KR950008880B1 - Apparatus and method for excrement treatment by photosynthetic bacteria - Google Patents

Abstract

The method comprises (A) anaerobic digestion process which decomposes organic compounds in excrement, (B) chemical treatment process which separates solid and liquid from the anaerobically digested excrement by adding flocculants, (C) decomposition process which decomposes the upper liqiud of chemically treated excrement into organic acids and low molecular weight compounds using bacteria, and (D) main treatment process which treats the pretreated excrement in undiluted state using photosyntheic bacteria.

Description

Manure treatment device using photosynthetic bacteria and method

Figure is a diagram schematically showing a part of the classification apparatus using photosynthetic bacteria as an embodiment of the present invention.

[Industrial use]

The present invention relates to a manure treatment device, and more particularly, to a manure treatment device and a method using photosynthetic bacteria.

[Private Technology]

In general, the preferred form of manure treatment is treatment based on flush toilets, which requires a gradual securing of sewage pipes leading directly from the home and building to the treatment plant and an end treatment plant capable of handling the entire amount of collected manure. In recent years, the flush toilets requiring sewer pipes and end treatment plants have been spread to rural areas with changes in the lives of resident households, and the proportion of flush toilets is gradually increasing. have.

A manure treatment plant is required to collect and collect the septic tank sludge periodically collected from such collection toilets or flush toilets, but the current situation is still insufficient in terms of the number and treatment capacity of the manure treatment plant.

In Korea, manure treatment plants have been widely used since 1976, but the number is still small and there are many technical problems. Currently, the water washing rate of the total amount of manure in Korea is 56%, and the collected manure, whether collected or flushed, is currently being treated at a rate of 14,106Kl / day at 180 treatment plants nationwide. This indicates that only about 32% of the manure 43,578 Kl that occurs per day is being treated. Of course, 30 manure treatment plants are still being constructed, but at present there is no shortage. Therefore, the remaining 68% of the manure is not treated naturally but is discharged to the rivers, and these discharged manure causes serious water pollution. In addition, water pollution may be caused by not only water pollution caused by untreated and discharged manure as described above, but also by manure released without being sufficiently processed in the current manure treatment plant.

In general, the manure treatment in the manure treatment plant is carried out by anaerobic digestion, aerobic digestion, wet oxidation, liquid corrosion, etc. as the primary treatment, and activated sludge method, rotary disc method, water spraying method, aeration group as secondary treatment. Methods, physicochemical treatments, etc. are selected and used in combination. However, the biological treatment method other than the liquid corrosion method of the above method requires a large amount of dilution water of about 20 times for the first treatment after the manure. However, in most manure treatment plants, it is difficult to secure lime water, which leads to severe fluctuations in the concentration of organic loads in the secondary treatment, which makes it impossible to operate stably. As a result, untreated manure is discharged as it is. have. In addition, when the secondary treatment using a large amount of dilution water, a lot of site area, facility installation costs, operation management costs, labor costs, etc. are required greatly, there is a problem that the manure treatment costs increase.

On the other hand, the liquid corrosion method that does not require a large amount of dilution water of the above method is a dilution-free treatment, but because the air supply must be higher than the general activated sludge method, the power cost is high and the residence time is long, so the capacity of the aeration tank is increased. It takes a lot of initial investment, a large amount of drug costs for dehydration, there is a problem that the cost of manure treatment eventually increases.

Also, in recent years, as the management standard is strengthened from the management of concentration standards to the management including the total amount regulation in the management of water pollution sources, it has become impossible to discharge water by simply reducing the concentration of water pollution sources through conventional wastewater treatment.

[Problem to solve the invention]

The present invention has been made to solve the problems of the prior art as described above, an object of the present invention is to provide a manure treatment method that does not require a large amount of dilution water first, and secondly provides an economical manure treatment method with a very low operation and maintenance costs. The third facility provides a lightweight manure treatment method, the fourth facility provides a manure treatment method that improves the treatment efficiency by eliminating load variation, provides a manure treatment method that can cope with the fifth total amount regulation, and occurs during the sixth manure treatment. The purpose of the present invention is to provide an economical manure treatment method that can increase the income by using surplus sludge as organic fertilizer.

[Means for solving the problem]

In order to achieve the object of the present invention as described above, the present invention is to decompose organic matter into organic acids and low molecular weight organic matter by organic nutrient microorganisms in the absence of dilution of the first manure and chemical pretreatment of manure through an anaerobic digestion process Provided is a method of treating manure, including a main treatment step of treating by photosynthetic bacteria and symbiotic bacteria.

