KR200303436Y1 - Manufacturing equipment of acid fermentation for biological denitrification using food waste and sewage sludge - Google Patents

Abstract

The present invention relates to an apparatus for producing an acid fermentation solution for biological denitrification by acid fermentation of food waste and sewage sludge, and more specifically, after hydrolyzing by adding an alkaline agent to the food waste slurry and sewage sludge separated by pretreatment, Acid fermentation using an upflow sludge blanket filter fermenter and then biological denitrification using food waste and sewage sludge to convert undissolved substances into easily dissolved dissolved substances and molecular structure by radiating ultrasonic waves to decomposed acid fermentation liquors. An apparatus for producing an acid fermentation liquid.

The present invention is an acid fermentation liquor manufacturing apparatus for use as a carbon source for biological denitrification using food waste and sewage sludge, food waste to be hydrolyzed by administering an alkaline agent to the food waste slurry and sewage sludge from which contaminants and foreign substances are removed An inlet tube into which the sludge and sewage sludge flows into the tank, an additive injecting tube for injecting additives such as an alkaline agent, an agitator for mixing the introduced food waste slurry and the sewage sludge with the alkaline agent, and a hydrolyzed slurry A hydrolysis tank composed of a slurry transfer pipe in communication with each other so as to be discharged; Slurry transfer tube and the high density sludge layer are installed so as to be in communication so that the hydrolyzed slurry can be introduced into the lower density of the sludge layer to acidify the slurry introduced from the hydrolysis tank using the microorganism, A stirring device, a medium layer formed on top of the dense sludge layer and formed of media of different sizes and shapes, and an acid fermentation liquor conveying pipe installed to communicate with the supernatant discharged through the medium layer. Characterized in that it comprises an upstream sludge blanket filter bed fermenter.

Description

Manufacturing equipment of acid fermentation for biological denitrification using food waste and sewage sludge}

The present invention relates to an apparatus for producing an acid fermentation solution for biological denitrification by acid fermentation of food waste and sewage sludge, and more specifically, after hydrolyzing by adding an alkaline agent to the food waste slurry and sewage sludge separated by pretreatment, Acid fermentation using an upflow sludge blanket filter fermenter and then biological denitrification using food waste and sewage sludge to convert undissolved substances into easily dissolved dissolved substances and molecular structure by radiating ultrasonic waves to decomposed acid fermentation liquors. An apparatus for producing an acid fermentation liquid.

In general, since food waste generated in homes or large restaurants is composed of organic substances with high moisture content, it is used in livestock feed or compost by processing in food waste recycling processes composed of processes such as crushing, sorting, separating, fermentation or dehydration. . As such, the recycling of food waste into livestock feed or compost prevents secondary environmental pollution caused by odors and leachate generated during landfill, thereby increasing the recycling rate of food waste.

However, when looking at the problems of these existing treatment methods, it is difficult to maintain the homogeneous quality due to the change of the characteristics of the waste in the facility, due to the incorporation of foreign matters in the feed. In addition, there is a problem that the production price of the feed is low due to the concern of the occurrence of livestock diseases when the nutrition material is insufficient compared to the grain feed and the sterilization treatment, stable production and supply is difficult due to the unstable supply system.

In the case of composting, it takes a lot of facility site as it goes through long-term aging process, and it is difficult to remove bad smell, which makes it difficult to secure the facility site, and there are many excipients (sawdust, rice bran, etc.) for removing water and salt. It is a cause which raises compost manufacturing cost. In addition, it is difficult to maintain homogeneous quality due to the change in the characteristics of seasonal wastes, and the demand is limited, which makes it difficult to supply and sell stably, and there is a tendency to avoid the use of farms due to fears of inhibiting the growth of crops.

On the other hand, sewage sludge is a by-product that is inevitably generated in the process of separating and removing contaminants in the sewage as solids in the sewage treatment plant.

The most basic unit process of a sludge treatment system consists of concentration, digestion, dehydration, drying, incineration and disposal. However, the final disposal of sludge cakes has been mainly dependent on landfilling after dehydration, but recently sludges cannot be landfilled, and only residues from incineration or composting are to be landfilled. There is an active research on re-use plans. However, the case of incineration has been pointed out that the economic burden of secondary pollution sources such as air pollution, and facility and maintenance costs is great. In addition, sludge reuse, green soil use, and external carbon source of sewage treatment plant are sporadically used as sludge reuse methods.However, composting methods are not properly made due to limitation of fertilization site, lack of economic feasibility, and lack of legal system maintenance. I'm not doing it.

