KR100463590B1 - Advanced Waste Water Treatment Methods with increasing Easily Biodegradable Oroganic Concentration for Nitrogen and phosphorous Removal - Google Patents

Abstract

The present invention relates to a method for removing nutrients from sewage and wastewater, and in order to remove nitrogen and phosphorus, a fermentation tank is installed in a highly advanced biological treatment process in which denitrification and dephosphorization are performed using inflowed organic matter as an electron donor. Alternatively, by mixing the fermentation broth produced by fermenting organic wastes such as residues into the influent sewage and utilizing the solid-liquid separation function of the first settler, the liquid organic matter is dissolved in the symbolic water of the first settler and denitrification and phosphorus release in the advanced treatment process. Increasing the concentration of the degradable organics available for the reaction, the poorly degradable organic matter which is difficult to denitrate and dephosphorize is recovered from the first settler as a precipitate and fermented, and the fermentation broth is introduced into the influent. By repeating the dissolving process, the concentration of the decomposable influent organic matter is increased in the symbolic water of the first settler, so that nitrogen, The present invention relates to advanced treatment method of removing with a high efficiency.

Description

Advanced Waste Water Treatment Methods with increasing Easily Biodegradable Oroganic Concentration for Nitrogen and phosphorous Removal}

The present invention relates to a method for increasing nutrient removal efficiency from sewage or wastewater, and more particularly, an advanced treatment process using mainly influent organic matter to remove nitrogen and phosphorus from sewage water treated in urban sewage treatment plants and industrial wastewater treatment plants. The fermentation tank is installed in the fermentation tank, and the organic matters contained in the fermentation broth produced by fermenting organic wastes such as raw waste or food waste and organic by-products generated in industrial factories can be dissolved in inflow water so that microorganisms can be easily used. By increasing the degradable organic matter concentration and separating the influent sewage in which the fermentation broth is dissolved in the first settler, the degradable organic substances dissolved in the supernatant are used for subsequent biological denitrification and dephosphorization reaction, Slowly degradable solid organic matter which is difficult to be used for denitrification and dephosphorization reactions is the first. Thereby to recover a precipitate from the cell cycle into effect the process of re-dissolved in a sewage inlet to the fermentation broth By repeating relates to an advanced treatment methods to increase the NOx removal, the inlet concentration of the organic substance is degradable available for the dephosphorization reaction.

Pollutants in sewage are classified into organic substances and nutrients such as nitrogen and phosphorus. Until now, sewage treatment plants have mainly treated organic substances, and a large part of nitrogen and phosphorus could not be removed and discharged into rivers, lakes or oceans. Increasing the nitrogen inflow of streams and lakes leads to eutrophication and causes red tides in the ocean. As nutrient nutrients become more severe, water pollution is increased, and the use of drinking water and water is restricted. So, nutrients such as nitrogen compounds or phosphates should be sufficiently removed from sewage treatment plants.

The biological nitrogen removal process first converts organic and ammonia nitrogen to nitrate by nitrifying bacteria in aerobic state. In the anoxic state, nitrogen is removed from the sewage by using microbial characteristics of reducing nitrate-bound combined oxygen to free nitrogen using dissolved oxygen, and organic matter is used as an electron donor.

The method of supplying organic materials for denitrification in anoxic state is very important in biological denitrification process. Almost all nitrification and denitrification methods developed so far are classified into total denitrification using organic materials contained in sewage and post denitrification using methyl alcohol from the outside.

The post denitrification method has the advantage of high treatment efficiency and a small capacity of the anoxic reactor, but it is difficult to bear the cost because it needs to continuously supply organic substances which are easily decomposed, such as methyl alcohol, to be used as an electron donor for denitrification. In order to reduce the procurement cost of electron donors such as methyl alcohol and organic acids, a method of using an organic material precipitated in the first settler, that is, an acetate-based organic acid produced by fermenting fresh sludge as an electron donor for denitrification, may be used. However, the denitrification method using the raw sludge fermentation broth has a problem in that a considerable amount of organic matter is disintegrated and difficult to settle, or the organic matter is insufficient to sufficiently remove nitrogen oxides, so that the denitrification efficiency is low. In addition, the raw sludge fermentation broth itself contains nitrogen compounds, so the nitrogen compounds to be removed may be increased.

In order to solve the problem that sufficient denitrification is not possible with only organic matter in the influent sewage, we use abundant organic wastes such as food waste, livestock manure and collected manure that are excessively generated in Korea and are suffering from disposal. The method of using organic waste, which can greatly improve the nitrogen and phosphorus removal efficiency, can be applied to the post-denitrification process as well as the high-treatment processes of the total denitrification series.

There are many methods for advanced processing using influent organic materials, including Ludzack-Ettinger, MLE, AO, A ₂ O, Bardenpho, Bio-DeNiPho proc processes and their variants in addition to the process illustrated in FIG. The use of influent organics does not require external carbon sources, and most processes can be easily operated and treated if the influent quality is stable.

