EP2242727A2

EP2242727A2 - Method and apparatus for the purification of waste water with the sequence of accumulating container, three biological reactors and apparatus for the afterpurification

Info

Publication number: EP2242727A2
Application number: EP20080871313
Authority: EP
Inventors: Alexandr Teterja
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-01-24
Filing date: 2008-12-26
Publication date: 2010-10-27
Also published as: WO2009093991A3; WO2009093991A2; EA201001169A1; UA87613C2

Abstract

The present invention relates to waste water treatment and can be used for the biological purification of the household waste water that comes from the dwelling houses and public buildings and from separately located objects, and also for the biological purification of the waste water that comes from small factories that are located in the places where the central collecting system is not available. The concept of the invention consists in the performance the biological purification of waste water consistently in the biological reactors of the three stages of purification by the water aeration, mixing and sludge mixing pumping. The water purification in the biological reactors of the first (1) and second (2) stages of purification is continued during the period of water sedimentation in the biological reactor of the third (3) stage of purification. At first the waste water is delivered into accumulating container (4) for waste water in order to prevention of the mixing a new portion of waste water with a partly treated water. Additional apparatus for the af terpurif ication of waste water in case of need for more efficiency of water treatment is also provided. The biological af terpurif ication of previously treated water is provided by the simultaneous performance of the thin- layer sedimentation as well as under the influence of a bacterium.

Description

«Method and apparatus (variants) for the purification of waste water, accumulating container for waste water and apparatus for the afterpurification of waste water»

The field of the invention

The present invention relates to waste water treatment and can be used for the biological purification of the household waste water that comes from the dwelling houses and public buildings and from separately located objects, and also for the biological purification of the waste water that comes from small factories that are located in the places where the central collecting system is not available.

Description and criticism of the prior art

The claimer knows many method and apparatus for the purification of waste water, among which the closest ones according to the essential features and the technical result are the following.

The method for the purification of waste water according to Pat. UA 50574 issued April 15, 2005 is known. According to said method the purification of waste water is performed in the biological reactor of the first stage of the purification and the biological reactor of the second stage of the purification that are connected by the pumping device. The aeration, mixing and water sedimentation periodically take place in each of the biological reactors. The treated water and the precipitated surplus sludge are periodically pumped away from the biological reactor of the second stage of the purification. The circulation of the sludge mixture is performed between said biological reactors by the recirculation circuit by the controlled airlifts.

Also the apparatus for the purification of waste water according to Pat. US 6,007,712 issued December 28, 1999 is known. The said apparatus comprises the biological reactors of two stages of purification, equipped with the device for the aeration, mixing and the sludge mixture pumping. The disadvantages of said method and apparatus are the mixing of the water treated to some extent with new portions of the untreated water during the uncontrolled waste water inflow. The process of nitrification is followed by the process of denitrification and the process of sedimentation with the following precipitated surplus sludge removal, after which the nitrogen and phosphorous are removed from the treated water, which requires a long period of waste water purification to reach the necessary purification level and, as a consequence, it leads to the increasing energetic expense and investment for the waste water purification in said method and apparatus.

The apparatus for the aerobic purification of waste water according to Pat. UA 48928 issued August 15, 2002 is prior art device of the accumulating container for waste water, which is equipped with the devices for the aeration, mixing and with the water removal, is also known. Said apparatus is also equipped with the separator for maintaining the necessary active sludge concentration.

The disadvantage of said apparatus for the aerobic purification of waste water is the availability of the additional devices for maintaining the necessary concentration of the active sludge, which complicate the construction and decrease the actual volume used for the incoming waste water accumulation. The said device is not equipped with the devices of the rough rubbish detention and fragmentation, which can be in waste water.

The apparatus for the purification of waste water that includes the container, the device for the water delivery, the device for the water removal and the device for the surplus sludge removal and the biological filter, according to Pat. RU 2058942 issued April 27, 1992 is prior art device for the apparatus for the afterpurification of waste water. The delivery of the water is performed onto the upper edge of the biological filter with its passing through the biological filter. The filtering filling in granules is used as a said biological filter. The recirculation of the sludge mixture is ϋerformed bv the airlift, which is connected UΌ to the device of the υressure aeration. The device for the water removal is a central vertical collector that connects the bottom of the device container with a vertical pipe, located above the biological filter.

The disadvantage of said apparatus for the purification of waste water is the availability of the special devices for the sludge mixture recirculation in the apparatus container. The delivery of the waste water into the container onto the upper edge of the biological filter results in the partial washing away of the bacterial layer from the surface of the biological filter, which decreases the reliability of the device functioning. Also the accumulating of the treated water for the removal from the bottom part of the container decreases the water quality on the outflow. The use of the filtering filling in granules as a biological filter doesn't allow to perform the thin-layer water sedimentation, which improves the treated water quality, during the removal of the treated water. The use of the central vertical collector for the water removal complicates the apparatus construction.

Summary of the invention

An object of the present invention is the improvement of the method for the purification of waste water, that should provide the possibility of the purification of a certain quantity of waste water without uncontrolled inflow of the new portions of waste water at certain stages of the purification of waste water up to the end of the purification cycle of waste water and reaching the necessary level of purification decreasing the energy expenses at the same time, which is reached by creating the conditions under which the stable processes of nitrification and denitrification and the water sedimentation take place as well simultaneously.

The object of the invention can be achieved by creating the conditions for performance of the preliminary waste water accumulating and primary biological purification of waste water at the same time. This object of the invention can be also achieved by the prevention of the rough rubbish ingress into the biological reactor of the first stage of purification and by the fragmentation of rough rubbish, as the rough rubbish can be contained in the waste water.

This object of the invention can be also achieved by providing the biological filtration of water, which consists of the additional water purification by the microorganisms, and of the following thin-layer water sedimentation during the one afterpurification stage.

In the present invention a method for the purification of waste water comprising the steps of the periodic aeration, mixing, sedimentation of the waste water and removal of the surplus sludge and treated water, characterizing in that

the waste water is delivered into the biological reactor of the first stage of purification after the removal of the treated and settled water from the biological reactor of the third stage of purification,

the circulation of the water and of the sludge mixture between the biological reactor of the first stage of purification and the biological reactor of the second stage of purification is provided,

the delivery of the water from the biological reactor of the second stage of purification into the biological reactor of the third stage of purification is provided,

the pumping of the sludge mixture from the biological reactor of the second stage of purification and the biological reactor of the third stage of purification into the biological reactor of the first stage of purification is performed,

the delivery of the water into the biological reactor of the third stage of purification and the pumping of the sludge mixture from the biological reactor of the third stage of purification into the biological reactor of the first stage of purification are stopped at the period of sedimentation of the water in the biological reactor of the third stage of purification,

while the circulation of the water and of the sludge mixture continues between the biological reactor of the first stage of purification and biological reactor of the second stage of purification, and the aeration and mixing in the biological reactor of the first stage of purification and the biological reactor of the second stage of purification takes place as well.

In a preferred embodiment of said method for the purification of waste water the circulation of the water and of the sludge mixture between the biological reactor of the first stage of purification and biological reactor of the second stage of purification is performed by the direct flow of the water from the biological reactor of the first stage of purification into the biological reactor of the second stage of purification and by the pumping of the sludge mixture from the biological reactor of the second stage of purification into the biological reactor of the first stage of purification.

In alternative embodiment of the present invention a method for the purification of waste water comprising the steps of the periodic aeration, mixing, sedimentation of the waste water and removal of the surplus sludge and treated water, characterizing in that

the waste water is previously accumulated in the accumulating container, where the mixing periodically is performed and from where the water is delivered into the biological reactor of the first stage of purification after the removal of the treated and settled water from the biological reactor of the third stage of purification,

the circulation of the water and of the sludge mixture between the biological reactor of the first stage of purification and biological reactor of the second stage of purification is provided, the delivery of the water from the biological reactor of the second stage of purification into the biological reactor of the third stage of purification is provided,

the pumping of the sludge mixture from the biological reactor of the second stage of purification and biological reactor of the third stage of purification into the biological reactor of the first stage of purification is performed,

the periodic pumping of the sludge mixture from at least one of the biological reactor of the first stage of purification, the biological reactor of the second stage of purification or the biological reactor of the third stage of purification into the accumulating container are provided,

the delivery of the water into the biological reactor of the third stage and the pumping of the sludge mixture from the biological reactor of the third stage into the biological reactor of the first stage are stopped at the period of sedimentation of the water in the biological reactor of the third stage,

In a preferred embodiment of said method for the purification of waste water the circulation of the water and of the sludge mixture between the biological reactor of the first stage of purification and the biological reactor of the second stage of purification is performed by the direct flow of water from the biological reactor of the first stage of purification into the biological reactor of the second stage of purification and by the pumping of the sludge mixture from the biological reactor of the second stage of purification into the biological reactor of the first stage of purification. In another preferred embodiment of said method for the purification of waste water the delivery of the water from the accumulating container into the biological reactor of the first stage of purification is performed after the mixing in the accumulating container is stopped.

