedimentation volume. In current conventional treatment processes, the energy of the activated activation air is no longer used. is disappearing.

Activation procedures for waste water treatment are diverse and their financial and technological demands are such that the state of protection of water pollution is not satisfactory. At present, the possibilities for greater improvement of waste water activation treatment processes are considered exhausted.

It is an object of the invention to simplify the technological treatment process, to reduce investment and operating costs and to ensure greater availability of groundwater and surface water protection.

SUMMARY OF THE INVENTION

This object addresses the method of wastewater treatment of small and medium-sized treatment plants, in which the waste water is recirculated through an oxic r C after the eventual removal of coarse dirt and / or waste water from the assigned anaerobic space by escaping air bubbles created after air introduction into the aeration means. rfcrrrr r.

r r c Γ r r

-2a anoxic part of activation. At the same time, sediments are washed away from the settling tank into the activation tank, and therefore this method of cleaning does not require recirculation of sludge from the settling tank. The effluent flowing in the lower part of the settling tank through the degassing space creates a flocculent cloud. Gases and possible denitrification contamination can escape through the degassing space into the activation tank, with a flocculent cloud having a favorable effect on settling efficiency. Since there is no need to increase the wastewater inflow into the settling tank by the recirculated water withdrawn, it is not necessary to increase the volume of the settling tank.

The escaping air from the aeration agent and the speed of the recirculated water will create a water jump on the slot, allowing the activation mixture to be pumped into the sludge space or even anaerobic space to remove phosphorus. The formation of a water jump results in a rise in the level and recirculation of the activated water by external recirculation due to the difference in hydrodynamic levels. outside the activation tank. Therefore, the requirements for pumping - external recirculation by eliminating forced recirculation of sludge from the settling tank are considerably less than the current method of collecting the diluted sludge water from the settling tank. Pumping requirements are only influenced by maintaining the required dry matter concentration in the activation tank and by removing phosphorus by the need to supply activated sludge to the anaerobic space.

If it is necessary to remove the phosphorus from the waste water, the activation mixture is fed to the anaerobic space. The treated waste water is discharged from the settling tank through a collecting trough into the recipient.

The aero selector according to the invention consists of a cylindrical, horizontally arranged activation tank. This construction is followed by a settling tank, whose bottom space extends radially into the space of the lower half of the activation tank, where the orifice region is adapted to degass the settling by the degassing space. The activation tank is internally equipped with an aeration means for aerating and recirculating the activation mixture.

The location of the aeration means affects the relationship between the energy intensity of aeration and the amount of air supplied and the interaction of the aeration rate of the water jump. Therefore, it is preferred that the aeration means be eccentric arranged relative to the vertical axis of the activation tank in the direction of flow of the activation mixture. The aeration means in the aero selector thus arranged performs the function of a submerged aeration cylinder.

The activation tank is equipped with an upper opening made along the length of the activation tank at the highest point of its wall. A slot formed between the inner wall of the activation tank and the plate-shaped part adjoins the upper opening.

It has been found that a properly selected gap shape, together with the rate of recirculated water, can substantially increase the efficiency of the water jump aeration so that part of the air bubbles escapes outside the gap. The bubbles will plunge into the falling water of the water jump, and the water jump will thus take up an important part of the oxygen supply to the activation tank.

The advantage of the aero selector is that the wall of the activation tank in the region of the placement of the plate-shaped part passes tangentially into a straight section and when the slot width decreases in the direction of flow of the activation mixture.

It has been found to be advantageous that in the area of the settling tank the wall section of the activation tank is straight and then tapered towards the bottom of the settling tank and the adjoining rounded wall is inclined towards the horizontal axis of the activating tank and 7: 1st

In order to maintain a higher sludge age, it is advantageous to insert a cylindrical sludge support with at least one opening into the activation tank. Much of the accumulated sludge is actively involved in the cleaning process. The inlet and outlet of the activation mixture from the sludge support may be variable, for example open from above with the upper inlet and outlet, with occasional depletion of the stabilized thickened sludge, or with the lower inlet and upper outlet with a small slot with automatic leakage of excess sludge.

The design of the aero selector makes it possible to partially cover the activation tank in a relatively simple way to prevent it from cooling in colder periods and regions.

An advantage of the process according to the invention is that no recirculation of sludge from the settling tank is required and there is no need to increase the inflow to the settling tank by recirculated water.

A further advantage is that the aero selector cleaning method does not require additional technological equipment to ensure internal and external recirculation, as sediments are washed away from the associated settling tank. In larger plants, sludge mopping is eliminated.

The cylindrical carrier ensures a high sludge age in the carrier and thus also in the activation tank, which considerably eliminates the effect of external recirculation on the sludge age and ultimately has a beneficial effect on the sensitivity of the cleaning process. The use of a sludge carrier will create selective conditions to suppress the growth of filamentous microorganisms, reduce the energy demand c o r f c <

r. f c r r r

-4-air supply by recirculating and aerating a reduced volume of wastewater with a sludge carrier volume, or an anaerobic environment in the sludge carrier needed to reduce phosphorus.

The method according to the invention using an aero selector achieves a purification efficiency of 90 to 98%. '

BRIEF DESCRIPTION OF THE DRAWINGS

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be explained in more detail in the accompanying drawings, in which: FIG. 1 is a cross-sectional view of an aero selector; and FIG. 2 is a plan view of a treatment plant with a separate anaerobic space.

Fig. 3 shows a cross-section of an aero selector, which also comprises a sludge support, and FIG. 4 is a plan view of the treatment plant using an aero selector with sludge support.