In view of these problems, studies have recently been conducted on the use of acid fermentation liquors fermented with food waste and sewage sludge as an external carbon source for biological nutrient removal processes. However, direct acid fermentation of food waste and sewage sludge results in low yield of volatic acid, the final product of acid fermentation, due to low solubilization of organic solid components present in food waste and sewage sludge itself. Appropriate pretreatment is necessary. As such pretreatment, heat treatment, heat-alkali treatment, alkali treatment, and the like can be cited. Until now, it has been mainly applied to increase the biodegradability of waste sludge. However, these methods consume a lot of energy due to heat treatment, and the chemical cost is excessively consumed, which causes problems in practicality.

Therefore, the main object of the present invention is to improve the solubilization of organic solids by administering an alkaline agent to a hydrolysis tank in the preparation of acid fermentation for biological denitrification using food waste and sewage sludge, and to increase the solubility of organic solids in the upflow sludge blanket bed fermenter. It is to provide an acid fermentation broth production apparatus that can improve the acid fermentation efficiency using a biofilm formed on the upper surface of the medium.

Another object of the present invention is not only to change the undissolved substances into dissolved substances and molecular structures which are easy to decompose by emitting ultrasonic waves to the produced acid fermentation liquor, but also the solid-liquid separated solids are returned to the hydrolysis tank and the supernatant is biodegraded and nitrogen. It is to provide an apparatus for producing an acid fermentation liquid that is excellent in removal.

1 is a schematic device diagram showing an example of an apparatus for producing a biological acid fermentation solution using food waste and sewage sludge according to the present invention.

Figure 2 is a schematic diagram showing another embodiment of the biological acid fermentation broth production apparatus using food waste and sewage sludge according to the present invention.

Figure 3 is a schematic process diagram showing a process for producing a biological acid fermentation using food waste and sewage sludge according to the present invention.

*** Explanation of symbols for main parts of drawing ***

10: hydrolysis tank

11: Food waste and sewage sludge inflow pipe

12: slurry transfer pipe

13: additive injection tube

14 gas discharge pipe

15: fine contaminant extraction pipe

16: stirring device

17: pH and ORP meta

18: Scum skimmer

20: acid fermentation tank (upflow sludge blanket filter bed fermentation tank)

30: ultrasonic decomposition and solid-liquid separation tank

33. Return pipe

34. Separator

35. Ultrasonic transducer (or vibrating element)

In order to solve the problems of the prior art described above, in the acid fermentation liquid production apparatus for using as a carbon source for biological denitrification using food waste and sewage sludge according to the present invention, food waste slurry and sewage sludge from which impurities and foreign substances are removed An inlet tube for introducing food waste slurry and sewage sludge into the lower part of the reaction tank so that the hydrolyzate can be hydrolyzed by adding an alkali agent, an additive inlet tube for injecting additives such as an alkali agent, and an alkali agent to the introduced food waste slurry and sewage sludge A hydrolysis tank provided with a stirring device for stirring to be mixed and a slurry transfer pipe for discharging the hydrolyzed slurry; The slurry transfer pipe and the high density sludge layer are installed to stir the hydrolyzed slurry into the high density sludge layer under the reactor so that the slurry discharged from the hydrolysis tank can be acid fermented using microorganisms. An acid fermentation liquor conveying pipe which is formed on top of the agitation device, the dense sludge layer and is in communication with each other so as to discharge the supernatant discharged through the medium layer, and at least two or more layers of media of different size and shape. Characterized in that it comprises an upstream sludge blanket filter bed fermenter consisting of.

The present invention also comprises a reaction tank consisting of a predetermined outer wall to radiate ultrasonic acid into an acid fermentation broth passed through the upflow sludge blanket filter fermentation tank, so that the undecomposed substance can be changed into an easily dissolved dissolved substance and a molecular structure. A separation plate installed inside, a plurality of ultrasonic transducers (or vibrators) installed in a zigzag manner on the outer wall and the separation plate, an acid fermentation liquid feed pipe installed in communication so that acid fermentation liquid flows between the separation plate, and installed in the lower part of the reaction tank. It characterized in that it comprises a sonication and solid-liquid separation tank consisting of a conveying tube to return a portion of the precipitate to the above-described hydrolysis tank.

