SK286874B6 - Device for waste water treatment - Google Patents

Abstract

It is described a device for continuous cleaning of waste waters through modified activating process, which connects in one tank activating space with non aerated anaerobic and anoxic zones and aerated oxic zone, sedimentation and retention space, with internal recirculation between the zones of activation space and recirculation of reverse sludge between activation space and sedimentation space, wherein the tank (1) with a bottom (2), an external housing (3) and a top (4) is divided to a non aerated activation space (8), an aerated activation space (9), a sedimentation space (10) and a retention space (25), where the non aerated activation space (8) is separated from the aerated activation space (9) by a separating wall (5) extending from the bottom (2) up to the top (4) of the tank (1) and having a leaching opening at the bottom (2) level of the tank (1) or at the level of an outflow piping (12) from the tank (1), the sedimentation space (10) is bordered inside the aerated activation space (9) by a housing (6) extending from the bottom (2) up to the top (4) of the tank (1) and having a leaching opening (7) at the bottom (2) level of the tank (1) and the retention space (25) is bordered in the tank (1) between the level of outflow piping (12) from the tank (1) and the level of a inflow piping (26) all over the surface of the tank (1) above the non aerated activation space (8), the aerated activation space (9) and the sedimentation space (10), where the non aerated activation space (7) is divided by at least five walls (13) facing the progressive flow, which are extending from the bottom (2) up to the top (4) of the tank (1), having leaching openings (14) alternately situated at the level of the bottom (2) of the tank (1) and inside the outflow piping (12) of the tank (1), wherein in the sedimentation space (10) is a flow controller (15) integrated on the outflow piping (12) from the tank (1).

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plant for continuous biological treatment of wastewater from small sources of pollution with a modified activation process which combines an activation space with spatially separated anaerobic, anoxic and oxic zones, a settlement space and a retention space in a tank. activation and setting space.

BACKGROUND OF THE INVENTION

Small wastewater treatment plants serve for waste water treatment with sewage pollution from sources that cannot be connected to public sewerage. Wastewater treatment from small pollution sources is a complex problem, as the problem of the considerable variability of wastewater flows and the variability of pollution from these small sources has to be addressed. In relatively short sections of sewage collectors the quantity and quality of waste water will not be balanced, and the individual technological stages of the waste water treatment process (buffer tank, mechanical, biological and eventual purification stage) must be adjusted so that they are not overloaded and the necessary delay time is not exceeded and loading the area in the bearing space. If conditions are not created to balance the quality and quantity of the wastewater flow, these levels should be significantly oversized. Waste water treatment plants are designed for an average flow rate of Q ₂₄ . Hourly flow unevenness is expressed by another dimensioned flow rate, maximum hourly flow rate Q _max .

DE4307288 discloses a biological waste water treatment device which does not comprise a separate buffer tank. The flow equalization takes place in the settling tank, activation tank and settling tank, possibly also in the sludge pit, ie in the entire waste water treatment plant. To equalize the amount of waste water, the waste water from the settling tank is continuously pumped until a certain lower limit of the water level in the settling tank is reached when pumping is stopped until a higher level is reached due to the wastewater inflow.

Also, U.S. Pat. No. 3,886,065 does not disclose a particularly dedicated buffer tank in the described sewage treatment plant; the equalization is achieved in the settling, activation and settling tank. The waste water from the settling tank is continuously pumped through the sub-level drain pipe to another tank.

DE 199 16 381 A1 describes a small wastewater treatment plant for biochemical treatment, in which the quality and quantity balance also takes place in the settling and activation space, but without the need to drain the collected amount of waste water to another tank. For capturing higher inflows, the actual volume of these tanks is used. Waste water from biological treatment is pumped by one pump or a pair of pumps to further treatment stages, with a constant flow rate. The pump performance is chosen to be higher than the average daily flow, but low enough to keep the pump off intervals as short as possible.

In all of the above solutions, the level and quality of the contaminated waste water is achieved directly in the activation area or in the activation area and other functional tanks or treatment plant areas without a dedicated buffer tank, but the leveling is achieved by pumping. .

