KR100735545B1 - Method for organic wastewater treatments - Google Patents

Abstract

A method for recycling and purification of high concentration organic wastewater, which can remove high concentration organic wastewater efficiently and stably on a limited area at a low cost by using a thermophilic digestion reactor, an expanded granular sludge layer, and an activated sludge process, is provided. A method for purification of high concentration organic wastewater comprises: a solid separation step(S10) of separating solids from high concentration organic wastewater by an adulteration removal equipment; a thermophilic aerobic digestion step(S20) of passing the solid-separated wastewater through a thermophilic aerobic digestion reactor to degrade organic matters and annihilate pathogenic microorganisms; a solid-liquid separation step(S30) of injecting an inorganic coagulant or/and a polymer coagulant into the thermophilic aerobic digested water and coagulating/dewatering the thermophilic aerobic digested water to separate dewatered cake and filtrate; an expanded granular sludge layer removing step(S40) of removing the filtrate separated in the solid-liquid separation step as an expanded granular sludge layer; and a settling step(S50) of intermittently aerating treated water obtained from the expanded granular sludge layer, and settling the treated water in a settling tank to discharge supernatant.

Description

Method for Organic Wastewater Treatments

1 is a process diagram briefly shown according to the purification step of the high concentration organic wastewater according to the present invention.

Figure 2 is a block diagram showing a method for purifying high concentration organic wastewater according to the present invention.

Figure 3 is a detailed view of the high temperature aerobic digestion reactor in the purification apparatus of high concentration organic wastewater according to the present invention.

4 is a detailed view of an expandable granular sludge bed reactor in a high concentration organic wastewater purification apparatus according to the present invention.

* Description of the symbols for the main parts of the drawings *

1: debris removal device 2: flow adjustment tank

3: high temperature aerobic digestion tank 4: solid-liquid separator

5: expandable granular sludge reactor 6: gas reservoir

7: intermittent aeration tank 8: settling tank

A: wastewater supply means B: air supply means

C: Foam removing means D: Foam vacuum suction means

E: control unit 10: air supply member

11: internal circulation pump 12: blower

13: vacuum pump 201: liquid pipe

202: air supply pipe 203: internal bubble collection pipe

204: buoyancy member 205: backwash pipe

206: external bubble collection pipe 210: vacuum suction pipe

220: corrugated pipe 301: liquid pipe opening and closing valve

303: check tube opening and closing valve 305: shut-off valve

402: temperature sensor

The present invention relates to a method for purifying high concentration organic wastewater using a high temperature aerobic digestion reaction tank and an expandable granular sludge layer. The present invention relates to a method for recycling and purifying a high concentration of organic wastewater that can be efficiently and reliably treated at a low cost in a limited area using a reactor, an expandable granular sludge layer and an activated sludge process.

Conventionally used methods for treating high concentration organic wastewater are composting, liquefaction, activated sludge and membrane filtration, anaerobic digestion, and the like.

The composting method is a method in which a high concentration of organic wastewater is mixed with sawdust and fermented for a long period of time, which requires a large site for long-term fermentation, a storage site, and a method of inferior economy in that a moisture control agent such as sawdust is required.

Liquefaction includes simple storage of high concentration organic wastewater in a storage container for a long time, supplying oxygen during storage, and removing odor by administering microbial agents in addition to supplying oxygen during storage. This method, which has been used in the past, lacks the concept of purification of waste water, which consumes a lot of power and is expensive to purchase microbial products, which is used to cause excessive aeration. This situation is not widely spread because of the inevitable increase in size. In addition, there is a problem that occurs such as the occurrence of odor and ungermination of seeds as the decomposition reaction occurs after spraying unfermented liquid fertilizer on the soil.

The activated sludge method treats high concentration organic wastewater by contacting the high concentration organic wastewater with microorganisms in the active sludge and ingesting and decomposing the organic matter in the high concentration organic wastewater. Due to its poor responsiveness, high concentrations of organic wastewater cannot be properly treated, and a large site is required for wastewater treatment.

Membrane filtration is a method of separating the solids from the treated water by filtering the wastewater treated with activated sludge method to overcome the limitation of activated sludge method. Due to membrane replacement, there are problems such as economic efficiency, difficulty in maintenance, and soil contamination by undecomposed organics when using concentrated water as a liquid ratio.

Anaerobic digestion is a method of generating organic substances of high concentration organic wastewater as the final oxide of methane gas and carbon dioxide by using anaerobic microorganisms.It is strong in changing concentration and load fluctuations of influent wastewater, Localized phenomena occur due to the inclusion of solids between the blocked or granular sludge layers. As a result, the rapid growth of acid producing bacteria causes the pH of the reaction tank to drop and the anaerobic digester that has to undergo hydrolysis, acid production, and methane production stops at the acid production stage due to the death of weak methane producing bacteria at low pH. There is a problem.

