EA008870B1 - Process for biological treating of residential and industrial waste waters, plant and flotator therefor - Google Patents

Abstract

The invention relates to a biologic treatment of residential and industrial waste waters. The invention is aimed at providing continuous operation of a water treatment plant for volley sewage. According to the process, the volley sewage is treated using continuous airation, flotation, silt recirculation and discharge of purified water. The proposed flotator comprises a housing with a disperser positioned in an receiving chamber. The disperser is designed as a gas-permeable partition provided with a sloping screen and a deflector baffle. The water treatment plant comprises a control unit, a water capacity with an airocontainer, a settling, filtration and clear water basins. The settling basin is executed as a buffer capacity for the volley of sewerage and equipped with a flotator. In other embodiments the water treatment plant has a by-pass pipe line; the setting basin has a labyrinth channel with aerators; the filter in the filtration chamber is provided with a filter cleaning means.For volley of sewage conditions the water treatment plant preserves active silt and keeps operation abilities quickly returning to standard values of waste water treatment at rated waste water consumption.

Description

The invention relates to the biological treatment of wastewater using activated sludge in suspension and is intended for the treatment of wastewater (effluent) of residential buildings.

A known method of cleaning wastewater and device for its implementation, containing the aeration tank, a cylindrical shaft, a clarifier, an aeration system with a compressor, see No. 8I No. 1174385, M.cl. C02E 3/02, 1984

This method and device are characterized by increased power consumption and low efficiency.

A similar method and device for biological wastewater treatment is known, containing an aeration chamber with aerators, a two-tier sludge settling tank, wastewater input, pipelines for pumping wastewater between the chambers and a wastewater disposal unit, see CI No. 819069, M.cl. C02E 3/02, 1978 and No. 2057085, cl. С02Е 3/02, 1994

The disadvantage of this analogue is that in case of salvo discharges of large volumes of effluents, their cleaning is not ensured, and there is also no protection against sludge entrainment with the stream of salvo discharge.

The closest analogue adopted for the prototype of the invention (in terms of the method and installation) is the method of biological wastewater treatment and installation for its implementation in patent KI No. 2201405, M.cl. С02Е 3/02, 2002

According to this method, when biological wastewater treatment is carried out, wastewater is supplied to the surge tank of the plant, wastewater is treated with activated sludge successively in surge tank and activation tanks with recirculation and trapping of spent sludge in the sludge collector, and the treated wastewater is cleaned in the purification chamber by filtration in the bulk filter from granular material and the withdrawal of treated wastewater from the cleaning device, while water purification is carried out cyclically with pauses between cycles.

Installation for the implementation of this method contains a surge tank with a nozzle input wastewater, aerator and level sensor; activation tank equipped with an aerator, level sensor, sludge recirculation pump, sump connected via an overflow pipe to a cleaning chamber with a filter, cleaning means and a pump for pumping treated wastewater; The sludge stabilization chamber is equipped with an aerator and communicated with a surge tank by means of an overflow pipe. The installation is also equipped with a control unit connected to aerators, pumps and level sensors.

The disadvantage of this method and installation is inefficiency when salvo discharges of waste due to the loss of sludge. At the same time, the installation has a complex and cumbersome design, is energy-intensive and unreliable in operation due to the rapid silting of the filter, equipped with an inefficient means of cleaning.

In terms of the flotation unit, a flotation unit is known in the art, made in the form of a separate tank containing pipelines for supplying a water-sludge mixture and removal of purified water, bunkers for collecting circulating and excess sludge. The upper edges of the tank walls are located above the level of the water-sludge mixture. The tank is also equipped with a belt conveyor with scrapers, and each bunker is equipped with an iodroben and a pipeline for feeding the transporting fluid, see No. 8I No. 1763391, C02E 3/12, 1992.

This flotation plant, which is an independent unit in the treatment plant, is structurally complex and energy-intensive. In addition, to ensure its operation, it is necessary to maintain a vacuum.

As the closest analogue chosen for the prototype, is a flotation cell containing a cylindrical tank with a central inlet pipe communicated with a water distributor, foam collector and collection trays, perforated aeration pipes placed at the bottom of the tank, as well as a floating loading clarification chamber and collecting compacted sludge . In addition, a mixer is installed in the central supply pipe, see KI No. 8351, C 02E 1/5, 1998.

