DE3500340A1 - Process for the biological purification of wastewater and an activated sludge tank for carrying it out - Google Patents

Abstract

The process for the biological purification of wastewater from organic impurities by activated sludge proceeds in two stages. In the first stage (2), the wastewater (1) is mixed with the activated sludge (3,4), aerated and the return sludge (19,20) and the sludge water (12) are separated off. The return sludge (19,20) is recovered and passed to mixing with the wastewater (1). In the second stage (13), the sludge water (12) of the first stage (2) is aerated and the remaining activated sludge (18) is separated therefrom. The return sludge arriving for activation is divided into two parts, of which one (19,20) comes immediately to activation and the other (21,22) is thickened prior to activation and is then mixed with the first part (19,20) of the return sludge for joint activation. In the first stage (2), in this case, the constant ratio between organic impurities of the wastewater (1) and activated sludge (3,4) is maintained. The activated sludge tank for carrying out the process contains a vessel (40) of the first stage and a vessel (52,53) of the second stage. The first stage (2) includes, connected in series, vessel (40), sludge separator (49) and activation chamber (61), connected to the inlet of the vessel (40). A sludge thickening vessel (66) is provided which [lacuna] by an inlet (67) to the sludge separator (49) and by outlets (69,70) to the activation chamber (61) and the vessel (52,53) ... Original abstract incomplete. <IMAGE>

Description

DESCRIPTION OF THE INVENTION

The present invention relates to the purification of wastewater from organic contaminants and in particular a method for biological wastewater treatment activated sludge and an activated sludge basin to carry out the process.

The invention can be most effectively used when it can is the fully biological treatment of concentrated commercial wastewater, which contains difficult to oxidize organic impurities, whereby it is unevenly arrives for cleaning both in terms of quantity and composition.

The present invention can also be applied to the fully biological Use municipal sewage purification in the mixed system where all accruing Wastewater - the domestic, commercial wastewater and the rainwater - in anOivlls & rnJll pipe and sewer network can be removed from the city.

Furthermore, the invention can be used for fully biological cleaning of urban sewage in the separation system, with the rainwater and conditionally pure Industrial wastewater in the one pipe and sewer network and domestic wastewater and contaminated Industrial wastewater is discharged in the other - in one or more networks, as well as in the combined drainage system.

The processes for biological wastewater treatment using activated sludge are based on the ability of aerobic microorganisms to emerge from different and priority organic matter in wastewater and nourish them during their vital activity to oxidize. The artificially cultivated microorganisms, their concentrate as activated sludge called, so rid the wastewater of pollutants by removing their Securing the energy demand and the growth of biomass. You can do it biologically treat (oxidize) a large number of composite and various organic substances. The treatment will also include some mineral compounds such as hydrogen sulfide, ammonia, Nitrites and other subjects. But the wastewater also contains substances that are biological Ways are not or partially oxidized. The biological cleaning becomes complete called when the full biochemical oxygen demand (BOD) of the purified Wastewater is below 20 mg / l, and it is incomplete if the biochemical Oxygen demand exceeds 2Q.mg/l u. This definition is to a certain extent @ u because even with fully biological cleaning there are certain impurities in the wastewater are still included.

Biological cleaning is usually carried out in reinforced concrete containers, the activated sludge basins are called. In the activated sludge basin one submits the mixture of water and activated sludge or the mixture of mud, usually of 1.5 ... 2.5 g, 'l concentration of continuous aeration with oxygen-containing Gas (air), supplied via diffuser nozzles during the movement from the inlet to the activated sludge basin until it emerges from this, then separates the activated sludge from the treated wastewater and sucks the activated sludge back into the activated sludge basin, depending on the hydrodynamic A distinction is made between displacement basins in which Drainage and activated sludge enter and exit at the front sides, and agitator basins, in which incoming wastewater practically momentarily with the entire contents of the activated sludge basin is mixed. It is found that displacement basins are used for high purification of the Wastewater with relatively low technological loads expediently are to be used, while agitator hedges, which do not ensure a high degree of withstand the high technological loads with 'rfo'g and the stability the technological process in the presence of toxic components in the wastewater can last longer SCit.

Originally there are single-stage activated sludge basins and two-stage activated sludge basins very common with regenerators. Opposite the others are single-stage activated sludge basins relatively easy to use, but their interest rate area is limited. The cleaning process in the activated sludge basin according to the one-step process has a number of significant drawbacks. Sewage treatment is in such basins not to intensify by increasing the activated sludge mass. At the point ~ The inflow of wastewater containing toxic impurities can also impair the quality activated sludge or even its disintegration take place. he mentioned disadvantages dispense with activated sludge basins with regenerators, in which the wastewater is mixed nit activated sludge in the shortest possible time to achieve the Required cleaning effect, based on BOD, is sufficient, after which the in a Cooling sludge separated from the sewage treatment plant is pumped into the regenerator, where the Oxidation processes of adsorbed pollutants end and the activated sludge its Gets Ausana properties. the vitalised water basin equipped with a regenerator requires a significantly smaller built-in work space in case of deterioration the properties of activated sludge in the activated sludge basin, for example through inflow toxic impurities also serves as a reliable reserve of the activated sludge in the regenerator. A special feature of the two-stage activated sludge basin is there in that a "specialized" activated sludge develops in each purification stage, as a result of which fully biological cleaning of highly concentrated, difficult to oxidize Waste water containing organic pollutants can be carried out.

Organic pollutants carried along by the wastewater end up in cleaning systems unevenly throughout the day, the unevenness from two Components from the unevenness of incoming wastewater quantities and from the unevenness of concentrations of pollutants arises. Temporal Coincidence of the specified irregularities leads aasu that to certain Time during the operation of the revitalized pool the technological loads the average lichen 3 to 5 times and sometimes exceeding that. The efficiency of the Activated sludge pools depend on a number of conditions, which include: Composition and day properties of wastewater, hydrodynamic conditions in the Mixing of the work medium, quantitative ratio between contaminated contaminants and existing activated sludge as well as oxygen supply of the activated sludge basin. Under actual conditions, the activated sludge is due to strong load fluctuations, which every living cell cannot stand, "sick", loses its oxidizing properties and separability, which is not only the sharp deterioration in the quality of cleaning but also the complete disruption to the operation of the activated sludge basin can. To make the operation of the activated sludge basin less sensitive to fluctuations To make the technological load, you have to use the converted work space and lecturing energy increase significantly for ventilation. Under actual cleaning conditions of urban wastewater, for example, the wastewater does not come into contact with the activated sludge in the activated sludge tanks an average of 6 to 8 hours and the specific one Air consumption depending on the degree of pollution of the wastewater is from 5 to 15 m3 per 1 m3 of treated wastewater. With an accumulation of 50,000 m3 of wastewater per day, what a corresponds to a medium-sized object, the volume of the activated sludge basin fluctuates between 20,000 and 25,000 m3 and the daily electrical energy consumption for ventilation between 7000 and IO 000 kWh, with a significant part of the specified volumes and outputs is consumed unproductively.

A method for biological wastewater purification is known Activated sludge in a single-stage activated sludge tank (YES registration 57-28316, Int. Cl. C 02 F) / j2), in which the incoming wastewater is mixed with the Activated sludge mixed, aerated the obtained sludge title and then from the sludge agent separates the return sludge and returns it to mix with the incoming wastewater, while the purified sewage for further processing, for example Chlorine disinfection reached. The process control in terms of load fluctuations Incoming pollutants are made by measuring the activated sludge concentration and oxygen consumption, and the optimal ratio between organic pollutants in the incoming wastewater and activated sludge is due to the change in the activated sludge concentration in the system as a result of the regulation of the amount of removable excess activated sludge kept constant.

This procedure ensures a good and safe purification of the wastewater with impurities only of a relatively simple composition, if the Fluctuations in the technological load are insignificant in terms of amplitude and have a gentle character.

However, such operating conditions are seldom observed in practice. In the balls most widely used in practice, when the drainage is a complicated one Composition of organic compounds and which last several hours If load fluctuations are significant, the use of this method does not have any noticeable effect.

The gravity separation of the concentrated sludge medium into return sludge and purified wastewater is also reduced by the increased discharge of suspended particles accompanies, which greatly reduces the cleaning effect. If according to the biological Cleaning high purification systems (sand or carbon filters, ozone systems, ion exchange filters and others) are used, the latter usually fall out quickly, if the suspended matter content of the incoming water exceeds 15 to 20 mg / l.

A method for the biological purification of the is also known Wastewater from organic contamination through activated sludge in two stages (DE registration 2936884 Ä I, Int. Cl. C 02 F 3/12), with the ventilation in the first stage of the sludge medium with subsequent separation of the same and sludge activation and in the second stage, the aeration and removal of the remaining activated sludge carried out, This process enables the purification of highly concentrated Wastewater (BOD over 1000 mg / l), which is difficult to break down industrial contaminants contains.