In another alternative embodiment of the present invention a method for the purification of waste water comprising the steps of the periodic aeration, mixing, sedimentation of the waste water and removal of the surplus sludge and treated water, characterizing in that

the waste water is previously accumulated in the accumulating container, where the aeration and mixing periodically is performed, and from which the water is delivered into the biological reactor of the first stage of purification after the removal of the treated and settled water from the biological reactor of the third stage of purification,

the delivery of the water from the biological reactor of the second stage of purification into the biological reactor of the third stage of purification is provide,

the delivery of the water into the biological reactors of the third stage of purification and the pumping of the sludge mixture from the biological reactor of the third stage of purification into the biological reactor of the first stage of purification are stopped at the period of sedimentation of the water in the biological reactor of the third stage of purification, while the circulation of the water and of the sludge mixture continues between the biological reactor of the first stage of purification and biological reactor of the second stage of purification, and the aeration and mixing in the biological reactor of the first stage of purification and biological reactor of the second stage of purification takes place as well,

the water is delivered to the biological reactor of the first stage of purification from the accumulating container space limited by the closed grating where the water aeration takes place, and the water aeration inside the closed grating continues when the water aeration of the accumulating container is stopped.

In preferred embodiment of said the method for the purification of waste water the circulation of water and of the sludge mixture between the biological reactor of the first stage of purification and the biological reactor of the second stage of purification is performed by the direct flow of the water from the biological reactor of the first stage of purification into the biological reactor of the second stage of purification and the pumping of the sludge mixture from the biological reactor of the second stage of purification into the biological reactor of the first stage of purification.

In another preferred embodiment of said the method for the purification of waste water the delivery of the water into the biological reactor of the first stage of purification is performed after the mixing and aeration in the accumulating container are stopped.

In another alternative embodiment of the present invention a method for the purification of waste water comprising the steps of the periodic aeration, mixing, sedimentation of the waste water and removal of the surplus sludge and treated water, characterizing in that the waste water is delivered to the biological reactor of the first stage of purification after the removal of treated and settled water from the biological reactor of the third stage of purification,

the circulation of the water and of the sludge mixture between the biological reactor of the first stage of purification and biological reactor of the second stage of purification is provided,

while the circulation of the water and of the sludge mixture continues between the biological reactor of the first stage of purification and biological reactor of the second stage of purification, and the aeration and mixing in the biological reactor of the first stage of purification and the biological reactor of the second stage of purification takes place as well,

the removal of the previously treated and settled water from the biological reactor of the third stage of purification is performed into the apparatus for the afterpurification of the waste water, where the aeration of the water is performed under the lower part of the biological filter submerged into water, in the plane that is less than the plane of cross-section of the biological filter, with further water the water is delivered into the said apparatus for the afterpurification of waste water to the lower part of the biological filter after the aeration, sedimentation of waste water and the surplus sludge removal are over and the delivery of the water into the biological filter is accompanied by forcing out the water that was previously settled in said apparatus of the afterpurification of waste water through the inclined channels of the biological filter with its further removal.

In preferred embodiment of said method for the purification of waste water the circulation of the water and of the sludge mixture between the biological reactor of the first stage and the biological reactor of the second stage is performed by the direct flow of the water from the biological reactor of the first stage of purification into the biological reactor of the second stage of purification and by the pumping of the sludge mixture from the biological reactor of the second stage of purification into the biological reactor of the first stage of purification.

It is another object of this invention to provide an improvement the apparatus for the purification of waste water, which should perform the purification of a certain quantity of waste water and the stable level of purification of waste water - not lower than the necessary one, increasing the effect of the power inputs that are necessary for reaching such level of the purification, which can be achieved by creating the conditions for the simultaneous stable processes of the water sedimentation, nitrification and denitrification by the devices.

This object of the invention can be also achieved by combining the functions of accumulating the waste water and preliminary purification of waste water in the single accumulating container for waste water.

This object of the invention can be also achieved by the availability of the devices for rough rubbish fragmentation in the accumulating container for waste water.

This object of the invention can be also achieved by combining the biological process of waste water afterpurification performed by the microorganisms and the process of thin-layer sludge sedimentation in a single apparatus for the afterpurification of waste water.

In the present invention an apparatus for the purification of waste water comprising the biological reactors of two stages, equipped with the devices for the aeration, mixing and the sludge mixture pumping, characterizing in that

said apparatus includes an biological reactor of the third stage of purification in additional, equipped with the device for the aeration, with the device for the water removal, with the device for the surplus active sludge removal and with the device for the sludge mixture pumping into the biological reactor of the first stage of purification,

the biological reactor of the first stage of purification is hydraulically connected with the biological reactor of the second stage of purification,

the biological reactor of the second stage of purification equipped with device for the water delivery into the biological reactor of the third stage of purification and the device for the sludge mixture pumping into the biological reactor of the first stage of purification.

In preferred embodiment of said apparatus for the purification of waste water the hydraulic connection between the biological reactor of the first stage of purification and the biological reactor of the second stage of purification is performed by a pipe located below the water level in the biological reactor of the first stage of purification.

In another preferred embodiment of said apparatus for the purification of waste water the device for the sludge mixture pumping is an airlift.

In another preferred embodiment of the said apparatus for the purification of waste water the device for the water delivery into the biological reactor of the third stage is an airlift. In another preferred embodiment of the said apparatus for the purification of waste water the device for the water delivery into the biological reactor of the third stage of purification is a pipe, which connects the upper parts of the biological reactor of the second stage of purification and the biological reactor of the third stage of purification.

In another preferred embodiment of the said apparatus for the purification of waste water the device for the water removal from the biological reactor of the third stage of purification is a controlled siphon.

In another preferred embodiment of the said apparatus for the purification of waste water the device for the surplus sludge removal from the biological reactor of the third stage of purification is a pump.

In another alternative embodiment of the present invention an apparatus for the purification of waste water comprising the biological reactors of two stages of purification, equipped with the devices for the aeration, mixing and the sludge mixture pumping, characterizing in that

said apparatus includes an accumulating container in addition, which is equipped with the devices for the mixing and the devices for the water delivery into the biological reactor of the first stage of purification,

said apparatus includes a biological reactor of the third stage of the purification equipped with the devices for the aeration, the device for the water removal, the device for the surplus sludge removal and device for the sludge mixture pumping into the biological reactor of the first stage of purification,

the biological reactor of the second stage of purification is equipped with the device for the water delivery into the biological reactor of the third stage of purification and device for the sludge mixture pumping into the biological reactor of the first stage of purification,

at least one of the biological reactor of the first stage of purification, the biological reactor of the second stage of purification or the biological reactor of the third stage of purification is equipped with the device for the sludge mixture pumping into the accumulating container.

In preferred embodiment of said apparatus for the purification of waste water the hydraulic connection between the biological reactor of the first stage of purification and the biological reactor of the second stage of purification is performed by a pipe located below the water level in the biological reactor of the first stage.

In another preferred embodiment of the said apparatus for the purification of waste water the device for the water delivery into the biological reactor of the third stage of purification is an airlift.

In another preferred embodiment of said apparatus for the purification of waste water the device for the water delivery into the biological reactor of the third stage of purification is a pipe, which connects the upper parts of the biological reactor of the second stage of purification and the biological reactor the third stage of purification.

In another preferred embodiment of the said apparatus for the purification of waste water the device for the water removal from the biological reactor of the third stage of purification is a controlled siphon. In another preferred embodiment of the said apparatus for the purification of waste water the device for the surplus sludge removal from the biological reactor of the third stage of purification is a pump.

