KR100491900B1 - Apparatus for sewage and wastewater treatment and method for sewage and wastewater treatment using the same - Google Patents

Abstract

The present invention relates to a waste and sewage treatment apparatus for more effectively treating nitrogen and phosphorus in waste and sewage, and a method for treating waste and sewage using the same, sequentially, an anaerobic tank, anaerobic tank, aerobic tank, sedimentation tank and these A waste / sewage treatment apparatus comprising pipes connected to each other, comprising: an inlet pipe for introducing waste and sewage into the anaerobic tank; A first internal circulation pipe that connects the anaerobic tank and the anoxic tank to each other to transfer the suspension of the anaerobic tank to the anoxic tank; A second internal circulation pipe which connects the aerobic tank and the anoxic tank to each other for conveying the suspension of the aerobic tank to the anoxic tank; A conveying sludge pipe which connects the settling tank and the anoxic tank with each other to convey the sludge of the settling tank to the anoxic tank; A treated water discharge pipe which is a passage through which the treated water is discharged from the settling tank; And a sludge discharge pipe which is a passage through which sludge is discharged from the settling tank.

Description

Biological waste and sewage treatment apparatus and biological waste and sewage treatment method using same {APPARATUS FOR SEWAGE AND WASTEWATER TREATMENT AND METHOD FOR SEWAGE AND WASTEWATER TREATMENT USING THE SAME}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a biological wastewater and sewage treatment apparatus and a method for treating the same, and in particular, in order to more effectively treat nitrogen and phosphorus in wastewater and sewage flowing into the wastewater and sewage treatment apparatus, microorganisms using nitrogen and phosphorus may be grown. The present invention relates to a wastewater and sewage treatment apparatus comprising the apparatus under the most suitable conditions, and a method for treating wastewater and sewage using the same.

In the conventional waste and sewage treatment, efforts have been made to treat waste and sewage so as to be suitable for appropriate values of COD and BOD. However, as the eutrophication of water by nitrogen and phosphorus in waste and sewage has been a problem recently, The amount of nitrogen and phosphorus in the treated water discharged from sewage treatment systems has been regulated, and this level of regulation is becoming more stringent.

A general facility for biologically treating nitrogen and / or phosphorus in waste and sewage is composed of a bioreactor and a precipitation tank, and the bioreactor consists of various combinations such as anaerobic zone, anoxic zone, and aerobic zone. In order to treat nitrogen biologically, aerobic and anoxic zones are basically required. When ammonia nitrogen is oxidized in the aerobic zone, the oxidized product, nitrate, is used by heterotrophic microorganisms that use nitrate as an electron acceptor in anoxic zones. Denitrified by nitrogen gas and removed. In addition, in order to treat phosphorus biologically, anaerobic and aerobic zones are basically required, and phosphate accumulating organism (PAO), a microorganism that excessively ingests phosphorus in the anaerobic zone, releases phosphorus and absorbs volatile organic acids, thereby inducing PHA in the body. When (poly-hydroxy alkanoate) is synthesized, the PAO grows in the aerobic region using PHA to ingest excess phosphorus, and thus removes the phosphorus by discharging the excess phosphorus PAO through sludge. Using this principle, a facility for biologically treating nitrogen and phosphorus at the same time has been developed, an example of the structure of which is shown in FIG.

The waste and sewage treatment method, called A ₂ O method, is a simple structured device consisting of a sequential arrangement of an anaerobic tank 101, an anaerobic tank 102, an aerobic tank 104, and a settling tank 105 as shown in FIG. It is a general method to treat nitrogen and phosphorus in waste and sewage using. However, according to this apparatus, since the sludge from the settling tank 105 also flows in through the conveying sludge pipe 205 into the anaerobic tank 101 into which the waste and sewage flows, the phosphorus is discharged by a considerable amount of nitrate contained in the sludge. There is a problem that the treatment is inhibited. That is, since the organic acid and biological dichotomous COD (RBCOD, readily biodegradable COD) contained in the inflowing waste and sewage are consumed by denitrifying microorganisms before being used by PAO in the anaerobic tank 101, the PAO has a sufficient amount of PHA in the body. Since it is not synthesized, phosphorus is not absorbed in the aerobic tank 104, and phosphorus is discharged together with the treated water as it is. In particular, as in general domestic sewage, TKN (total kjeldahl nitrogen) / COD and TP (total phosphorus) / COD ratio is high and the content of RBCOD in the low COD inevitably decrease the phosphorus treatment efficiency by the A ₂ O method.

In order to solve the above problems of the same A ₂ O process, the anaerobic tank 101, the anoxic tank 102, the aerobic tank 104 is similar to changing the arrangement of the bioreactor, such as, or further adding a portion of the bioreactor A ₂ O Method This development continues, and a method for removing nitrogen and phosphorus by additionally supplying an external carbon source to increase the content of RBCOD in the anaerobic tank 101 (Korean Patent Registration No. 375413) is also being developed. However, according to these methods, since there is still a fundamental problem of conveying the nitrate-containing sludge of the settling tank 105 into the anaerobic tank 101, there is a limit in the efficient removal of phosphorus.