In such a high-treatment process, all the denitrification-based processes commonly perform denitrification or phosphorus releasing reactions at all stages, so that low-molecular-weight, organic, soluble and degradable organic substances in sewage are denitrated or dephosphorized by microorganisms. Although it can be used for the reaction, solid-degradable organic matter is not used in the anoxic or anaerobic reactor in the previous stage, but enters the aerobic reactor in the subsequent stage, increasing the organic load, reducing nitrification and denitrification. It is a waste of construction.

In order to remedy these disadvantages, there is also a method of directly supplying fresh sludge and organic waste or fermentation broth fermented to them to an anaerobic reactor for denitrification or an anaerobic reactor for phosphate release. Was raised.

① Organic wastes, such as raw sludge or food waste, which are to be fermented with organic acids and used for denitrification, are composed of a mixture of degradable, slow degradable or hardly decomposable organic substances. Therefore, in organic acid fermentation, a large part of the dissolvable dissolved organic matter is decomposed into methane gas and is wasted beyond the organic acid fermentation stage, and some of the slow-decomposable solid organic matter is not liquefied and remains in the fermentation broth as a solid. Maintaining optimal fermentation conditions with the highest organic acid content of acetate series has a very difficult problem in reality.

② If the fermentation broth, which is a mixture of degradable and degradable solid organic matters, is directly added to the reaction tank, only dissolvable degradable organic matter is used for denitrification. As it passes through, it cannot be used for denitrification, but enters the aerobic reactor at the end, which acts as an organic load and inhibits nitrification.

③ Inorganic solids such as nito and sesa are present in organic wastes such as fresh sludge and food waste, and when the organic waste fermentation liquid is directly added to the reactor, the inorganic solids are also introduced into the reactor. Even if the solids retention time is the same, the occupational solids in the suspended solids mixture (MLSS) in the reaction tank is increased compared to the case where the inorganic solids are removed in advance, thereby degrading the activity of the activated sludge.

④ As a solution to the above three problems, a separate solid-liquid separation process such as a dehydrator, a sedimentation basin, etc. may be provided, and only the dissolved organic matter may be separated from the fermentation broth, and only the filtrate may be directly used in a denitrification / dephosphorization reactor. However, this method is difficult to separate the solid-liquid separation by gravity precipitation because of the increased cost of facilities, complicated treatment facilities, odors, volatilization, high solids concentration and high fermentation viscosity.

Accordingly, the present invention has been made to solve the above-mentioned problems, specifically, the configuration of the device is simple, the operation method is stabilized, and the raw sludge to improve the efficiency of the advanced treatment process using the influent organic matter for denitrification and dephosphorization reaction. Another object of the present invention is to provide a method in which organic wastes such as food waste are effectively fermented and degradable organic wastes can be selected and used.

In the method of the present invention, while the solid organic matter contained in the influent sewage, that is, the fermentation broth produced by organic acid fermentation of fresh sludge precipitated and separated in the first settler, is used for denitrification and dephosphorization in a high-treatment process, the fermentation broth is directly added to the reactor. In order to solve the above-mentioned four problems caused by the input, the first settler is configured to utilize the raw sludge fermentation broth for washing and solid-liquid separation.

The fermentation tank for fermenting the fresh sludge consisting of the first settler and the sedimentation of the solid precipitated in the first sedimentation in which the sedimentation of the solid contained in the inflow sewage in the step of entering the sewage in the advanced treatment process of the total denitrification series The raw sludge fermentation liquid, which is a mixture of organic acid and liquid organic matter produced by fermentation and disintegration of organic sludge in the fermentation tank, inorganic solids such as fine earth and unfermented organic solids, and the inlet pipe, the sedimentation basin, and the inflow pump The fermentation broth is mixed and diluted in the influent sewage and flows into the first settler to improve solid-liquid separation.

The organic acid contained in the fermentation broth introduced into the first settler and the liquid organic matter attached to the solids are washed and dissolved by the influent sewage and dissolved in the inlet along the inlet sewer through the symbolic water of the first settler. The low molecular weight organic materials available for the denitrification and phosphorus release reaction increase with the organic materials and flow out to the high treatment process, thereby improving the nitrogen and phosphorus removal efficiency.

The unfermented organic solids in the fermentation broth and organic solids further introduced through the inflow sewage, ie, the raw sludge, are precipitated and recovered in the first settler, flow back into the fermenter, and the fermentation broth is again fermented. The process of solid-liquid separation in is repeated.