The area of application of this process includes commercial wastewater, but remains limited. Under conditions of fluctuation in technological load in the first stage of biological cleaning, in the one with constant activated sludge concentrations is worked, the optimal ratio between the amount of organic Impurities and activated sludge concentration disrupted several times within a day. The aluminum trapping zones of the first cleaning stage are particularly heavily overloaded, which means the purification quality of the wastewater loses its stability, the sludge to buoyancy tends to deteriorate its clarification and go to the second stage purification in addition to the excess suspended matter, a significant amount of not in the first stage oxidized pollutants begin to arrive. As a result, the operation of the second stage is disturbed, and there is a "hatred breakthrough" that is difficult to oxidize Impurities in the treated wastewater.

In order to increase the stability of the technological process, must the first cleaning stage is to be carried out more slowly, i.e. the converted work area increase two to three times, which increases construction costs and expanded building site requires. The operating costs and primarily the ventilation-related expenses increase sharply because the ventilation intensity, so that the activated sludge in the event of a lack of oxygen does not come to a standstill, the maximum load must be adjusted. With diminished Loads, for example at real time, the activated sludge is caused by the excess Aeration crushed and, due to insufficient supply, into difficult-to-settle particles relatively easily broken. The crushed sludge is used by the individual Air bubbles are entrained and carried to the surface by scum or floating Look: educate. Such foaming disturbs the sludge separation, affects the quality of the treated wastewater and results in a strong degradation the activated sludge concentration in the system. This is usually at night time Case when the visual inspection of the technological process causes difficulties.

In the known method described, the ventilation intensity is regulated depending on the applied load in such a way that the number of operated Air blower is changed, resulting in lowering the evenness of ventilation and the Degree of utilization of the oxygen leads.

The invention is based on the object of a method for biological To develop wastewater treatment and an active sleeping basin to carry out the same, in the case of the operational control of the activated sludge concentration in the first Purification stage by changing the amount of oxygen-containing gas supplied and the hydrodynamic flow form of the sludge medium the optimal ratio between organic contamination in the incoming wastewater and activated sludge is kept constant.

The essence of the invention is that in the process of biological Wastewater treatment of organic pollutants through activated sludge in two stages, in which the incoming wastewater is mixed with the activated sludge in the first stage, the obtained sludge medium aerated and then from the sludge medium of the end zone of the the first stage separates the return sludge, subjects it to the activation and the recovered activated sludge for mixing with that in the initial zone of the first Incoming wastewater is directed in the second stage, while in the second stage that after the Separation of the return sludge from the sludge medium resulting sludge water aerated and removed from this the remaining activated sludge, according to the invention the return sludge supplied for activation is separated into two parts, one one of which is directed to the stimulation and the other before the stimulation thickened and then with the first part of the return muddy for the purpose of common animation is mixed by the ratio between organic Impurities in the incoming wastewater and activated sludge kept constant in the first stage will.

By running the return sludge flow directed to the activated sludge in two parts, one of which is thickened before the animation, one tann the time for the separation of the return sludge from the sludge medium from usual I to Shorten 1.5 hours to 15 and 30 minutes, which is the residence time of the return sludge reduced to a minimum under anaerobic conditions and its activity better receives. The increase in the return sludge concentration in turn increases the Degree of utilization of the working volume of the regenerators and that required for the activation oxygen-containing gas. And finally the increase in the activated sludge clay concentrate results in CNn in the hegeneratorei whereby the mean activated sludge concentration in the Syste.u increases, the increase of the activated sludge concentration in the first cleaning stage, whereby their ability to oxidize and resistance in conditions of increased technological pollution increases and the optimal ratio between organic impurities is kept constant in the incoming wastewater and activated sludge.

This enables the process of shiamin deposition to accelerate to aas three to four times the volume of the stimulation supplied To reduce the return sludge by 1.5 to 2 times the aeration time of To shorten wastewater in the first stage by 1.1 to 1.3 times as well as the Scillamm activation required amount of oxygen-containing gas (nut) by 3 to 12Ro to belittle.

It is advisable that the returned sludge part in the essentially from 0.2 to 0.8 total mass of the return sludge supplied for activation amounts to.

The concentration of the Rücklaut'schlamms supplied for the activation depends on its thickenability and separability availability (sedimentation properties) and can vary widely. The sedimentation properties of the mud, determined by its species composition and the physiological condition of the microorganisms, depends primarily on the type of sewage and on a number of the lactors from which the physico-chemical conditions in the implementation of the technological Determine the process. By changing the part of the return sludge to be thickened A predetermined weight can essentially be in a range from 0.2 to 0.8 of its total mass Average return sludge concentration with different sedimentation properties of the activated sludge are kept constant.

With increased sewage inflow, it is advisable to use part of the wastewater supplied to the first stage with the recovered water supplied to the first stage To mix activated sludge and a post-aeration by the supply of oxygen-containing To subject the gas, then the obtained sludge medium with the remaining part of the to mix the initial zone of the first stage fed wastewater and after the In the first stage, treatment of part of the medium flow of sludge from the end zone of the first stage to the starting zone of the first stage and connect it to the to mix the return sludge coming to the activated sludge, while the oxygen-containing To supply gas for post-ventilation in an amount that causes intensive longitudinal circulation of the sludge medium of the first stage through the return circulation of the sludge medium flow between Secures the end and start zones of the first stage.

Realization of post-ventilation with increased sewage inflow ensures the introduction of the required amount of oxygen. To get the oxygen during To make full use of the post-ventilation, it is desirable to use part of the flow a waste water supplied from the first stage with that supplied to the first stage Recovered activated sludge mix, increasing the rate of oxygen consumption and the sludge for a workload is already prepared in the activation stage. tet.

The effective longitudinal circulation of the Mud midway between the Shd and initial zones of the first stage changes its hydrodynamic Flow form from the state of displacement to the state of complete mixing, what a quick and even distribution of the incoming impurities causes. Concentration vessels of organic impurities, dissolved oxygen and activated sludge in the length of the medium flow are minimal. The at increased wastewater inflow required proportional increase in activated sludge concentration in the first stage, through the mutual averaging of the currents, again ~ obtained activated sludge and sludge agent.

The specified operations increase the oxidation ability of the first cleaning stage to several times without affecting the initial quality of the cleaned Reduce wastewater with this at the minimum level of energy consumption as well as without Enlargement of the system work volumes is achieved, regardless of the fact that the Wastewater inflow by 1.5 to 2 times and the technological load by Can increase 3 to 5 times.

It is beneficial if the oxygen-containing gas is used for post-ventilation is passed in an amount which is essentially between 3 and IO The ratio of the return sludge to the wastewater to be cleaned is guaranteed.

The oxygen-containing gas that is added to the sludge medium during post-aeration is added serves two purposes at the same time: firstly, to generate the hydrodynamic Form of flow that approaches the state of perfect mixing if the oxygen-containing gas the reverse movement of the sludge agent between the end and start zones of the first stage favored: secondly, to the addition of an additional Amount of dissolved oxygen in the sludge medium that is required to make the carry out oxidative wastewater purification process.

In the balls when the wastewater related to BOD ~ concentration is low (about 150 mg / l), the first purpose and that turns out to be decisive Minimum ratio of the sludge medium outflow to the wastewater to be cleaned 3 equals. In the stables when the concentration of organic pollutants in the wastewater coming for cleaning is high, the second purpose and that dominates Maximum ratio of the return sludge agent to the wastewater to be cleaned is IO the same.

This makes it possible with the increased sewage inflow as well as at the moment of so-called load peak the energy consumption at the optimal level by the full utilization of the supplied oxygen-containing gas to awaken both the To keep promotion as well as oxidation.

It is beneficial to mix with the recovered material beforehand Sludge essentially from 1/3 to 2/3 the flow of that arriving for cleaning Waste water are fed.

There are practically possible fluctuations in the sewage inflow Range from 1.3 to 3 based on the inflow of funds. Illit other '.'iorten will be in the time of the increased sewage inflow additionally from 1/3 to 2/3 sewage to Cleaning arrive. In order to keep the stable cleaning in the first stage is the additional amount of wastewater from post-aeration and mixing with the recovered Subsequently, activated sludge is expediently subjected.

The range given above is optimal because it falls below the same would result in greater loss of oxygen by expectoration into the open air, while the exceeding of the same the lack of dissolved oxygen in the post-ventilation would produce, which will adversely affect the wastewater treatment process.

It is advisable to reduce the water produced by thickening part of the return sludge supplied for activation, to be supplied to the second stage and one To subject aeration and the activated sludge stream separated after the second stage to mix with the return sludge to be activated.

The sludge water created by the thickening of the return sludge contains a significant amount of suspended particles that are difficult to settle v Settling for flooding after the aeration method by blowing through with small portions of oxygen-containing gas are to be brought, this causes the enlargement the electrostatic surface charge of mud fluff, making their mutual Attraction increases and the settling process is accelerated. In individual cases In addition, some impurities that are difficult to break down get into the second cleaning stage from the first stage, which by sludge means of the second stage, which under conditions low technological loads are operated, should be post-oxidized.

The total amount of sludge that went from the sludge water to the second Cleaning stage is brought, the amount of excess sludge can exceed. In addition, it is advisable to have a Part of the activated sludge that can be removed after the second stage for mixing with to lead the return sludge coming to the activated sludge in order to achieve high activated sludge concentrations to be kept constant in the cleaning system.