This flotation device is not used due to the complexity of the design and inefficiency at work.

The problem solved by the claimed invention is to ensure the preservation of health in conditions of uneven inflows, as well as effective and quality wastewater treatment with cost reduction in the construction and operation of sewage treatment plants.

The solution of this problem (in terms of the method) is due to the fact that in the method of cleaning household and industrial wastewater, including periodic cycles of treating wastewater with activated sludge in a biological treatment plant, according to the invention, with volley tributaries of wastewater, the volume of volley tributaries is processed with continuous aeration and continuous flooding of sludge from the water-sludge mixture, which is recycled, while the purified from the sludge water is continuously removed from the installation.

In terms of installation, the solution of this task is ensured by the fact that the installation for biological treatment of domestic wastewater includes a tank divided by partitions into process compartments in the form of a receiving chamber with an inlet node, an aeration chamber, a settling chamber, a sludge collection chamber, a filtering chamber with a filter and a chamber for the collection of clean water with a node for the withdrawal of clean water, as well as aeration system with aerators and airlifts, level sensors of the water mixture with activated sludge in the tank, connected to the control unit of the installation, according but the invention sludge collection chamber is formed as a buffer tank for receiving waste water inflows salvo and additionally about

- 1 008870 ore floatator with inlet, waste and outlet nozzles, while the waste and output nozzles are made in the form of airlifts, discharge lines which are connected, respectively, to the receiving chamber and the filtration chamber. In preferred embodiments, the installation is additionally equipped with a bypass discharge pipe; the sludge collection chamber is additionally equipped with at least two partitions installed at a distance from each other to form a labyrinth channel in which aerators are installed; The filtration chamber is additionally equipped with a level sensor and filter cleaning means, made in the form of an I-shaped airlift with an inlet collecting funnel located on the surface of the filter, as well as a purge element located under the filter and made in the form of a perforated casing with through perforations connected through an electro-valve pressure line of compressed air supply, while the solenoid valve is installed at the outlet of this chamber; the filter is made of three layers with different grain sizes of the load in layers, which decrease from layer to layer in the direction from the entrance to the exit from the chamber, while the filter layers are located on the mesh bases with the corresponding cell size; the node for the withdrawal of clean water is equipped with an electrovalve.

The solution of this problem is also provided by the fact that the flotation device contains a housing with a water-sludge mixture inlet pipe, foam and purified water outlet pipes and a dispersant connected to the compressed air supply line, according to the invention the flotation machine is provided with a receiving chamber with a dispersant and a suction pipe connected to the airlifts , made in the form of waste and outlet pipelines, the dispersant is made in the form of a gas-permeable partition located under the outlet of the suction nozzle; A sloped screen and a baffle plate are installed above the disperser, with a channel between the baffle plate and the disperser connected to the outlet pipe, and between the inclined screen and the wall of the receiving chamber there is a channel connected to the waste pipe.

The technical effect of the use of the proposed invention is to ensure reliable operation of the UBO under uneven conditions, including emergency salvo tributaries of waste water.

The invention is illustrated in the drawings, where:

in fig. 1 - a general (in plan) view of the proposed installation;

in fig. 2 - the same, section A-A of FIG. one;

in fig. 3 - longitudinal section of the filtration chamber (enlarged);

in fig. 4 - a general view of the flotation cell (longitudinal section);

in fig. 5 is a section BB of FIG. four.

The proposed method is explained on the basis of the description of the installation.

The plant for biological wastewater treatment (UBO) contains chambers 1-6, of which chamber 1 is the receiving (averaging) chamber; chamber 2 - sludge collection; chamber 3 - filtration; chamber 4 is a collection of pure water; chamber 5 - settler; camera 6 - aero tank.