The fermentation broth of organic waste fermented in the fermenter is circulated to the first settler, and the precipitated solids of the first settler are circulated to the fermenter, whereby dissolvable dissolved organic matters such as organic acids and dissolved organics are introduced into the influent. To be used for denitrification and dephosphorization. On the other hand, it is hard to be used for denitrification and dephosphorization reactions.So, solid organic matter is precipitated in the first settler, so that the precipitated solid is recovered and put into the fermenter to be fermented and decomposed into a degradable organic acid or dissolved organic material. It is a configuration to repeatedly circulate the fermentation tank and the first settler. In the circulation of the solids and fermentation broth, some solids include a series of processes in which waste sludge is periodically disposed out of the system.

In addition to raw sludge, which is a solid organic matter contained in the influent sewage, food wastes such as residues, which are excessively produced in Korea, are suffering from disposal, collection manure, livestock manure, and organic by-products generated in industrial plants. Of organic waste directly into the fermenter, mixed and diluted fermentation broth fermented with fresh sludge into the influent sewage, solids recovery and fermentation process in the first settler and dissolved organic fermented in supernatant By repeating the process, raw sludge alone can make up for organic matter.

In addition, in the present invention, by adding and diluting food waste, collected manure, livestock manure, organic by-products or other organic wastes generated in an industrial plant into the influent sewage, not the fermentation tank, the organic liquid is separated from the first settler, the organic The dissolved organic matter contained in the waste was added to the dissolved organic matter in the influent sewage and introduced into the advanced treatment process through the symbolic water of the first settler to be used for denitrification and dephosphorization.

In addition, in the first settler, the organic sludge contained in the raw sludge and the introduced organic waste in the sewage is precipitated, so that it is collected and collected into the fermentation tank. In the fermentation tank, a fermentation broth composed of a mixture of organic acids, liquid organics, and unfermented organic solids produced by fermentation and disintegration of the precipitated solids recovered from the first sedimentary battery is mixed again into the inflow sewage, and the dissolved organic matter is added to the first sedimentation battery. It is dissolved in supernatant water and used for denitrification dephosphorization, and the precipitated solid organic matter is recovered and fermented.

In this way, in addition to the dissolved organic matter contained in the influent sewage, liquid organic substances such as organic acids contained in the fermentation broth and liquid organic matters and organic acids attached to solids are also dissolved in the symbolic water of the first settler and the advanced treatment process. Since only the low molecular weight organic materials available for denitrification and dephosphorization reactions are selectively increased, the nitrogen and phosphorus removal efficiency is improved. The unfermented solids contained in the fermentation broth and the solids additionally introduced through the inflow sewage, that is, the raw sludge, are precipitated in the first settler, so that they are recovered, flowed into the fermenter, fermented, and some of the processes are periodically discarded. do.

Food wastes, such as residue, decay in the process of being collected and brought in, and some of them are converted to organic acids and liquefied. Therefore, when directly added to the fermenter, a considerable amount may be decomposed into gas and wasted. On the other hand, when organic waste such as residue is mixed in sewage at the first stage of the first settling, dissolved organic matter such as organic acid is dissolved in the sewage and used immediately for denitrification and phosphorus release reaction, and the smelly residue is short. Dilution occurs in large amounts of sewage in time, reducing odor.

In addition, it is more economical to transport organic waste to the sewage treatment plant by injecting organic waste into sewage collection pipes adjacent to the waste generating source and transporting organic waste to sewage treatment plants by sewage flowing down the pipeline. In this case, the proper flow rate to prevent sedimentation in the pipeline, the watertightness of the collecting pipeline and the sewage and sewage classification system should be ensured.

In FIG. 7, a part of the first settling symbolic water in which dissolved organic matter is dissolved or a part of the sludge fermentation liquid is introduced into the sludge denitrification tank of the Johannesburg Process illustrated in FIG. 7 in which the conveying sludge passes through the sludge denitrification tank. It is possible to improve the denitrification efficiency of the nitrogen oxide contained in and to shorten the denitrification reaction time. In addition, the remaining organic matter consumed in the sludge denitrification tank is introduced into the anaerobic reactor and the anaerobic reactor, which constitute the main stream, and used for phosphorus release and denitrification. As in Phostrip and the like illustrated in FIG. 7, the method may be equally applied to reactors installed in the side stream.

In order to apply the present invention, when the organic waste is introduced into the inflow sewage, crushing means such as a crusher for finely crushing the organic particles having a large particle size before the addition and the removal of impurities such as plastic bags, screens and the like so as to remove impurities It is preferable to pass by means. In particular, injecting organic waste into influent sewage is more economical because it is not necessary to install a separate screen if it is input at the previous stage of the screening process installed in the sewage treatment plant to remove contaminants in the influent sewage.

In addition, by introducing the fermentation broth from the fermenter into the inlet sewage through the settling basin installed in the sewage treatment plant, the inlet pump well or the first settler distribution tank, the vortex formed during the pumping or distribution process than the direct input to the first settler By doing so, the solid organic matter in the fermentation broth can be washed and the dissolved organic matter can be dissolved in the sewage well.