Thanks to the implementation of the aforementioned technological operations there is the possibility of a stable and high purification of the wastewater in the case of uneven Inflow of the same with minimal energy consumption and 1.5 to 2-fold reduction to guarantee the enclosed space of the system.

The method according to the invention is expediently in an activated sludge basin to realize which a mixing container provided with compressed air sprinkler the first stage and an initial zone with inlet devices housed therein for feeding wastewater and activated sludge into the mixing tank and a sand zone in which there is a sludge agent outlet connected to a sludge separator communicates which the separation of the return sludge from the sludge agent concerned and an outlet for the treated wastewater, which communicates with a displacement tank of the second stage, the compressed air diffuser and sludge separator, and an outlet for return sludge, which is connected to an aeration chamber, which has compressed air diffusion nozzles and on their outlet with the inlet device for the supply of the recovered activated sludge communicates in the container of the first stage, which according to the invention with a Sludge thickening tank is provided to increase the return sludge concentration serves and an inlet, connected to a sludge separator outlet for the return sludge, and has two exits, one of which with the entry of the aeration chamber and the other communicates with the inlet of the displacement tank in the second stage.

By using the sludge thickener, adjusted to the increase the ücklauschlammonzentration in connection with the short separation time of the Not only can sludge contain the amount of living microorganisms that purify wastewater procure, enlarge, but through the thickening under aerobic conditions the Keep the oxidation properties of the activated sludge at the highest level.

This results in significantly higher odation speeds of Impurities, which gives the possibility of a significant reduction in the working space from activated sludge tanks.

It is desirable to have the activated sludge basin with an additional Equip antechamber that has compressed air nozzle and is located between the aeration chamber outlet and inlet means for feeding the activated sludge into the container of the first stage is located, the antechamber with the jlin inlet device for supplying the wastewater is also connected to the container of the first stage, while the aeration chamber communicates with the end zone of the first stage container.

The real fluctuation curve of the amount of wastewater arriving for cleaning Over time usually contains two zones, namely brewing and afternoon zones from SxtremalgIaximal) values. The more precise the step curve of the change to be controlled the oxidizing capacity of the activated sludge basin in the swing curve of the wastewater volume is inscribed, the lower the electrical energy consumption and unproductive the higher the technological and economic parameters of the cleaning system. This is achieved through the appropriate selection of the number of antechambers and the determination of the antechamber output achieved. From the standpoint of ease of use while achieving The activated sludge basin with a The main antechamber and an additional antechamber are expediently equipped.

It is convenient to have the second stage dirt separator through his Connect the outlet for the activated sludge to the activated sludge inlet.

The possibility of the activated sludge of the activated sludge chamber from the sludge separator the second stage to feed what is called periodic return circulation of the activated sludge can be viewed from the second purification stage to the first stage necessary activated sludge concentrations in the first cleaning stage at the time of Keep loadon peaks constant. This also ensures the necessary balance in the cleaning system circulating activated sludge and excess activated sludge, which is to be eliminated from the system.

It is recommended that the activated sludge basin is open from above Contains longitudinal housing that is divided into two sections by a transverse partition, in the first of which longitudinal partitions are housed, which are in the longitudinal axis of the housing a container of the first stage, inside which nozzles for oxygen Gas are arranged, and with housing walls the main aeration chamber and an additional one Form aeration chamber, which from both sides of the container of the first stage Angel and are provided with wall partitions, which the aeration chambers divide them into sections, each of which has diffuser nozzles for oxygen-containing gas, being close to the initial zone of the container on the outside of the Longitudinal partitions Longitudinal and transverse partitions are set up, which the main antechamber and the additional Form antechamber, which through passages with the main aeration chamber una the additional Activation chamber and connected to the container by overflows and with litter nozzles are provided for oxygen-containing gas; in the second section along its axis there is a horizontal gravity sludge separator that overflows is connected to the container of the first stage and a container of the second stage forms with the walls of the second section, being close to the transverse partition of the Housing vertical gravity clamming containers are arranged with the Main aeration chamber and communicate with the additional aeration chamber while the .3 dirt separator with compressed air pumps for conveying the backflow sludge in The thickening tank is equipped with compressed air pumps for conveying of the return sludge of increased concentration in the main aeration chamber and the additional aeration chamber are provided.

The arrangement of all main systems in a uniform housing is tracked multiple goals at the same time. Thanks to this solution you can reduce the building material consumption and Reduce building space requirements by making extensive use of adjacent partition walls and the length of the distribution devices and the dimensions of inlet devices zoom out.

This grouping is more fundamental in a number of systems Meaning. For example, by connecting aeration chambers and Pre-chambers with the mixing container of the first cleaning stage, which in the increased Wastewater inflow to be operated as communicating vessels, the energy expenditure Reduce to a minimum for pumping the return fluid. Heavy force -Sludge separators and sludge thickening tanks are available at a minimum cost as well as a high return sludge concentration without disturbing the structure of the Blockensonlamms to keep constant.

The use of compressed air pumps to convey the Activated sludge from the sludge separator into the sludge thickening tank and from the sludge thickening tank in the aeration chamber is easiest to implement under actual conditions, and it also enables the activated sludge to be saturated during thickening same with dissolved oxygen, what the useful properties of the activated sludge to get helps.

To explain the invention, the following examples are specific Execution of the same described with reference to the accompanying drawings, in which shows: Fig. I - schematically the sequence of the technological operations in the process for biological cleaning with an average sewage inflow Fig. 2 - the Dependence of the concentration (a2) of the return sludge part to be thickened on the Time (t) of its residence in the sludge thickening tank; Fig. 3 the Schera with increased Wastewater inflow according to the invention; 4 shows the scheme at the maximum sewage inflow according to the invention; Fig. 5 - the dependence of the hydrodynamic flow form the sludge mean (D / µL) from the recirculation ratio (R); vig. 6 - the overall view the activated sludge basin according to the invention; Fi. 7 - len Schnitu VII-s.JII in Fig. C; Fig. 8 - len section VIII-VIII in Br. 6; Fig. 9 - the section IS-IY in Fig. 6; Fig.lO - a diagram of the change in the amount of oxygen supplied under hour division within one day through the operation of the main antechamber and the additional ones Antechamber.

The essence of the process according to the invention for biological wastewater purification by activated sludge consists in the following. The starting wastewater I (Fig.I) is the first cleaning stage 2, where it can be the won Activated sludge 3.4 of about 8 / l hose concentration, which is from the regenerators 5.6 comes, mixed and the sludge medium obtained from 1.5 to 2.5 g / l sludge concentration with oxygenated. Gas 7 for example ventilated with runs. In the course of the fine-bubble Ventilation under sarbotage, the oxygen from gas bubbles dissolves in the liquid side, creating aerobic conditions for the microorganisms of the activated sludge be created who take care of the wastewater treatment. In the first cleaning stage 2, incoming organic impurities are adsorbed by activated sludge flakes and partially oxidized, after which from the sludge means 8 of the indzone of the first Stage 2 the return sludge of 4 to 7 g / l concentration, for example after Gravity process in the dirt separator 9 of the first stage 2 separates.

To the activated sludge from the end zone of the first stage 2 its initial activity recover those with the absorption of incoming organic impurities decreases, the activated sludge is subjected to activation, namely aerobic storage over the course of a few hours, the activated sludge by being placed in regenerators 5, 6 befinuet, adsorbed impurities processed and ventilation with oxygenated Gas 10.11 is subjected. The activated sludge obtained in Vienna is used for mixing with the wastewater I arriving in the initial zone of the first stage 2, and the technological process is repeated.

in the separation of the return sludge from the sludge means 8 of the End zone of the first stage under short-term (15 to 30 min) contact occurs the sludge water 12, consisting of at least 90% purified wastewater and mainly difficult to remove. Activated sleepiness from 0.2 to, 5 g / l concentration.

For the purpose of complete elimination of suspended matter that is difficult to dispose of from the sludge water as well as biological post-oxidation difficult to oxidize organic Impurities becomes the sludge water of the second cleaning stage '13 where it is subjected to ventilation 14 during ventilation in the second stage 13 is the enlargement or weighting of flocs of the activated sludge through its biological coagulation, after which from the sludge agent 15 of the second stage 13 in the sludge separator 16 of the second stage during I to 1.5 hours the activated sludge of completely cleaned (BOD = IO to 15 mg / l) Waste water 17 is deposited, which from the activated sludge basin addition, for example is directed into a receiving water for disinfection before discharge. The deposed and in the second stage sludge separator 16 to a concentration of 9 to 12 g / l thickened excess sludge 18, created by the increase in the return sludge the first stage, is sent for further treatment or recovery.

According to the invention, the return sludge supplied for activation is separated into two parts, of which one 19, 20 goes directly into the regenerators, while the other 21.22 before regeneration in sludge thickening tanks 23.24 before is thickened (i.e. the concentration is increased), after which the thickened sludge 25.26 mixed with the first part 19.20 of the return sludge for joint activation will.