And the upper part of the hydrolysis tank, upflow sludge blanket filter fermentation tank, ultrasonic decomposition and solid-liquid separation tank is provided with a gas discharge pipe and scum skimmer to remove the generated gas and scum, and a fine contaminant withdrawal tube for removing the fine contaminants at the bottom One side of the reaction tank is installed, characterized in that the pH and ORP meta is installed to check the appropriate operating conditions.

With reference to the accompanying drawings will be described in detail the manufacturing apparatus of the acid fermentation using food waste and sewage sludge according to the present invention.

First, Figure 1 is a schematic device diagram showing an example of an acid fermentation acid production apparatus for biological denitrification using the food waste and sewage sludge according to the present invention (hereinafter abbreviated as "acid fermentation liquid production apparatus"), as shown, The acid fermentation liquor manufacturing apparatus is composed of a hydrolysis tank 10 and an upflow sludge blanket filter fermentation tank 20. An inlet pipe 11 through which food waste slurry and sewage sludge flows into the lower portion of the hydrolysis tank 10, and an additive injection pipe 13 that injects an alkali agent or an additive into the food waste slurry and sewage sludge introduced into the reactor. The fine contaminant withdrawal tube 15 for removing the fine contaminants is installed. In the center of the reaction tank, a stirring device 16 for mixing food waste slurry and sewage sludge with an alkaline agent is provided.

Subsequently, a gas discharge pipe 14 and a scum skimmer 18 are installed at the upper portion of the hydrolysis tank 10 to remove gas and scum generated in the hydrolysis process, and at one side, a slurry for discharging the hydrolyzed slurry. The feed pipe 12 is provided in communication. And the hydrolysis tank 10 is provided with a pH and ORP meta (17) to check the appropriate operating conditions.

And the hydrolysis slurry discharged from the hydrolysis tank 10 is introduced into the upflow sludge blanket filter fermentation tank 20 is acid fermented. A high density sludge layer (S) is formed at the bottom of the upstream sludge blanket filter fermentation tank (20) so that the slurry pretreated in the hydrolysis tank (10) of the high density sludge layer (S) through the slurry feed pipe (12). Flows into the bottom. And the high density sludge layer (S) is provided with a stirring device 16 to promote the decomposition reaction, one side is formed with a fine contaminant take-out tube 15 for removing the fine contaminants.

In addition, at least two or more media layers 26 including media M1 and M2 having different sizes and shapes are formed on the high density sludge layer S. FIG. Therefore, the slurry decomposed by the microorganisms of the high density sludge layer S passes upward and passes through the microbial membrane formed in the media layer 26. In addition, a gas discharge pipe 14 and a scum skimmer 18 are installed at an upper portion of the upflow sludge blanket filter fermentation tank 20 to remove gas and scum generated from a scattering effect well, and the high density sludge layer S is provided. PH and ORP meta 17 are installed to check proper operating conditions.

Therefore, the acid fermentation liquor manufacturing apparatus according to the present invention is decomposed first by the microorganisms of the high-density sludge layer (S), and then decomposed secondly while passing through the microbial membrane of the media layer 26, as well as the media layers having different sizes and shapes. It is discharged through to prevent clogging and drift.

Next, Figure 2 is a schematic device diagram showing another embodiment of the acid fermentation acid production apparatus for biological denitrification using the food waste and sewage sludge (hereinafter abbreviated as "acid fermentation liquid production apparatus") according to the present invention, As such, an ultrasonic decomposition and a solid-liquid separation tank 30 are further installed at the rear end of the upstream sludge blanket filter bed fermentation tank 20 of the above-described embodiment to ultrasonically decompose the undecomposed material contained in the acid fermentation broth.

The ultrasonic decomposition and solid-liquid separation tank 30 is a reaction tank composed of a predetermined outer wall 36, a separator plate 34 provided inside the reaction tank, and the separation plate 34 and / or the outer wall 36 are zigzag. It consists of a plurality of ultrasonic transducers 35 installed in such a manner. In addition, the acid fermentation broth transfer pipe 22 is installed in communication with the acid fermentation liquid to be introduced between the separation plate 34, the stirring means 16 is provided between the separation plate 34.