In the present invention, in the sewage treatment plant that is already constructed and in operation, it is possible to omit a separate fermentation tank installation and to utilize the first settler itself for solid-liquid separation and fermentation in case there is no space and space for installing the fermentation tank. That is, by increasing the solids retention time in the first settler by adjusting the withdrawal amount of fresh sludge or solid form organic matter in the first settler, the organic wastes are fermented in the sludge concentration zone below the settling basin and are produced during the fermentation process. Soluble organic substances such as organic acids are dissolved in the sewage flowing into the sedimentation basin and flow along the supernatant water, so they can be used for denitrification and dephosphorization in advanced treatment processes.

When the fermented dissolved organic matter is diffused and dissolved from the sludge layer below the sedimentation basin to the water body simply by concentration gradient, the dissolved organic matter is slow to dissolve and low molecular weight organic matter contained in the gap water between solids cannot be eluted in a long time. This can cause side effects such as decomposition and waste of gas and sludge rise. Therefore, the organic acid and soluble organic matter contained in the fermentation sludge of the sedimentation basement are extracted by pumping the fermentation sludge from the lower part of the first settler to the first settler symbol water so as to be better dissolved in the settling basin, the inflow pump well or the first settler. When it is mixed into the inflow sewage through the distribution tank and circulated into the first settler, the dissolved organic matter contained in the fermentation solution is better dissolved in the sewage due to the stirring force in the circulation and dilution process, and the surface and the gap between the organic solids The dissolved organic matter contained can also be washed well and flowed out through the symbolic water of the first settler, so that it can be effectively used for subsequent denitrification and dephosphorization reactions, and pure solids can be precipitated and subjected to fermentation.

Most sewage treatment plants are equipped with gravity sludge concentration tanks or sludge digesters for methane fermentation. However, due to the low concentration of solids, gravity sludge is introduced into the water treatment process through the return water, and the methane fermentation process is a complex operation and difficult to grow microorganisms. There are many situations. Therefore, in the present invention, the existing gravity type sludge concentration tank or sludge digestion tank having many problems as described above can be easily used as a fermentation tank of organic waste, so it is economical in terms of site requirements and construction costs. In addition, since the return water generated in the concentration tank, the digestion tank, and the dehydrator in the existing treatment plants is introduced into the inflow pump well, the present invention can be easily realized by utilizing the installed pipes as they are.

In addition, since the fermenter is installed separately from the first settler, the solid precipitated from the first settler is taken out by a pump and transferred to the fermenter, so that the pump and piping facilities are required and the operation is cumbersome. By increasing the capacity of the lower sludge collection unit, it is used as a fermentation tank, or by installing a fermentation space separate from the settling space like the conventional Imhoff Tank in the lower part of the first settler. The lower part of the fermenter was naturally discharged to allow fermentation.

The fermentation tank may be provided with a stirring means to facilitate fermentation, and the stirring means may be connected to the sludge collector driving shaft of the sedimentation basin and may be stirred using the driving force of the sludge collector. In addition, by installing a separate stirrer and connected to the sludge collector so that the stirrer is moved along with the movement of the sludge collector, the entire reaction tank can be smoothly and evenly stirred even with a small capacity stirrer.

By repeating the process of diluting and dissolving the fermentation broth through the first settler and recovering the precipitated solids and fermentation, organic waste such as fresh sludge and remnant are fermented and dissolved to reduce organic matter, Since minerals are not decomposed but continue to circulate, the concentration is increased. Part of the fermentation broth or precipitated solids should be taken out of the system periodically to dispose of the minerals.

Waste sludge disposed of in the fermenter contains dissolved organic matter in addition to organic or inorganic solids, which makes it difficult to handle and manage, and waste may result in organic waste and odor. Therefore, it is preferable to dispose of the solids from which dissolved organic matter is removed by washing the waste sludge with inflow sewage or treated sewage in a washing process and solid-liquid separation in a solid-liquid separation process. The washed filtrate in which dissolved organic matter is dissolved may be introduced into the first settler together with the influent sewage to be used for denitrification and dephosphorization.

Cleaning and solid-liquid separation of waste sludge only reduces the size of the facility by washing and solid-liquid separation of some sludge that is discarded, unlike solid-liquid separation of the entire fermentation broth. Solids can be easily washed and dehydrated using a press or centrifugal dehydrator to be taken out as cakes.

As described above, in the present invention, the organic solids are fermented, and the fermentation broth, which is a mixture of dissolved organics and solid organics, is introduced into the inflow sewage, and the solids are separated from the first settler. The dissolved organics are used for denitrification and dephosphorization, and the precipitates are recovered as precipitates. By going through the process of fermenting solid organic matter, the above four problems can be solved.