In the case of livestock manure in high concentration organic wastewater, it is liquefied and treated with anaerobic digestion tanks and activated sludge, but in the case of liquefaction, liquid fertilizer is produced by simple storage, so pathogenic microorganisms are not killed and soil microorganisms and crops are not fermented. It is difficult to ensure the safety of workers and the stability of the production fabric in the state that is not easy to absorb. In the case of the purification process, the air volume increases due to the increase of the initial installation cost and the required site due to the increase of the aeration tank capacity due to the high concentration of organic matter, and the required air volume due to the high concentration of organic matter. This is a problem that the economic feasibility decreases due to the increase in power costs and the increase in maintenance costs by supplying a large amount of external carbon source to the activated sludge to treat high concentration nitrogen.

In the case of food waste desorption filtrate in high concentration organic wastewater, the wastewater treatment process consists of chemical coagulation, pressure flotation tank, and anaerobic digestion tank, and the treated water is generally linked to sewage treatment plant. This is because the low pH of the food waste desorption filtrate is mainly caused by acid-producing bacteria which contain a large amount of lactic acid bacteria by fermented foods, which is a characteristic of Korean food. Acid producing bacteria generally have the most active decomposition activity at pH 3 to 4 to generate various oxides such as acetic acid, propionic acid, bulic acid and ethanol to continuously lower the pH. When the low pH of the desorption filtrate is chemically coagulated, it is neutralized using a large amount of alkaline agent to form a floc using an inorganic coagulant or a polymer coagulant, and solid-liquid separation is performed through a solid-liquid separator such as a pressure flotation tank or a centrifugal dehydrator. As the pH of the coagulant adjusted to fall again, the phenomenon of the coagulation floc is dismantled, so that the design treatment efficiency cannot be satisfied, thereby increasing the load ratio of the rear end process. Most of anaerobic digesters in food waste and wastewater from effluent wastewater treatment process were designed for the upflow Anaerobic Sludge Blanket (UASB) to prepare for inflow flow and organic load fluctuations, A large amount of unprocessed suspended solids enters the influent of the reactor. The introduced solids adhere to the granular sludge layer or close the pores so that acid-producing bacteria become active again due to local decay, resulting in the decrease of the pH of the anaerobic reactor, resulting in the death of weak methane-producing bacteria at low pH. The resulting organic acid may cause problems such as no further decomposition. For this reason, when the pH is lowered by the rapid growth rate and decomposition products of acid producing bacteria in the associated treatment with the sewage treatment plant, microorganisms in the existing sewage treatment plant are killed due to the predominance of the acid producing bacteria.

The present invention has been made in view of this point, and installed a straight or radial air supply means on the bottom of the high-temperature aerobic digestion reaction tank and supplying air to the blower while supplying wastewater to the internal circulation pump to provide air and wastewater from the air supply means Mixing and discharging to exposed and discharge nozzles removes pathogenic microorganisms and Escherichia coli and promotes organic decomposition of useful microorganisms, which not only increases the efficiency of decomposition of organic matter but also minimizes foam formation by using internal foam removing means and foam vacuum suction means. Therefore, it is an object of the present invention to provide an economical and efficient method for the purification of high concentration organic wastewater that can overcome the problems of pretreatment of high concentration organic wastewater and the technical limitations of biological purification.

The object of the present invention is to provide a method for recycling and purifying a high concentration of organic wastewater, and to separate the solids of the high concentration of organic wastewater by a contaminant removal device, and to decompose organic matter through the high temperature aerobic digestion reaction tank. Aerobic digestion step that kills pathogenic microorganisms, and solid-liquid separation separating the dehydrated cake and desorption filtrate by coagulation / dehydration with or without the administration of an inorganic flocculant to the high temperature aerobic digestion treatment water And a step of treating the desorption filtrate obtained from the solid-liquid separation step with an expandable granular sludge layer and intermittently aeration of the treated water obtained from the expandable granular sludge layer and precipitating in a settling tank to discharge the supernatant. .

And, the high temperature aerobic digestion step, the waste water supply step of supplying waste water to the high temperature aerobic digestion reaction tank by waste water supply means formed on one side of the high temperature aerobic digestion reaction tank, and air supply means connected to the liquid pipe of the waste water supply means Air supply step of supplying air from the air and mixing wastewater and air, and the bubble removing means inhales the bubbles generated during the decomposition of organic matter by activation of the high temperature aerobic microorganism by mixing the wastewater and air by the air supply step. Defoaming step and the high temperature aerobic microbial activity maintaining step of maintaining the optimized active state of the aerobic microorganisms by controlling the temperature, pH and redox potential of the waste water of the high temperature aerobic digestion reactor.

The defoaming step includes: an internal bubble removing means for sucking and removing the bubbles generated by the activation of organic matter by the mixing of the wastewater and air supplied from the wastewater supply means and the air supply in a high temperature aerobic digestion reaction tank by vacuum; And a foam vacuum suction means for sucking and removing the foam generated by the waste water and the air supplied by the waste water supply means and the air from the outside of the high temperature aerobic digestion reaction tank.

When the temperature of the high temperature aerobic digestion reactor is low, the internal circulation pump is operated to enable strong agitation and the rotation speed of the blower motor is increased to supply excess air to the inside of the reaction tank, and when the temperature of the high temperature aerobic digestion reactor is high, the minimum It is preferable to fix the internal circulation of the internal circulation pump to enable the stirring, and to reduce the rotational speed of the blower motor to reduce the air supply of the reactor to reduce the activity of the high temperature aerobic microorganisms.