In another preferred embodiment of the said apparatus for the purification of waste water the device for the water delivery into the biological reactor of the first stage of purification is a pump.

said apparatus includes an accumulating container in addition, which is equipped with the devices for the mixing and aeration and the device for the water delivery into the biological reactor of the first stage of purification,

said apparatus includes a biological reactor of the third stage of purification equipped with the device for the aeration, the device for the water removal, the device for the surplus sludge removal and the device for the sludge mixture pumping into the biological reactor of the first stage of purification,

the inlet of the device for the water delivery into the biological reactor of the first stage of purification is located inside the closed grating at the upper boundary of the active sludge volume, which is the minimum quantity of the sludge which is necessary for the stable biological purification process,

the closed grating is at least partly located below the upper boundary of the active sludge volume, which is the minimum quantity of the sludge which is necessary for the stable biological purification process,

the additional devices for the aeration are located in the space limited by the closed grating.

In another preferred embodiment of said apparatus for the purification of waste water the device for the water delivery into the biological reactor of the third stage of purification is an airlift.

In another preferred embodiment of said apparatus for the purification of waste water the device for the water delivery into the biological reactor of the third stage of purification is a pipe, which connects the upper parts of the biological reactors of the second and the third stages of purification.

In another preferred embodiment of the said apparatus for the purification of waste water the device for the water removal from the biological reactor of the third stage of purification is a controlled siphon. In another preferred embodiment of said apparatus for the purification of waste water the device for the surplus sludge removal from the biological reactor of the third stage of purification is a pump.

In another preferred embodiment of said apparatus for the purification of waste water the device for the water delivery into the biological reactor of the first stage of purification is a pump.

In another alternative embodiment of the present invention an apparatus for the purification of waste water comprising the biological reactors of two stages equipped with the devices for the aeration, mixing and the sludge mixture pumping, characterizing in that

said apparatus includes a biological reactor for the third stage of purification in addition, equipped with the devices for the aeration, with the device for the water delivery into the device for the afterpurification of waste water, with the device for the surplus sludge removal and with the device for the sludge mixture pumping into the biological reactor of the first stage of purification,

the biological reactor of the second stage is equipped with the device for the water delivery into the biological reactor of the third stage of purification and with the device for the sludge mixture pumping into the biological reactor of the first stage of purification,

the device for the afterpurification of waste water includes the container, the device for the water removal, the device for the surplus sludge removal, the cellular biological filter and the devices for the aeration,

devices for the aeration located under the cellular biological filter in the plane that is less than the plane of cross-section of the cellular biological filter, the cells of the cellular biological filter are inclined channels,

the upper edge of the cellular biological filter is located below the minimal level of water in the device for the afterpurification of waste water,

the outlet of the device for the water delivery into the device for the afterpurification of waste water is located under the lower edge of the cellular biological filter.

In another preferred embodiment of said apparatus for the purification of waste water the device for the water removal from the biological reactor of the third stage of purification is a controlled siphon. In another preferred embodiment of said apparatus for the purification of waste water the device for the surplus sludge removal from the biological reactor of the third stage of purification is a pump.

In another preferred embodiment of said apparatus for the purification of waste water the device of the water removal from the device for the afterpurifϊcation of waste water is the outlet located in upper parts of the device for the afterpurification of waste water.

In the present invention an accumulating container for waste water comprising the devices for the aeration, mixing and the water removal, characterizing in that

the inlet of the device for the water removal is located inside the closed grating at the upper boundary of the active sludge volume, which is the minimum quantity of the sludge which is necessary for the stable biological purification process,

In preferred embodiment of said accumulating container for waste water said device for the water removal is a pump.

In the present invention an apparatus for the afterpurification of waste water comprising the container, device for the water delivery, device for the water removal, device for the surplus sludge removal and the biological filter, characterizing in that in addition said device for the afterpurification of waste water is equipped with the devices for the aeration located under the biological filter in the plane that is less than the plane of cross-section of the biological filter,

the biological filter includes a cell,

the cells of the biological filter are inclined channels,

the upper edge of said biological filter is located below the minimal level of water in the device for the afterpurification of waste water,

the outlet of said device for the water delivery is located under the lower edge of the biological filter.

In preferred embodiment of said apparatus for the afterpurification of waste water the device for the water removal is an outlet located in the upper part of the container.

There is a following cause-effect relation between the critical limitations of the method and apparatus for the purification of waste water, accumulating container for waste water and apparatus for the afterpurification of waste water that are claimed, and said objects of the invention can be achieved.

The waste water that delivered for the purification passes the connected biological reactor of the first stage of purification, biological reactor of the second stage of purification and biological reactor of the third stage of purification one by one. The waste water undergoes the repeated steps of the aeration and mixing necessary for the biological purification in each of the biological reactor of the first stage of the purification and the biological reactor of the second stage of the purification. The periodic aeration is performed in the biological reactor of the third stage of the purification, after which the biological reactor of the third stage of the purification switched to the sedimentation mode, which is followed by the treated water and the precipitated surplus sludge that contains the absorbed from waste water phosphorous removal.

By the devices for sludge mixture pumping (for example, the devices for sludge mixture pumping are an airlifts) the circulation of the sludge mixture between the biological reactor of the second stage of purification and biological reactor of the first stage of purification and also between the biological reactor of the third stage of purification and the biological reactor of the first stage of purification is provided. Using of these circulation circuits the sludge mixture gets into the same purification stage more than once with the changed quantities of the nitrates and nitrites each time, which increases the effect of the denitrification process that results in the nitrogen compounds splitting with the gaseous nitrogen release into the atmosphere. Owing to the sludge mixture pumping from the biological reactor of the second stage of purification the conditions of a low concentration of the organic substances are provided in the biological reactor of the second stage of purification, which results in the improvement of the nitrification process, necessary for obtaining the nitrates and the nitrites.

Also owing to the water circulation performed by the direct flow from the biological reactor of the first stage of purification into the biological reactor of the second stage of purification and by the sludge mixture pumping from the biological reactor of the second stage of purification into the biological reactor of the first stage of purification, the purification of water in the biological reactor of the first stage of purification and the biological reactor of the second stage of purification can take place simultaneously with the water sedimentation that takes place in the biological reactor of the third stage of purification.

So a few stages of waste water purification take place at the same time while it is guaranteed that said stages of waste water purification are separated in space, which increases the quality of waste water treatment and decreases the energy expenses needed for providing the necessary treated water quality. The availability of the accumulating container for waste water, equipped with the device for water delivery into the biological reactor of the first stage of purification, allows to create an accumulation space necessary for providing the delivery of a certain volume of water into the biological reactor of the first stage of 5 purification after the removal of the treated water from the biological reactor of the third stage of purification, which prevents the mixing of partially treated water with the new portions of the fresh waste water. The availability of the devices of mixing in the accumulating container and the sludge mixture pumping from at least one of the biological reactor of the first stage of the purification, the biological

10 reactor of the second stage of the purification or the biological reactor of the third stage of the purification provides the beginning of the water biological purification process in the accumulating container already owing to the contact of the fresh waste water and the sludge mixture. This allows to deliver the previously treated water into the biological reactor of the first stage of purification, which results in

15 the increasing of the waste water purification quality and in the decreasing the time necessary for purification of the waste water. The pumping of the sludge mixture into the accumulating container is performed periodically, at the necessity to maintain of the active sludge volume, which is the minimum quantity of the sludge which is necessary for the stable biological purification process.

20. The active sludge volume, which is the minimum quantity of the sludge which is necessary for the stable biological purification process, is defined by the optimum quantity of the active sludge necessary for the biological purification process in a certain volume of the container, for example, the biological reactor. The factors, that affect the development and the vital activity of the active sludge that is

25 contained in the sludge mixture, are, for example, the average daily temperature, the availability of the nutrient substances, the quantity of the oxygen dissolved in the sludge mixture, the pH parameter, the concentration of toxic substances and so on. As a result of these factors' influence the active sludge volume, which is the minimum quantity of the sludge which is necessary for the stable biological purification process, can change. Carrying out the experiments the inventor established that the active sludge volume, which is the minimum quantity of the sludge which is necessary for the stable biological purification process, is within 20% and 30% of the accumulating container volume. So, depending on the active sludge volume, which is the minimum quantity of the sludge which is necessary for the stable biological purification process, and on the shape of the accumulating container the height of the inlet of the device for the water delivery into the biological reactor of the first stage of purification is defined, which helps to provide the stable active sludge volume, which is the minimum quantity of the sludge which is necessary for the stable biological purification process.