① The organic acid-fermented decomposable organic matter enters the methane fermentation stage, and the fermentation broth is withdrawn and washed and dissolved in the influent sewage prior to being consumed as methane gas. It can be used for denitrification and dephosphorization reaction. Precipitated solids from which dissolved organic matter has been washed are recovered as precipitates from the first settler and fermented in fermenters. Therefore, no special effort is required to maintain optimum fermentation conditions, and the capacity of fermenters is reduced and economical. It is also possible to prevent waste from being decomposed.

② Because it is slow decomposition, solid organic matter which was not used for denitrification reaction and acted as organic load in the subsequent aerobic reaction tank can be dissolved and dissolved in influent sewage. However, the washed sedimentary solids are precipitated and recovered from the first settler, put into and fermented into the fermenter, and then put into the first settler. Only dissolved organic matter is dissolved, and the precipitated solids are recovered and fermented. Therefore, the side-degradable solid organic matters cannot be introduced into the reaction tank, so the side effects of increasing organic load and decreasing nitrification efficiency in the aerobic reaction tank can be eliminated.

③ If fermentation broth is added directly to the denitrification or phosphorus discharge tank, inorganic solids that cannot be converted into active substances and cannot be decomposed, such as nito and sesa contained in organic waste such as fresh sludge and food waste, are precipitated in the second settler Accumulation is continued while circulating the inside of the system through the conveying sludge. As a result, a portion of the suspended solids (MLSS) in the reactor is occupied by an inactive inorganic material, thereby reducing the proportion of active microorganisms in the suspended solids. In the present invention, since the fermentation broth is washed using the first settler and the inorganic solids are precipitated and collected and disposed of periodically, the concentration of active microorganisms in the reactor can be maintained high.

④ Nearly all sewage treatment plants are equipped with a first settler, and in the present invention, since the fermentation broth can be separated into influent sewage using the existing first settler, such as a dehydrator and a sedimentation basin to separate the fermentation broth separately. There is no need to install a solid-liquid separation facility. Therefore, the facility cost is reduced, the treatment facility is simple, the fermentation broth is diluted in a large amount of sewage, so less odor is generated and the solid-liquid separation efficiency can be improved.

As described above, the present invention can be applied to the intermittent air treatment process of the intermittent air stream or the side stream series, and one or more anaerobic reaction tanks in which denitrification of nitrogen oxides are performed, and one or more aerobic reaction tanks in which aerobic decomposition of organic matters and nitrification of organic nitrogen and ammonia nitrogen are performed. It is composed of a second settler that separates solids and supernatant from the final reaction solution, and sludge transport and internal circulation are performed, and in addition to denitrification, an anaerobic reactor induces phosphorus release from microorganisms to increase phosphorus removal efficiency. It is easy to improve the efficiency of the advanced treatment process of the total denitrification system, which is also added.

1 is a schematic process diagram of a first embodiment according to the present invention;

2 is a schematic process diagram of a second embodiment according to the present invention;

3 is a schematic process diagram of a third embodiment according to the present invention;

4 is a schematic process diagram of a fourth embodiment according to the present invention;

5 is a cross-sectional view of a first settler in a fourth embodiment according to the present invention;

6a and 6b is the first settler and the fermenter according to the present invention is composed of the same structure

A plan cross section of an embodiment,

7 is a schematic process diagram of the advanced processing processes to which the present invention is applicable.

※ Explanation of code for main part of drawing

1, 1a: first settler 2: anaerobic reactor

3: anoxic reaction tank 4: aerobic reaction tank

5: secondary precipitate 6, 6a: fermentation tank

7: sludge denitrification tank 8: washing process

9: solid-liquid separation process 11: symbolic water

12: return sludge 13: internal circulation water

14 precipitate precipitate solid 15 fermentation broth

21, 21a: circulation pump 22, 22a: sludge collector

23, 23a, 23b: stirrer or stirring means 24, 24a: sludge collector drive unit

25: sludge collection unit

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a process diagram of a first embodiment showing a high-treatment method of increasing the decomposable inflow organic matter concentration in order to improve the nutrient removal efficiency according to the present invention.

In this embodiment, the anoxic reaction tank 3 in which denitrification of nitrogen oxides is carried out, the aerobic decomposition tank in which organic matters are decomposed, and the aerobic reaction tank 4 in which nitrification of organic nitrogen and ammonia nitrogen are carried out, and the solids and the symbolic water are separated from the final reaction solution. The first settler (1) is composed of a second settler (5), and the first settler (1) for sedimentation and separation of the solids contained in the influent sewage at the first stage of the advanced treatment process in which the sludge conveying (12) from the second settler to the oxygen-free reaction tank is made. And a fermentation tank 6 for fermenting sediment solids 14 such as fresh sludge composed mainly of organic solids precipitated and separated from the first settler, wherein the organic sludge is produced by fermentation and disintegration of fresh sludge in the fermentation tank. Fermentation broth (15) consisting of a mixture of liquid organic matter, inorganic solids such as fine earth and unfermented organic solids It is incorporated into the influent sewage to circulate into the first settler.