Biogas is collected as an expandable granular sludge reaction by-product of the step of treating with the expandable granular sludge layer.

In addition, in the precipitation step, part of the sedimentation tank supernatant is characterized in that it is returned to the expandable granular sludge reactor.

The expandable granular sludge reaction of the step of treating with the expandable granular sludge layer and surplus sludge generated in the settling tank of the precipitation step are transferred to a high temperature aerobic digestion reaction tank.

The treated water that has undergone the high temperature aerobic digestion reaction of the high temperature aerobic digestion step is used as the liquid ratio.

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

1 is a process diagram briefly shown according to the step of the recycling and purification of high concentration organic wastewater in accordance with the present invention, Figure 2 is a block diagram showing the recycling and purification method of high concentration organic wastewater in accordance with the present invention, Figure 3 Detailed description of the high temperature aerobic digestion reaction tank of the high concentration organic wastewater recycling and purification apparatus according to the invention, Figure 4 is a detailed view of the expandable granular sludge bed reactor of the high concentration organic wastewater purification apparatus according to the present invention.

Recycling and purification method of high concentration organic wastewater according to the present invention, in the method for refining and purifying the high concentration organic wastewater, the step of separating the solids of the high concentration organic wastewater by the debris removal device (S10), and The high-temperature aerobic digestion step (S20) for decomposing organic matter and killing pathogenic microorganisms through the high-temperature aerobic digestion reactor (3) and the solid-liquid separated wastewater, and the polymer coagulant with or without the administration of an inorganic flocculant to the high temperature aerobic digestion treatment water. A solid-liquid separation step (S30) for separating the dehydrated cake and the tally filtrate by coagulation / dehydration with or without administering the treatment, and the step of treating the releasing filtrate obtained from the solid-liquid separation step (S30) with an expandable granular sludge layer (S40). And intermittently aeration of the treated water obtained in the expandable granular sludge layer and settling in a settling tank to discharge the supernatant water. It comprises a precipitation stage (S50).

Preferably, the high temperature aerobic digestion step (S20) is a wastewater supply step (S21) for supplying the waste water to the high temperature aerobic digestion reaction tank (3) by the waste water supply means (A) formed on one side of the high temperature aerobic digestion reaction tank (3). And an air supply step (S21) of supplying air from the air supply means (B) connected to the liquid pipe of the wastewater supply means (A) to mix wastewater and air, and the wastewater by the air supply step (S21). The bubble removing step (S23) for removing the bubbles generated by the activation of the organic material by the air mixture by suction in a vacuum (S23), and the temperature, pH and redox potential of the waste water of the high temperature aerobic digestion reactor (3) Controlled by (E) is made of a high temperature aerobic microorganism activity maintenance step (S24) to maintain the optimized active state of high temperature aerobic microorganisms.

The waste water supply means (A) is connected to one side of the bottom surface of the high temperature aerobic digestion reaction tank (3) and suction pipe 209 for sucking the stored waste water; An on / off valve 305 for opening and closing the suction pipe 209; An internal circulation pump (11) installed at the suction pipe (209) to exert suction power and earth output of the waste water to supply the liquid pipe (201); A liquid pipe inlet valve 301 which is installed at the inlet of the liquid pipe 201 of the high temperature aerobic digestion reaction tank 3 to open and close the waste water; A discharge nozzle 207 and a discharge nozzle 208 for injecting waste water to the bottom or side surfaces of the liquid pipe 201; It consists of a bottom support 212 to support the liquid pipe 201 from the bottom.

And, the air supply means (B) is connected to the discharge nozzle 207 of the liquid pipe 201, the air supply member 10 for mixing air and waste water, and connected to the air supply member 10 And an air supply pipe 202 to supply air, and a blower 12 to blow air into the air supply pipe 202.

Opening and closing valve 302 is provided in the air supply pipe 202 to open and close the movement of air.

The bubble removing means comprises an internal bubble removing means (C) and a bubble vacuum suction means (D), wherein the internal bubble removing means (C) is fixed to one inner surface of the high temperature aerobic digestion reaction tank (3), and has a center. The inner bubble collecting pipe 203 is provided with a bubble inlet hole for introducing bubbles over a portion from the upper portion to the upper portion, and is fixed to the outside of the inner foam collecting tube 203 so as to be slidably fixed by buoyancy of the wastewater. The buoyancy member 204 for raising and lowering the bubbles floating on the water surface of the waste water, and fixed to the shape surrounding the inner bubble collecting pipe 203 on the bottom of the buoyancy member 204 and the other end of the inner bubble collecting pipe ( Sealed on the outer surface of the 203 is made of a corrugated pipe 220 to prevent waste water from flowing into the foam inlet hole of the lower portion of the buoyancy member 204.

And, the foam vacuum suction means (D), the vacuum suction pipe 210 is fixed to one side of the high temperature aerobic digestion reaction tank (3) to absorb the foam; A vacuum pump 13 for compressing the bubbles sucked from the vacuum suction pipe 210 to make a liquid; The return pipe 211 for returning the liquefied wastewater from the vacuum pump 13 to the high temperature aerobic digestion reaction tank (3).