An alternative option for wastewater treatment with high flow and quality variability is the use of sequencing batch reactor (SBR). This system uses two or more reactors that are operated in a periodic mode: filling, cleaning, settling and discharging. SBR systems perform all cleaning processes including quality and quantity balancing in one tank. Unlike multi-reactor continuous systems, it is difficult to maintain conditions within the same tank for diametrically different processes such as e.g. nitrification and denitrification. It is difficult to determine the process run time (eg nitrification) at different flow rates and contaminants of the inflow, so these reactors must be rated for the worst case scenario, leading to oversizing of the SBR reactors.

Demand for the quality of discharged treated waste water from small wastewater treatment plants is also increasing. In cases where treated wastewater is discharged to sensitive areas in terms of eutrophication, or treated wastewater is discharged into groundwater or recycled, high and stable efficiencies of wastewater treatment plants, even from small pollution sources, must be ensured. In such cases, small treatment plants must also ensure the removal of nitrogen and phosphorus from the waste water. In order to ensure biological removal of nitrogen and phosphorus from wastewater in large wastewater treatment plants, modified activation processes such as waste water treatment are used. UCT PROCES, developed at the University of Cape Town, using a suitable sequence of processes in the anaerobic, anoxic and oxic reaction zones. This process was further modified to MUCT PROCES (modified UCT). In these processes, there are more anoxic zones and the return activated sludge is directed not to the anaerobic, but to one of the anoxic zones. The nitrate-depleted activation mixture is recirculated to the anaerobic zone by so-called internal recirculation from the anoxic zone. The obvious disadvantage of these processes is the high cost of pumping machines through the equipment

- by pumps, in recirculating the sludge, recirculating the activation mixture between the oxic and anoxic spaces and recirculating the activation mixture between the anoxic space and the anaerobic space. Another disadvantage is the cost of mixing non-aerated anaerobic and anoxic machine spaces

- submersible mixers. These processes have not yet been applied in small sewage treatment plants due to the need for a complex internal division of tanks into a plurality of non-aerated and aerated zones and expensive mixing technique to mechanically agitate the contents of the non-aerated spaces.

When designing and implementing small sewage treatment plants, small sewage treatment plants need to be easily transportable finished products or mountable on site with a minimum of construction work, conforming to the application or terrain conditions in order to be modular and scalable in parallel with the growth in the quantity produced waste water. Small wastewater treatment plants with an integrated retention space according to the state of the art do not meet all these requirements simultaneously.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a wastewater treatment plant design for small wastewater sources which can be made in one compact unit with variation in shape and modularity using simple concrete load-bearing structures and light thermoplastic wall or structural elements. as a whole, fulfill the task of balancing variable flow rates and achieve the highest possible efficiency of biological treatment with nitrogen and phosphorus removal at low demands on pumping and mixing technology.

SUMMARY OF THE INVENTION

This problem is solved and the deficiencies of the known devices are substantially eliminated by the continuous wastewater treatment plant by a modified activation process which combines an activation space with un aerated anaerobic and anoxic zones and an aerated oxic zone, the settling space and retention space with internal recirculation in one tank. activation space and recirculation of the return sludge between the activation and settlement space according to the present invention, characterized in that the tank consisting of the bottom, outer shell and ceiling is divided into a non-aerated activation space, aeration activation space, settlement space and retention space so that the non-aerated activation space is separated from the aerated activation space by a partition extending from the bottom to the ceiling of the tank and having a through hole at the bottom level n The tank is defined within the aerated activation space by a shell extending from the bottom to the ceiling of the tank and having a through hole at the bottom of the tank and the retention space is defined in the tank between the level of the tank drain and the inlet pipe level. into the tank over the entire surface of the tank above the non-aerated activation space, the aerated activation space and the mounting space, the non-aerated activation space is divided by at least five dividing walls extending from the bottom to the ceiling of the tank, having through holes alternating at the bottom of the tank a flow regulator is provided on the drain line from the tank.

Due to the formation of anaerobic and anoxic conditions in the non-aerated activation space, it is essential that the number of internal partition walls is at least five, thus defining one anaerobic zone and two anoxic zones in the non-aerated activation space according to the direction of internal recirculation between the activation space zones and activation and setting space.

In order to resolve the mixing of the contents of the non-aerated activation space, it is essential that the alternating arrangement of the through holes on successive internal partition walls in the direction of successive flow through the non-aerated activation space creates conditions for ideally mixing the contents of the non-aerated space without mechanical agitators.