DETAILED DESCRIPTION OF THE INVENTION

The aero selector shown in FIG. 1 is characterized in that it consists of a cylindrical, horizontally arranged activation tank 1, which is structurally connected to the settling tank 2, the bottom space of which extends radially into the space of the lower half of the activation tank 1 and this outlet region is adapted to degass the settling. The activation tank 1 is provided internally with aeration means 8 for aeration and recirculation of the activation mixture, which is arranged eccentric relative to the vertical axis 1.4 of the activation tank 1 in the direction of flow of the activation mixture. The activation tank 1 is provided with an upper opening 5 made along the length of the activation tank 1 at the highest point of its wall. The upper opening 5 is followed by a collecting trough 11 and a slot 7 formed between the inner wall of the activation tank 1 and the plate-shaped part 6. The wall of the activation tank 1 in the area of the placement of the plate-shaped part 6 represents a straight section 1.3.

The aero selector shown in FIG. 3 differs from the aero selector shown in FIG. 1 by placing a cylindrical-shaped sludge support 9 with a single opening in the activation tank 1.

The method of purification of waste water by means of the aero selector shown in FIG. 1 is apparent from FIG. 2. Waste water 14 is recirculated through the oxic and anoxic portions t Γ after the possible removal of coarse impurities after passing through the anaerobic space 17 by means of escaping air bubbles created after the introduction of air into the aeration means 8 in the activation tank 1.

-5aktivácie. At the same time, the sediment from the settling tank 2 is washed away into the activation tank 1. The effluent flowing in the lower part of the settling tank 2 through the degassing space 3 forms a flocculent cloud. At the same time, gases and denitrification contaminants escape from the degassing space 2 through the discharge opening 4 into the activation tank 1. The air escaping through the slot 7 from the activation tank 1 together with the recirculated water speed creates a water jump 10. By water jump 10 the activation mixture is raised. recirculation 16, in which the activation mixture passes into the anaerobic space 17 to supply activated sludge to reduce phosphorus and to sludge space 12 to collect excess sludge. At the same time, the recirculated water flushes the sediment sliding walls from the settling tank 2 into the activation tank 1. In the anaerobic space 17, the activation mixture is mixed by means of a separate mixer. The sludge water 13 flows gravitationally back from the sludge compartment into the activation tank 1. The purified waste water 15 is discharged via a collecting trough 11 to a recipient.

The method of purification of waste water by the aero selector shown in FIG. 3 and 4, in comparison with the aero selector purification method shown in FIG. 1 and 2 is the same, the only difference being that the sludge support 2 with the top opening is inserted into the activation tank 1 and the cleaning does not have a separate anaerobic space.

The cylindrical sludge support 2 ensures a high sludge age in the carrier and thus in the activation tank 1, which considerably eliminates the effect of external recirculation 16 on the sludge age and ultimately has a beneficial effect on the sensitivity of the cleaning process. By using the sludge support 2, selective conditions are created to suppress the growth of filamentous microorganisms, reduce the energy consumption of the air supply by recirculating and aerating the reduced water volume by the sludge support 2 volume, and possibly the anaerobic environment in the sludge support 2 required for phosphorus reduction.

Industrial usability

The aero selector is suitable for small to medium-sized waste water treatment plants.

Claims (9)

Waste water purification method, characterized in that it is carried out by means of an aero selector, wherein the waste water after the optional removal of coarse impurities and / or the waste water from the associated anaerobic space (17) by means of escaping air bubbles generated after introduction of air into the aeration means ( 8) is recirculated in the activation tank (1) through the oxic aanoxic activation part, while leaching the sediment from the settling tank (2), or by creating a water jump (10) on the slot (7) using the recirculated water speed and escaping air from the aeration means ( 8) the activation mixture is pumped into the sludge compartment or anaerobic compartment during phosphorus removal and thus the treated waste water from the sedimentation tank is discharged through a collecting trough (11) to the recipient. Aero selector for carrying out the method according to claim 1, characterized in that it consists of a cylindrical, horizontally arranged activation tank (1), structurally connected to a settling tank (2), provided with a trough (11) for the discharge of purified water, the bottom of which the space extends radially into the space of the lower half of the activation tank (1) and this opening area is adapted to degass the settling, the activation tank (1) being equipped with both aeration means (8) for aerating and recirculating the activation mixture and an upper opening (5) made along the length of the activation tank (1) at the highest point of its wall. Aero selector according to claim 2, characterized in that a slot (7) formed between the inner wall of the activation tank (1) and the plate-like part (6) opens into the upper opening (5). Aero selector according to claims 2 and 3, characterized in that the activation tank (1) is equipped with an aeration means (8) for recirculating and aerating the activation mixture arranged eccentrically relative to the vertical axis (1.4). activation tank (1) in the direction of flow of the activation mixture. ^rr r. rr _r ~ irrr. · r ·· t -Ί- Aero selector according to claims 2 to 4, characterized in that it is advantageous for the wall of the activation tank (1) to tangentially extend into the flat section (1.3) in the region of the placement of the plate-like part (6). Aero selector according to claims 2 to 5, characterized in that it is advantageous if the width of the slot (7) decreases in the direction of flow of the activation mixture. Aero selector according to claims 2 to 6, characterized in that in the region of the location of the settling tank (2), the wall section (1.2) of the activation tank (1) is straight, inclined towards the settling tank (2) and the adjacent rounded wall (1.1) ) to the section (1.2) is inclined in the direction of the horizontal axis (1.5) of the activation tank (1). Aero selector according to claims 2 to 7, characterized in that the settling tank (2) is formed by inclined walls (1.2, 2.1), preferably with a slope of 1.7: 1. Aero selector according to claims 2 to 8, characterized in that it is advantageous if the activation tank (1) is provided with a sludge support (9) of cylindrical shape with at least one opening.