Subsequently, instead of returning the sludge of the sedimentation tank 105 to the anaerobic tank 101, which has been pointed out as a fundamental problem of the A ₂ O method and similar methods, the anaerobic tank 101 and the anaerobic tank (A ₂ O method) The arrangement of 102 is changed so that the sludge of the settling tank 105 is returned to the anoxic tank 102 (the anaerobic tank 102 is referred to as the first anoxic tank), and an additional anoxic tank is disposed to make it the second anoxic tank 103. As shown in Fig. 2, the DNR for treating waste and sewage using the apparatus of the first anoxic tank 102-anaerobic tank 101-the second anoxic tank 103-the aerobic tank 104-the settling tank 105 is arranged. A method was developed. According to the DNR method, since the nitrate contained in the sludge of the settling tank 105 is denitrified in the first anoxic tank 102 and then transferred to the anaerobic tank 101, the organic matter absorption of PAO in the anaerobic tank 101 is hindered. Without giving, the PAO can be grown in the aerobic tank 104 to absorb the excess phosphorus to increase the phosphorus removal efficiency. However, since the denitrification is performed by endogenous respiration using the organic material of the microorganism in the first anoxic tank 102, the DNR method is pointed out that the speed is significantly low. In the case of general sewage, the denitrification rate using organic material of influent is 0.04 ~ 0.15g NO ₃ ^-- N / gVSS (volatile suspended solid) / day, while denitrification by endogenous respiration is 20 ~ of denitrification rate using organic material of influent. Very low, about 50%.

An object of the present invention is to provide a wastewater and sewage treatment apparatus for simultaneously removing nitrogen and phosphorus with higher efficiency.

Moreover, the objective of this invention is providing the method of treating waste and sewage using the waste and sewage treatment apparatus which concerns on this invention.

As a result of repeated studies in order to solve the above problems, the present inventors have minimized the inflow of nitrate load due to the return of sludge into the anaerobic tank, which is a disadvantage of A ₂ O, and is faster than denitrification by endogenous denitrification, which is a disadvantage of DNR. The present invention has been completed by developing a biological waste and sewage treatment apparatus which can cause denitrification to occur, and thereby further increase phosphorus removal efficiency.

That is, the present invention is a waste and sewage treatment apparatus consisting of an anaerobic tank, anaerobic tank, aerobic tank, sedimentation tank and pipes sequentially connecting them, comprising: an inlet pipe for introducing waste and sewage into the anaerobic tank; A first internal circulation pipe that connects the anaerobic tank and the anoxic tank to each other to transfer the suspension of the anaerobic tank to the anoxic tank; A second internal circulation pipe which connects the aerobic tank and the anoxic tank to each other for conveying the suspension of the aerobic tank to the anoxic tank; A conveying sludge pipe which connects the settling tank and the anoxic tank with each other to convey the sludge of the settling tank to the anoxic tank; A treated water discharge pipe which is a passage through which the treated water is discharged from the settling tank; And a sludge discharge pipe which is a passage through which sludge is discharged from the settling tank.

In addition, the present invention is a wastewater and sewage treatment apparatus consisting of a first anaerobic tank, an anaerobic tank, a second anoxic tank, an aerobic tank, a settling tank and pipes connecting them sequentially, the inlet pipe for introducing waste and sewage into the anaerobic tank ; A first internal circulation pipe connecting the anaerobic tank and the first anoxic tank to each other for transferring the suspension of the anaerobic tank to the first anoxic tank; A second internal circulation pipe connecting the aerobic tank and the first anoxic tank to each other for conveying the suspension of the aerobic tank to the first anoxic tank; A third internal circulation pipe connecting the aerobic tank and the second anoxic tank to each other for conveying the suspension of the aerobic tank to the second anoxic tank; A conveying sludge pipe which connects the settling tank and the first anoxic tank to each other to convey the sludge of the settling tank to the first anoxic tank; A treated water discharge pipe which is a passage through which the treated water is discharged from the settling tank; And a sludge discharge pipe which is a passage through which sludge is discharged from the settling tank.

In addition, the present invention is a wastewater and sewage treatment apparatus consisting of a first anaerobic tank, an anaerobic tank, a second anoxic tank, an aerobic tank, a settling tank and pipes connecting them sequentially, the inlet pipe for introducing waste and sewage into the anaerobic tank ; A first internal circulation pipe connecting the anaerobic tank and the first anoxic tank to each other for transferring the suspension of the anaerobic tank to the first anoxic tank; A third internal circulation pipe connecting the aerobic tank and the second anoxic tank to each other for conveying the suspension of the aerobic tank to the second anoxic tank; A conveying sludge pipe which connects the settling tank and the first anoxic tank to each other to convey the sludge of the settling tank to the first anoxic tank; A treated water discharge pipe which is a passage through which the treated water is discharged from the settling tank; And a sludge discharge pipe which is a passage through which sludge is discharged from the settling tank.

In addition, the present invention is a wastewater and sewage treatment apparatus consisting of an anaerobic tank, a first anoxic tank, a second anoxic tank, an aerobic tank, a settling tank and pipes connecting them sequentially, the inlet pipe for introducing waste and sewage into the anaerobic tank ; A sludge internal circulation pipe which connects the first anoxic tank and the anaerobic tank to each other to convey the sludge of the first anoxic tank to the anaerobic tank; A second internal circulation pipe connecting the aerobic tank and the first anoxic tank to each other for conveying the suspension of the aerobic tank to the first anoxic tank; A third internal circulation pipe connecting the aerobic tank and the second anoxic tank to each other for conveying the suspension of the aerobic tank to the second anoxic tank; A conveying sludge pipe which connects the settling tank and the first anoxic tank to each other to convey the sludge of the settling tank to the first anoxic tank; A treated water discharge pipe which is a passage through which the treated water is discharged from the settling tank; And a sludge discharge pipe which is a passage through which sludge is discharged from the settling tank.