Locating the inlet of the device for the water delivery into the biological reactor of the first stage of purification on the height of the upper boundary of the active sludge volume, which is the minimum quantity of the sludge which is necessary for the stable biological purification process allows to provide the constant level of the active sludge in the accumulating container, which contains the necessary quantity of the microorganisms, that performed oxidation and processing the pollutants, which results in the stable biological process of decomposition of the dissolved organic substances that are contained in waste water.

During the experiment that was carried out by the inventor and concerned providing the detention of the rough rubbish, that are contained by the waste water during the certain purification stage, the following conclusions were made.

The additional devices of aeration, located in the accumulating container space limited by the closed grating, perform the water aeration in this space and creating the microscopical zones of pressure on the closed grating under the influence of the aeration air bubbles. The aeration of the accumulation container of waste water which takes place at the same time beyond the said space limited by the closed grating creates the pressure of the air bubbles from the other side of the closed eratins. Owine to the nressiirei microsconir.al zones of different directions in the closed grating zone the fragmentation of the rough rubbish of the waste water takes place. Locating the inlet of the device for the water delivery into the biological reactor of the first stage of purification inside the space limited by the closed grating allows to delivery previously treated water into the biological reactor of the first stage of purification, which essentially decreases the time, necessary for treating water to the given level.

Continuing the water aeration inside the space limited by the closed grating and stopping the water aeration in the accumulating container of waste water beyond the closed grating zone allows to perform the cleaning of the closed grating surface from the unbroken rough rubbish at the period of water delivery from the accumulating container of waste water into the biological reactor of the first stage of purification.

The availability of the devices of aeration in the accumulating container of waste water also allows to control the process of water biological purification by the changing the extent of the sludge mixture saturation with oxygen.

The delivery of water after its mixing and aeration into the biological reactor of the first stage of purification, allows to prevent the inflow of the unbroken rough rubbish that are contained by the fresh waste water into the biological reactor of the first stage of purification from the accumulating container of waste water.

The inflow of water into the apparatus for the afterpurification of waste water and the performance of biological filtration and the performance of the thin-layer sedimentation of previously treated water allows to reach a higher water purification extent, which is necessary for the household needs, comparing to the level of water purification in all of the biological reactor of the first stage of purification, biological reactor of the second stage of purification and biological reactor of the third stage of purification. The afterpurification of waste water is performed creating the simultaneous ascending flow of water with its aeration and container of the apparatus for the afterpurification of waste water. These circumstances provide the periodic multiple contact of water with the biological filter channels and, accordingly, with the microorganisms concentrated there, which results in the removal of the rests of organic substances from the water. Performing water aeration in the plane that is less than the plane of the cross- section of the biological filter of the apparatus for the afterpurification of waste water provides the dividing of the said biological filter into two zones, where different chemical processes take place. In the zone limited by the plane where aeration is provide, the process of nitrification takes place, after which the water enters the zone of "oxygen hunger" beyond the zone limited by the plane where aeration is provide. In this zone the denitrification process takes place. Locating the upper edge of the said biological filter below the minimum water level in the container of apparatus for the afterpurification of waste water allows to perform the circulation of water from the zone, where nitrification dominates, into the zone where denitrification dominates.

The delivery of water under the lower part of the biological filter provides the displacing of the settled water in the apparatus for the afterpurification of waste water by the water that delivered from the biological reactor of the third stage. While the displaced water passes the biological filter channels, the thin-layer sedimentation of the active sludge particles takes place, that is to say the particles of the sludge, that didn't precipitate during the sedimentation process in the biological reactor of the third stage of purification, adhere to the walls of the biological filter with further sinking through the inclined channels of the biological filter under the gravity influence and with their further pumping from the apparatus for the afterpurification of waste water by the surplus sludge removal device.

The device for the water removal can be made as a drainage hole located in the upper part of the container of the apparatus for the afterpurification of waste water, which simplifies the construction and increases reliability of the apparatus for the Broadening paragraphs

To explain the character of the invention the examples of the apparatus for purification of waste water according to the embodiments and the method and for the purification of waste water that can be performed by the using each of the embodiments of the apparatus for purification of waste water, and also the examples of the accumulating container for waste water and the apparatus for the afterpurifϊcation of waste water are given below. The embodiments of the invention are shown in the simplified drawings, where is showed the schematic plan of the apparatus for purification of waste water. The simplified drawings and the examples of the method and apparatus for the aflterpurification of waste water, the examples of the accumulating container for waste water and the apparatus for the afterpurification of waste water in no way limits the scope of appended claims and only explains the character of the invention.

Drawings and brief description of its views

Fig.l is schematic said view of the apparatus for the purification of waste water with three biological reactors.

Fig.2 is schematic said view of the apparatus for the purification of waste water with three biological reactors and accumulating container for waste water.

Fig.3 is schematic said view of the apparatus for the purification of waste water with three biological reactors and accumulating container for waste water.

Fig.4 is schematic said view of the apparatus for the purification of waste water with three biological reactors and apparatus for the afterpurification of waste water.

Fig.5 is schematic said view of the apparatus for the purification of waste water with three biological reactors where the device for the water delivery into the biological reactor of the third stage of purification is an airlift. Fig.6 is enlarged schematic said view of the accumulating container for waste water.

Fig.7 is enlarged schematic said view of the apparatus for the afterpurification of waste water.

Detailed description

The apparatus for the purification of waste water (Fig.l) comprises the biological reactor 1 of the first stage of purification, the biological reactor 2 of the second stage of purification and the biological reactor 3 of the third stage of purification. Each of the biological reactors I₅ 2 and 3 is a container, which is made of polypropylene for example.

The containers of the biological reactors 1, 2 and 3 are equipped with the devices for the aeration 4. The devices for the aeration 4 can be made as sprayers located on the bottom of the containers of the biological reactors and connected to at least one compressor with a piping.

The containers of the biological reactors 1 and 2 are equipped with the devices for the mixing 5. The devices for the mixing 5 can be made as mixers, for example, screw propellers or mixing screw conveyers located inside the containers of biological reactors 1 and 2 and connected to the electric drive. The best way for the embodiment of the devices for the mixing 5 for the suggested technology decision is either locating the sprayers similar to the devices for the aeration but having a more intensive mode of air supply, or the periodic increasing of the aeration intensity of the devices for the aeration 4 inside the biological reactor, owing to which the mixing of the sludge mixture will take place inside the biological reactor.

The biological reactors 1 and 2 are connected with a pipe 6 which is located below the water level in the biological reactor 1. The biological reactor 2 is equipped with the device for the sludge mixture pumping 7 into the biological reactor 1 and with the device for the water delivery 8 into the biological reactor 3. The device for the sludge mixture pumping 7 into the biological reactor 1 is an airlift. The device for the water delivery 8 is either a pipe, which connects the upper parts of the biological reactor 2 and the biological reactor 3, or an airlift that pumps the water into the biological reactor 3 (Fig.5).

The biological reactor 3 is equipped with the device for the sludge mixture pumping 9, with the device for the surplus active sludge removal 10 and with the device for the water removal 11. The device for the active sludge pumping 9 is an airlift. The device for the surplus sludge removal 10 is a pump. The removal of the surplus sludge can be performed into the surplus sludge container, by which the apparatus for the purification of waste water are as a rule equipped. The device for the water removal 11 is a controlled siphon. The removal of water can be performed into the water system that delivers water for the household needs or into the system of the waste water afterpurification, which can be equipped with a filter or a membrane module for getting most treated water or water with certain characteristics.

The method for the purification of waste water according to said apparatus for the purification of waste is performed in the following way.