The separation of the return sludge flow supplied for activation in two parts, of which one 21,22 thickened before revitalization and thus the middle The concentration of the SücklauSludge is increased, gives the possibility of a number to solve technical problems: the separation time of the return sludge from the Shorten the sludge mean 8 to 15 to 30 minutes instead of the usual I to 1.5 hours, what maintains its activity better because its dwelling in anaerobic conditions the effectiveness of the regenerator working area is reduced to a minimum IO, II to increase by 50 to IOü% and the degree of utilization of the regenerators IOII by at least 3 to 4% of the oxygen entering during aeration to increase, which in turn increases the utilization of the oxygen-containing gas by 15 to Is enlarged by 20%; the activated sludge concentration in the first cleaning stage to increase to 2.5 5 to 3 g / l, increasing the stability of the cleaning process by keeping the ratio between organic impurities constant of the sewage inflow and activated sludge at the optimal level under increased technological stress increases.

The ratio between organic contaminants of the sewage inflow and activated sludge is expressed by the biochemical oxygen demand (BOD), based on I g of activated sludge in the unit of time (day). The local relationship depends on the type of wastewater, mode of operation, and the degree of purification required determined from case to case based on experience. D.1en can assume that in urban and the most optimal for this type of industrial wastewater, which is close to composition Relationship between organic contamination of the sewage inflow and activated sludge in the first stage of biological cleaning essentially in one area from 0.8 to 1 BOD / g activated sludge per day. This ratio at what practical the complete biological cleaning is achieved, is to be regarded as optimal, because with lower values the cleaning quality is retained, but the hydration ability of the activated sludge is incompletely used, while with higher values the Activated sludge tends to float, which impairs wastewater treatment and will cause significant operational difficulties.

With this the concentration of the return lamella coming to life does not depend on its sedimentation properties, it is advisable that the Previously to be thickened return sludge part essentially from 0.2 to 0.8 of the total mass of the return sludge to be revitalized.

This enables the concentration a of the activated sludge to be 3 g / l in the first row of activated sludge basins to keep the inclination level constant, whereby the stability of the Process achieved under increased loads will. The concentration a of the activated sludge in the first cleaning column and the Concentrations aO of the sludge to be activated are linked by the relationship a ~ .t =, 1 + α where a is a return flow sludge part between 0.5 and 0.6, based on the design wastewater inflow, means. Then we get 1 + 0 < 1 + 0.6 a0 = a (α) = 3. 0.6 = 8 g / 1 The value ao is in turn related to the concentration a1 of the non-thickened and with the concentration a2 of the thickened return sludge connected by the relationship a1q1 + a2q2 a0 = ------------- q1 + q2, where q1 and q2 quantities of non-thickened or thickened return sludge, expressed in fractions of the unit, mean.

e values a1 and a2 depend on the nature of the sewage as well on many other factors that affect the thickenability and separability of the Determine the mud.

Accordingly, a1 = 7 g / l, q1 applies to easily settable sludge = 0.8 and a2 = 12 g / 1, q2 = 0.2. and for sludge that is difficult to settle a1 = 4 g / l, q1 = 0w2 and a2 = 9 g / l, q2 = 0.8. The correctness of the chosen conditions can easily be generated in the following way: with easily settled sludge 7 # 0.8 + 12 # 0.2 a0 = -------------------- = 8 g / 1 0.8 + 0.2 for those who are difficult to withdraw Sludge 4. 0.2 + 9. 0 8 @@ @ @@@@@ a0 = --------------- = 8 g / 1 0.2 + 0.8 the Activation of the activated sludge with a concentration exceeding 8 g / 1 is inappropriate, because this worsens the circulation of the sludge, the Mass transfer resistance of oxygen and liquid increases, foam formation increases and sludge conveyance increases Causes difficulties.

In Fig. 1,3,4 showing the order of the technological operations in the process of biological purification show are flows of output wastewater and purified sewage dots, streams of reclaimed, recirculating and excess activated sludge with a concentration of 4 g / l and beyond, Flows of the sludge agent from the end zones of the first and second cleaning stages and the sludge water after sludge separation and thickening, dash-dotted lines designated.

2 shows the calculated dependence of the concentration a2 des return volume q2 to be thickened in g / l of the time expressed in hours (t) of lingering in the sludge thickening tank for easily settable (curve A) and Hard-to-settle (curve B) activated sludge.

The period from 0 to 2 hours essentially represents the range aerobic thickening of the return sludge when the active microorganisms still show their functional properties. In the case of those exceeding 2 hours Thickening time increases the concentration of the return sludge to 20 to 30 g / l, but this already takes place under anaerobic conditions, under which the activity has been lost to a significant extent and takes a long time to restore can.

As the cited curves A and B show, they can be calculated Concentrations a2 of the return scalamm, the different sedimentation properties (9 or 12 g / l) can be achieved under aerobic thickening conditions.

With increased wastewater inflow, when the concentration is more organic Contamination in the wastewater increases or the mentioned factors act at the same time, becomes (by 1.5 times and beyond> the optimal ratio between organic Impurities in the incoming wastewater and activated sludge in the first stage of biological purification exceeded, To the said ratio on one of the optimal approaching level with increased wastewater inflow to hold, the concentration of the activated sludge in the sludge mean is also on that 1.5 times and moreover operationally enlarged. The technical cleaning process should also be secured with the additional amount of oxygen and the hydrodyoemic The flow form of the sludge means closer to the conditions of complete mixing so that the cleaning data can be kept constant from the initial up to the end zone of the first stage of reconciliation is reached.

This can be achieved by (zig.3) that one with the increased Wastewater inflow the partial flow 27 of the wastewater coming to the first stage with the the first stage fed recovered activated sludge 3 mixed and through Supply of oxygen-containing gas> subject to additional ventilation 28, then the obtained sludge medium with the remaining part of the initial zone of the first Stage 2 supplied wastewater mixed, with the partial flow 29 of the Schlamiiiittels from the end zone of the first stage 2 after the treatment in the first stage to the start zone the first stage comes by using the return sludge supplied for activation 19.2N is mixed.

The increase in concentration required with increased sewage inflow de activated sludge in the first cleaning stage proportional to the increasing load results from the rapid mutual averaging of the currents of the recovered Activated sludge from the regenerator 5 and the sludge agent. that the concentration of the recovered activated sludge 3 is essentially 8 g / l and the concentration of the activated sludge of the sludge medium 8 is average is 2 g / l, the working concentration of the activated sludge is increased when the Wastewater inflow in consideration of possible volumes of the regenerator 5 and the mixes container of the first cleaning stage 2 amount to an average of 4 g / l. This means, that the use of the above-mentioned technological processes promotes the wonXtant attitude of Ratio between added organic impurities and activated sludge at the optimum level under conditions of rapid change of the occurring The load is at least twice as high.

To the oxygen during the additional ventilation 28 as possible to fully utilize it, it is advisable to use the partial flow supplied to the first stage 27 of the wastewater recovered from the regenerator supplied to the first stage Mixing activated sludge 3, which increases the degree of utilization of oxygen on IO up 12% increased by higher speeds of its consumption and the sludge adapts to the workload in the final resuscitation stage.

The oxygen-containing gas for additional ventilation 28 is in a amount to be supplied which is not only sufficient to achieve a higher rate of oxidation to keep from impurities, but also the violent longitudinal rolling of the sludge medium the first stage by return circulation 29,30 of the sludge medium flow between ind- resp. First level secures zones.

The one coming into the first purification stage with the increased sewage inflow larger amount of impurities gives a tendency to local overload of the activated sludge and to reduce the concentration of in the sludge medium dissolved oxygen below 2 mg / l in the initial zone of the first stage. this fact is undesirable because of the stability of the high biological purification process of wastewater is disturbed by the activated sludge. To avoid this, it is necessary the power of the circulating stream 29,30 of the sludge medium between üid and initial zones of the first stage 2 to keep at a certain level, the corresponds to the increased amount of incoming organic impurities. That will achieved by the additional supply of oxygen-containing gas 28 in such an amount, in which the hydrodynamic flow form of the sludge medium corresponds to the conditions of the closer to perfect mixing, while the concentration of activated sludge, organic pollution purifications and dissolved oxygen along the first stage 2 is practically constant.

Over the course of individual periods of time, if the increased sewage inflow the When the highest values are reached, the increase in the activated sludge concentration is evident in the first cleaning stage to 4 g / l as insufficient to achieve the optimal ratio between organic impurities and activated sludge. That is for example the case when the burden is related to organic impurities is not tripled but tripled. About the cleaning quality of the wastewater Being able to get high at the maximum influx is subject to the additional Aeration 31 through oxygen-containing as in addition to the return flow 29,30 also the Return flow 32,33 of the sludge medium 8 from the end zone of the first stage 2 in the regenerator 6 or from the regenerator 6 into the initial zone of the first stage, to which a Deil 34 of the incoming wastewater (Fig.4) is fed. The one that stayed Part 35 of the wastewater flows into the first purification stage. Thanks to the quick mutual Average of the flows of the recovered activated sludge of 8 g / l concentration the regenerators and the sludge agent become the working concentration of the activated lamb average 6 g / l in the first cleaning stage. That proves that the use of the mentioned technological operations Relationship between added organic impurities and activated sludge at the optimal level under conditions of rapid change of the entering Load at least around the thing as well as the additional addition of the amount of dissolved Oxygen secures, which is required for the successful activity of aerobic microorganisms will.