Subsequently, the precipitate in the ultrasonically decomposed acid fermentation solution sinks to the bottom, and some of the precipitate is returned to the above-described hydrolysis tank 10 through the conveying pipe 33, and the supernatant liquid is discharged through the outlet pipe 32 installed in the upper portion. . In addition, a gas discharge tube 14 and a scum skimmer 18 are installed at an upper portion of the ultrasonic decomposition and solid-liquid separation tank 30 to remove gas and scum generated in the ultrasonic decomposition and solid-liquid separation process, and remove fine particles from the lower portion. The drawing pipe 15 for this purpose is provided.

Hereinafter, an acid fermentation solution providing well according to the present invention will be described with reference to the schematic process diagram of FIG. 3.

<Step 1: Hydrolysis Process>

First, the food waste is introduced into the hydrolysis tank 10 in which the slurry and sewage sludge diluted to 1.5 to 3 times the amount of the incoming materials in the separation and pretreatment process of the contaminants and foreign substances in the primary crushing and screening separation process. Food waste slurry and sewage sludge are introduced into the tank through the inlet pipe 11, and the alkali agent (caustic soda, potassium hydroxide, lime based NaOH standard 0.025 to 0.15 g NaOH / gTS) is administered through the additive injection pipe 13 into the tank. . Subsequently, the temperature in the tank is maintained at 35 to 37 ° C. to solubilize for about 6 to 24 hours, or the hydrolysis enzyme is added through the additive injection tube 13 and treated, followed by an upward flow through the upper slurry transfer tube 12. The sludge blanket is passed to the filter bed fermenter 20.

<Step 2: Acid Fermentation Process>

The slurry pretreated in the hydrolysis bath 10 is then introduced into the bottom of the upflow sludge blanket filter bed fermenter 20 in which media of different sizes and shapes are filled at least about 30% of the volume of the bath. The slurry introduced into the high-density slurry layer (S) through the slurry transfer pipe 12 undergoes an acid fermentation process at about 35 to 37 ° C. for about 1-3 days, and then passes through a biofilm formed in the media layer 26. It is transferred to the ultrasonic decomposition and solid-liquid separator 30 through the acid fermentation broth transfer pipe 22 of the upper portion. In this case, since the media layers M1 and M2 formed of media having different sizes and shapes are provided in at least two stages, the media layer 26 prevents clogging and drift.

<Step 3: Ultrasonic Decomposition Process>

The acid fermentation liquid decomposed in the upstream sludge blanket filter fermentation tank 20 is introduced into the ultrasonic decomposition and solid-liquid separator 30. The acid fermentation solution introduced between the separation plate 34 made of stainless steel through the acid fermentation liquid conveying pipe 22 is a continuous wave or multi-wave radiated from the ultrasonic transducer (or vibrator) 35 zigzag installed on the separation plate 34. The pulsed ultrasound changes the molecular structure of the undecomposed material (eg, from polymer to monomolecular structure), making it easy to dissolve into dissolved materials. And the supernatant of the ultrasonically decomposed acid fermentation liquid is discharged to the outlet pipe 32 of the upper portion, some of the precipitate is returned to the hydrolysis tank 10 through the conveying pipe 33 to about 50-100%. At this time, the supernatant of the acid fermentation liquid is decomposed once more by the ultrasonic wave radiated from the ultrasonic transducer 35 installed on the outer wall 36 to increase the decomposition efficiency. And the gas and scum generated in the ultrasonic decomposition and sedimentation separation process is removed through the gas discharge pipe 14 and the scum skimmer 18, fine contaminants are removed through the withdrawal pipe (15).

Hereinafter will be described a specific embodiment of the acid fermentation broth production apparatus according to the present invention.

Example 1 Hydrolysis and Acid Fermentation

The average concentrations of the slurry of pretreated food waste were TCOD 206,900 mg / l, SCOD 82,800 mg / l, TS 158,300 mg / l, VS 131,300 mg / l, Cl ^- 3,500 mg / l, and SCOD / TCOD, VS / TS The ratios were 0.4 and 0.83, respectively. Samples were prepared by diluting twice with deionized water based on TS concentration.