In addition, in the waste and sewage treatment apparatus according to the present invention, when the exhalation tank includes a second internal circulation pipe, the settling tank and the conveying sludge pipe, the treated water discharge pipe and the sludge discharge pipe connected thereto are removed, and An immersion type ultrafiltration membrane is provided inside, and a wastewater and sewage treatment apparatus can be configured by connecting a treated water discharge pipe and a sludge discharge pipe to the aeration tank. In addition, the waste and sewage treatment apparatus according to the present invention may be additionally filled with a flow carrier or a fixed carrier in the aerobic tank, the front of the inlet pipe, for removing waste and sewage contaminants The apparatus may further include at least one device selected from a screen, a sedimentation basin for removing sediment such as sand, a flow rate adjustment tank for equalizing flow rate and water quality, and a primary sedimentation tank for removing suspended matter. In addition, the anaerobic tank and / or the first anaerobic tank of the waste / sewage treatment apparatus according to the present invention may include organic waste liquids such as methanol, acetic acid, organic waste liquids such as methanol and acetic acid, manure, septic tank waste liquid, Solid organic waste liquor such as livestock waste water and food waste, fresh sludge generated in the first sedimentation tank of waste and sewage treatment plant, condensate of waste and sewage treatment plant, distilled water discharged from digester, dehydration unit, organic waste liquid, solid organic At least one external carbon source selected from the group consisting of an acidic fermentation broth and fresh sludge may be introduced to promote the treatment of nitrogen and phosphorus.

Hereinafter, a biological waste and sewage treatment apparatus according to the present invention and a waste and sewage treatment method using the same will be described in detail with reference to the drawings showing an embodiment of the present invention. The following drawings and description do not limit the invention, and the invention may be appropriately modified and modified based on the details set forth in the claims.

Figure 3a is a schematic diagram showing an example of the biological waste and sewage treatment apparatus according to the present invention.

Waste and sewage introduced from the outside through the inlet pipe 201 are first passed through the anaerobic tank 101, and organic matter in the waste and sewage is anaerobic fermented and converted into fermentation products such as organic acids. It is absorbed and stored as PHA, through which the microorganisms release phosphorus in the anaerobic tank 101. When the reaction in the anaerobic tank 101 is completed, the organic matter is present in the suspension of the anaerobic tank 101 in the form of fermentation products, PHA stored in PAO cells, unfermented influent organic matter and the like. The suspension of the anaerobic tank 101 in which the above reaction has been performed is sequentially transferred to the aerobic tank 104 or the anaerobic tank 102 through the first internal circulation pipe 202.

The oxygen-free tank 102 is a biological reaction tank for denitrifying nitrate by transferring electrons generated while the organic material as the electron donor is oxidized to the nitrate which is the electron acceptor. The supply of the organic material to the oxygen-free tank 102 for such a reaction is the anaerobic tank. This is done by transferring the suspension of 101 to the anoxic tank 102 via the first internal circulation pipe 202. On the other hand, as described later, the supply of nitrate is an anoxic tank (2) through the second internal circulation pipe 203 and the conveying sludge pipe 205, respectively, of the suspension of the aerobic tank 104 containing nitrate and the sludge of the settling tank 105. By returning 102). Since the nitrate supplied to the anoxic tank 102 is transferred to the anaerobic tank 101 after the denitrification reaction in the anoxic tank 102 is completed, competition between PAO and denitrifying microorganisms for intake of RBCOD is blocked in advance. The problem of inhibition of phosphorus treatment is solved.

The organics of the suspension transferred from the anaerobic tank 101 to the anaerobic tank 102 consist of anaerobic fermentation products, PHA stored in PAO cells, unfermented influent organics and the like, as mentioned above. These organics can be used as electron donors for denitrification caused by denitrifying microorganisms that do not overdose phosphorus in the anaerobic tank 102 and denitrifying phosphorus accumulating organisms (dPAOs), which are overdose phosphorus. Among these, dPAO is an oxygen-free state, that is, using nitrate as an electron acceptor to decompose PHA to synthesize cells, absorb phosphorus and store in the form of poly-phosphate (poly-phosphate), anoxic tank 102 The suspension of the anaerobic tank 101 introduced into the state is a state in which PAO has already been stored in the body as PHA using organic materials available in the anaerobic state among the organic matters of the influent water, so that denitrifying microorganisms that do not ingest excessive phosphorus cannot be used.

The aerobic tank 104 is a biological reaction tank in which oxidation of an organic substance is performed by transferring electrons to oxygen, which is an electron acceptor, while an organic substance, which is an electron donor, is oxidized, and the organic substance is supplied through a suspension of the anaerobic tank 101. The PAO, which stores the organic PHA in the body, present in the suspension, decomposes the PHA in the aerobic tank 104 to synthesize the cells, and absorbs excessively of phosphorus to store the cells in the form of multi-P. On the other hand, ammonia nitrogen and the like of the inflow wastewater and sewage are converted into nitrates by nitrifying microorganisms, which are independent nutrient microorganisms that grow and grow in the aerobic tank 104. Thus, the suspension of the aerobic tank 104 containing nitrate is conveyed to the anoxic tank 102 through the 2nd internal circulation pipe 203, and is reprocessed, and some are conveyed to the precipitation tank 105 as it is, without returning.

The settling tank 105 is a place for solid-liquid separation of the suspension of the bioreactor, and the supernatant of the settler 105 is discharged through the treated water discharge pipe 206 as treated water, and the precipitated sludge is mixed liquor suspended solids of the bioreactor. ) To the oxygen-free tank 102 through the conveying sludge pipe 205 in order to maintain the appropriate concentration and to further treat the nitrate remaining in the sludge. The discharge of the excess sludge is made by discharging the sludge of the sedimentation tank 105 through the sludge discharge pipe 207, at which time the phosphorus excess intake microorganism is also discharged, the phosphorus treatment is completed.