The created recirculation of streams 29,50,32,33 of the sludge agent variable intensity 43 of the Endzo ne of the first cleaning stage 2 in the initial zone technically the simplest and at the same time most effective means of flexible control the wastewater treatment in the activated sludge basin. In the initial zone of the first Cleaning level, the one that is most heavily burdened, it comes with it not only for the hydraulic dilution of the incoming wastewater with purified Wastewater but also for the biological dilution of the incoming wastewater violent return flows 29,30,32,33 of the fresh activated sludge. To cheap Conditions for the process of biological oxidation of organic impurities To create in the wide range of the change of the occurring load, one leads the oxygen-containing as for additional ventilation 28.31 in such an amount, which has an essentially between 3 and 10 ratio of return circulation flow of the sludge agent to the one for purification; incoming wastewater flow I guaranteed.

The lower limit of the ratio of the return flow of the sludge medium to the wastewater stream to be cleaned or the dimensionless return flow ratio R can be illustrated with the help of the curve in Fig. 5. On the ordinate are Dimensionless values of the diffusion number D / μl are plotted, which represent the hydrodynamic Characterized the flow shape of the sludge medium, where D is the diffusion coefficient in m² / s, u the flow velocity in m / s, 1 the length of the activated sludge basin in m mean. As the curve obtained on experimental basis shows, it results an approximation of the ratios of perfect mixing when D / ul a 0.5 is, in the sludge stream already at values R of about 3.

When cleaning urban and this after the composition for near commercial wastewater, the range between 3 and 5 is usually sufficient Size of the parameter R, the technological process with the additional length of oxygen brought in by the recirculating sludge agent, too to supply.

The maximum size of the parameter R = 10 applies when cleaning highly concentrated wastewater (BOD> I000 mg / l) if the crucial one the task wins an additional amount of dissolved oxygen to the initial zone the first purification stage, which limits the respiratory functions aerobic microorganisms of the living omitted mud.

Since practically possible fluctuations in the increased sewage inflow are in a range from 1.3 to 3, based on the inflow of funds, one leads for prior mixing with the recovered from the regenerators 5,6 Sludge 3,4 excess partial flows 27s 34 of the total flow 1 of the wastewater, which is essentially from 1/3 to 2/3 of the total flow of incoming cleaning Form wastewater (Fig.3,4).

Such a technological operation requires several tasks at the same time namely facilitates the work of the activated sludge in the initial zone of the first Level, enables a more complete (10 to 12%) utilization of the oxygen during the additional ventilation 28.51 due to the accelerated consumption of the same due to the mixture of the recovered sludge and incoming wastewater, the activated sludge fits the workloads.

Sludge water 56,37, arising in thick sludge tanks 23,24 during the thickening of return sludge, for example according to the gravity method, contains a significant (up to 2 g / l) amount of suspended matter that is difficult to dispose of. It is the second cleaning stage 13 expediently fed and the ventilation 14 and the stream 38.39 of the atisscheidbaren after the second purification stage 13 Activated sludge for mixing with the return sludge 19,20,25,26 coming to the activation to feed.

The activated sludge concentration in the sludge medium of the second cleaning stage 13 is from 1 to 1.5 g / l, which is not only the same during aeration 14 Improvement of the edimentation properties of the activated sludge before it is supplied in the sludge separator 16 of the second stage, but also the purification of the wastewater of some impurities that are difficult to remove and which result from the first cleaning stage 2 Come, made possible.

The through the muddy water 362v7 to the second cleaning stage 13 total amount of sludge discharged usually your own of animated cell lamp to be removed 18. In the times when the increased and the maximum sewage inflow is to be noted, one therefore hears with the disposal of excess activated sludge 18 provisionally and conducts the activated sludge from 8 to 12 g / l concentration from the dirt separator 16 of the second stage in an amount of 0.1 to 0.2 of the total wastewater consumption in one 5 or the other two regenerators 5,6 according to Fig. 3.4. This kairn the activated sludge balance ensure constant maintenance in the cleaning system as well as during peak loads Favor higher live sludge concentrations in the first cleaning stage.

The activated sludge basin for carrying out the process for biological Waste water purification by activated sludge according to Fig. 6 contains an elongated isiisch tank 40 of the first stage, which is provided with diffuser nozzles 41 for oxygen-containing gas and has a start and end zone, which depend on the location of the inlet devices for feeding wastewater and activated sludge into the container or the outlet straighten for sludge.

The biological wastewater treatment takes place, for example, in reinforced concrete tanks, in those under continuous aeration through oxygenated via sprinkler nozzles flowing gas aerobic microorganisms, the concentrate of which is referred to as activated sludge will process organic impurities in the course of their secondary activity adsorb and partially oxidize these impurities. Called the mud means Mixing of wastewater and recovered activated sludge points in the activated sludge basin with a minimal inflow of pollutants, a concentration ranging from 1.5 to 2.5 g / l.

To increase the oxidizing capacity of the return sludge from 4 to 7 g / l concentration, which is obtained by separating the sludge water from the sludge medium, to restore, it is first introduced into the regenerator. In the reenerator is under continuous Aeration the oxidation of sorbed by living sludge flakes Impurities made, whereby the ederher position of the initial properties of the activated sludge and its conversion into the recovered activated sludge is achieved which is ins Activated sludge basin reached again. The recovered activated sludge interacts with the new portion of incoming sewage and the technological process of the biological oxidation of organic contaminants is repeated.

Inlet means for feeding the waste water into the container 40 contain a distribution channel 42 with a rotary flap 43 for waste water, a central opening 44 and overlying front openings 45 and 46. The mud is used for the purpose of Separation into return sludge and sludge water via a calming partition 47 and a water overflow 48 and the outlet communicates with one Sludge separator 49. The sludge separator serves to separate out the return sludge and is designed for 15 to 20 minutes. . The dirt separator 49 has one Outlet for purified water with a concentration of approx. 0.5 g / l of suspension substances analogous to the sludge outlet with the help of an EyasserEber fall 50 and a calming partition 51, which is connected to a displacement tank 52,53 of the communicates with the second stage, which is supplied with litter for oxygen-containing gas 54.55, Longitudinal partitions 56,57, which the Verdran.gungsbe container 52,53 of the second stage in Divide passages 58 and 59, as well as with the sludge separator not shown in Figure 6 Is provided.

The two-stage cleaning enables the completely biological Purification of highly concentrated wastewater containing impurities that are difficult to oxidize, by the additional oxidation of the same with the help of the for the given purification stage characteristic microorganisms of a certain kind to pre-real ones.

An outlet 60 for return sludge from the sludge separator 49 is connected to an aeration chamber 61, the sprinkler nozzles 62 for containing oxygen-containing gas, an outlet 63 of the activation chamber with a Inlet means for feeding the recovered activated sludge into the tank 40 of the first stage communicates. The inlet device for the recovered Activated sludge contains a passage 64 and an overflow 65 (Fig. 7).

the activated sludge basin has a sludge thickening tank 66, which is used to increase the concentration of part of the Schlalsmabscheider 49 separated return activated sludge is used. By separating what is coming to life Mud flow in two parts, one of which is additionally thickened before eleoung the separation time of the return sludge from the sludge medium can be reduced to 15 to 20 min instead of the usual I to 1.5 hours, which reduces the residence time of the Return sludge reduced to a minimum under anaerobic conditions and the Keeping its activity constant. In this case, the middle Increase the concentration of the activated sludge to be activated to 4.5 to 5 g / l, which in turn results in a greater degree of utilization of regenerators and oxygen-containing Gas, as well as the increase in the mean concentration of activated sludge in the system of the first iteinigunastufe to 2.5 to 3 g / l results, which the xonstantilalting of the ratio between organic contamination of the sewage inflow and activated sludge the optimal level as well as the system stability under conditions of fluctuations technolonic loads.

The Schlammeindickbehalter 66 at an input 67 connected to an outlet 68 for return sludge from the sludge separator 49, and outlets 69 and 70 for return sludge and sludge water, respectively, the first of which with the entry of the aeration chamber and the second with the entry of the displacement tank communicated in the second stage. The clarified liquid after additional thickening of the return activated sludge is called and contains mud water a significant amount of suspended solids (up to 2 g / l) in the second cleaning stage Will get removed.

In addition to the above, there is the activated sludge basin with an antechamber 71 equipped, which i) has return air scattering nozzles 72 and is located between the outlet 63 the activation chamber 61 and the inlet device for supplying the activated sludge is located in a first stage vessel 40 which has passage 64 and overflow 65 (Fig. 7) contains. The aeration chamber 61 also communicates with the container 40 in FIG its end zone through a Ulaur Canal 73.