And the average concentration of primary sludge in sewage treatment plant was TCOD 25,550mg / l, SCOD 2,178mg / l, TS 23,752mg / l, VS 16,556mg / l, Cl ^- 317mg / l, and SCOD / TCOD, VS / The TS ratio was prepared as 7: 3 and 3: 7 based on the volume ratio of primary sludge and drinking water waste of 0.09 and 0.70, respectively.

The above-mentioned effective volumes of the hydrolysis tank 10 and the acid fermentation tank 20 were 5 L and 10 L, respectively, and the tank temperature was 35-37 ° C., the stirring strength was 150 rpm, and the amount of alkaline agents injected with food waste and sewage sludge 0.075 and 0.025 g NaOH / The gTS and the medium (Φ15mm Pall ring) were filled with 30% of the volume of the acid fermentation tank, and the results of the acid fermentation of food waste and sewage sludge mixtures were shown in <Table 1>.

<Table 1> Characteristics of Food Waste and Acid Fermentation Sewage Sludge

Item Food waste Mixed food waste and sewage sludge Exclusive 7: 3 3: 7 Residence time (day) 0 2 0 2 0 2 pH 4.2 6.0 4.2 6.2 4.8 6.3 TCOD (mg / ℓ) 103,450 75,640 78,520 72,513 55,063 52,017 SCOD (mg / ℓ) 41,400 53,350 38,807 42,643 17,733 21,173 SCOD / TCOD (%) 40 70 50 59 32 41 Ps (%) * - 64 - 25 - 17 TS (mg / l) 79,150 40,290 54,083 40,000 36,923 30,453 % Decrease in TS ** - 49 - 26 - 18 TSS (mg / l) 40,980 21,150 29,220 22,200 26,060 21,700 TSS Reduction (%) ** - 48 - 24 - 17 VFAs (mg / l) 8,450 19,070 5,567 7,583 2,846 5,104 % VFAs Generated *** - 126 - 37 - 80

Note) * Ps (%) = (initial IDCO-t hours after OICOD) / initial OICO × 100

** TS (TSS) Reduction Rate (%) = (Initial TS (TSS) -t After Time TS (TSS)) / Initial TS (TSS) × 100

***% of VFAs generated (%) = tFAs after tFA- initial VFAs) / initial VFAs × 100

As shown in <Table 1>, food waste alone, food waste and sewage sludge mixtures were 70%, 59%, and 41% at 7: 3 and 3: 7, respectively, and the solubilization effect of granular COD was shown in Table 1. In 64%, 25% and 17% of cases, food waste alone was the highest. TS (TSS) reduction rates were 49 (48)%, 26 (24)% and 18 (17)%, respectively, and the VFA _S concentrations were 19,070 mg / l, 7,583 mg / l and 5,104 mg / l, respectively. VFA _S production rate was 126%, 37%, 80%, which was the highest in food waste alone.

Example 2 Ultrasonic Decomposition of Primary Sludge

After injection of 0.05 gNaOH / gTS into the primary sludge of the sewage treatment plant, the initial TCOD was 22,700 mg / l, 20,850 mg / l, and the SCOD was 2,933 mg / l and 3,333 mg / l, respectively. Used. Each sample was treated at 35 kHz for 6 hours at 20 ° C. in an ultrasonic thermostat, and then analyzed for the effects of solubility and solubilization.

<Table 2> Comparison of Ultrasonic Treatment by Primary Sludge Pretreatment Method

division gNaOH / gTS Hr item 0 0.5 One 2 3 4 5 Soluble solution 0.05 SCOD / TCOD (%) 13 30 32 38 41 47 53 Ps (%) 0 19 22 28 32 39 46 Acid Fermentation Liquid 0.05 SCOD / TCOD (%) 16 36 36 36 37 37 38 Ps (%) 0 24 24 24 25 26 26

After sonication of primary sludge solubilizer and acid fermentation solution, the SCOD / TCOD change was 13-53% and 16-38%, respectively, and the change of SCOD / TCOD and solubilization effect of granular COD (Ps) Increased. However, the highest efficiency was achieved within 1hr of reaction time.

Example 3 Ultrasonication of Food Waste

The initial pH of acid-fermented food waste was 6.6, and the supernatant superseded by simple precipitation and 35 ㎑ for 60 minutes was measured for 60 minutes at 10 minutes interval for samples with TCOD and SCOD of 53,000mg / l and 39,000mg / l, respectively. The results of the analysis of the changes in SCOD / TCOD and solubilization are shown in Table 3.