As mentioned above, since the pipes connected to the oxygen-free tank 102 vary (first internal circulation pipe 202, second internal circulation pipe 203, conveying sludge pipe 205, etc.), according to the present invention, In order to properly treat nitrogen and phosphorus, it is important to adjust the flow rate to the oxygen-free tank (102).

First, the internal circulation rate (internal circulation amount / influent flow rate) for returning the suspension of the aerobic tank 104 containing nitrate to the oxygen-free tank 102 should be adjusted in accordance with the nitrogen concentration of the treated water and the organic load of the influent. When the nitrogen concentration of the treated water is to be kept low, the internal circulation rate should be increased, but more than 500% is not preferable because the increase in the circulation amount of nitrate becomes insignificant as the internal circulation rate increases. In addition, a low organic load of the influent cannot denitrify the internally circulated nitrate, so the internal circulation should be limited, and eventually the internal circulation rate should be adjusted according to the organic load of the influent.

On the other hand, the inflow of organic matter into the anaerobic tank 102 is adjusted by the suspension conveyance rate (suspension conveyance amount / inflow water flow rate) from the anaerobic tank 101 to the anaerobic tank 102. The suspension transfer rate should be adjusted according to the load of nitrates in the sludge returned from the settling tank 105 and the nitrates in the suspension returned from the aerobic tank 104, but more than 500% is not preferred, which is due to the increase in the suspension transfer rate. This is because the amount of the suspension to the oxygen-free tank 102 is small.

The sludge conveyance from the settling tank 105 to the anoxic tank 102 is 10 to 100 depending on the general sludge conveyance rate (conveyed sludge amount / influent flow rate) for maintaining the appropriate concentration of MLSS when the wastewater and general sewage are subjected to general wastewater. Adjust to%.

Figure 4a is a schematic diagram showing another example of the biological wastewater and sewage treatment apparatus according to the present invention.

The apparatus according to the present invention shown in FIG. 4A prevents the flow of waste and sewage by the apparatus of FIG. 3A from flowing into the aerobic tank 104 without being transferred to the anaerobic tank 102 from the suspension of the anaerobic tank 101. For this purpose, an anaerobic tank 103 is further disposed between the anaerobic tank 101 and the aerobic tank 104 (hereinafter, the first anaerobic tank and the second anoxic tank are classified according to the flow order of the inflow waste and sewage). When the suspension of the anaerobic tank 101 flows directly into the aerobic tank 104, aeration energy is required because the organic matter in the suspension consumes oxygen in the aerobic tank 104. In addition, there is a problem that the organic matter in the suspension useful for denitrification is not used for denitrification, and is consumed as it is. Therefore, when the suspension of the anaerobic tank 101 passes through the second anaerobic tank 103 before entering the aerobic tank 104, the cost of aeration energy can be reduced, as well as the denitrification efficiency can be increased. In addition, the third internal circulation pipe connecting the aerobic tank 104 and the second anoxic tank 103 to each other so that the nitrate generated in the aerobic tank 104 is reprocessed not only in the first anoxic tank 102 but also in the second anoxic tank 103. By providing and conveying 204, denitrification efficiency can be improved more. In this case, the third internal circulation pipe 204 may be installed by branching from the second internal circulation pipe 203.

The adjustment of the flow rate in the apparatus shown in FIG. 4A is sufficient for the organic matter necessary for denitrification in the first anoxic tank 102 when the inflow water has a high COD / TKN ratio. The internal circulation rate from the anaerobic tank 102 to the first anaerobic tank 102, and correspondingly the suspension transfer rate from the anaerobic tank 101 to the first anaerobic tank 102. At this time, the suspension not transferred from the anaerobic tank 101 to the first anaerobic tank 102 is introduced into the second anaerobic tank 103. On the other hand, when the COD / TKN ratio of the influent is low, since the organic content of the influent is low, the internal circulation rate from the aerobic tank 104 to the first anoxic tank 102 is limited by the organic of the influent. As such, when the COD / TKN ratio of the influent is low, the suspension transfer rate from the anaerobic tank 101 to the first anaerobic tank 102 is increased, thereby increasing the internal circulation rate from the aerobic tank 104 to the first anoxic tank 102. However, even though the suspension transfer rate is maintained high, it is practically difficult and economical to transfer the suspension of the anaerobic tank 101 to the first anaerobic tank 102 in part, so that some are introduced into the second anaerobic tank 103, which is a subsequent biological reaction tank. In the waste and sewage with low COD / TKN ratio, if the organic matter of the suspension of anaerobic tank 101 cannot be used for denitrification, the nitrate corresponding to the organic matter of the suspension transferred to the second anaerobic tank 103 is thus ineffective. Inflow by circulation increases denitrification and reduces aeration energy. Herein, the internal circulation rate from the aerobic tank 104 to the first anoxic tank 102 is referred to as a first internal circulation rate (internal circulation amount / influent flow rate into the first anoxic tank), and the interior of the aerobic tank 104 to the second anoxic tank 103 is The circulation rate is described by dividing it into the second internal circulation rate (internal circulation rate / inflow rate of flow into the second anoxic tank). As described above, the first internal circulation rate and the second internal circulation rate are usually adjusted according to the nitrogen concentration of the treated water and the organic load of the influent, and in particular, the second internal circulation rate is the first internal circulation rate and the first anoxic tank 102. Adjust to the load of organics that are not transported to. The suspension transfer rate from the anaerobic tank 101 to the first anoxic tank 102 is adjusted according to the nitrate load of the return sludge returned from the settling tank 105 and the nitrate load by the first internal circulation rate.