To effectively equilibrate fluctuating flow of raw sewage into the facility for wastewater treatment, it is essential that due to throttling effect of regulating the flow at the outlet of the device according to the invention occurs in the case of a higher flow rate than the average sized flow Q ₂₄ to increase the water level in the whole basin of the level water level corresponding to the level of the outlet pipe up to the water level corresponding to the level of the inlet pipe, respectively. level of the safety case, whereby the internal partitions in the non-aerated activation space, the partition between the aerated activation space and the non-aerated activation space and the enclosure of the installation space do not allow unrestricted intermixing of the contents of the individual spaces and zones and therefore all wastewater treatment processes can take place undisturbed in the retention area. In order to allow modularity and adaptation to the gradual increase in wastewater production, it is advantageous that the continuous wastewater treatment plant by the modified activation process according to the invention may consist of a quadrangular floor plan with a bottom, outer shell and ceiling, in the non-aerated activation space. extending from the bottom of the tank to the ceiling of the tank, with through holes alternating at the bottom of the tank and at the level of the downstream pipe, arranged in one row or in two or more rows, the rows being separated by a guide wall.

The device for continuous treatment of waste water by a modified activation process according to the invention can conveniently be realized in a tank of circular plan with a bottom, an outer jacket and a ceiling. The tank of the device according to the invention may also have a polygonal shape, for example a square or hexagon, the tank being divided by one concentrically arranged dividing wall of circular or polygonal ground plan into a non-aerated activation space and an aerated activation space with a through hole at tank level or tank bottom . In the non-aerated space there are radially arranged inner dividing walls extending from the bottom to the ceiling of the tank with permeable openings alternately at the bottom of the tank and at the level of the outlet pipe in the direction of the flow.

The device according to the invention is preferably realized in monolithic or prefabricated concrete tanks made of watertight concrete with a circular, quadrilateral and polygonal ground plan, where the bottom, the outer shell, the partition between the non-aerated activation space and the aeration activation space and the waterproofed concrete deflector are made. the walls and casing of the seating space made of thermoplastic structural elements based on polyethylene, polypropylene or polycarbonate. The device according to the invention is preferably also realized in tanks with a circular, quadrilateral and polygonal ground plan, where the bottom, the outer shell, the partition wall between the non-aerated activation space and the aeration activation space and the deflector are made of thermoplastic structural elements based on polyethylene, polypropylene or polycarbonate.

For ease of operation of the flow controller without maintenance, it is important that the throttle orifice inside the flow controller is protected against clogging of dirt and activated sludge flake by a screen which is periodically flushed with purified waste water, the flushing mechanism being periodically blown in the pressurized air or pressurized water through an opening into the hollow body of the flow regulator below the outlet orifice and the pressurized air or pressurized water displaces the purified water present in the flow regulator in the space between the flow regulator housing and the passage inside the flow regulator; only after reaching the level of the inlet opening of the overflow pipe, pressurized water starts to escape, resp. air through the throttle orifice, the short-time impact of the pressurized water or the mixture of pressurized air and pressurized water thus created is sufficient for the cleaning of the screen.

By addressing the shortcomings of the prior art for the small wastewater treatment plants of the present invention, a wastewater treatment plant design for small wastewater sources has been designed that can be made in one compact unit with variation in shape and modularity using simple concrete support structures and lightweight thermoplastic wall or structural elements, while allowing in one functional unit to fulfill the task of balancing variable flow rates and achieving the highest possible efficiency of biological treatment with removal of nitrogen and phosphoium at low demands on the mixing technique.

BRIEF DESCRIPTION OF THE DRAWINGS

BRIEF DESCRIPTION OF THE DRAWINGS The invention is further illustrated by the following examples, which are described in the accompanying drawings, in which:

FIG. 1 a, b, a waste water treatment plant according to the invention,

FIG. 2 a, b, c waste water treatment plant with a quadrangular plan,

FIG. 3 a, b, c Wastewater treatment plant with a circular, square or polygonal plan,

FIG. 4 flow controller.