As shown in Table 3, after the simple precipitation and sonication, the sedimentation height sharply decreased to about 50% after 30 minutes but slightly decreased thereafter. The change of SCOD / TCOD was about 10 times difference between simple settling and sonication, 2% and 21%, respectively. After 40 minutes of sonication, 95% high dissolved substance was obtained. In addition, the solubilization effect (Ps) of the granular COD was up to 4.4% in simple settling, but 80% in sonication, which was about 18 times higher. This is because fine particles of the particulate COD material are decomposed by ultrasonic waves, and some solids are separated into solids and settled to the bottom. Therefore, it is effective to increase the ratio of soluble substance (SCOD) when the acid fermentation product passed through the acid fermentation tank for 40 to 60 minutes by ultrasound.

<Table 3> Simple Precipitation and Ultrasonic Treatment

division Time (minutes) item 0 10 20 30 40 50 60 Simple precipitation Sedimentation height (cm) 16 15 9.5 9.0 7.8 6.9 6.8 Ultrasonic treatment 16 15 9.6 8.0 7.8 7.4 7.3 Simple precipitation SCOD / TCOD (%) 74 74 74 75 75 76 76 Ultrasonic treatment 74 79 81 84 94 95 95 Simple precipitation Ps (%) 0 0.7 1.5 1.5 3.7 3.7 4.4 Ultrasonic treatment 0 19.1 27.2 39.0 76.5 79.4 80.1 Simple precipitation TSS Reduction (%) 0 0.6 1.1 2.4 4.6 6.6 7.1 Ultrasonic treatment 0 3.6 4.1 6.1 7.6 8.6 12.6

Example 4 Biodegradation of Acid Fermentation Solution

A sample prepared by diluting the pretreated food waste slurry twice based on the TS concentration was prepared using the hydrolysis and acid fermentation apparatus mentioned in <Example 1>, and the tank temperature was 35-37 ° C., the stirring strength was 150 rpm, the food waste and sewage sludge. Acid fermentation liquor obtained under the operating conditions of 0.075 and 0.025 g NaOH / gTS and retention time of 2 days, and two kinds of food waste and acid fermentation sewage sludge samples sonicated at 35 kPa for 40 minutes were used. Based on the results of biodegradation under aerobic conditions with a water temperature of 20 ° C and an MLSS concentration of about 3000 mg / ℓ, the results of calculating the substrate removal rate constant and non-substrate consumption are shown in <Table 4>.

As shown in <Table 4>, the substrate removal rate constants for the food waste simple acid fermentation solution, the ultrasonically treated solution after acid fermentation, and the acid fermentation sewage sludge were 0.96, 0.98 and 0.91. The removal ability was excellent. On the other hand, the non-substrate consumption rate constant for each reaction time was calculated based on the non-substrate consumption rate and the relative fermentation rate of methanol, food waste and sewage sludge was 0.88∼0.94.

<Table 4> Result of Biodegradability

division gNaOH / gTS Substrate Removal Rate Constant (K, hr ^-1 ) Specific substrate consumption rate constant (a, hr ^-1 ) Methanol 0 0.45 (1.0) 0.17 (1.0) Food waste simple acid fermentation 0.075 0.43 (0.96) 0.15 (0.88) Ultrasonic Treatment after Food Waste Acid Fermentation 0.075 0.44 (0.98) 0.160.94) Sewage Sludge Fermentation Liquid 0.025 0.41 (0.91) 0.15 (0.88)

Note) C = Co-e ^-kt , U = (So-S) / tX, U = Uoe ^-at

Example 5 Denitrification of Acid Fermentation Solution

Based on the results of denitrification experiments using the same sample used in Example 4 in an anoxic tank with a water temperature of 20 ° C. and an MLSS concentration of 3000 mg / l, the nitrogen removal rate constant (k _DN ), denitrification rate, and organic material consumption rate according to denitrification were calculated. The results are shown in Table 5.

The relative nitrogen removal rate constants of the food waste simple acid fermentation solution, the ultrasonically treated one liquor after acid fermentation, and the sewage sludge acid fermentation were 0.84, 0.92 and 0.83 based on methanol, and the denitrification rate was 0.82, 0.92 and 0.64. Compared with methanol, the denitrification effect of food waste acid fermentation was excellent.