Chamber 1 is provided with an inlet 7 for injecting wastewater, chamber 2 is equipped with a flotation cell 8, chamber 3 is equipped with an overflow branch pipe 9, chamber 4 is equipped with a branch pipe 10 for outputting purified water. In addition, the UBO is equipped with an aeration system in the form of compressors (not shown) connected to aerators 11a, 11b, 11b, and 11d and airlifts 12, 13, 14, 15, 16, 17, 18, 19, 20, 21. In the separation partition Between chambers 1 and 2 there is an overflow pipe 22, see FIG. 1, 2, for bypass into chamber 2 of the critical flow rate of a salvo discharge. Above nozzle 22 is located nozzle 23 for outputting emergency inflows into bypass pipeline 24. Chamber 1 is also equipped with a level sensor 25 with signaling devices located at levels a, b, c, b and ί connected to a control unit (conventionally not shown) for automatic switching UBO operating modes, depending on the position of the level of effluent in chamber 1 relative to the established levels (a, b, c, b,). Chamber 2 has longitudinal partitions 26a and 26b, which form a labyrinth channel for the flow of wastewater. It is advisable that aerators of 11d and 11th were installed at the entrance and exit of this channel.

The flotation cell 8 is provided with a suction nozzle 27, a waste nozzle 28, an outlet nozzle 29, a chamber 30 with a permeable partition 31. The chamber 30 is connected to the pressure line 32 of the compressed air supply. A sloped screen 33 is installed above the chamber 30, as well as a fender visor 34. A slotted channel is formed between the permeable partition 31 and the fender visor 34, which communicates with a receiving chamber 35 connected to the outlet nozzle 29. The nozzles 28 and 29 are made in the form of airlifts and are connected, respectively , to pressure lines 36 and 37 of compressed air supply.

Chamber 3 is equipped with a three-layer filter with different loading grains in layers 38a, 38b, 38c. The grain in the layers of the filter decreases from layer to layer in the direction from the entrance to the exit of the chamber, while the layers 38a-v are located on the mesh bases 39a and 39b with the corresponding cell size. In the chamber 3 there is also an I-shaped airlift 40, the entrance of which is equipped with a collection funnel 41 located on the surface of the filter layer 38a. In addition, a water level sensor 42 is installed in the chamber 3. A purge element 43 is installed in the form of a cylindrical perforated shell with through perforations under the three-layer filter. It is connected to the nozzle 44 with an electro-valve 45. The outlet nozzle 10 is also equipped with an electro-valve 46a connected to the level sensor 47.

- 2 008870

Due to the fact that when cleaning waste water having a variable flow, the calculation of utilities and facilities is performed taking into account the maximum flow, it is advisable that the volume of chamber 2 be at least 1/3 of the total volume of chambers 1, 3-6, which ensures averaging over the composition of incoming effluent and stabilization of the conditions of their treatment in the UBO. Accordingly, the performance of the aforementioned airlifts should be selected from the condition of ensuring the possibility of uninterrupted operation of the UBO under conditions of maximum inflows.

UBO works as follows.

For tributaries (including periodic), the volume of which does not exceed the level of effluent in chamber 1 above the established level (b), the plant operates in periodic mode with cyclic treatment of effluent with activated sludge in each period including the period of sedimentation of sludge, filtration and release treated effluent. In this case, the effluents entering chamber 1 are averaged by composition and pumped into chamber 6, where they are cleaned with active sludge. From chamber 6, a mixture of water with activated sludge (sludge mixture) is pumped by airlift 19 into chamber 5, and after a period of sedimentation of silt, the settled water is pumped by airlift 17 for purification into a filtration chamber 3, from where it goes through outlet 9 to outlet 4 and then to outlet through pipe 10.

When the level of waste in chamber 1 falls below the set minimum level (a), the activation process (in chamber 6) is automatically interrupted, and after a set time delay (set in the control unit), part of the sludge mixture is pumped from chamber 6 to chamber 1, which is periodically aerated. If the drains do not arrive for a long time (the time is set in the control unit), then the sludge life is maintained by automatically switching to the standby mode with periodic ring transfer of the sludge mixture from chamber 4 to chambers 1, 2, 6 and 5 during the period of no runoff .