And, the control unit (E), the sensing member 15 for detecting whether the bubble height of the waste water in the high temperature aerobic digestion reaction tank 3 is abnormally high; A temperature sensor 402 for sensing a temperature of waste water in the high temperature aerobic digestion reactor 3; An acidity measuring sensor 401 for measuring acidity of wastewater in the high temperature aerobic digestion reactor 3; A redox potential sensor (403) for sensing a redox potential value of the wastewater in the high temperature aerobic digestion reactor (3); The wastewater supply means (A) and air supply means (B) are controlled by receiving signals from the sensing member 15, the temperature sensor 402, the acidity measurement sensor 401, and the redox potential sensor 403. It consists of a control panel 16 which controls to optimize temperature, acidity and redox potential values.

In addition, the sensing member 15, using an ultrasonic radar for detecting the water level of the waste water using ultrasonic waves, the temperature sensor 402, 55 ℃ ~ 65 ℃ temperature inside the high temperature aerobic digestion reaction tank (3) It is configured to stop the blower 12 and to operate only the internal circulation pump 11 when it is detected as 72 ℃ or more.

And, as shown in Figure 3, the outer bubble collecting pipe 206 is withdrawn from the upper outer surface of the outer side of the high temperature aerobic digestion reaction tank 3 is connected to the liquid pipe 201 to collect bubbles in the reaction tank, It is connected inward from the upper end of the high temperature aerobic digestion reactor (3) to block the opening and closing valve 305 in the liquid pipe 201 and operate the blower 12 to reverse the foreign matter caught in the discharge nozzle 208 to back into the reaction tank A backwash pipe 205 for washing is further provided.

The back washing pipe 205 is provided with a back washing pipe opening / closing valve 303, and the outer bubble collecting pipe 206 is preferably provided with a valve to block or open the movement of waste water or foam.

When applying the high temperature aerobic digestion reactor (3), the entire reaction tank has an effective depth of about 5 ~ 7.5m and uses a role of a heat insulating layer to hold the heat escaping to the top of the reactor by placing the height of the foam layer 0.5 ~ 1.5m It is desirable to install the depth of 5.5 ~ 9m.

The operation of the high temperature aerobic digestion reactor (3) can be operated in a batch, semi-continuous, continuous inflow operation mode, in the present invention, the influent is distributed so as not to affect the temperature and pH, such as critical operating factors of the high temperature aerobic digestion reactor It is preferable to adopt the semi-continuous and continuous inflow operation method flowing into the reactor.

In the present invention, by performing a high temperature aerobic digestion tank to reduce the concentration of organic matter in the influent wastewater and to reduce the hardly decomposable substances, toxic substances and volumes to facilitate the subsequent stage step. In addition, high temperature aerobic microorganisms accumulate oxidative heat (3.5 kcal / gVS) generated during oxidative decomposition of organic substances in the reaction tank to form high temperature conditions. Among microorganisms, Basillus sp., Strenotrophomonas, etc. can reduce odor and use high temperature aerobic digestion treatment water with low molecular weight of polymer material to facilitate absorption of soil microorganisms and crops.

Table 1

Pathogen Growth temperature (degrees) Extinction Temperature Time (minutes) Dysentery 10-40 60 5 Typhoid bacteria 15-41 60 5-15 Paratyphoid bacteria 15-40 60 10 Cholera 23-37 56 15 Brucella 8-43 60 10 Diphtheria bacteria 15-40 58 10 Staphylococcus 12-45 60 30-60 Enterococci 15-41 55 5 Escherichia coli 10-40 60 15 Enteritis Vibrio 10-37 60 15 Streptococcus 10-45 60 30-60

As shown in Table 1, most pathogenic microorganisms are killed by thermal treatment for about 30 minutes at 55 to 65 ℃. Therefore, in the high temperature aerobic digestion reactor (3) having a residence time of 3 to 12 days at a high temperature of 55 to 65 ℃ depending on the high concentration organic wastewater, most pathogenic microorganisms are killed and a good liquid ratio can be obtained.

In addition, the high-temperature aerobic digested water has a low molecular weight of polymer, that is, cellulose and hemicellulose are decomposed to become granular or liquid, and only the lignin remains in the entire liquid solution and the viscosity is high. This feature prevents organic matter from accumulating and degrading and decaying in the soil during land reduction of the produced liquid fertilizers.The nitrogen of the soil microorganisms, such as azotobacter, root-knot bacteria, clostridium, and anabena, It creates an environment that can absorb fixed and ammonia nitrogen, nitrite nitrogen and nitrate nitrogen quickly.

When the food waste desorption filtrate in the high concentration organic wastewater is treated with a high temperature aerobic digestion reactor (3), it has the following characteristics. The pH of the food waste desorption filtrate shows about 3 to 4, so that during the initial operation, alkaline agent is injected to adjust the pH to neutral to prevent the growth of acid-producing bacteria and to prevail in high temperature aerobic microorganisms. Agitation leads to an increase in the temperature of the high temperature aerobic digestion reactor (3). When acid producing bacteria are killed and high temperature aerobic microorganisms dominate, the temperature of the reaction tank is 55 to 65 ° C. and the pH is increased to 8 to 9 so that all of the acid producing bacteria are killed. In addition, by operating in a semi-continuous or continuous manner, even if the acid-producing bacteria are introduced, the effect on the reaction tank is minimized, and no additional alkaline agent is injected into the high temperature aerobic digestion reactor (3). In the present invention, a high temperature aerobic digestion process can be utilized as a biological pretreatment process with the characteristics of solving low pH problem by acid producing bacteria, low molecular weight of polymer material, homogenization of solid particle size.