The waste water flows into the biological reactor 1, where by the devices for the aeration 4 and the devices for the mixing 5 the periodic water aeration and mixing take place. The water is delivered through the pipe 6 from the biological reactor 1 into the biological reactor 2. The periodic water aeration and mixing is also performed in the biological reactor 2. After that the water is delivered into the biological reactor 3 by the device for the water delivery 8. The periodic water aeration takes place in the biological reactor 3. The sludge mixture from the biological reactor 2 is pumped into the biological reactor 1 by the device for the sludge mixture pumping 7 and from the biological reactor 3 into the biological reactor by the device for sludge mixture pumping 9 at the same time. When the water reaches the maximum level in biological reactor 3 the water delivery from the biological reactor 2 into the biological reactor 3 is terminated. The termination of the water delivery from the biological reactor 2 into the biological reactor 3 is performed depending on the device for the water delivery 8 and can be performed, for example, either by terminating the water delivery into the biological reactor 1 and flowing the rest of water from the pipe into the biological reactor 3 or by the termination of the airlift operation. The sludge mixture pumping from the biological reactor 3 is also terminated. After that the water sedimentation is performed in the biological reactor 3, during which the water aeration in the biological reactor 3 is terminated. The circulation of the sludge mixture from the biological reactor 2 into the biological reactor 1 by the direct flow of water through the pipe 6 into the biological reactor 2 and by the sludge mixture pumping from the biological reactor 2 into the biological reactor 1 by the device 7 for the sludge mixture pumping are performed simultaneously. The water is removed from the biological reactor 3 by the device for the water removal 11 after the sedimentation. The precipitated surplus sludge is removed from the biological reactor 3 by the device for the surplus sludge removing 10 if necessary. The next portion of water is delivered into the biological reactor 1 after the removal of treated water and of the precipitated surplus sludge from the biological reactor 3 is complete.

According to alternative embodiment of the present invention (Fig. 2) an apparatus for the purification of waste water comprising the biological reactor 1 of the first stage of purification, the biological reactor 2 of the second stage of purification and the biological reactor 3 of the third stage of purification and an accumulating container 4. Each of the biological reactors 1, 2 and 3 is container.

The containers of the biological reactors 1, 2 and 3 are equipped with the devices for the aeration 5. The containers of the biological reactors 1 , 2 and the accumulating container 4 are equipped with the devices for the mixing 6.

The biological reactors 1 and 2 are connected to each other with a pipe 7, which is located below the water level in the biological reactor 1.

The biological reactor 2 is equipped with the devices for the sludge mixture pumping 8 into the biological reactor 1 and with the devices for the water delivery 9 into the biological reactor 3. The device for pumping the sludge mixture 8 into the biological reactor 1 is an airlift. The device for water delivery 9 is a pipe that connects the upper parts of the biological reactors 2 and 3.

The biological reactor 3 is equipped with the device for the sludge mixture pumping 10 into the biological reactor 1, with the device for the surplus sludge removal 11 and with the device for cleared water removal 12. The device for active sludge pumping 10 is an airlift. The device for the surplus sludge removal 11 is a pump. The device for the water removal 12 is a controlled siphon.

The accumulating container for waste water 4 is equipped with the device for water delivery 13 into the biological reactor 1. The device for water delivery 13 is a pump.

At least one of the biological reactors 1, 2 and 3 (according to this embodiment - biological reactor 3) comprises the device for the sludge mixture pumping 14 into the accumulating container for waste water 4. The device for sludge mixture pumping 14 is an airlift.

The waste water flows into the accumulating container 4, where by the devices for the mixing 6 the periodic water mixing take place. The water is pumped from the accumulating container 4 into the biol^ical reactor 1 by the device for the water delivery 13. The periodic water aeration and mixing takes place in the biological reactor 1 by the devices for the aeration 5 and the devices for the mixing 6. The water is delivered from the biological reactor 1 into the biological reactor 2 through the pipe 7. The periodic water aeration and mixing also take place in the biological reactor 2. After that water is delivered into the biological reactor 3 by the device for the water delivery 9. The periodic water aeration takes place in the biological reactor 3. The sludge mixture is pumped from the biological reactor 2 into the biological reactor 1 by the device for the sludge mixture pumping 8, and from the biological reactor 3 into the biological reactor 1 by the device the sludge mixture pumping 10, and also the periodic pumping of the sludge mixture from at least one of the biological reactors 1, 2 or 3 (according to this embodiment - from the biological reactor 3) into the accumulating container for waste water 4 by the device for the sludge mixture pumping 14 is performed. When the water reaches the maximum level in the biological reactor 3 the water delivery from the biological reactor 2 into the biological reactor 3 is terminated. The sludge mixture pumping from the biological reactor 3 into the biological reactor 1 and the sludge mixture pumping from the biological reactor 3 into the accumulating container 4 are terminated too. After that water sedimentation is performed in the biological reactor 3, while the aeration in the biological reactor 3 is terminated. The circulation of the sludge mixture from the biological reactor 1 into the biological reactor 2 by the direct flow of water through the pipe 7 and by the pumping of the sludge mixture from the biological reactor 2 into the biological reactor 1 by the device for the sludge mixture pumping 8 are performed simultaneously. After the sedimentation the water is removed from the biological reactor 3 by the device for the water removing 12. The surplus sludge is removed from the biological reactor 3 by the device for the surplus sludge removal 11 if necessary. The next portion of water is delivered into the biological reactor 1 for the purification after the treated water and the surplus sludge are removed from the biological reactor 3 and after the mixing in the accumulating container for waste water 4 is compete. According to another alternative embodiment of the present invention (fig.3) an apparatus for the purification of waste water comprising the biological reactor 1 of the first stage of purification, the biological reactor 2 of the second stage of purification and the biological reactor 3 of the third stage of purification and an accumulating container for waste water 4. Each of the biological reactors 1, 2 and 3 is performed is a container.

The containers of the biological reactors 1, 2, 3 and the accumulating container for waste water 4 are equipped with the devices for the aeration 5.

The containers of the biological reactors 1, 2 and the accumulating container for waste water 4 are equipped with the devices for the mixing 6.

The biological reactors 1 and 2 are connected with a pipe 7, which is located below the level of water in the biological reactor 1.

The biological reactor 2 is equipped with the device for sludge mixture pumping 8 into the biological reactor 1 and with the device for water delivery 9 into the biological reactor 3. The device for pumping the sludge mixture 8 is an airlift. The device for the water delivery 9 is a pipe that connects the upper parts of the biological reactors 2 and 3.

The biological reactor 3 is equipped with the device for the sludge mixture pumping 10, with the device for the surplus sludge removal 11 and with the device for the water removal 12. The device for sludge mixture pumping 10 is an airlift. The device for the surplus sludge removal 11 is a pump. The device for the water removal 12 is a controlled siphon.

The accumulating container 4 is equipped with the device for the water delivery 13 into the biological reactor 1. The device for the water delivery 13 is equipped with an inlet 14 and a grating 15. The grating 15 is a closed circuit. The inlet 14 is located inside the closed circuit of the grating 15. Inside the closed circuit of the inlet 14 location is equal to the height H of the upper boundary of the active sludge volume, which is the minimum quantity of the sludge which is necessary for the stable biological purification process. The grating 15 is located at least partly lower than the height H. The device for the water delivery 13 is a pump.

The waste water flows into the accumulating container 4, where by the devices for the mixing 6 and the devices for the aeration 5 the periodic water aeration and mixing take place. Owing to the device for the water delivery 13 the water from the accumulating container for waste water 4 is delivered into the biological reactor 1. The water delivery is performed through the inlet 14 from the space limited by the closed circuit of the grating 15. The aeration of water in the accumulating container for waste water 4 and the aeration of water inside the closed circuit of the grating 15 by the additional devices for the aeration 16 are performed simultaneously. When the water aeration in the accumulating container for waste water 4 is terminated, the aeration inside the closed circuit of the grating 15 still takes place.