Jie pollution of wastewater treatment plants by organic pollution is distributed unevenly within a day, whereby this unevenness from two components and zv.ar from the unevenness of the cleaning Wastewater quantities and from the unevenness of the concentrations of pollutants is put together. During certain periods of the operation of activated sludge tanks (usually In the early morning and afternoon hours) the technological loads exceed the mean values by aas 3 to 5 times. Under the conditions of strong fluctuations in loads the activated sludge, which is very sensitive to overload, loses its oxidizing properties, Separability, which deteriorates the quality of the wastewater to be cleaned. In order to ensure the stability of the sewage treatment grid, one has to convert it Increase the working space and the ventilation intensity, assuming the load peak erittein. In the times when the loads are reduced, therefore exceeds the ventilation intensity the average value to a significant extent, which is unproductive Electric energy consumption, breaking of activated sludge flakes and consequently for discharge suspended solids from the activated sludge basin and foam formation.

In order to eliminate the contradiction between dynamic loading and the inertia of the system, the cleaning process has to be controlled, i.e. one has to operationally on the amount of dissolved oxygen, activated sludge concentration and hydrodynamic flow form act, the antechamber takes care of the extraction of the sludge medium from the final stage of the activated sludge basin, the saturation of the same with dissolved oxygen and the supply to the particularly stressed initial zone of the Activated sludge basin as well as for the primary biological cleaning of the partial Flow rate of wastewater, which with increased inflow into the activated sludge basin got.

The ventilation system that ensures the antechamber operation is called one additional, while the continuously acting ventilation system in the activated sludge basin, that is tailored to the minimum load is referred to as the basic system.

It is advisable that the second stage sludge separator (not shown in Fig. 6) through its outlet for live sludge with one inlet 74 of the aeration chamber 61 communicates.

Thanks to the possibility of the activated sludge of the activated sludge chamber 61 The required activated sludge concentration is fed to the sludge separator of the second stage in the first cleaning stage kept constant at peak loads. As a result of The vitality of the microorganisms in the activated sludge occurs when the sludge increases, which is called excess activated sludge. With the one described above The work step is the necessary balance of the activated sludge in the cleaning system umlau; and the excess activated sludge that needs to be removed from the system and is then to be used, achieved.

The activated sludge basin contains a. Longitudinal housing open at the top 75, separated by a transverse partition 76 into two sections. In the first section are Longitudinal partitions 77 and 78 housed in the longitudinal axis of the housing 75 the Form container 40 of the first stage, in the scatter cans 41 for oxygen-containing Gas are arranged.

The Langstrennwäde 77 and 78 form with the walls of the Housing 75 the main aeration chamber 61 or an additional aeration chamber 79.

The animation chambers 61 and 79 are located on both sides of the Container 40 of the first stage and have main transverse partitions and additional transverse walls 80 and 819 which divide these chambers 61 and 79 into sections. Each section contains main sprinkler nozzles and additional sprinkler nozzles 62 and 82 for oxygen-containing Gas.

Near the starting zone of the container 40 on the outside of the longitudinal partition walls 77 and 78 are main longitudinal and transverse partitions 83 and 84, respectively, and additional ones Length and transverse partitions 85 and 86 attached, which the main antechamber 71 and the additional prechamber 87 form the passage through the main 64 and an additional passage 88 with a main aeration chamber 61 and an additional aeration chamber 79 and through the main overflow 65 and an additional overflow 89 with the container 40 communicate. The main antechamber 71 and the additional antechamber 87 are with the main spray nozzles 72 and additional spray nozzles 90 equipped.

The real fluctuation curve of the load on wastewater treatment plants The hourly division is divided into three areas, namely the area of the minimum load up to 2000 g BOD / m3 day, the range of exposure increased to 5000 g 3SB / m3 per day and the range of the maximum load that exceeds 5000 g BOD / m3 per day separate. The oxidation work of the activated sludge basin, depending on the technological The fluctuation curve of incoming impurities can be controlled in such a way that that one has the main antechamber and the additional antechamber and, accordingly, the main aeration chamber or the additional aeration chambers are put into operation one after the other. This measure enables the optimum technical and economic data to be obtained as a result of the mining the oxidation performance of the activated sludge basin with the minimum loads the work of the basic system of belauf tion below their minimum Intensity sufficient to keep the activated sludge in suspension, and as a result of the increase in the oxidation capacity of the activated sludge basin at the maximum Loads from the successive commissioning of the main antechamber and the additional antechamber.

In the second section along its axis, for example, is the horizontal one Gravity sludge separator 49 arranged through the overflow 48 and the calming partition 47 communicates with the container 40 of the first stage and with walls of the second Section forms the container 52, 53 of the second stage, which with scatter nozzles 54, 55 for gas containing oxygen.

Near the transverse partition 76 of the container 75 are, for example, vertical Gravity sludge thickening tank, namely the main sludge thickening tank 66 and the additional sludge thickening tank 91 (Fig.8) is arranged.

The dirt separator 49 is equipped with compressed air pumps 92, the sludge container 93 of the sludge separator 49 with sludge discharge channels 94 and 95, calming partitions 47, 51 and water raids 48, 50 connect (g.0,6) The main sludge thickener 66 and additional sludge thickener 91 have conical bottoms 96 and 97 and are with central pipes 98, 99, overflow nozzle 100 or IOI, connected to the sludge discharge channels 94 and 95 of the sludge separator 49 and inserted into Mibten pipes 98 and 99 of the sludge thickening container 66 and 91, as well as with the main aeration chamber 61 and the additional aeration chamber 79 connected Compressed air pumps 102 and 103 for the highly concentrated return sludge and peripheral men I04 and I05 equipped welched @ e sludge thickening tanks 66 and 91 with "tanks52, Connect 53 of the second stage.

Thanks to the chosen construction of the dirt separator, you can use the Realize even separation of the activated sludge along the plant, operating costs the collecting residue due to the waiver on mechanical Means for collecting the same decrease and the degree of clarification of the liquid as a result increase lack of slurry. The gravity sludge separators and sludge thickening tanks also allow the high concentration of activated sludge in the system without disturbing the To keep the structure of the block sludge constant. The use of compressed air pumps to convey the separated activated sludge from the sludge separator into the It contains the sludge thickener and from the sludge thickener into the aeration chambers In addition to the intended purpose, enables the saturation of the activated sludge with dissolved Oxygen.

It should be noted that the scattering nozzles 62 and 82 in the main aeration chamber 61 or the additional aeration chamber 79 as well as scatter nozzles 41 of the container 40 the first stage and nozzles 54 and 55 of the container 52, 53 of the second stage through pressure lines I06, which have a uniform designation due to their identity, are connected to fans I07 of the basic ventilation system, while scatter nozzles 72 and 90 of the main antechamber 71 or

the additional prechamber 87 through pressure lines I08 and 109 with Blown IIO or III for additional ventilation and also with blowers I07 des Basic ventilation system through cross connections II2 and II3, provided with non-return valves II4 and II5, are connected.

The activated sludge basin also has bypass channels arranged along the circumference II6 and II7 for waste water with overflow thresholds 118 and II9 and inlet openings I20 and 121, the bypass channels IIb and II7 with the starting zone of the main aeration chamber 61 and the additional aeration chamber / 9, as well as bypass channels I22 and I23 for thickened sludge with inlets 74 and 124 that form the bypass gutters 122 and 123 for thickened sludge with the initial zone of the main aeration chamber 61 and the additional activation chamber 79 connect, beam-guiding vertical Partition walls' 125 and 126, which are perpendicular to the transverse partition wall 76 stand and form circulation channels 73 and 127, as well as La.ngstreimwand 56 and 57, which in the Containers 52, 53 of the second stage are present and these in passages 58, 59, and an outlet opening 128.

By arranging the main systems in a uniform housing you can reduce the consumption of building materials and space requirements by adding adjacent partitions widely used and the length of distribution facilities and the Reduced dimensions of inlet devices; by connecting the aeration chambers and antechambers with the mixing tank of the first cleaning stage, which at the increased Wastewater inflow are operated as communicating vessels, the funding costs for the return medium to reduce its activity and structure to the minimum obtain; the mutual arrangement of the sludge separator and sludge thickener reduces the costs for the supply of the thickened return activated sludge, reduced its residence time under anaerobic conditions (without access to oxygen) to the minimum, and the use of compressed air pumps as a means of conveyance allows the structure from mud flakes and their activity through the additional saturation increase with oxygen.

The activated sludge basin according to the invention is operated as follows.

At the minimum1 exposure of around 2000 g BOD / m per day, when the rotary flap 43 assumes the intermediate position, the waste water passes over Distribution channel 42 through central openings 44, which are located under end openings 45 and 46 and are designed for a minimum constant flow rate into the mixing container 40 of the first stage, where it is mixed with the activated sludge from the activation chambers 61 and 79 is supplied by airlift action by means of antechambers 71 and 87, The Airlift effect of the antechambers 71 and 87 is achieved when conveying a part of the air in the basic ventilation system via cross connections 112 and 113 by fans I07 in scatter nozzles 62 and 82 for oxygen-containing gas in the main antechamber 71 and the additional prechamber 87. The check valves II4, 115 in cross connections 112 and 113 close the possible passage of air from the additional ventilation system the fans IIO and 111 to the base system of the fans I07, but prevent the No return of the oxygen-containing gas.