The solid substance and phosphorus are separated from the desorption filtrate in a dehydrated cake state by the coagulation and dehydration reaction with or without the administration of the inorganic flocculant to the high temperature aerobic digested water or without the administration of the polymer flocculant. It is conveyed to the expandable granular sludge reactor 5. On the other hand, the treated water in the nitrate nitrogen state returned from the settling tank (8) is denitrified by the denitrification reaction using the organic material of the desorption filtrate in the expandable granular sludge reactor (5), and the organic material of the desorption filtrate is methane gas by the anaerobic reaction. It is generated by converting into biogas such as and carbon dioxide, and collecting useful biogas generated and transported to the gas storage tank (6) to produce electricity using a heat source such as steam and a generator. have.

Intermittent aeration and precipitation are carried out to remove the residual organic matter of the expandable granular sludge treated water and nitrogen by nitrification / denitrification reaction, and the supernatant of the nitrification state is returned to the expandable granular sludge reactor (5) to the anaerobic reactor. By denitrifying nitrate nitrogen using organic materials, the capacity of the anoxic tank in the intermittent aeration tank can be reduced, the amount of external carbon source injection is also reduced, and finally the treated water below the discharged water quality standard is discharged.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings. However, the accompanying drawings are the most preferred embodiments exemplified to help the understanding of the present invention, and the spirit and implementation of the present invention are not necessarily limited or limited thereto.

Figure 1 is a process diagram briefly shown according to the step of the recycling and purification of high concentration organic wastewater according to the present invention.

According to the present invention, the high concentration organic wastewater is stored in the flow rate adjusting tank 2 after removing the contaminants through the contaminant removal device 1 in the solid separation step (S10). In the debris removal device 1, the debris is removed by screen or centrifugation, and the high temperature aerobic digestion reactor 3 requires a reaction time of about 3 to 12 days depending on the type of organic wastewater and the amount of volatile solids. The flow rate adjusting tank 2 for supplying the wastewater to be treated in the high temperature aerobic digestion reaction tank 3 is designed with sufficient capacity in consideration of the inflow flow rate.

The high concentration organic wastewater in the flow adjusting tank 2 and the surplus sludge returned from the expandable granular sludge reactor 5 and the sedimentation tank 8 are supplied to the high temperature aerobic digestion reaction tank 3 and the excess oxygen is injected thereinto Induces self-exothermic reaction while decomposing organic matter, maintains reaction temperature at 55-65 ℃, accumulates pollutants such as organic matter, nitrogen, phosphorus and heat of oxidation in reaction tank to maintain high temperature conditions to remove pathogens and reduce odor . In general, the microorganisms contained in the high concentration of organic wastewater itself are sufficient for the high temperature aerobic digestion reaction, but when the heat generation is insufficient in consideration of the inflow wastewater properties, the high temperature aerobic microorganisms can be used as an auxiliary.

After the solid separation step (S10) to perform an aerobic digestion step (S20). The high temperature aerobic digestion reactor 3 in the high concentration organic wastewater treatment apparatus according to the present invention is shown in FIG.

The high temperature aerobic digestion reaction tank (3) used in the high temperature aerobic digestion step (S20) stores the wastewater in the high temperature aerobic digestion reaction tank (3) and operates the internal circulation pump 11 of the waste water circulation supply means (A) for the intake pipe ( The wastewater is sucked through 209 to be supplied again through the liquid pipe 201 (S21).

Then, the air is blown to the air supply pipe 202 through the blower 12 of the air supply means (B) (S22).

In this state, the wastewater conveyed to the liquid pipe 201 is discharged to the discharge nozzle 207 on the side and the discharge nozzle 208 on the bottom, respectively, and is transferred to the air supply pipe 202 and discharged to the discharge nozzle 207. It is mixed with the waste water to generate bubbles to activate the organic matter in the high temperature aerobic digestion reaction tank (3).

Wastewater discharged to the bottom surface through the discharge nozzle 208 serves to circulate the solids deposited on the bottom surface of the reaction tank.

As such, the air and the wastewater mixture discharged to the high temperature aerobic digestion reaction tank 3 through the discharge nozzle 207 generate bubbles to supply oxygen to activate the high temperature aerobic microorganisms, and generate heat of oxidation to generate internal temperature of the reaction tank. Raises the temperature of the waste water and induces bubbles to promote the active conditions.

The high temperature aerobic microorganisms in the high temperature aerobic digestion reaction tank (3) is most active at 45 ~ 65 ℃, but pathogenic microorganisms and E. coli are mostly killed when contacted for 30 minutes at 50 ℃, so the temperature inside the reaction tank to 55 ~ 65 ℃ It is most desirable to maintain.

The concentration of the solid organic wastewater in the high temperature aerobic digestion tank (3) is about 2.5 to 5% is suitable, if the concentration of the solid is too low, there is a problem that the microorganism does not generate enough heat of oxidation.