5 is a schematic view showing still another example of the apparatus for treating biological wastewater and sewage according to the present invention.

The apparatus according to the present invention shown in FIG. 5 is a device in which only the second internal circulation pipe 203 in FIG. 4A is removed, and the suspension of the aeration tank 104 and the sludge of the settling tank 105 in the first anoxic tank 102. All of these can be prevented from being inhibited by overloading or load variations of nitrates, which are of concern when returned. According to this apparatus, since the first anoxic tank 102 receives only the nitrate load by the sludge of the settling tank 105, it is possible to stably denitrify the nitrate in the sludge of the settling tank 105, and the amount of organic matter to denitrify it. Since less is needed, the transfer rate of the suspension from the anaerobic tank 101 can also be reduced. In addition, the suspension of the aerobic tank 104 is conveyed only to the second anoxic tank 103 in which the suspension from the anaerobic tank 101 is partially transported, and the nitrate contained therein is denitrified, so that the phosphor of FIG. And stable processing. Compared with the apparatus of FIG. 2, which is a device used in the conventional DNR method, in the conventional DNR method, since denitrification occurs through inhalation using organic materials of microorganisms, the endogenous denitrification rate is very low, and thus, to obtain a desired effect. Since the amount of microorganisms needs to be increased, the volume of the bioreactor must be increased. However, according to the apparatus of FIG. 5 according to the present invention, since the organic matter contained in the suspension of the anaerobic tank 101 is supplied to the first anoxic tank 102 through the first internal circulation pipe 202, the nitrate is denitrated more quickly. It can be oxidized and therefore no increase in volume of the bioreactor is required.

In the apparatus shown in FIG. 5, the flow rate of the suspension from the anaerobic tank 101 to the first anoxic tank 102 is determined according to the nitrate load in the conveying sludge from the settling tank 105 to the first anoxic tank 102. The second internal circulation rate from the aerobic tank 104 to the second anoxic tank 103 is determined according to the load of organics introduced into the second anoxic tank 103 without being transferred to the first anoxic tank 102 according to the suspension transfer rate.

Figure 6a is a schematic diagram showing another example of the biological waste and sewage treatment apparatus according to the present invention.

In the apparatus according to the present invention shown in FIG. 6A, the arrangement of the first anaerobic tank 102 and the anaerobic tank 101 in FIG. 4A is changed, and the sludge of the first anaerobic tank 102 is returned to the anaerobic tank 101. An apparatus in which the internal circulation pipe 208 is provided, according to which, in the first anaerobic tank 102, the nitrate contained in the suspension of the aerobic tank 104 and the sludge of the settling tank 105 is denitrified and then to the anaerobic tank 101. Since it is conveyed, competition between PAO and denitrification microorganism can also be prevented, and as a result, efficiency of phosphorus removal can be improved. At this time, the internal circulation of the sludge from the first anaerobic tank 102 to the anaerobic tank 101 through the sludge internal circulation pipe 208 is made by conveying the suspension of the first anoxic tank 102 to the anaerobic tank 101, and the sludge inside The circulation rate (sludge internal circulation amount / influent flow rate) should be properly adjusted according to the appropriate microbial concentration (MLSS concentration) of the anaerobic tank 101. In order to increase the MLSS concentration of the anaerobic tank 101, the sludge internal circulation rate must be increased. However, if the sludge internal circulation rate is 500% or more, the increase in the MLSS concentration of the anaerobic tank 101 is not preferable. In addition, according to the apparatus of FIG. 6A, similar to the apparatus of FIG. 4A and the apparatus of FIG. 5, the suspension of the anaerobic tank 101 passes through the first anoxic tank 102 and the second anoxic tank 103 and is then transferred to the aerobic tank 104. Therefore, the denitrification efficiency can be increased while reducing the cost of aeration energy. Here, the adjustment of the first internal circulation rate from the aerobic tank 104 to the first anoxic tank 102 and the second internal circulation rate from the aerobic tank 104 to the second anoxic tank 103 is usually carried out with the nitrogen concentration of the treated water and the organic load of the influent. However, it is also affected by fluctuations in the load of influent nitrogen and organics. If there is a variation in the load of nitrogen and organics in the influent, such as most waste and sewage, the untreated nitrates from the first anaerobic tank 102 and the nitrate load are transferred from the first anaerobic tank 102 to the anaerobic tank 101. Influx will impair phosphorus treatment. Therefore, the first internal circulation rate to the first oxygen-free tank 102 is adjusted to the extent that the nitrate can be treated stably, and the second internal circulation rate to the second oxygen-free tank 103 is the untreated organic material in the first oxygen-free tank 102. Adjust to handle the nitrate corresponding to the load.

In treating waste and sewage using the treatment apparatus according to the present invention, an anaerobic tank 101 and an anoxic tank (first anaerobic tank) in the case of treating general sewage using the apparatus of FIGS. 3A, 4A, 5 and 6A. 102, second anaerobic tank 103, aerobic tank 104, hydraulic retention time of sewage in sedimentation tank 105, MLSS concentration, suspension transfer rate, internal circulation rate (first internal circulation rate), second internal The circulation rate, sludge internal circulation rate, and sludge conveyance rate are collectively shown in Table 1 below.