The Schlammmfttel is through scattering nozzles 41 for oxygen-containing Gas ventilates the through pressure lines I06 with fans 107 of the basic ventilation system are connected; during aeration and agitation of the mixing of sewage with the activated sludge in tank I of the first stage is subjected to biochemical oxidation of contamination by microorganisms in the activated sludge.

In the sludge separator designed for a settling time of 15 to 20 minutes 49, into which the biochemically treated wastewater via calming partition wall 47 and If water overflow 48 arrives, the main mass of the activated sludge is in the sludge tanks 93 collected, then from this by means of compressed air pumps 92 to the sludge drainage channels 94 and 95 and from there to the central pipes 98 and 99 of the main sludge thickening tank 66 or the additional sludge thickening container 91 via the overflow nozzle 100 and IOI promoted.

Gen conical bottom 96 and 97 of the sludge thickening tank 66 and 91, designed for I to I, S-hour thickening of the activated sludge, is the the latter with the help of compressed air pumps I02 and I03 for the return sludge from increased concentration to the main activation chamber 61 and the additional activation chamber 79 headed. The thickening of the activated sludge requires around two to one Three times smaller rooms compared to the usual flow diagram with secondary settling basins, and the mutual arrangement of the sludge separator 49 and the sludge thickener 66 and 91 allow the energy consumption for supplying the return sludge to decrease, the double contact of the return sludge with the atmospheric oxygen during its Conveying by means of compressed air pumps avoids anaerobic conditions and its thickening favored.

The clarified liquid containing the activated sludge in an amount from IO to 20 </ a of the initial concentration, flows into the container 52, 53 of the second stage, in which the sludge water from peripheral channels I04 and I05 des Main sludge thickening container 66 or the additional sludge thickening container 91 is also directed. The biochemical process takes place in container 52, 53 of the second stage Post-oxidation of remaining impurities and to improve the sedimentation properties of the activated sludge through the barbotage with the aid of scatter nozzles 54 and 55 through pressure lines I06 with the fan I07 of the basic ventilation system.

Slurry brought to flocculation together with purified wastewater It is fed through the outlet opening 128 to the second cleaning stage, where under conditions of reduced activated sludge concentration (from 0.5 to 1.5 g / l) the post-oxidation of remaining impurities, deposition of the sciilamm and the Realized removal of excess activated sludge from the system.

Under these operating conditions of the activated sludge basin, i.e. The activated sludge concentration is at loads that do not exceed 2000 g BOD / m3 per day in the plant in a range from 1.5 to 2.5 g / l and that of the return sludge between 6 and 7 g / l.

The aeration chambers 61 and 79 are combined with the one in the sludge separator 49 separated activated sludge of 4 to 6 g / l concentration and with the additional activated sludge thickened in sludge thickening tanks 66 and 91 from 8 to 10 g / l concentration, the 0.2 to 0.8 return sludge fraction from the sludge separator 49 is filled. The sludge flow ratio enables the activated sludge concentration in the aeration chambers between 6 and 10 g / l and in the system between I keep 1.5 to 2.5 g / l constant.

In the case of increased sewage inflow, when the burden on the living sleeping pool When reaching 5000 g BOD / m3 per day, the rotary flap 43 assumes one of the end positions. The steady flow of wastewater flows through one of the open central openings 44 into the container 40 of the first stage, and the liquid main mass is through the front opening 45 or 46 of the main antechamber 71 or the additional antechamber 87 forwarded. In connection with the fact that the wastewater pressure is at a part untei The given conditions of operated center openings 44 remains increased the amount of wastewater flowing through it remains unchanged and the flow rate through all central openings 44 are the same at the minimum sewage level in the distribution channel 42.

Sin circuit is used when operating under these conditions of Blown IIO or III of the additional ventilation system before which through pressure lines 106 with scatter nozzles 72 or 90 for oxygen-containing gas of the main antechamber 71 or the additional prechamber 87 are connected.

As a result of the increase in back pressure in the pipeline network on the part of the additional ventilation system speaks one of the non-return valves 114 or 115 in the corresponding cross connection 112 or 113, which is the airflow separation in the basic system and system of additional ventilation results. By feeding oxygen-containing gas via scattering nozzles 72 or 90 of one of the antechambers 71 or 87 it comes to the fact that the liquid flows from below upwards and the mixture from recovered sludge and sewage via passages 64 or 88 from the Main activation chamber 61 or the additional activation chamber 79 to overflows 65 or 89 rises and enters container 40 of the first stage. The amount of work of the sludge agent comes to Ilarung, the calming partition 47 and water overflow 48 of the dirt separator 49, and the three- up to five times the return volume of the sludge mixture exceeding the working length enters the corresponding main aeration chamber bl or additional aeration chamber 79 via one of the circulation channels 73 or 127.

Thus the energy expenditure for the NilAung of a controllable return flow of the sludge medium if the liquid in the antechamber 71 or 87 is above the liquid level in the container 40 of the first stage by 0.1 to 0.5 m increases, reduced to the minimum is, the container 40 and the activation chamber 61 or 79 as koiinnunizierende Vessels operated. The delivery of the specified amount of sludge agent from the activated sludge manager 61 or 79 in the container 40 of the first stage via the corresponding antechamber 71 or 87 causes the same amount of liquid to flow back out of the end part of the container 40 to the initial part of the activation chamber 61 or 79, whereby the on the return flow of the sludge mixture exceeding 3 to 5 times the waste water flow rate with 4.5 to 5 g / 1 activated sludge concentration arises, in which the biochemical Oxidation of organic substances is intensified.

In order to utilize the oxygen, one of the antechambers is in operation during operation To increase 71 or 87 to 8 to 10%, i.e. to increase 1.5 times, one leads the proportion of the wastewater flow rate, which is 1/3 to 1/6 of the total flow rate, avoiding the container 40, directly to the antechamber.

When working in these conditions, the removal of the excess activated sludge from the second cleaning stage and that in the activated sludge with a concentration of 8 to 12 g / l in an amount of 0.1 to 0.2 of the total flow rate of the wastewater is about one of the by-pass channels 122 or 124 for the thickened sludge through inlet openings 74 or 124 of the initial zone of the main aeration chamber 61 or the additional Aeration chamber 79 supplied. The working concentration of the activated sludge in the tank system first stage aeration chamber "reaches 4.5 to 5 g / l, whereby the optimal ratio kept constant between the biomass and the nutrient medium in the event of increased wastewater inflow will. The biochemical oxidation in the flow to be ventilated from 4.5 to 5 g / l Activated sludge concentration is reduced by temporarily reducing the size of the Mud flakes, compensation of mud loads for a long time of the flow of the degree of utilization The oxygen in the air intensifies in the antechamber, where the main mass of initial impurities is quickly removed in the wastewater.

The created return circulation of the sludge mixture from the end zone of the The container in the first stage to its initial zone is technically the most accessible Control parameters of the biochemical process in the activated sludge basin, which not only does the hydraulic but also the "biological" dilution of the incoming Wastewater generated by the fresh activated sludge.

In the period of further increasing the load that the 4 to thing reaches the middle values, the rotary flap 43 takes the intermediate position again a, the steady waste water flow rate passes through the center openings 44 in the first stage container 40 and the bulk of the liquid is between two antechambers 71 and 87 evenly distributed.

1. Check valves 114 and 115 typically respond and operate the precautions 71 and 87. The working amount of the sludge mixture comes to the clarification, and the return amount, which increases the amount of work 6 to 10 times over, arrives Via circulation channels 73 and 127 into the main aeration chamber 61 and the additional one Aeration chamber 79. In the system t 'tank 40 of the first stage and acting antechambers 71 and 87rt two ring flows to be ventilated arise during conditions for Preserve intensification of the biochemical oxidation of organic impurities stay.

The utilization of the return circulation of the sludge mixture in the activated sludge basin enables the zone with insufficient amount of solute to be greatly reduced Oxygen in wastewater and the regulation of its amount in the most polluted initial sections of the activated sludge basin.

This way you can reduce the intensity of the basic ventilation and it rit the nnahw.-e that the load at the beginning of the plant is minimal and the Activated sludge is kept in suspension, i.e. taking into account that maintain the homogeneity of the sludge mixture according to the height of the activated sludge basin will calculate. With a higher load, the additional amount of oxygen is through the recirculating mixture introduced, the amount of oxygen according to the number the effective fore chambers is regulated. Since the load according to the T concentration of impurities is determined at the beginning of the system, which decreases with the return circulation, so the maximum intensity of the additional ventilation is much less than in the design of ordinary activated sludge tanks. With an increase in the number the acting antechamber shorten the neit sections where the particularly intense Aeration takes place, and consequently the amount of that directed to the aeration increases oxygen-containing gas.

About the degree of oxygen utilization during the work of two antechambers To increase to II to 15%, i.e. twice as much, one leads the proportion of wastewater ~ flow rate, which is 2/3 of the total amount, directly to the antechamber.