On the other hand, when excessive bubbles are formed and overflowed in the high temperature aerobic digestion reaction tank (3), it is collected by the external bubble collection pipe 206 formed on one side of the reaction tank and circulated again through the liquid pipe (201).

In addition, if the bubble is not removed by the outer bubble collecting pipe 206, the buoyancy member 204, which is the inner bubble removing means (A) shown in FIG. It is collected through the bubble inlet hole of the inner bubble collection pipe 203 is returned to the liquid pipe 201 connected to the lower portion.

The bottom and the other end of the buoyancy member 204 is at one end of the inner bubble collecting tube 203 to prevent wastewater from flowing through the foam inlet hole of the inner bubble collecting tube 203 in the lower section of the buoyancy member 204. The corrugated pipe 220 is installed in a shape that protects the bubble inlet hole in a sealed state in the middle section of the cover.

As the buoyancy member 203 is raised and lowered on the outer surface of the inner bubble collection tube 203, the corrugated pipe 220 is repeatedly closed or unfolded.

And, if the bubbles are not removed by the inner bubble collection pipe 203, by operating the vacuum pump 13 of the bubble vacuum suction means (D) forcibly sucked bubbles through the vacuum suction pipe 210 and condensing the bubbles By returning to the return pipe 211 to remove the bubble (S23).

In addition, a control unit E is installed to measure temperature, acidity, redox potential, etc. in the high temperature aerobic digestion reactor 3, and an acidity measurement sensor 401 and a temperature sensor 402 of the control unit E. And the redox potential sensor 403 detects the acidity amount, temperature and redox potential value of the wastewater in the reaction tank to determine whether the appropriate holding temperature in the control panel 160 to determine the internal circulation pump of the wastewater supply means (A) (11) ) And the blower 12 of the air supply means (B), and by adjusting the amount of waste water and air to adjust the degree of activation of microorganisms, it is possible to maintain an appropriate oxygen supply amount, temperature, acidity and redox potential value.

The acidity refers to a pH value, and determines whether the wastewater in the reaction tank is acidic or alkaline by using the acidity measurement sensor 401, and when the acidity in the reaction tank deviates from the reference value, it is determined by the control panel 160. By adjusting the internal circulation pump 11 and the blower 12 to adjust the acidity.

In addition, the redox potential is a control panel when the wastewater in the reaction vessel is oxidized to acid or reduced to alkaline, and a small potential difference occurs and the redox potential in the reaction vessel deviates from this value, for example, when the reference value is set to ± 200 mV. Sensing at 160 and controlling the internal circulation pump 11 and the blower 12 to adjust the redox potential in the reactor.

The acidity measurement sensor 401, the temperature sensor 402 and the redox potential sensor 403 of the control unit E are comprehensively determined and controlled by the control panel 160 to adjust wastewater of the reactor. do.

In addition, the sensing member 15 of the control unit E mainly uses an ultrasonic radar, and detects a signal for firing and returning ultrasonic waves to the wastewater stored in the reaction tank to control the wastewater supply pipe not shown in the control panel 16. Maintain an appropriate level (S24).

On the other hand, the inner portion of the discharge nozzle 207 in which the liquid pipe 201, the air pipe and the discharge pipe meet in the air supply member 10 is likely to be clogged due to foreign matter of high concentration organic wastewater.

In order to solve this problem, when the operation of the internal circulation pump 11 is stopped, the shut-off valve 305 is closed from the outside, and the blower 12 is operated to inject air into the air pipe 202, the discharge nozzle 207 is formed. When the pressure drops to the ejector method, the liquid flows into the discharge nozzle 207 through the movement force of the air, and moves in the opposite direction to the usual flow direction of the fluid, so that the foreign substances stuck in the nozzle part are connected to the liquid pipe 201 and the backwash pipe 205. By returning to the outside or inside of the reaction tank (3) through the) to the foreign matter remaining inside the discharge nozzle 208 is backwashed.

In the present invention, in the case of livestock manure in high concentration organic wastewater, the high temperature aerobic digestion treatment water is supplied to the demand source only in the spring and autumn seasons, which contributes to the recycling of livestock manure. In addition, the high-temperature aerobic digestion reaction sufficiently removes organic substances, reduces hardly decomposable substances, toxic substances and odors, and can reduce volume by more than 30% by evaporation of water by high temperature treatment. The effect as a pretreatment which makes a process smooth can be anticipated.

In order to reduce the suspended solids and phosphorus concentration in the high temperature aerobic digestion water, chemical coagulation is performed after the high temperature aerobic digestion reaction. Since the temperature of the high-temperature aerobic treated water is 55 to 65 ° C., the solid-liquid separation can be performed only by cooling with a heat exchanger or a treated water tank in order to drop to room temperature. Cooling water can be expected to increase the treatment efficiency by increasing the reactivity by lowering the temperature of the high temperature aerobic digestion water using the influent of the expandable granular sludge layer and increasing the temperature of the expandable granular sludge influent. The floc is formed with or without the administration of an inorganic flocculant to the high temperature aerobic digested water, with or without a polymer flocculant, and dehydrated with a solid-liquid separator (4) such as a centrifugal dehydrator, a filter press or a belt press. After separation (S30) into the desorption filtrate, the separated dewatering cake may be disposed of as dewatering sludge or used for composting, and the desorption filtrate is transferred to the expandable granular sludge reactor (5).