When the water has been delivered into the biological reactor 1, the periodic water aeration and mixing take place by the devices for the aeration 5 and the devices for the mixing 6. The water is delivered from the biological reactor 1 into the biological reactor 2 through the pipe 7. The periodic water aeration and water mixing also take place in the biological reactor 2. After that the water is delivered into the biological reactor 3 by the device for the water delivery 9. The periodic water aeration takes place in the biological reactor 3. The sludge mixture from the biological reactor 2 is pumped into the biological reactor 1 by the device for the sludge mixture pumping 8, and the sludge mixture from the biological reactor 3 is pumped into the biological reactor 1 by the device for the sludge mixture pumping 10. When the water reaches the maximum level in the biological reactor 3 the hydraulic connection between the biological reactors 2 and 3 is terminated. The sludge mixture pumping from the biological reactor 3 into the biological reactor 1 is terminated too. After that water sedimentation is performed in the biological reactor 3, while aeration in the biological reactor 3 is terminated. The circulation of the sludge mixture from the biological reactor 1 into the biological reactor 2 through the pipe 7 into the biological reactor 2 and by the sludge mixture pumping from the biological reactor 2 into the biological reactor 1 by the device for the sludge mixture pumping 8 take place at the same time. The water is removed from the biological reactor 3 after the sedimentation by the water removal device 12. The precipitated surplus sludge is removed from the biological reactor 3 by the device for the surplus sludge removal 11 if necessary. The next portion of water is delivered for purification into the biological reactor 1 after the treated water is removed from the biological reactor 3 and after the mixing and aeration in accumulating container of waste water 4 are complete.

According to another alternative embodiment of the present invention (fig.3) an apparatus for the purification of waste water comprising the biological reactor 1 of the first stage of purification, the biological reactor 2 of the second stage of purification, the biological reactor 3 of the third stage of purification and the apparatus for the afterpurification of waste water 4. Each of the biological reactors 1, 2 and 3 is a container.

The containers of the biological reactors 1, 2 and 3 are equipped with the devices for the aeration 5.

The containers of the biological reactors 1 and 2 are equipped with the devices for the mixing 6.

The biological reactors 1 and 2 are connected with a pipe 7, which is located below the water level in the biological reactor 1. The biological reactor 2 is equipped with the device for the sludge mixture pumping 8 into the biological reactor 1 and with the device for water delivery 9 into the biological reactor 3. The device for sludge mixture pumping 8 is an airlift. The device for the water delivery 9 is a pipe that connects the upper parts of the biological reactors 2 and 3.

The biological reactor 3 is equipped with the device for the sludge mixture pumping 10 into the biological reactor 1, with the device for the surplus sludge removal 11 and with the device for the water removal 12. The device for the active sludge pumping 10 is an airlift. The device for the surplus sludge removal 11 is a pump. The device for the water removal 12 is a controlled siphon.

The apparatus for the afterpurification of waste water 4 comprises the devices for the aeration 5, that are located in the container 13, the device for water removal 14, the device for the surplus sludge removal 15 and the cellular biological filter 16. The cellular biological filter 16 comprises the channels 17, the upper edge 18 and the lower edge 19. The channels 17 are located at an angle α with the horizon. The upper edge 18 is located below the minimum possible water level Hi in the container 13. The devices for the aeration are located under the lower edge 19 in the plane Si which is less than the plane of the cross-section of the cellular biological filter 16. The outlet 20 of the device for the water removal 12 is located under the lower edge 19. The device for the water removal 14 is an outlet, located in the upper part of the container 13.

The waste water flows into the biological reactor 1 , where by the devices for the mixing 6 and the devices for the aeration 5 the periodic water aeration and mixing take place. The water is delivered from the biological reactor 1 into the biological reactor 2 through the pipe 7. The periodic water aeration and mixing also take reactor 3 by the device for the water delivery 9. The periodic water aeration takes place in the biological reactor 3. The sludge mixture is pumped from the biological reactor 2 into the biological reactor 1 by the device for the sludge mixture pumping 8, and the sludge mixture from the biological reactor 3 is pumped into the biological reactor 1 by the device for the sludge mixture pumping 10. When the water reaches the maximum level in the biological reactor 3, the hydraulic connection between the biological reactor 2 and the biological reactor 3 is terminated. The pumping of the sludge mixture from the biological reactor 3 is terminated too. After that water sedimentation takes place in the biological reactor 3 and the aeration of the biological reactor 3 is terminated. The circulation of the sludge mixture from the biological reactor 1 into the biological reactor 2 through the pipe 7 and from the biological reactor 2 into the biological reactor 1 by the device for the sludge mixture pumping 8 are performed simultaneously with the sedimentation in the biological reactor 3. After the sedimentation the water is removed from the biological reactor 3 by the device for the water removal 12. The surplus sludge is removed from the biological reactor by the device 11 for the sludge removal if necessary. The water removal from the biological reactor 3 is performed into the apparatus for the afterpurification of waste water 4 through the outlet 20 under the lower part 19 of the cellular biological filter 16. After that the aeration by the devices for the aeration 5 under the lower part of the cellular biological filter 16 in the volume limited with the plane S] and the water delivery through the channels 17 up the cellular biological filter 16 are performed inside the apparatus for the afterpurification of waste water 4. The water circulates through the channels 17 upwards in the volume limited with the plane Si and through the channels 17 down beyond the volume limited with the plane Si in the apparatus for the afterpurification of waste water 4. After the aeration in the apparatus for the afterpurification of waste water 4 is complete the water sedimentation with further surplus sludge removal by the device for the surplus sludge removal 15 are performed. After that the water delivery into the apparatus for the afterpurification of waste water 4 through the outlet 20 of the device for the water removal 12 is performed. The new portion of water displaces the treated and settled water in the apparatus for the afterpurification of waste water through the channels 17 of the cellular biological filter 16 and forth through outlet of the device for the water removal 14, this is the way the water removal from the apparatus for the afterpurification of waste water 4 is performed.

The next portion of water is delivered in the biological reactor 1 after the treated water and the precipitated surplus sludge are removed from the biological reactor 3.

The accumulating container for waste water (Fig.6) comprises the container 1 and the device for the water removal 2. The device for the water removal 2 equipped with an inlet 3 and a grating 4. The grating 4 is a closed circuit. The inlet 3 is located inside the closed circuit of the grating 4. The container 1 is equipped with the devices for the aeration 5 and with the devices for the mixing 6. Inside the closed circuit of the grating 4 additional devices for the aeration 7 are located. The height where the inlet is located is equal to the height H of the upper boundary of the active sludge volume, which is the minimum quantity of the sludge which is necessary for the stable biological purification process. The grating 4 is located at least partly below the height H. The device for the water removal 2 is a pump.

The accumulating container for waste water is used in the following way.

The waste water inflows into the container 1, where by the devices for the mixing 6 and the devices for the aeration 5 the periodic water aeration and mixing take place. The water aeration inside the closed circuit of the grating 4 by the additional devices for the aeration 7 is performed simultaneously with the water aeration in the container 1. The water removal from the container 1 is performed through the inlet 3 of the device for the water removal 2 from the volume limited by the closed circuit of the grating 4. When the water aeration in the container 1 is complete the water aeration inside the closed circuit of the grating 4 still takes The apparatus for the afterpurification of waste water (Fig.7) comprises the container 1, and the device for the water delivery 2, the device for the water removal 3, devices for the aeration 4, the device for the surplus sludge removal 5 and the cellular biological filter 6 located inside the container 1. The cellular biological filter 6 comprises channels 7, the upper edge 8 and the lower edge 9. The channels 7 are located at an angle α with the horizon. The upper edge 8 is located below the minimum possible water level Hi in the container 1. The devices for the aeration 4 are located under the lower edge 9 in the plane Si which is less than the plane S of the cross-section of the cellular biological filter 6. The outlet 10 of the device for the water delivery 2 is located under the lower edge 9. The device for the water removal 3 is an outlet, located in the upper part of the container 1.

The apparatus for the afterpurification of waste water is used in the following way.