When working the system under the specified conditions will the activated sludge separated in the second cleaning stage via the bypass channels 122 and 123 for the thickened sludge the two aeration chambers 61 and 79 in an amount equal to 0.2-0.3 of the total sewage flow rate from 8-12 g / l concentration is supplied. The working concentration of the activated sludge, averaged in the system "container of the first stage main aeration chamber l? and", container the first stage - additional aeration chamber ", achieved thereby 5.5 5 to 6.5 g / l, creating the optimal ratio between biomass and nutrient medium is kept constant at the peak load.

In those possible skins, when the load exceeds the load peak, the excess waste water reaches over the overflow thresholds 118 and 119 in the bypass gutters 116 and 117 of the sewage and then through the inlet openings I20 and 121 in sections of the activation chambers 61 and 79, those of the antechambers 71 and 87 are particularly far. This operation is made possible by enlarging it the mean path length of the wastewater to be cleaned, the degree of treatment of the same at the required level without additional expenses.

Main difficulties in realizing the economic procedural conditions for biochemical wastewater treatment in conventional activated sludge basins due to significant fluctuations in load, which result in the constant optimal ratio between concentrations of wastewater contaminants, activated sludge and dissolved sludge Disrupt oxygen.

The inventive system for performing the method for biological wastewater treatment has the disadvantage mentioned not what the possibility results, the oxidizing ability of the activated sludge with practically any fluctuations to use the incoming waste water as much as possible.

Pig.I0 shows the wastewater hydrograph under hour division (curve C) and (ic? JS diagram of the work of basic ventilation and additional ventilation (broken line D) to the ordinate axis are by rungs of the wastewater inflow, based on B3, and the amounts of oxygen introduced in relative units.

The lower layer of the broken line D corresponds to the operating mode of the basic ventilation system, the mean altitude of line D corresponds to the side, where the flow of Abeasser is increased and the main antechamber switched on will, the upper position of the line D corresponds to the point where the sewage inflow has its maximum values and the additional antechamber is sunk.

The more precise the step curve of the change in the ability to oxidize to be controlled of the activated sludge basin "inscribed" in the fluctuation curve of the wastewater quantity becomes, the lower the unproductive electrical energy consumption and the more oats are technological and economic parameters of the cleaning system. This is going through the suitable selection of the myriad of antechambers and instruments in operation the efficiency of the same achieved.

When the load peaks, the additional prechamber is in operation to switch on the standing main antechamber. The switch-on times of the Antechamber, for example, according to the indicators in the sewerage channel arranged level meter with correction of the work of the antechambers according to Qer Display of the sender for the dissolved oxygen in suitable points on the container of the first stage.

- L e r s e i t e -

Claims (10)

PROVIDED FOR BIOLOGICAL SEWAGE PURIFICATION AND AN ACTIVATED SLUDGE BASIN THE EXECUTION OF THIS PATENT CLAIMS: I. Process for the biological purification of the Wastewater from organic contaminants through an activated sludge in two stages, in the first (2) of which one receives a incoming wastewater (I) with the activated sludge (3,4) mixed, the obtained sludge medium aerated and then from the sole sludge medium (8) the end zone of the first stage (2) the return sludge (19, 20) separates him subjected to the activation (5,6) and the recovered delebt sludge (5,4) for mixing with the wastewater (I) arriving in the initial zone of the first stage (2), while in the second (13) stage that after the separation of the return sludge (19,20) aerated from the sludge agent sludge water (12) and from this the remaining activated sludge (18) is removed, that is to say e t that the activated sludge supplied for activation is separated into two parts, of which one (19) is led directly to the activation, and the other (21,22) thickened before activation and then with the first part (19,20) of the return sludge for the purpose of common animation is blurred by the relationship between organicc contamination in the incoming wastewater (I) and activated sludge (3, 4) is kept constant in the first cleaning stage (2). 2. The method according to claim I, d a d u r c h g e -k e n n z e i c That is, the return sludge part (21, 22) to be thickened is essentially 0.2 up to 0.8 of the total mass of the return sludge supplied for activation (19.20, 25.26) amounts to. 3. The method according to claim I or 2, d a d u r c h g e k e n n z e i c h n e t that with increased wastewater inflow (I) a partial flow (7.34) the wastewater supplied to the first stage (2) with that supplied to the first stage (2) recovered activated sludge (3,4) mixed and the additional aeration through Subject to the supply of oxygen-containing gas, then the sludge medium obtained with the remaining part (35) of that supplied to the initial zone of the first stage (2) Wastewater mixed and after the treatment in the first stage (2) a part (29,32) of the sludge medium flow from the bottom zone of the first stage (2) back to the start zone the first stage (2) is fed, while it is supplied with the return sludge coming to the activation mixed, the oxygen-containing gas (28,31) for the purpose of additional ventilation is initiated in an amount that the circulation of the sludge means of the first Stage (2) by the return circulation of the sludge medium flow between the end and start zones the first stage (2) secures. 4. The method according to claim 3, d a d u r c h g e I k e n n z e i c Not that the oxygen-containing gas is introduced in an amount for post-ventilation which has a ratio of the return sludge mean lying essentially between 3 and 10 to the wastewater (I) to be cleaned. 5. The method according to claim 3 and 4, d a d u r c h g e k e n n z e i c h n e t that prior to mixing with the recovered sludge (3,4) essentially lichen from I / 3 to 2/3 @ e @ current (27,34) of the for cleaning incoming sewage. 6. The method according to any one of the above claims, d a d u r e k e k e nn n n n z e i n e t that one can do this by thickening the part of the for Activated return sludge (21.22) resulting sludge water (36.37) the second stage (i3) zuftitiert and ventilated, and after the second stage (13) separated activated sludge stream (38,39) for mixing with the coming to the activation Return sludge (19,20,25,26) passes. 7. activated sludge basin for performing the method according to claim I, which is a longitudinal mixing container provided with diffuser nozzles (41) for oxygen-containing gas (4G) of the first stage (2) and an initial zone with housed therein Bin inlet devices (42,43,44,45,46) for the supply of waste water (I) and activated sludge (3, 4) into the container (40) and has an end zone in which there is a sludge agent outlet (47,48) is located, which communicates with a dirt separator (49), which the Separation of the return sludge from the sludge medium and an outlet (50.51) for the purified sludge water, which is connected to a displacement tank (52,53) of the second stage communicates, the scattering nozzles (54,55) for oxygen-containing Total gas and a sludge separator (9), and an outlet (60) for return sludge has, which is connected to an aeration chamber (61), the scatter cans (62) for Has oxygen-containing gas and at its outlet (63) with the inlet device (64,65) for feeding the recovered activated sludge into the container (40) of first stage communicates that it is with a sludge thickening tank (66) is provided, which is used to increase the SucklauS sludge concentration and an inlet (67), pre-connected with an outlet (U8) for return sludge from the sludge separator (49), and outlets (o9.7O) for return sludge and sludge water has, of which the first (69) with the entry of the activation chamber (61) and the second (70) with the entry of the displacement container (52) of the second stage communicates. 8. activated sludge basin according to claim 7, d a d u r c h g e k e n n indicates that it is additionally equipped with an antechamber (71) which bruckluftstreudu.sen (72) and located between outlet (63) of the aeration chamber (61) and inlet device (64,65) for feeding the activated sludge into the container (40) of the first stage is located, wherein the antechamber (71) with the inlet device (45) also connected to the supply of the waste water into the container (40) of the first stage is, while the activation chamber (61) with the container (40) of the first stage in communicates in its south zone. 9. activated sludge basin according to claim 8, d a d u r c h g e k e n n notes that the second stage dirt separator (16) is through its outlet for the activated sludge connected to an inlet (74) of the activated sludge bar (61) is. 10. activated sludge basin according to claim 7, d a d u r c h g e k e n it is noted that it contains a longitudinal housing (75) which is open from above and which passes through a Cu partition (76) is divided into two sections, in the first of which Longitudinal partition walls (77,78) are accommodated, which are in the longitudinal axis of the housing (75) the container (40) of the first stage, in the interior of which there are nozzles (41) containing oxygen Gas are arranged, and with sand of the housing (75) the main aeration chamber (61) and form an additional activation chamber (79), which is located on both sides of the Container (40) attached to the first stage and provided with transverse partitions (80,81) which divide the aeration chambers (61,79) into sections, each of which Has scatter doses (62,82) for oxygen-containing gas, wherein near the starting zone of the Container (40) on the outer side of the longitudinal partition walls (77, 78) longitudinal and transverse partition walls (8) ', 84,85,86), which are the main antechamber and the additional antechamber (71,87), which through passages (64,88) with the main aeration chamber (61) and the additional aeration chamber (79) and through overflows (65,89) with the container (40) are connected and provided with scatter cans (72,90) for oxygen-containing gas, while in the second section there is a horizontal gravity sludge separator along its axis (49) is located through the overflow (47, 48) with the container (40) of the first stage is connected and with the walls of the second section a container (52,53) of forms the second stage, near the transverse partition (76) of the Gehä s it (75) vertical Gravity sludge thickening tanks (66,91) are arranged, which are connected to the main aeration chamber (61) and the additional aeration chamber (79) communicate while the sludge separator (49) with compressed air pumps (92) for conveying (94,95) the return sludge from increased Sonocentration in the main aeration chamber (61) and the additional aeration chamber (79) is equipped.