In the mechanism of the chemical coagulation reaction, flocculents are formed by cohesion and crosslinking of each other, and colloidal materials are formed by injecting opposite charge material or reducing electric repulsive force. It is taken out completely in the purification process in the state containing it.

In the present invention as a method of separating the aggregates, but dehydrated and separated in the form of a dehydrated cake, it is also possible to precipitate and separate in the form of precipitate. As the inorganic flocculant, aluminum sulfate, ferrous sulfate, ferric chloride, polyaluminum chloride, or the like can be used.

The detailed view of the expandable granular sludge reactor 5 in the high concentration organic wastewater treatment apparatus according to the present invention is shown in FIG. 4. The expandable granular sludge reactor 5 may have a cylindrical or quadrangular shape, and the inside of it maintains an anaerobic state in which no air is supplied. The desorption filtrate separated from the dewatering cake by the solid-liquid separator 4 is introduced into the inlet tank 51 of the expandable granular sludge reaction tank 5 together with the internal circulation water and the treated water returned from the settling tank 8. In addition, in order to uniformly introduce the inflow wastewater in an upflow manner, an apparatus such as an inflow water tank 51, an inflow water distribution tank 52, an inflow water distribution pipe 56, and the like is used. The desorption filtrate, the internal circulating water, and the treated water are completely mixed in the inlet tank 51 located in the upper portion of the reaction tank and then transferred to the inlet distribution tank 52 on the side, and the reaction tank through the inlet water distribution pipe 56 at the bottom. It is supplied uniformly throughout. As described above, the wastewater is introduced into the expanded granular sludge layer attached to the microorganisms in the reaction tank in an upflow manner to activate the reaction between the wastewater and the granular sludge to purify contaminants (S40). The expandable granular sludge treated water circulates 4 to 8 times the inflow flow rate in the treated water tank through an internal circulation pump, and the rest is transferred to the intermittent aeration tank 7.

In the expandable granular sludge reactor (5), the sludge is in the form of particles by the rising flow rate of the internal circulating water and the rising flow rate of the biogas, which is an organic decomposition product. It is advantageous. The internal circulation of the expandable granular sludge treated water has the advantage of minimizing the impact load and diluting toxic substances in the influent wastewater in addition to the above roles.

The expandable granular sludge reaction serves to remove organic matter from the influent wastewater and nitrate nitrogen from the return water. The following describes each in more detail.

The expandable granular sludge reaction is a process in which anaerobic microorganisms of various kinds of anaerobic microorganisms are gradually decomposed and finally converted into biogas containing methane, carbon dioxide, etc. Are anaerobic bacteria and some are absolute anaerobes, such as methane-producing bacteria. Decomposition of organic matter consists of two steps, acid production and methane production. First, in acid production, carbohydrates such as cellulose and starch are sugars, and proteins and fatty acids are amino acids, glycerol or fatty acids. Decomposed and in the anaerobic state, the organic acid bacteria to produce organic acids such as propionic acid, butyric acid. The resulting organic acid is produced by acetic acid and hydrogen by methane producing bacteria and then converted into gaseous final products such as methane and carbon dioxide. In other words, in the expandable granular sludge reactor 5, the organic component in the wastewater is converted into biogas mainly composed of methane, the final product, through anaerobic reaction.

The methane generation rate through the methane production reaction is theoretically about 0.35 m 3 produced when 1 kg of COD or BODu organic matter is decomposed and removed. The biogas generated in the expandable granular sludge reactor 5 is moved upward and separated from the wastewater in the biogas separation device 57 and collected. The collected gas is transferred to the gas storage tank 6 through the biogas delivery pipe 55. After storage, the boiler can be operated to produce a power source by turning a heat source or a generator to use as an energy source.

The biological nitrogen elimination reactor is largely composed of nitrification and denitrification. The organic nitrogen in the egg nitrate wastewater is converted into nitric acid through ammonia nitrogen by nitrosomonas, a nitrifying bacterium under aerobic conditions, and finally into nitrate nitrogen by Nitrobacter. Denitrification refers to the release of nitrate nitrogen from the water in the form of nitrogen gas by Pseudomonas, Micrococcus, etc., which are denitrification under anaerobic conditions. In particular, a denitrification reaction requires a carbon source such as an organic material. In general, since organic matter is removed during nitrification, an external carbon source such as methanol must be separately supplied from the outside for denitrification. However, according to the present invention, the wastewater is completely nitrified in the intermittent aeration tank (7) and solid-liquid separated in the settling tank (8), and then the treated water, which is the supernatant containing nitrate nitrogen, is returned to the expandable granular sludge reactor (5). By denitrification with a carbon source, there is no need for a separate organic material supply.

The expansion granular sludge reaction for removing organic matter and nitrogen is considerably faster than general anaerobic treatment, and because it does not need air supply to maintain aerobic conditions, it consumes less energy and responds to changes in inflow water quality compared to aerobic reaction. It has the advantage of less sludge generation.