In addition to the dissolved organic matter contained in the influent sewage, the organic acid contained in the fermentation broth and the liquid organic matter attached to the solids are dissolved in the influent sewage to increase the low molecular weight organic matter available for the denitrification reaction. Since the symbol water 11 of the sedimentation basin is introduced into the advanced treatment process, the nitrogen removal efficiency is improved. The non-fermented solids in the fermentation broth and the solids introduced further through the fresh sludge in the inflow sewage are precipitated in the first settler, so that the process of recovering them and fermenting them in the fermentation tank is repeated. It also includes a series of processes in which the fermentation broth or a portion of the precipitated solids are periodically discarded.

The fermentation tank can replenish organic matter by adding organic waste such as food waste, livestock manure and collected manure, such as residue, and can be utilized by converting existing gravity type sludge concentration tank or sludge digestion tank installed in the sewage treatment plant into a fermentation tank. In addition, it is possible to increase the nitrogen removal efficiency by adding an internal circulation 13 for flowing back the reaction solution of the aerobic reaction tank to the anoxic reaction tank.

Figure 2 is a process diagram of a second embodiment showing a high-treatment method for increasing the degradable inflow organic matter concentration in order to improve the nutrient removal efficiency according to the present invention. In this embodiment, an anaerobic reactor (2), an anoxic reactor (3), an aerobic reactor (4), and a second settler (5), and sludge conveying (12) from the second settler to the anaerobic reactor (2) In this process, the first settling cell 1 and the fermentation tank 6 are further provided in the process in which the internal circulation water 13 flows into the anoxic reaction tank from the aerobic reaction tank, and food waste, collected manure, livestock manure, and industrial plant. By introducing and diluting the organic by-products or other organic wastes generated in the influent into the first sedimentation, dissolved organic matter contained in the influent sewage and the organic wastes is the symbolic water of the first sedimentation (11) Sedimentation solids consisting of fresh sludge in the influent sewage and solids contained in organic wastes, which are used for phosphorus release and denitrification in the advanced treatment process through The fermentation broth (14) is fermented in the fermentation tank (6), and the fermentation broth (15), which is a mixture of organic acids, liquid organics, inorganic solids such as microsoil, and unfermented organic solids produced in the fermentation tank (6), is incorporated into the inflow sewage. It is the structure that circulates to a sedimentation basin.

In addition to the dissolved organic matter contained in the organic waste introduced into the influent sewage, the organic acid contained in the fermentation broth and the liquid organic matter attached to the solid are dissolved in the influent sewage, and the advanced treatment is performed through the symbol water of the first settler. It is introduced into the process and used to remove nitrogen and phosphorus. In addition, since the non-fermented solids in the fermentation broth and the solid introduced further through the fresh sludge and organic waste in the inflow sewage are precipitated in the first settler, the process of recovering the precipitated solids 14 and introducing them into the fermenter is repeated. In the high-treatment process, it is possible to increase the concentration by selecting only mainly dissolvable dissolved organic substances which are readily available to microorganisms.

Before the organic waste is introduced into the inflow sewage, it is preferable to pass through a crushing means such as a crusher [not shown] or a debris removing means such as a screen [not shown] so as to remove crushed or contaminants. The input is advantageous because it can be omitted in the previous step of the screening process to remove contaminants in the influent sewage.

Wherein the fermentation broth 15 is introduced into the inflow sewage is to be disposed in the sedimentation basin installed in the sewage treatment plant, the inflow pump well or the distribution tank of the first sedimentation cell by the vortex formed during the pumping and distribution process to wash the solids and dissolved organic matter It is preferable because it dissolves well.

The waste sludge which is periodically discarded in the fermentation tank 6 is washed and dissolved with sewage or treated water by the washing process 8 to discard the solids separated in the solid-liquid separation process 9 and the filtrate is removed together with the inflow sewage. It is easy to dispose of waste sludge and to make maximum use of dissolved organic matter.

FIG. 3 is a process in which a sludge denitrification tank 7 is additionally formed in the conveying sludge 12 in the advanced treatment process of FIG. 2, wherein a part of the first settling symbol water 11 or the sludge fermentation liquid 15 is added to the sludge denitrification tank. Injecting a portion is an embodiment for the denitrification reaction of the nitrogen oxide contained in the conveying sludge. This embodiment can be applied to side stream series denitrification and dephosphorization processes such as Phostrip and Modified Phostrip Process.

FIG. 4 illustrates that the organic solid precipitated in the first settler 1 is eluted in a water body in which an organic acid is fermented at the bottom of the first settler and liquid organic matter passes through the first settler. By increasing the solids residence time in the first settler so as to flow through the) is an embodiment to omit the installation of the fermenter.