The water delivery is performed into the container 1 by the device for the water delivery 2. The water delivery is performed through the outlet 10 under the lower part 9 of the cellular biological filter 6. After that the aeration is performed under the lower part 9 of the cellular biological filter 6 in the volume limited with the plane Si by the devices for the aeration 4 and the water delivery upwards through the channels 7 takes place in the container 1. The water in the apparatus for the afterpurification of waste water circulates through the channels 7 upwards in the volume limited with the plane Si and through the channels 7 down beyond the volume limited with the plane Si. After the aeration is terminated in the container 1, the water sedimentation with further surplus sludge removal by the device for the surplus sludge removal 5 is performed. After that next water delivery is performed into the container 1 through the inlet 10. The new portion of water replaces the afterpurified and settled in the container 1 water upwards through the channels 7 of the cellular biological filter 6 and forth through the outlet of the device for the water removal 3 the water removal from the apparatus for the afterpurification of waste water is performed. Exemplary embodiment of the invention

The apparatuses for the purification of waste water according to the Claim 11-45 for the method for the purification of waste water performance according to the Claim 1 - 10 is connected to the collecting system of a small hotel in such a way that waste water of the collecting system outlet inflows into the accumulating container for waste water. When the waste water inflows into the accumulating container the primary biological purification, the rough rubbish removal and the rough rubbish fragmentation are performed by the intensive aeration and mixing, the sand removal takes place as well. The deprived of the rough rubbish water is delivered into the biological reactor of the first stage of purification, where to the part of recycle sludge is pumped by an airlift from the biological reactor of the third stage of purification. The water is partly biologically treated in the biological reactor of the first stage of purification, as the water is subjected the repeated processes of the aeration and mixing under the lack of air. Thanks to which the process of denitrification at the availability of the nitrites and nitrates that came with the sludge mixture from the biological reactor of the third stage of purification and the availability of the light organic substances that came with fresh waste also takes place here. The water that was processed in the biological reactor of the first stage of purification flows directly into the biological reactor of the second stage of the purification, where there is also a part of recycle sludge mixture protected from the effect of the toxic substances that may come into the apparatus for the purification of waste water. During the water pumping forth into the biological reactor of the third stage by an airlift the foam is blown into the biological reactor of the second stage of purification. The water is also subjected to the repeated processes of the aeration and mixing in the biological reactor of the second stage of purification. The process of nitrification starts in the biological reactor of the second stage of purification because more than 50% of organic substances are oxidized in the biological reactor of the first stage of purification. Since the nitrites and nitrates come to the biological reactor of the second stag of purification, iust as they come into the biological reactor of the first stage, with the recycle sludge mixture - the two parallel processes take place here - nitrification and denitrification. As the organic substances get decomposed, the process of the nitrification starts to dominate. The partly treated water from the biological reactor of the second stage of purification either is pumped with an airlift or flows into the biological reactor of the third stage of purification, and the removal of the gases that appeared during the biological purification process in the biological reactor of the first stage of purification and the biological reactor of the second stage of purification (carbon oxide and so on) and also the satiation of water with oxygen take place. Because of the low contents of the organic substances in the biological reactor of the third stage of purification, the oxidation of the hard organic substances and the nitrification majorly take place here. The process of the purification passes in such a way that the nitrogen compounds are usually transformed into the nitrites (redox not more than 100), which allows to perform the denitrification faster and more effective (the reduction chain of the nitrites to the gaseous nitrogen is shorter in this case, than of the nitrates). The water undergoes the aeration in the biological reactor of the third stage of the purification with further sedimentation and the previously treated waste water removal into the apparatus for the afterpurification of waste water by the siphon. While the sedimentation takes place in the biological reactor of the third stage of purification the sludge mixture from the biological reactor of the second stage of purification is pumped by an airlift into the biological reactor of the first stage of purification, from which it flows back through the pipe into the biological reactor of the second stage of purification. This process takes place more than once and is accompanied by aeration and mixing in both biological reactors performing the corresponding processes described above. The removal of the surplus sludge into the aerobic stabilizer for instance takes place together with the previously treated water removal from the biological reactor of the third stage of purification. The water aeration and circulation through the channels of the plastic biological filter filling take place in the apparatus for the afterpurification of waste water. The finally treated waste water is removed from the apparatus for the purification of waste water.

The use of the apparatus for the purification of waste water that includes the biological reactors of the first, second and third stage of purification allows to perform the waste water purification to the parameters that correspond to the moderate grade of the pollution, for example, according to SanPiN N2 4630-88

(Sanitary Rules and Norms of protection the surface water from water pollution:

SanPiN JNb 4630-88 - Moscow.: CITP, 1989). If a higher grade of the waste water purification is necessary, the apparatus for the afterpurification of waste water is used.

The biological reactors 1, 2, 3 and the apparatus for the afterpurification of waste water can be located in a cascade one by one to provide the water delivery from the one their container into another by treated water flowing under the gravity influence in all the apparatus for the purification of waste water embodiment.

Statement of the advantages to be gained by the invention

Each of the claimed methods and apparatuses for the purification of waste water, and also the accumulating container for waste water and the apparatus for the afterpurification of waste water allow to achieve the necessary purification level with decreasing the energy expenses at waste water purification process and decreasing the investments, that are necessary for installing the apparatus for the purification of waste water and its components, and also allow to exclude the uncontrolled inflow of the new waste water portions at certain stages of the purification until the full purification cycle is over.

Claims

1. A method for the purification of waste water comprising the steps of the periodic aeration, mixing, sedimentation of the waste water and removal of the surplus sludge and treated water, characterizing in that

while the circulation of the water and of the sludge mixture continues ._s between the biological reactor of the first stage of purification and biological *" reactor of the second stage of purification, and the aeration and mixing in the biological reactor of the first stage of purification and the biological reactor of the second stage of purification takes place as well.

2. The method for the purification of waste water according to the Claim 1, wherein the circulation of the water and of the sludge mixture between the biological reactor of the first stage of purification and biological reactor of the second stage of purification is performed by the direct flow of the water from the biological reactor of the first stage of purification into the biological reactor of the second stage of purification and by the pumping of the sludge mixture from the biological reactor of the second stage of purification into the biological reactor of the first stage of purification.

3. A method for the purification of waste water comprising the steps of the periodic aeration, mixing, sedimentation of the waste water and removal of the surplus sludge and treated water, characterizing in that

the waste water is previously accumulated in the accumulating container, where the mixing periodically is performed and from where the water is delivered into the biological reactor of the first stage of purification after the removal of the treated and settled water from the biological reactor of the third stage of purification, {

4. The method for the purification of waste water according to the Claim 3, wherein the circulation of the water and of the sludge mixture between the biological reactor of the first stage of purification and the biological reactor of the second stage of purification is performed by the direct flow of water from the biological reactor of the first stage of purification into the biological reactor of the second stage of purification and by the pumping of the sludge mixture from the biological reactor of the second stage of purification into the biological reactor of the first stage of purification.

5. The method for the purification of waste water according to the

Claim 3, wherein the delivery of the water from the accumulating container into the biological reactor of the first stage of purification is performed after the mixing in the accumulating container is stopped.

6. A method for the purification of waste water comprising the steps of the periodic aeration, mixing, sedimentation of the waste water and removal of the surplus sludge and treated water, characterizing in that the waste water is previously accumulated in the accumulating container, where the aeration and mixing periodically is performed, and from which the water is delivered into the biological reactor of the first stage of purification after the removal of the treated and settled water from the biological reactor of the third stage of purification,

the delivery of the water into the biological reactors of the third stage of purification and the pumping of the sludge mixture from the biological reactor of the third stage of purification into the biological reactor of the first stage of purification are stopped at the period of sedimentation of the water in the biological reactor of the third stage of purification,

while the circulation of the water and of the sludge mixture continues between the biological reactor of the first stage of purification and biological reactor of the second stage of purification, and the aeration and mixing in the biological reactor of the first stage of purification and biological reactor of the second stage of purification takes place as well,

7. The method for the purification of waste water according to the Claim 6, wherein the circulation of water and of the sludge mixture between the biological reactor of the first stage of purification and the biological reactor of the second stage of purification is performed by the direct flow of the water from the biological reactor of the first stage of purification into the biological reactor of the second stage of purification and the pumping of the sludge mixture from the biological reactor of the second stage of purification into the biological reactor of the first stage of purification.

8. The method for the purification of waste water according to the Claim 6, wherein the delivery of the water into the biological reactor of the first stage of purification is performed after the mixing and aeration in the accumulating container are stopped.