<Table 5> Denitrification and Organic Consumption Rate Calculation Results

division gNaOH / gTS Nitrogen removal rate constant (k _DN , mgNO ₃ -N / ℓ · hr) Denitrification Rate (mgNO ₃ -N / gVSS · hr) Organic material consumption rate (gSCOD / gNO ₃ -N) Methanol 0 31.3 (1.0) 12.9 (1.0) 2.8 (1.0) Simple food waste acid fermentation liquid 0.075 26.4 (0.84) 10.6 (0.82) 3.2 (1.14) Ultrasonic Treatment after Food Waste Acid Fermentation 0.075 28.80.92 11.8 (0.92) 3.1 (1.10) Sewage Sludge Fermentation Liquid 0.025 26.0 (0.83) 8.2 (0.64) 3.3 (1.18)

The inflow of sewage treatment plant is lower than planned, which leads to considerable difficulties in the maintenance of facilities due to poor loads, as well as the economic problem of supplying organic carbon sources from outside to increase the denitrification rate of anoxic tank during advanced treatment. Facing. In addition, in recent years, there is a difficulty in supplying methanol to an external carbon source to treat nitrogen compounds generated in an acid washing process in industrial wastewater due to strengthened discharge water quality standards. Therefore, the expensive methanol purchase cost has a significant burden on the operation cost of the advanced treatment process, which makes the advanced treatment of sewage and wastewater more difficult.

As a solution to this problem, by replacing food waste and sewage sludge acid fermentation with an external carbon source for biological denitrification in place of methanol in the denitrification process, not only drastically lowers the treatment cost but also the existing treatment of food waste and sewage sludge. It is expected that the problem can be solved at the same time.

In addition, the acid fermentation liquid produced in this process will be more effective in terms of environment-friendliness by reducing treatment costs and recycling waste resources by recycling to high quality carbon sources with improved biodegradability and increased soluble organic matter.

Claims (4)

In the acid fermentation liquid production apparatus for using as a carbon source for biological denitrification using food waste and sewage sludge, Food inlet sludge and sewage sludge are introduced into the tank to hydrolyze food waste slurries and sewage sludge from which debris and foreign substances are removed, and an inlet pipe for injecting additives such as alkaline agents; A hydrolysis tank composed of a stirring device for mixing the introduced food waste slurry and the sewage sludge with the alkali agent, and a slurry transfer pipe connected to discharge the hydrolyzed slurry; Slurry transfer tube and the high density sludge layer are installed so as to be in communication so that the hydrolyzed slurry can be introduced into the lower density of the sludge layer to acidify the slurry introduced from the hydrolysis tank using the microorganism, A stirring device, a medium layer formed on top of the dense sludge layer and formed of media of different sizes and shapes, and an acid fermentation liquor conveying pipe installed to communicate with the supernatant discharged through the medium layer. An apparatus for producing an acid fermentation solution for biological denitrification using food waste and sewage sludge, characterized by comprising an upflow sludge blanket filter bed fermenter. The method of claim 1, A reaction tank consisting of a predetermined outer wall so as to radiate ultrasonic acid into the acid fermentation broth passed through the upflow sludge blanket filter fermentation tank so as to change undissolved material into an easily dissolved dissolved substance and a molecular structure; Ultrasonic decomposition and solid-liquid separation tank consisting of a plate, a plurality of ultrasonic transducers (or vibrators) provided in a zigzag manner on the separation plate, and a conveying tube installed in the lower portion of the reaction tank to convey a part of the precipitate to the hydrolysis tank described above. Apparatus for producing an acid fermentation for biological denitrification using food waste and sewage sludge, characterized in that comprising. The method according to claim 1 or 2, The media layer is made of at least two or more stages of media layers of different sizes and shapes to prevent clogging, drift and mudball (mudball) formation, characterized in that the production of acid fermentation for biological denitrification using food waste and sewage sludge . The method of claim 2, The apparatus for producing an acid fermentation solution for biological denitrification using food waste and sewage sludge, wherein the plurality of ultrasonic transducers are installed in a zigzag manner on the outer wall of the reactor to increase the decomposition efficiency of undecomposed substances.