3a 4a 5 6a Mathematical retention time (hours) Anaerobic tank 0.3 to 3 0.3 to 3 0.3 to 3 0.3 to 3 (1) anaerobic tank 1 to 5 0.1 to 4 0.1 to 2 0.5 to 5 The second anaerobic tank - 0.1 to 4 0.2 to 4 0.1 to 3 Aerobic 3 to 8 3 to 8 3 to 8 3 to 8 Sedimentation tank 2 to 5 2 to 5 2 to 5 2 to 5 MLSS concentration (mg / l) 1,000 to 5,000 1,000 to 5,000 1,000 to 5,000 1,000 to 5,000 Suspension Transfer Rate (%) 10 to 500 10 to 500 5 to 400 - (1) Internal circulation rate (%) 10 to 500 5 to 500 - 10 to 500 Second internal circulation rate (%) - 5 to 400 10 to 500 5 to 400 Sludge Return Rate (%) 10-100 10-100 10-100 10-100 Sludge Internal Circulation Rate (%) - - - 10 to 500

Under such conditions, when treating general sewage with the treatment apparatus according to the present invention, total nitrogen (TN) and total phosphorus (TP) in the treated water are treated up to about 6-12 mg / l and about 1-2 mg / l, respectively. Good treatment effect can be obtained.

The waste and sewage treatment apparatus according to the present invention can be additionally applied to conventionally known apparatuses and methods as necessary. That is, before inflow of the inflow water into the anaerobic tank 101, the screen for removing waste and sewage contaminants at the front end of the inflow pipe 201, and the equalization of the settlement, the flow rate and the water quality for removing the sediments such as sand. In order to remove the suspended solids, the flow may be passed through a primary settling tank. In the treatment apparatus according to the present invention, a suitable agitator for mixing is provided in the anaerobic tank 101, the first anaerobic tank 102, and the second anaerobic tank 103, and the aerobic tank 104 supplies oxygen and air for supplying oxygen to the microorganisms. It is preferable that each device is provided.

In addition, an immersion type ultrafiltration membrane 301 for solid-liquid separation of the suspension may be provided in the aerobic tank 104 of FIGS. 3A, 4A, and 6A according to the present invention. At this time, by additionally installing the treated water discharge pipe 206 and the sludge discharge pipe 207 in the exhalation tank 104, the sedimentation tank 105 and the pipe connected thereto (conveying sludge pipe 205, in the apparatus according to the present invention), The treated water discharge pipe 206 and the sludge discharge pipe 207 may be removed to increase space efficiency. 3B, 4B, and 6B show the application of the immersion type ultrafiltration membrane 301 in the aerobic tank 104 in the apparatus of FIGS. 3A, 4A, and 6A according to the present invention, respectively. The immersion type ultrafiltration membrane 301 is a kind of separation membrane, and the separation mechanism is sieving and adsorption, and if necessary, the molecular weight cutoff may be selected in the range of 1,000 to 200,000 and pore diameter of 0.1 to 0.001 μm. Can be. Moreover, the form can also be selected from a plate shape, a tubular shape, a hollow fiber type, and a spiral winding type according to a filtration membrane module, and it is especially preferable to use a plate shape, a tubular shape, and a hollow fiber type. The treatment principle of waste and sewage using the immersion type ultrafiltration membrane 301 is as follows. That is, the immersion type ultrafiltration membrane 301 immersed in the aerobic tank 104 suction-filters the suspension which flowed into the aerobic tank 104. FIG. The suspension is generally sucked into the submerged ultrafiltration membrane 301 by the suction pump 302 at 0.5 kg / cm2 or less, and the solids that do not pass through the submerged ultrafiltration membrane 301 remain in the aerobic tank 104 as it is. The filtered water passed through the ultrafiltration membrane 301 is discharged as treated water. Since the treated water sucked by the suction pump 302 has passed through the immersion type ultrafiltration membrane 301, turbidity is remarkably low. The discharge of the excess sludge is made through the sludge discharge pipe 207 installed in the aeration tank 104, the maintenance of the proper microbial concentration of the bioreactor, the role of the settling tank is the suspension of the aeration tank 104 through the second internal circulation pipe 203 Is made through the return of. In the case of using the immersion type ultrafiltration membrane 301, since the foreign matter may adhere to or be trapped on the surface or the pore diameter of the filtration membrane as the treatment apparatus is operated, cleaning is necessary, and thus an additional cleaning apparatus may be provided. When waste and sewage are treated by the treatment apparatus using the immersion type ultrafiltration membrane 301 as described above, the SS reduction effect of the treated water can be obtained as compared with the treatment apparatus using the precipitation tank, and the MLSS concentration in the biological reactor can be maintained high. Specifically, in the case of biological nitrogen and phosphorus treatment using a precipitation tank, SS of treated water is 10 to 30 mg / l, and MLSS is generally 1,000 to 4,000 mg / l, but biological nitrogen and phosphorus using the immersed ultrafiltration membrane 301 In the case of the treatment, the SS of the treated water is 2 mg / l or less, and the MLSS is about 2,000 to 8,000 mg / l, so that the volume of the biological reactor can be reduced to about 1/2.