When the wastewaters (including uneven) enter and their level in chamber 1 rises to the set level (s), the installation is automatically switched to the operation mode using chamber 2 as a buffer with pre-treatment of the effluent with active sludge. In this mode, part of the effluent is pumped into chamber 2 with feed to the aerated entrance of the labyrinth channel between partitions 26a and 26b, while chamber 2 is continuously aerated. When the level of effluent in chamber 1 decreases to level (b) due to pumping of the sludge mixture into chamber 2, as well as periodic pumping into chamber 6, pumping of the sludge mixture from chamber 1 into chamber 2 stops. If during this period fresh wastewaters do not enter chamber 1, then when the sludge mixture transfer from chamber 1 to chamber 6 is switched on, the sludge mixture transfer from chamber 2 to chamber 1 is automatically switched on, in which the level of drains is automatically maintained at the set level (b), t . E. When this level is reached, the pumping of the sludge mixture from chamber 2 to chamber 1 is automatically stopped. When the level of effluent in chamber 1 decreases as a result of their pumping into chamber 6, the pumping of the sludge mixture from chamber 2 into chamber 1 is automatically resumed. Thus, in this mode, the camera 2 is functionally a buffer chamber with the provision of reception and pre-treatment of a salvo discharge, the volume of which raises the level of drains in chamber 1 to the level (s).

If, as a result of salvo discharge, the level of effluent in chamber 1 rises to the overflow pipe 22, located at level (b), the operation mode with the inclusion of the flotation unit 8 is automatically activated. In this mode, the drains in chambers 1 and 2 are intensively aerated and mixed with active sludge. At the same time, due to the length of the labyrinth canal and placement of the outlet of the overflow pipe above the aerated entrance section of this labyrinth canal, the length of the path of the overflowing sludge mixture from chamber 1 to chamber 2 and, accordingly, the time of contact of sewage with sludge before entering the flotator 8, increases. it is divided into two streams, one of which, water cleared of sludge, flows from the flotation cell 8 to the additional treatment in chamber 3, then to chamber 4 and is removed from the installation. Another stream, which is a silt-rich silt-water mixture, is pumped into chamber 1.

For salvo tributaries, the volume of which increases the level of waste in chamber 1 to the established level (1), i.e. the level of the installation of the drain pipe 23, part of the effluent is discharged through this pipe into the bypass pipe 24, while at the outlet of this pipeline the waste water is mixed in the outlet section of the pipe 10 with purified water and diluted, partially purified by reducing the concentration of contaminants. In this mode, part of the effluent enters through the overflow pipe 22 for processing into chamber 2 and further into the flotation cell 8 with subsequent release through the nozzle 10. The flotation cell 8 is activated by the signal from the sensor 25 when the level of drains in chamber 1 rises to the set level (b) , this turns on the air supply to pressure lines 36 and 37. During operation of the flotation unit 8, the sludge mixture is sucked through pipe 27 and flows out onto the porous element 31, when flowing through which the mixture is blown with air to trap the sludge particles and air bubbles form A visor-cut layer 34. The cut-off foam layer through the discharge pipe 28 is sent for recirculation into the chamber 1, and the wastewater cleared through the slit channel enters the receiver 35 and through the pipe 29 enters the filter 3 into the chamber 3.

Waste water entering the after-treatment (filtration) from chamber 5 and flotation unit 8 passes layers 38a-into the filter and through pipe 9 equipped with a normally open solenoid valve 46a is discharged into chamber 4, from where it is removed from the UBO through pipe 10 equipped with electro valve 46b . When blockage

- the level of water in chamber 3 rises to the set value, the filter purge is automatically activated by sensor 42, the normally opened solenoid valves 46a and 46b are closed, the normally closed solenoid valve 45 opens and compressed air is supplied to the porous element 43 through line 44 which breaks through the layers of the filter and brings sediments to the surface of the filter, sucked through the funnel 41 by an airlift 40 with pumping into chamber 2. At the end of the purge, the time of which is set in the control unit, the solenoids are reset to the initial position with the air supply to line 44 discontinued. It should be noted that during long interruptions in the flow of fresh effluents into the UBO, it is advisable that the control unit be set to periodically purge the filter.

When the water level in the chamber 4 falls below the set level sensor 47 automatically closes the solenoid valve 46b, due to which there is always a supply of clean water in this chamber. If necessary, the camera 4 can also be equipped with an ultraviolet emitter (conventionally not shown) for disinfection of treated wastewater.

Thus, in the absence or at uneven (within the established levels), the tributary inflow is automatically transferred to the most economical, periodic mode of operation with wastewater treatment cycles. Volley inflows are processed with the inclusion of flotation mode, and this mode is activated to process the excess volume of inflows to prepare the UBO to receive the following inflows. With a decrease in the level of the sludge mixture in chamber 2 to the set, the flotation cell 8 is turned off and the installation is switched to a periodic mode of operation.