DETAILED DESCRIPTION OF THE INVENTION

Example # 1

A continuous wastewater treatment plant by a modified activation process according to the invention; 1a, b, consists of a tank 1 with a bottom 2, an outer shell 3 and a ceiling 4. The tank 1 is divided by a partition 5 into a non-aerated activation space 8 and an aerated activation space 9. The ratio of the non-aerated space 8 to the aeration space is approximately 1: 1, as shown in the prior art for nitrogen and phosphorus removal systems from waste waters with a high proportion of unfermented organic carbon. The settling space 10 is allocated within the aerated activation space 9 by the housing 6 of the settling space. In accordance with established design principles for the activated sludge feeder space, the feeder space housing 6 has the shape of a complete inverted and truncated cone or prism (Fig. 1a), or a portion of an inverted and truncated cone, a prism (Fig. 1b). of the space 10 encloses with the bottom 2 of the tank 1 a minimum inclination of 60 °. The dividing wall 5 and the housing 6 of the settlement space 10 extend from the bottom 2 to the ceiling 4 of the tank 1. In the dividing wall 5, the opening 11 is permeable at the level of the outlet pipe 12 or at the bottom 2 of the tank 1. The non-aerated activation space 8 is further divided by a series of inner partition walls 13 that extend from the bottom 2 to the ceiling 4 of the tank 1. The individual successive partition walls 13 have through holes 14 alternately at the bottom 2 of the tank 1 and at the level of the outlet pipe 12 from the tank. A flow regulator 15 is arranged below the surface of the purified water in the settling space 10, FIG. 4. The flow regulator 15 is a hollow body consisting of a casing 16, an inlet opening 17 and an outlet orifice 18, the inlet opening 17 being protected by a protective screen 19. In the outlet orifice 18 there is a throttling orifice 20 with a dimensioned permeability for waste water flow. that is equal to the average rated flow rate of the waste water treatment plant Q ₂₄ . Inside the flow regulator 15 there is a leakage conduit 21 whose inlet port 22 is just behind the inlet port 17 of the flow regulator 15 and the outlet port 23 is connected to the throttle port 20. There is purified water in the space between the leakage port 21 and the casing 16. Under the outlet orifice 18, an opening 24 is provided in the flow regulator housing 16 for supplying a fluid pressure medium, e.g. compressed air or pressurized water. A safety opening 30 is provided in the settling space 10, which serves for draining waste water with a higher flow rate than the maximum flow rate Q _max .

Purified water flows from the safety case 30 to a drain, bypass or other tank not shown in the figures.

The retention space 25 is defined in the tank 1 between the level of the outlet pipe 12 from the tank 1 and the level of the inlet pipe 26 into the tank 1 over the entire surface of the tank 1, i.e. above the non-aerated activation space 8, aerated activation space 9 and settling space 10, the partition wall 5 , the inner partition walls 13 and the housing 6 of the bearing space 10 define in the retention space 25 anaerobic, anoxic, oxic and separation conditions for the activated sludge. The method of aerating the contents of the aerated activation space 9 is well known in the art. The compressed air source (not shown) is also a source of compressed air for the mammoth pumps 27, 28, 29, which recirculate the sludge from the settling space 10 to the non-aerated activation space 8, recirculating from the aerated activation space 9 to the non-aerated interior activation space 8 and. within the non-aerated activation area 8.