9. A method for the purification of waste water, comprising the steps of the periodic aeration, mixing, sedimentation of the waste water and removal of the \ surplus sludge and treated water, characterizing in that

the waste water is delivered, to the biological reactor of the first stage of purification after the removal of treated and settled water from the biological reactor of the third stage of purification,

the delivery of the water from the biological reactor of the second stage of purification into the biological reactor of the third stage of purification is provided, the pumping of the sludge mixture from the biological reactor of the second stage of purification and biological reactor of the third stage of purification into the biological reactor of the first stage of purification is performed,

the removal of the previously treated and settled water from the biological reactor of the third stage of purification is performed into the apparatus for the afterpurification of the waste water, where the aeration of the water is performed under the lower part of the biological filter submerged into water, in the plane that is less than the plane of cross-section of the biological filter, with further water delivery through the inclined biological filter channels,

the water is delivered into the said apparatus for the afterpurification of waste water to the lower part of the biological filter after the aeration, sedimentation of waste water and the surplus sludge removal are over and the delivery of the water into the biological filter is accompanied by forcing out the water that was previously settled in said apparatus of the afterpurification of waste water through the inclined channels of the biological filter with its further removal.

10. The method for the purification of waste water according to the Claim 9, wherein the circulation of the water and of the sludge mixture between the biological reactor of the first stage and the biological reactor of the second stage is performed by the direct flow of the water from the biological reactor of the first stage of purification into the biological reactor of the second stage of purification and by the pumping of the sludge mixture from the biological reactor of the second stage of purification into the biological reactor of the first stage of purification.

11. An apparatus for the purification of waste water comprising the biological reactors of two stages, equipped with the devices for the aeration, mixing and the sludge mixture pumping, characterizing in that

12. The apparatus for the purification of waste water according to the Claim 11, wherein the hydraulic connection between the biological reactor of the first stage of purification and the biological reactor of the second stage of purification is performed by a pipe located below the water level in the biological reactor of the first stage of purification.

13. The apparatus for the purification of waste water according to the

14. The apparatus for the purification of waste water according to the Claim 11, wherein the device for the water delivery into the biological reactor of the third stage is an airlift.

15. The apparatus for the purification of waste water according to the Claim 11, wherein the device for the water delivery into the biological reactor of the third stage of purification is a pipe, which connects the upper parts of the biological reactor of the second stage of purification and the biological reactor of the third stage of purification.

16. The apparatus for the purification of waste water according to the Claim 11, wherein the device for the water removal from the biological reactor of the third stage of purification is a controlled siphon.

17. The apparatus for the purification of waste water according to the Claim 11, wherein the device for the surplus sludge removal from the biological reactor of the third stage of purification is a pump.

18. An apparatus for the purification of waste water comprising the biological reactors of two stages of purification, equipped with the devices for the aeration, mixing and the sludge mixture pumping, characterizing in that

the biological reactor of the first stage of purification is hydraulically connected with the biological reactor of the second stage of purification, the biological reactor of the second stage of purification is equipped with the device for the water delivery into the biological reactor of the third stage of purification and device for the sludge mixture pumping into the biological reactor of the first stage of purification,

19. The apparatus for the purification of waste water according to the Claim 18, wherein the hydraulic connection between the biological reactor of the first stage of purification and the biological reactor of the second stage of purification is performed by a pipe located below the water level in the biological reactor of the first stage.

20. The apparatus for the purification of waste water according to the Claim 18, wherein the device for the sludge mixture pumping is an airlift.

21. The apparatus for the purification of waste water according to the Claim 18, wherein the device for the water delivery into the biological reactor of the third stage of purification is an airlift.

22. The apparatus for the purification of waste water according to the Claim 18, wherein the device for the water delivery into the biological reactor of the third stage of purification is a pipe, which connects the upper parts of the biological reactor of the second stage of purification and the biological reactor the third stage of purification.

23. The apparatus for the purification of waste water according to the Claim 18, wherein the device for the water removal from the biological reactor of the third stage of purification is a controlled siphon.

24. The apparatus for the purification of waste water according to the Claim 18, wherein the device for the surplus sludge removal from the biological reactor of the third stage of purification is a pump.

25. The apparatus for the purification of waste water according to the Claim 18, wherein the device for the water delivery into the biological reactor of the first stage of purification is a pump.

26. An apparatus for the purification of waste water comprising the biological reactors of two stages of purification, equipped with the devices for the aeration, mixing and the sludge mixture pumping, characterizing in that

the inlet of the device for the water delivery into the biological reactor of the first stage of purification is located inside the closed grating at the upper boundary of the active sludge volume, which is the minimum quantity of the sludge which is necessary for the stable biological purification process, the closed grating is at least partly located below the upper boundary of the active sludge volume, which is the minimum quantity of the sludge which is necessary for the stable biological purification process,

27. The apparatus for the purification of waste water according to the Claim 26, wherein the hydraulic connection between the biological reactor of the first stage of purification and the biological reactor of the second stage of purification is performed by a pipe located below the water level in the biological reactor of the first stage of purification.

28. The apparatus for the purification of waste water according to the Claim 26, wherein the device for the sludge mixture pumping is an airlift.

29. The apparatus for the purification of waste water according to the Claim 26, wherein the device for the water delivery into the biological reactor of the third stage of purification is an airlift.

30. The apparatus for the purification of waste water according to the Claim 26, wherein the device for the water delivery into the biological reactor of the third stage of purification is a pipe, which connects the upper parts of the biological reactors of the second and the third stages of purification.

31. The apparatus for the purification of waste water according to the

Claim 26, wherein the device for the water removal from the biological reactor of the third stage of purification is a controlled siphon.

32. The apparatus for the purification of waste water according to the Claim 26, wherein the device for the surplus sludge removal from the biological reactor of the third stage of purification is a pump.

33. The apparatus for the purification of waste water according to the Claim 26, wherein the device for the water delivery into the biological reactor of the first stage of purification is a pump.

34. An apparatus for the purification of waste water comprising the biological reactors of two stages equipped with the devices for the aeration, mixing and the sludge mixture pumping, characterizing in that

the biological reactor of the . first stage of purification is hydraulically connected with the biological reactor of the second stage of purification,

the biological reactor of the second stage is equipped with the device for the water delivery into the biological reactor of the third stage of purification and with the device for the sludge mixture pumping into the biological reactor of the first stage of purification, ^.

devices for the aeration located under the cellular biological filter in the plane that is less than the plane of cross-section of the cellular biological filter,

the cells of the cellular biological filter are inclined channels,

the upper edge of the cellular biological filter is located below the minimal level of water in the device for the afterpurification of waste water, the outlet of the device for the water delivery into the device for the afterpurification of waste water is located under the lower edge of the cellular biological filter.

35. The apparatus for the purification of waste water according to the Claim 34, wherein the hydraulic connection between the biological reactor of the first stage of purification and the biological reactor of the second stage of purification is performed by a pipe located below the water level in the biological reactor of the first stage of purification.

36. The apparatus for the purification of waste water according to the Claim 34, wherein the device for the sludge mixture pumping is an airlift.

37. The apparatus for the purification of waste water according to the Claim 34, wherein the device for the water delivery into the biological reactor of the third stage of purification is an airlift.

38. The apparatus for the purification of waste water according to the Claim 34, wherein the device for the water delivery into the biological reactor of the third stage of purification is a pipe, which connects the upper parts of the biological reactor of the second stage of purification and the biological reactor the third stage of purification.

39. The apparatus for the purification of waste water according to the Claim 34, wherein the device for the water removal from the biological reactor of the third stage of purification is a controlled siphon.

40. The apparatus for the purification of waste water according to the Claim 34, wherein the device for the surplus sludge removal from the biological reactor of the third stage of purification is a pump.

41. The apparatus for the purification of waste water according to the

Claim 34, wherein the device of the water removal from the device for the afterpurification of waste water is the outlet located in upper parts of the device for the afterpurification of waste water.

42. An accumulating container for waste water comprising the devices for the aeration, mixing and the water removal, characterizing in that

43. The accumulating container for waste water according to the Claim 42, wherein the device for the water removal is a pump.

44. An apparatus for the afterpurification of waste water comprising the container, device for the water delivery, device for the water removal, device for the surplus sludge removal and the biological filter, characterizing in that

in addition said device for the afterpurification of waste water is equipped with the devices for the aeration located under the biological filter in the plane that is less than the plane of cross-section of the biological filter,

the biological filter includes a cell,

the cells of the biological filter are inclined channels, the upper edge of said biological filter is located below the minimal level of water in the device for the afterpurification of waste water,

45. An apparatus for the afterpurification of waste water according to the Claim 45, wherein the device for the water removal is an outlet located in the upper part of the container.