Here, the fermentation broth 15 of the lower part of the first settler is taken out and introduced into the upper part of the first settler together with the inflow sewage, and the unfermented organic solid is washed and precipitated to resume fermentation under the first settler. Liquid organic matter is dissolved in the influent sewage and dissolved organic matter in the fermentation sludge by the vortex formed in the process of circulating the fermentation broth of the lower part of the first settle to the upper portion of the first settle so as to flow through the supernatant (11) This can be easily dissolved in the symbol water of the first settler.

5 shows a cross-sectional view of the first settler 1 constituting the process of FIG. 4 in which fermentation and solid-liquid separation proceed simultaneously, so that a separate fermentation tank can be omitted. In the lower part of the sedimentation basin, when the solid matter is fermented and converted into a liquid phase, it diffuses into the upper body and flows out through the supernatant water. The stirring means 23a such as an impeller is moved inside the sludge collector 22 by the driving part 24 of the sludge collector 22. The solids of can be stirred. In addition, the capacity of the sludge collection unit 25 may be increased to increase the fermentation space.

The sludge collector 22 may protrude a plurality of stirring means 23b, such as a screw or a blade, on the upper part of the sludge collector 22 so that the sludge collector may be stirred as the sludge collector rotates, and the fermentation broth (a) may be formed by the circulation pump 21. 15) may be taken out and circulated to allow the liquid fermentation broth to dissolve well.

6 is a fermenter installed in the lower part of the first settler so that the organic precipitated solid 14a precipitated in the first settler 1a can naturally fall into the fermenter 6b by gravity. It relates to an embodiment provided with a stirrer (23).

The stirrer may be directly connected to the driving unit for driving the sludge collector 22a installed in the first settler battery, so that the stirrer reciprocates inside the fermentation tank along the sludge collector, so that the presence of the fermentation tank may be smoothly mixed with a few stirrers.

Figure 7 illustrates a high-treatment process to which the present invention can be applied, but is not limited to the denitrification or phosphorus-release reaction by the influent organic matter regardless of the high-treatment process or internal circulation of all the total denitrification series including their modifications. Mainly influent sewage such as intermittent aeration process, Orbal process, flow-change intermittent aeration process (Bio-DeNitro) and step feeding process, and Bio-DeNiPho process where anaerobic dephosphorization reactor is added to Bio-Denitro process The present invention can also be effectively applied to all advanced treatment processes for removing nitrogen and phosphorus by organic matter contained therein.

As described above, the fermentation broth produced by fermenting organic wastes such as fresh sludge and residues is mixed with influent sewage to separate the solids, and the solids are recovered to repeat the process of fermentation and mixing with the influent sewage to denitrification and dephosphorization reaction. The following effects can be achieved by applying the advanced treatment method to select available dissolved degradable organic matter and increase its concentration.

① It can increase the removal efficiency of nitrogen and phosphorus in all the denitrification type advanced processing processes.

② It can be easily applied to the treatment plant in operation to improve the treatment efficiency.

③ It can contribute to disposal of organic waste such as fresh sludge and residue.

④ Since the sludge which is difficult to handle and manage is not generated, some of them are converted to surplus activated sludge, and the biological removal efficiency is high.

⑤ It can prevent the cleaning of activated sludge and maintain high activity even in low concentration sewage with insufficient inflow organic matter.

Claims (15)