The raw wastewater inflow is connected through the inlet pipe 26 to the non-aerated activation space 8. The activation mixture, which is formed by mixing raw wastewater and recirculated activated sludge, flows through a series of internal partition walls 13 having an alternately permeable opening 14 at the bottom 2 of tank 1 and at the level of the outlet pipe 12. The alternating arrangement of the through holes 14 at different heights on the partition walls 13 in the flow direction creates conditions for ideally and gently mixing the contents of the non-aerated space 8 without using mechanical stirrers in which anaerobic and anoxic conditions for activated sludge. From the non-aerated space 8, the activating mixture flows through a permeable opening 11 in the partition 5 into the aerated activation space 9. In the aerated space 9, the oxic conditions for activated sludge are maintained by aeration. From the aeration chamber 9, the activating mixture flows into the settling space 10 through a through hole 7 in the housing 6 of the settling space 10. In the settling space 10, activated sludge is separated from the treated water by gravity and the activated sludge is sucked out of the settling space 10 by means of a mammoth pump 28 into the non-aerated activation space 8 and the purified water flows through the flow regulator 15 and the outlet pipe 12 from the tank 1 of the waste water treatment plant. Purified water enters the flow regulator 15 via the screen 19 at the inlet port 17 of the flow regulator 15. Inside the flow regulator 15 downstream of the screen 19 is the inlet port 22 of the discharge conduit 21 which at the other end opens in the throttle port 20 of the outlet orifice 18. aperture 18 flows freely treated waste water through the outlet pipe 12 of the tank 1. the function flow 15 is that through calibrated throttle bore 20 can flow only purified water in such a flow rate equal to or less than the average flow rate Q ₂₄ to which they are dimensioned area and volume of the settling space 10. In the case of a higher flow, the water level in the entire tank 1 will increase from water level A up to level B due to the throttling effect of the flow regulator 15. Inner dividing walls 13, dividing wall 5 and housing 6 10 do not allow unlimited mixing of the content j Thus, all the wastewater treatment processes can take place undisturbed also in the retention space 25. The throttle opening 20 and the transfer pipe 21 are protected against clogging of the sludge and the activated sludge flake by a protective screen 19 which is periodically flushed with purified waste water. The flushing mechanism is such that periodically pressurized air or pressurized water is blown through the opening 24 into the hollow body of the flow regulator 15 below the outlet orifice 18. The pressurized air or pressurized water displaces the purified water present in the flow regulator 15 first through the protective screen 19 and only after reaching the level of the inlet opening 22 of the passage pipe 21, pressurized water starts to escape through the throttle opening 20. The short-term impact of the pressurized water or the pressurized air / pressurized water mixture is sufficient to completely clean the protective screen 19 which never needs to be manually cleaned. The material of the outer shell 3, the bottom 2 of the tank 1, the partition wall 5 and the inner dividing walls 13 of the tank 1 and the housing 6 of the seating space 10 can be made of thermoplastic wall or structural elements of polyethylene, polypropylene or polycarbonate. The container 1 may have standard external container dimensions to facilitate transportation. The tanks 1 may be joined at the installation site into larger units at once or gradually as the amount of waste water produced increases.

The material of the load-bearing walls - the outer sheath 3, the bottom 2 of the tank 1 and the partition wall 5 can be made of waterproofing concrete and the inner partition walls 13 and the housing 6 of the seating space 10 can be made of thermoplastic wall or construction elements of polyethylene, polypropylene or polycarbonate or a combination of these materials.

Example # 2

The device for continuous waste water purification by a modified activation process according to the invention, FIG. 2 a, b, c, consists of a tank 1 of a rectangular plan with a bottom 2 outer shell 3 and a ceiling 4. The tank 1 is divided by one partition 5 into an aerated 8 and aerated space 9 with a through hole 11 at the level of the drain 12 from tank 1 or at the bottom 2 of the tank 1. In the non-aerated activation space 8 there is a series of inner partition walls 13 extending from the bottom 2 of the tank to the ceiling 4 of the tank with through holes 13 alternating at the bottom 2 of tank 1 and at the level of the outlet 12 in the flow direction, which are arranged in one row (Fig. 2a) or in two or more rows (Fig. 2b). If the inner partition walls 13 are arranged in a plurality of rows, they are separated by a guide wall 31, the direction of successive flow being opposite to the left and right sides of the guide wall 31 so that the principle that waste water flows sequentially through all the inner dividers wall 13 and finally flows through the permeable opening 14 into the aerated activation space 9. Multiple tanks 1 according to the invention may be connected in parallel to larger units (Fig. 2c), thus allowing a gradual increase in wastewater treatment plant capacity as the raw wastewater production increases.

Example # 3

The device for continuous waste water purification by a modified activation process according to the invention, FIG. 3 a, b, c, consists of a tank 1 of circular plan view with a bottom 2 of the outer shell 3 and a ceiling 4. The tank 1 may also have a regular polygonal shape, for example a square or a hexagon. The tank 1 is divided by one concentrically arranged partition wall 5 of circular or regular polygonal plan view into an un aerated activation space 8 and an aerated activation space 9 with a through hole 11 at the level of the outlet pipe 12 from the tank 1 or at the bottom 2 of the tank 1. In the un aerated activation space 8 there are radially arranged inner dividing walls 13 extending from the bottom 2 to the ceiling 4 of the tank 1 with through holes alternately at the bottom 2 of the tank 1 and at the level of the outlet pipe 12 in the direction of the flow.