The expandable granular sludge treated water is transferred to the intermittent aeration tank (7), and the organic and nitrogen are removed by sequentially repeating the aerobic-anaerobic condition, and precipitated in the settling tank (8) to separate the treated sludge and the treated water as supernatant (S50). ). Although some denitrification reaction occurs in the intermittent aeration tank 7, the main nitrogen removal method in the present invention is to return the nitrified treated water to the expandable granular sludge reactor 5 for denitrification.

The treated water separated and precipitated as described above is finally discharged except for the amount returned, and by passing through an ozone sterilization or ultraviolet disinfection device before final discharge, E. coli and some hardly decomposable substances in the discharged water can be removed.

The present invention, by using a high temperature aerobic digestion reaction in the early stage of the purification method of high concentration organic wastewater, is excellent in adaptation to extreme fluctuations of the influent wastewater, it is possible to self-treat the excess sludge generated in the biological process, a separate carbon source in the denitrification process It is an economical method to clean high concentration organic wastewater that does not require injection.

In addition, the present invention is not only limited to the purification method, but also contributes to the recycling of high concentration organic wastewater. It kills pathogenic microorganisms under high temperature aerobic digestion reactions as high temperature conditions, and it becomes easy to absorb soil microorganisms and nutrients through plant's low molecular weight. In other words, the production of liquid fertilizer through high temperature aerobic digestion reaction contributes to environmentally friendly agricultural activities.

In addition, the biogas generated in the expandable granular sludge layer may be collected in a gas storage tank to be used as a heat source using a boiler or to generate electric power using a generator to supply power to a power stream in a treatment plant.

In addition, it is possible to flexibly change the operation of the process in accordance with the demand of the useful biomass produced through high concentration organic wastewater.

Claims (9)

In the method of recycling and purifying high concentration organic wastewater, Solids separation step of separating the solids of the high concentration organic wastewater by the debris removal device; A high temperature aerobic digestion step of decomposing organic matter and killing pathogenic microorganisms through the high temperature aerobic digestion reaction tank from the solid-liquid separated waste water; A solid-liquid separation step of separating the dewatered cake and the desorption filtrate by coagulation / dehydration with or without the administration of an inorganic flocculant to the hot aerobic digested water; An expandable particulate sludge layer treatment step of treating the detached filtrate obtained from the step of separating the dewatered cake and the detached filtrate with an expandable granular sludge layer; And And a precipitation step of intermittently aeration of the treated water obtained in the above-mentioned expandable granular sludge layer and precipitating in a settling tank to discharge the supernatant. The method of claim 1, The high temperature aerobic digestion step may include: a waste water supply step of supplying waste water to the high temperature aerobic reaction tank by a waste water supply means formed on one side of the high temperature aerobic reaction tank; An air supply step of supplying air from air supply means connected to the liquid pipe of the waste water supply means to mix waste water and air; A bubble removing step of removing bubbles generated by activation of organic matter by mixing the wastewater and air by the air supplying step by suctioning the bubble removing means into a vacuum; The high temperature aerobic digestion tank of the high concentration of aerobic microorganisms, characterized in that the control step of controlling the temperature, pH and redox potential of the waste water to maintain the active state of high temperature aerobic microorganisms to maintain the active state of high-temperature aerobic digestion. The method of claim 2, The bubble removing step is to suck and remove the bubbles generated during activation of the high-temperature aerobic microorganism and decomposition of organic matter by vacuum in the inside of the high-temperature aerobic digestion reaction tank by mixing the wastewater and air supplied from the wastewater supply means and the air supply means. Internal foam removing means; And a foam vacuum suction means for suctioning and removing the foam generated by the waste water and the air supplied from the waste water supply means and the air supply from the outside of the high temperature aerobic digestion reaction tank by vacuum. The method of claim 1, When the temperature of the high temperature aerobic digestion reaction tank is low to operate the internal circulating pump to enable strong agitation and increase the rotational speed of the blower motor to supply excess air into the reaction tank; When the temperature of the high temperature aerobic digestion reactor is high, the internal circulation of the internal circulation pump is fixed to allow a minimum of agitation, and the number of revolutions of the blower motor is reduced to reduce the air supply of the reactor to reduce the activity of the high temperature aerobic microorganisms. Purification method of high concentration organic wastewater to make. The method of claim 1, When the high temperature aerobic microorganisms bubbles generated during the decomposition of organic matter rises above a certain level, the ultrasonic pump radar to operate the vacuum pump, characterized in that for operating the vacuum pump. The method of claim 1, A method for purifying high concentration organic wastewater, characterized in that the biogas that is the byproduct of the expandable granular sludge reaction in the step of treating the expandable granular sludge layer is collected. The method of claim 1, Part of the sedimentation tank supernatant in the precipitation step is returned to the expandable granular sludge reactor, characterized in that the high concentration organic wastewater purification method. The method of claim 1, A method for purifying high concentration organic wastewater, characterized in that the expandable granular sludge reaction of the step of treating the expandable granular sludge and the excess sludge generated in the settling tank of the settling stage are transferred to a high temperature aerobic digestion reaction tank. The method of claim 1, Purifying method of high concentration organic wastewater, characterized in that the treated water undergoes a high temperature aerobic digestion reaction of the high temperature aerobic digestion step as a liquid ratio.

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