In connection with the need to adjust the amount of sludge in the UBO, which is generated especially actively during periods of increased irregular inflows, it is advisable that the UBO be equipped with a viscosity sensor of sludge 48 placed in chamber 2, ensuring periodic airlift 16 for pumping excess sludge at the signal of this sensor (Sensor 48 can be made in the form of a rotor mounted on the motor shaft by means of a tear-off mechanical clutch. When the motor is turned on in the event of a slip of the driving elements of the clutch due to evozmozhnosti rotationally vane due to the high viscosity of the sludge is given a signal to switch the drain airlift 16). It is also advisable that camera 1 be additionally equipped with a sensor 49 for entering drains to automatically set the time delay for transferring the UBO to the mode of preserving the vital activity of active sludge during periods of absence or rare inflow of fresh effluents. In these cases, a time delay is automatically set in the control unit, which (according to the signal from sensor 49) is measured from the time of the last arrival of the drains. In the mode of conservation of vital activity of activated sludge from chamber 4, the supply of purified water is periodically pumped into chamber 1 (airlift of chamber 4 conventionally not shown) with further pumping between chambers 2, 5.6, see above.

Thus, with any tributaries, including emergency, the proposed UBO does not lose active sludge and maintains operability with quick access to the established indicators of wastewater treatment while normalizing the flow of effluent.

Claims (8)

CLAIM 1. The method of cleaning household and industrial wastewater, including periodic cycles of wastewater treatment with activated sludge in a biological treatment plant, characterized in that with salvaged inflows of wastewater, the volume of volley tributaries is treated with continuous aeration and continuous flotation of sludge from the water-sludge mixture, which is recycled, while the purified water from the sludge is continuously removed from the installation. 2. Installation for biological treatment of domestic wastewater, including a tank divided by partitions into technological compartments in the form of a receiving chamber with an inlet node, aerotank chambers, a settling chamber, a sludge collection chamber, a filtering chamber with a filter and a clean water collection chamber with a node for output of clean water, as well as aeration system with aerators and airlifts, water level sensors with activated sludge in the tank, connected to the control unit of the plant, characterized in that the chamber for collecting sludge is made in the form of a buffer The receptacle for receiving salvage inflows of wastewater and is additionally equipped with a flotation cell with inlet, outlet and outlet connections, while the discharge and outlet connections are made in the form of airlifts, discharge lines of which are connected, respectively, to the receiving chamber and filtration chamber. 3. Installation according to claim 2, characterized in that it is additionally equipped with a bypass discharge pipeline. 4. Installation according to claim 2, characterized in that the sludge collection chamber is additionally equipped with at least two partitions installed at a distance from each other to form a labyrinth channel in which aerators are installed. 5. Installation according to claim 2, characterized in that the filtration chamber is additionally equipped with a level sensor and filter cleaning means made in the form of a V-shaped airlift with an inlet collecting funnel located on the surface of the filter, as well as a purge element located under the filter and in the form of a perforated shell with perforations through, connect - 4 008870 through the solenoid valve to the pressure line of the compressed air supply, while the solenoid valve is installed at the outlet of this chamber. 6. Installation according to claim 2, characterized in that the filter is made of three layers with different grain sizes of the load in the layers, decreasing from layer to layer in the direction from the entrance to the exit of the chamber, while the filter layers are located on the mesh bases with the corresponding cell size. 7. Installation according to claim 2, characterized in that the node for the withdrawal of clean water is equipped with an electric valve. 8. A flotator comprising a housing with a water-sludge mixture inlet pipe, foam and purified water outlet pipes, and a dispersant connected to a compressed air supply line, characterized in that the flotation cell is equipped with a receiving chamber with a dispersant and a suction pipe connected to airlifts made the form of waste and output pipelines, the disperser is made in the form of a gas-permeable partition, located under the outlet of the suction nozzle, an inclined screen and a fender visor are installed above the disperser, while the baffle a visor and a dispersant is a channel, communicating with the outlet conduit, and between the inclined screen and the wall of the receiving chamber is channel connected with the bleed conduit.