Alternatively, a flow carrier 401 or fixed carrier 408 may be provided to provide a space or surface for trapping or attaching microorganisms to the aerobic tank 104 of FIGS. 3A, 4A, 5 and 6A according to the present invention. By filling, the concentration of microorganisms can be increased. Increasing the concentration of microorganisms by the growth and growth of the microorganisms in the flow carrier 401 or the fixed carrier 408 may reduce the volume and the use site area of the aerobic tank 104 by about 1/2 to 2/3. Gives the effect. In addition, considering the slow growth rate of nitrifying microorganisms causing nitrification in the aerobic tank 104 and the nitrification at low temperatures by the nitrifying microorganisms is not easy, the flow carrier 401 or the fixed carrier 408 is used. Stable retention of nitrifying microorganisms can achieve more efficient nitrification effects. At this time, the size, shape, material, etc. of the filled carrier 401 or fixed carrier 408 is not particularly limited. For the carrier 401, a polyhedral carrier such as a sphere or a cube of several mm to several cm may be used. The fixed carrier 408 may be selected and filled, and a carrier such as a fibrous, honeycomb, plate, or the like having a length of several tens of cm to several m may be selected and filled. In addition, the material of the fluid carrier 401 or the fixed carrier 408 is inorganic material such as clay, sand, natural or artificial zeolite, waste tires, waste such as waste vinyl, synthetic resin such as polyethylene, polystyrene, polyamide, these Any of activated carbon-added synthetic resins to which activated carbon is added to the synthetic resins can be selected and used.

In order to prevent the filled carrier from being separated and lost in the aerobic tank 104, the carrier using the flow of the aerobic tank 104 suspension, the gravity of the carrier and the inertia force, as shown in FIG. It is possible to install a device for rotating the screen, or as shown in Figure 7b, the screen 407 can be installed in the aerobic tank 104, in the case of the fixed carrier 408 is fixed to the frame as shown in Figure 7c top and bottom The aerobic tank 104 can be filled with a fibrous carrier, a honeycomb carrier fixed in a lattice frame, or a plate carrier. As shown in FIG. 7A, in order to rotate the carrier by using the flow of the aerobic tank 104 suspension, the gravity and the inertia of the carrier, when the aeration device 405, the rotation guide plate 402, etc. are installed in the aerobic tank 104, the flow is performed. A barrier plate 403 and a separator plate 404 may be additionally installed to prevent overflow of the suspension including the carrier 401. When some of the suspension and the flow carrier 401 overflow the blocking plate 403, they are induced by gravity to the lower portion of the aerobic tank 104, and then the rotation of the suspension and the gravity and inertia of the carrier The flow carrier 401 can continue to be recycled in the aeration tank 104 as it separates from one another at the boundary 403 and only the suspension flows out through the separator plate 404. In addition, in the case where the screen 407 is provided in the aerobic tank 104 as shown in FIG. 7B, a carrier circulation pipe 406 for circulating the fluid carrier 401 can be additionally installed, and the fluid carrier 401 is provided. A circulation device of the fluid carrier 401, such as an air lift pump, may be further installed to prevent the fluid carrier 401 from concentrating on the screen 407 in accordance with the flow of the suspension.

In addition, when treating waste and sewage using the waste and sewage treatment apparatus according to the present invention, in order to maintain COD / TKN and COD / TP at a constant ratio in order to treat nitrogen and phosphorus more efficiently, the anaerobic tank ( 101) and / or solid organic waste liquids such as organic waste liquids containing large amounts of organic chemicals such as methanol and acetic acid, etc., organic waste such as methanol and acetic acid, manure, septic tank waste liquid, livestock waste water and food waste in the first anoxic tank 102 In the group consisting of fresh sludge generated in the first sedimentation tank of waste and sewage treatment plant, condensate discharged from the waste and sewage treatment plant, digester, dewatering device, organic waste liquid, solid organic waste liquid, and acid sludge acid fermentation broth. At least one selected external carbon source may be introduced. In particular, in order to treat phosphorus more effectively, since organic acids are effective among CODs, high concentration organic waste liquids such as organic waste liquid, solid organic waste liquid, and fresh sludge may be converted into organic acids through anaerobic acid fermentation and then introduced. When the inflow point of the external carbon source is the anaerobic tank 101, the absorption and phosphorus emission amount of the organic material by PAO is increased, resulting in increased phosphorus treatment efficiency, and the inflow point of the external carbon source to the first anoxic tank 102. In this case, the nitrogen treatment efficiency is increased because the external carbon source becomes an electron donor and the nitrate is actively denitrified.

According to the wastewater and sewage treatment apparatus of the present invention, the organic matter absorption and phosphorus release by PAO in the anaerobic tank can be smoothly achieved, and the efficiency of nitrogen removal can be increased. In addition, by applying a conventional filtration membrane and a carrier based on the waste and sewage treatment apparatus of the present invention, it is possible to reduce the volume and required site area of the waste water treatment apparatus while maintaining high removal efficiency of nitrogen and phosphorus.

1 is a schematic view of a wastewater and sewage treatment apparatus for a conventional A ₂ O method.

2 is a schematic view of a wastewater and sewage treatment apparatus for a conventional DNR method.

3A, 4A, 5 and 6A are schematic diagrams showing an example of a biological waste and sewage treatment apparatus according to the present invention.

3B, 4B, and 6B are schematic views of another biological waste and sewage treatment apparatus according to the present invention, in which an immersion type ultrafiltration membrane is provided in an aerobic tank.

7A to 7C are schematic views of another biological waste and sewage treatment apparatus according to the present invention, in which a carrier is filled with an aerobic tank.