Industrial usability

The device according to the invention can be used for the treatment of waste water from various, especially small sources, both municipal and industrial, with biodegradable pollution. Thanks to its flexibility, the device is particularly suitable for decentralized wastewater treatment solutions for small municipalities, schools, restaurants, hotels, guest houses, industrial parks built on a green field and the like. The equipment is modular, can be gradually joined into larger units according to the increase in wastewater production. The advantage is low construction costs, as the technical solution allows to deliver ready-made, "packaged" waste water treatment plants that require minimal assembly and construction work on site, while the quality of the purified water also meets the increased requirements in terms of waste water quality. can also be used for discharging purified waste water into surface waters in sensitive areas where there is a risk of eutrophication of surface waters or for discharge into groundwater, as well as for recycling of treated waste water.

Claims (6)

1. A continuous wastewater treatment plant by a modified activation process which combines an activation space with un aerated anaerobic and anoxic zones and an aerated oxic zone, a settlement space and a retention space in one tank, with internal recirculation between the activation space between the activation space and the recirculation space and a settling space, characterized in that the tank (1) with the bottom (2), the outer shell (3) and the ceiling (4) is divided into a non-aerated activation space (8), an aerated activation space (9), a settling space (10) ) and a retention space (25), wherein the non-aerated activation space (8) is separated from the aerated activation space (9) by a partition wall (5) extending from the bottom (2) to the ceiling (4) of the tank (1) and having a through hole ( 11) at the bottom (2) of the tank (1) or the level of the outlet pipe (12) from the tank e (1), the seating space (10) is defined within the aerated activation space (9) by a shell (6) extending from the bottom (2) to the ceiling (4) of the tank (1) and having a through hole (7) at the bottom ( 2) the tank (1) and the retention space (25) is defined in the tank (1) between the level of the drain pipe (12) from the tank (1) and the level of the inlet pipe (26) to the tank (1) over the entire surface of the tank (1) above the non-aerated activation space (8), the aerated activation space (9) and the seating space (10), the non-aerated activation space (8) is divided by at least five dividing walls (13) in a flow direction extending from the bottom (2) to the ceiling ( 4) tanks (1) having through holes (14) alternately at the bottom (2) of the tank (1) and at the level of the drain line (12) from the tank (1), which is arranged on the drain line (10) 12) a flow regulator (15) from the tank (1). Wastewater treatment plant according to claim 1, characterized in that the tank (1) has an outer shell (3) of circular or polygonal plan view with at least four angles and a partition wall (5) between the non-aerated activation space (8) and the aerated activation space. the space (9) is concentrically arranged with a circular or polygonal plan view with at least four angles, wherein the non-aerated activation space (8) is divided by at least six radially arranged inner dividing walls (13) in the direction of successive flow. Wastewater treatment plant according to claim 1, characterized in that the tank (1) has an outer shell (3) of rectangular plan and in the non-aerated activation space (8) there are at least two rows of inner partition walls (13) separated by a guide wall (31). ), with internal partition walls (13) extending from the bottom (2) of the tank to the ceiling (4) of the tank with through holes (13) alternating at the bottom (2) of the tank (1) and at the level of the drain pipe (12) flow, with a guide wall (31) extending from the bottom (2) of the tank to the ceiling (4) of the tank. Waste water treatment plant according to claims 1 to 3, characterized in that the material of the bottom (2), the outer shell (3) and the partition wall (5) between the non-aerated activation space (8) and the aerated activation space (9) and The guide wall (31) is a waterproofing concrete and / or thermoplastic such as polyethylene, polypropylene or polycarbonate and the material of the inner partition walls (13) and the sheath (6) is a thermoplastic such as polyethylene, polypropylene or polycarbonate. Wastewater treatment plant according to claims 1 to 4, characterized in that the flow regulator (15) comprises / comprises a throttling orifice (20), a coarse dirt screen (19) at the inlet neck (17), a housing (15). 16) a flow regulator (15), a passage line (21) and an inlet (24) of a pressurized fluid medium into the interior of the flow regulator (15). Wastewater treatment plant according to claim 5, characterized in that the pressurized fluid medium is pressurized air or pressurized water.