An aerobic reaction tank (3) for denitrification of nitrogen oxides, an aerobic reactor (4) for aerobic decomposition and nitrification of organic matter, a second settler (5) for solid-liquid separation of the final reaction solution, and a sludge conveyance (12) In the treatment step, a fermentation tank (6) for fermenting fresh sludge, which is a first settler (1) in which sedimentation and separation of solids contained in the influent sewage is performed, and a settling solid (14) sedimented and separated from the first settler, with an organic acid In addition, the fermentation broth 15, which is a mixture of organic acid, liquid organic matter, and inorganic solids such as fine earth and unfermented organic solids produced by fermenting the fresh sludge, is introduced into the inflow sewage to separate solid-liquid separation from the first settler. Made, the first sludge collected in the fermentation broth and the solid sludge introduced further through the inflow sewage to recover the precipitated solids, The solids are introduced into the fermentation tank and fermented, and the fermentation broth is circulated to the first settler so as to be added to the dissolved organic matters contained in the influent sewage and attached to the organic acids and liquid organics and the solids contained in the fermentation broth. It is possible to use the denitrification and dephosphorization reaction which improves the nitrogen / phosphorus removal efficiency by allowing the symbolic water 11 of the first settler, in which the liquid organic substances are dissolved and the concentration thereof, is introduced into the advanced treatment process. Advanced treatment method to increase the concentration of degradable organic matter. The method according to claim 1, wherein the circulation of the internal circulating water (13) for introducing the reaction liquid of the aerobic reaction tank (4) back into the anoxic reaction tank (3) is performed. Advanced treatment method to increase the concentration of degradable organic matter. The anaerobic reaction tank (2), the anaerobic reaction tank (3) and the aerobic reaction tank according to claim 1, wherein the advanced treatment step includes an anaerobic reaction tank (2) in which a phosphorus-release reaction is performed in the previous stage of the anoxic reaction tank (3). ), The second settler (5), the sludge conveying (12) is made from the second settler to the anaerobic reactor (2), the internal circulation water (13) from the aerobic reactor is introduced into the anoxic reactor An advanced treatment method for increasing the concentration of degradable organic substances available for denitrification and dephosphorization reactions. The method of claim 1, wherein the advanced treatment process is composed of one or more reaction tanks and a second settling battery, characterized in that the repeated intermittent aeration process of aeration and non-aeration stirring, the combination process of the flow path change and intermittent aeration method, or variations thereof. An advanced treatment method for increasing the decomposable organic substance concentration available for denitrification and dephosphorization reaction. The process of claim 1, wherein the advanced treatment process is a side stream-based advanced treatment process in which the return sludge is subjected to an anaerobic reaction tank or an anaerobic reaction tank as in the Phostrip Process or a variant thereof. Or a portion of the sludge fermentation liquor (15) is injected into the anoxic reactor or an anaerobic reactor to increase the concentration of degradable organic matter available for denitrification and dephosphorization. The method of claim 1, wherein food waste, collected manure, livestock manure, organic by-products or other organic waste generated in an industrial plant are introduced into the inflow sewage to be introduced into the first settler 1, and the first settler Precipitated solids (14) consisting of fresh sludge in the influent sewage separated from the sewage and organic waste contained in organic wastes are fermented in the fermentation tank (6), organic acids, liquid organic matter, and inorganic solids such as fine soil The fermentation broth 15, which is a mixture of unfermented organic solids, is mixed into the influent sewage to separate the solids from the first settler. The organic solids are recovered from the first settler as precipitate solids (14), flowed into the fermenter, and fermented. By repeating the circulating process to the first settler, in addition to the dissolved organic matter contained in the influent sewage and the injected organic waste, the organic acids contained in the fermentation broth, the liquid organic matter and the liquid organic matter attached to the solid are dissolved and the concentration is Advanced treatment method for increasing the decomposable organic substance concentration available for denitrification and dephosphorization reaction by improving the nitrogen and phosphorus removal efficiency by allowing the increased symbol water (1) of the first settler to flow into the advanced treatment process. . According to claim 1, wherein the fermentation tank (6) is decomposable for denitrification, dephosphorization, characterized in that the addition of food waste, waste manure, livestock manure, organic by-products or other organic waste generated in industrial plants. Advanced treatment method to increase organic matter concentration. 2. The method of claim 1, wherein the fermentation broth 15 is introduced into the influent sewage through a settling basin, an inlet pump well or a distribution tank of the first settler. Treatment method. The method of claim 1, wherein the installation of the fermentation tank (6) is omitted, the organic solid precipitated by increasing the solids residence time of the first settler (1) is an organic acid fermentation at the bottom of the first settler, the solid is fermented And the eluted liquid organic material is introduced into the advanced treatment process through the symbol water (11) of the first settler. The advanced treatment method of increasing the decomposable organic substance concentration available for denitrification and dephosphorization reaction. The method of claim 1, wherein the solid 14a precipitated in the first settler (1a) is characterized in that the fermentation tank is installed in the lower part of the first settler so that the fermentation can fall naturally into the fermentation tank (6b) by gravity. An advanced treatment method for increasing the decomposable organic substance concentration available for denitrification and dephosphorization reaction. According to claim 1, wherein the sedimented solid (14) or fermentation broth (15) is periodically disposed, the waste sludge disposed in the fermentation tank (6) sewage or treatment by the washing step (8) and solid-liquid separation step (9) Solids are discarded by washing with water and separated into solids, and the filtrate is introduced into the advanced treatment step. The method according to claim 1, wherein the fermentation tank (6) uses an existing gravity sludge concentration tank or a sludge digestion tank installed in a sewage treatment plant. 4. The conveying sludge (12) according to claim 3, wherein the conveying sludge (12) is configured to pass through a sludge denitrification tank (7), and a portion of the symbol water (11) of the first settler (1) or a part of the fermentation broth (15) is sludged. An advanced treatment method for increasing the concentration of decomposable organic substances available for denitrification and dephosphorization reactions, which is injected into a denitrification tank. 10. The decomposability of claim 9, wherein the fermentation broth 15 under the first settler 1 is circulated into the first settler using a circulation pump 21. Advanced treatment method to increase organic matter concentration. According to claim 9, Stirring means (23a, 23b) for agitating the sludge layer and the sludge collector 25 is a fermentation proceeds in the lower part of the first settled battery (1) is connected to the sludge collector 22, the sludge collection mechanism driving unit (24) An advanced treatment method for increasing the decomposable organic matter concentration which can be used for denitrification and dephosphorization reaction, which is driven by (24).