<Explanation of symbols for the main parts of the drawings>

101: anaerobic tank 102: anaerobic tank (first anaerobic tank)

103: second anaerobic tank 104: aerobic tank

105: sedimentation tank 201: inlet pipe

202: first internal circulation pipe 203: second internal circulation pipe

204: third internal circulation pipe 205: conveying sludge pipe

206: treated water discharge pipe 207: sludge discharge pipe

208: sludge internal circulation pipe 301: immersion ultrafiltration membrane

302: suction pump 401: flow carrier

402: rotation guide plate 403: prevention plate

404: separator plate 405: aeration device

406: carrier circulation piping 407: screen

408: fixed carrier

Claims (8)

In the wastewater and sewage treatment apparatus which consists of an anaerobic tank, an anaerobic tank, an aerobic tank, a sedimentation tank, and piping which connects them sequentially, An inlet pipe for introducing waste and sewage into the anaerobic tank; A first internal circulation pipe that connects the anaerobic tank and the anoxic tank to each other to transfer the suspension of the anaerobic tank to the anoxic tank; A second internal circulation pipe which connects the aerobic tank and the anoxic tank to each other for conveying the suspension of the aerobic tank to the anoxic tank; A conveying sludge pipe which connects the settling tank and the anoxic tank with each other to convey the sludge of the settling tank to the anoxic tank; A treated water discharge pipe which is a passage through which the treated water is discharged from the settling tank; And A sludge discharge pipe which is a passage through which sludge is discharged from the settling tank; Waste and sewage treatment apparatus comprising a. In the wastewater and sewage treatment apparatus which consists of a 1st anoxic tank, an anaerobic tank, a 2nd anoxic tank, an aerobic tank, a settling tank, and piping which connects them sequentially, An inlet pipe for introducing waste and sewage into the anaerobic tank; A first internal circulation pipe connecting the anaerobic tank and the first anoxic tank to each other for transferring the suspension of the anaerobic tank to the first anoxic tank; A second internal circulation pipe connecting the aerobic tank and the first anoxic tank to each other for conveying the suspension of the aerobic tank to the first anoxic tank; A third internal circulation pipe connecting the aerobic tank and the second anoxic tank to each other for conveying the suspension of the aerobic tank to the second anoxic tank; A conveying sludge pipe which connects the settling tank and the first anoxic tank to each other to convey the sludge of the settling tank to the first anoxic tank; A treated water discharge pipe which is a passage through which the treated water is discharged from the settling tank; And A sludge discharge pipe which is a passage through which sludge is discharged from the settling tank; Waste and sewage treatment apparatus comprising a. In the wastewater and sewage treatment apparatus which consists of a 1st anoxic tank, an anaerobic tank, a 2nd anoxic tank, an aerobic tank, a settling tank, and piping which connects them sequentially, An inlet pipe for introducing waste and sewage into the anaerobic tank; A first internal circulation pipe connecting the anaerobic tank and the first anoxic tank to each other for transferring the suspension of the anaerobic tank to the first anoxic tank; A third internal circulation pipe connecting the aerobic tank and the second anoxic tank to each other for conveying the suspension of the aerobic tank to the second anoxic tank; A conveying sludge pipe which connects the settling tank and the first anoxic tank to each other to convey the sludge of the settling tank to the first anoxic tank; A treated water discharge pipe which is a passage through which the treated water is discharged from the settling tank; And A sludge discharge pipe which is a passage through which sludge is discharged from the settling tank; Waste and sewage treatment apparatus comprising a. In the wastewater and sewage treatment apparatus which consists of an anaerobic tank, a 1st anoxic tank, a 2nd anoxic tank, an aerobic tank, a settling tank, and piping which connects them sequentially, An inlet pipe for introducing waste and sewage into the anaerobic tank; A sludge internal circulation pipe which connects the first anoxic tank and the anaerobic tank to each other to convey the sludge of the first anoxic tank to the anaerobic tank; A second internal circulation pipe connecting the aerobic tank and the first anoxic tank to each other for conveying the suspension of the aerobic tank to the first anoxic tank; A third internal circulation pipe connecting the aerobic tank and the second anoxic tank to each other for conveying the suspension of the aerobic tank to the second anoxic tank; A conveying sludge pipe which connects the settling tank and the first anoxic tank to each other to convey the sludge of the settling tank to the first anoxic tank; A treated water discharge pipe which is a passage through which the treated water is discharged from the settling tank; And A sludge discharge pipe which is a passage through which sludge is discharged from the settling tank; Waste and sewage treatment apparatus comprising a. The method according to any one of claims 1, 2 or 4, Remove the settling tank and the conveying sludge pipe, sludge discharge pipe and treated water discharge pipe connected thereto, An immersion type ultrafiltration membrane is installed in the exhalation tank provided with the second internal circulation pipe, and the sludge discharge pipe and the treated water discharge pipe are connected to the exhalation tank. Waste and sewage treatment device. The method according to any one of claims 1 to 4, A fluid carrier or a fixed carrier is additionally filled in the aerobic tank. Waste and sewage treatment device. The method according to any one of claims 1 to 4, In front of the inlet pipe, a screen for removing waste and sewage contaminants, a settling basin for removing sediments such as sand, a flow regulating tank for equalizing flow rate and water quality, and a primary sedimentation tank for removing suspended solids are selected. At least one device further comprising: Waste and sewage treatment device. The method according to any one of claims 1 to 4, Solid waste organic waste such as organic waste liquid, manure, septic tank waste liquid, livestock waste water, food waste, etc., containing a large amount of organic chemicals such as methanol and acetic acid, methanol, acetic acid, etc. in the anaerobic tank and / or the first anoxic tank ㆍ At least one selected from the group consisting of fresh sludge generated in the initial sedimentation tank of sewage treatment plant, condensate discharged from the condensation tank, dehydration apparatus of waste and sewage treatment plant, the organic waste liquid, solid organic waste liquid, and acid fermentation liquid of fresh sludge Characterized by introducing one external carbon source Waste and sewage treatment device.