When using photosynthetic bacteria as in the present invention, high load operation of high concentration wastewater is possible due to the inherent characteristics of photosynthetic bacteria as compared to the activated sludge method using conventional organic material decomposition microorganisms. That is, the dilution treatment of the first treatment manure is possible. In more detail, the method of treating manure by photosynthetic bacteria is very efficient under the condition that the ratio of carbon and nitrogen in the manure is slightly unbalanced. The reason for this is that nitrogen in the air can be fixed to maintain a balance between carbon and nitrogen, and denitrification or decarbonation is performed, so that carbon compounds in the manure are taken into the cells or released into the air, thereby increasing the removal efficiency of the BOD value.

Photosynthetic bacteria have a symbiotic relationship with many organotrophic bacteria. For example, they grow well in wastewater due to symbiosis with Rhodobacter capsulatus and Bacillus megaterium. By contributing to the process of manure treatment with photosynthetic bacteria and symbiotic bacteria, the purification efficiency is much better and the sedimentation property is good, which eliminates the need for agglomerate manipulation by the addition of flocculating sediment. In addition, photosynthetic bacteria have strong flame resistance, grow well at a salt concentration of about 10%, and decompose toxic hydrogen sulfide or amines, and thus have an odor removal effect. It is very resistant to the load fluctuations of the raw waste water and its resistance to temperature. The amount of sludge produced is 1/3 to 1/2 compared to the activated sludge method, and the area of the treatment plant is 1/3. In addition, the sludge can be used as an organic fertilizer and the operation of the manure treatment plant is stable, which has the advantage of significantly reducing the operating cost.

Representative photosynthetic bacteria that can be used at this time are Rhodobacter capsulatus, Rhodobacter gelatinosa, Rhodobacter spaeroides, Rhodopirillum rubrum, etc. There is this. In the present invention, the pretreatment step of producing organic acid using organic matter in the manure is treated with raw manure to generate volatile organic acids (VFA: Volatile Fatty Acid) such as acetic acid, propionic acid, butyric acid, and converted to methane gas. Analytical treatment is carried out to reduce the concentration of organic matter. The undegraded organic matter is treated by photosynthetic bacteria and symbiotic bacteria under initial conditions.

In the present invention described above, in addition to the photosynthetic bacteria described above, it is preferable to further add symbiotic bacteria (hereinafter, symbiotic bacteria) of photosynthetic bacteria. As such, when the symbiotic bacteria are added, more efficient and rapid manure treatment can be achieved by symbiosis between photosynthetic bacteria and these symbiotic bacteria. The symbiotic bacteria of such photosynthetic bacteria are Bacillus, Streptococcus, Candida, Pseudomonas, Nocardia, Aspergillus, and Lactobacillus. Etc. In addition, the photosynthetic bacteria is preferably supplied from the outside or by a feed bag. That is, some of these photosynthetic bacteria are removed outside the reaction system together with the treated water and the sludge, and it is preferable to periodically add photosynthetic bacteria to maintain a constant concentration of photosynthetic bacteria in the photosynthetic symbiotic bath. At this time, the amount of the photosynthetic bacteria added from the outside is preferably 5-15ppm to the photosynthetic symbiosis. When the amount of the photosynthetic bacteria added is less than 5 ppm, the manure treatment by the photosynthetic bacteria does not occur sufficiently, and when the amount of the photosynthetic bacteria exceeds 15 ppm, no further improvement occurs.

In the present invention, it is preferable that the pretreatment step of producing the organic acid and the low molecular organic material includes a step of converting the organic material in the manure into an organic acid and other low molecular organic materials using microorganisms. The organic acid produced by such a process is suitable as a substrate of photosynthetic bacteria, so that the manure wastewater treatment using photosynthetic bacteria can be efficiently carried out.

In the present invention, the entire pretreatment process includes a screen and precipitation process for removing bulky and heavy suspended solids present in the manure, an anaerobic digestion process for decomposing organic matter in the manure from which the suspended matter is removed, and the anaerobic digested manure. It is preferred to include a chemical treatment step of separating a solid solution by adding a flocculant to the step, and a step of decomposing the organic matter decomposition step of decomposing the supernatant of the chemical precipitated manure into an organic acid using a microorganism. The screen and sedimentation process removes contaminants, soils, and large suspended solids present in the wastewater introduced into the treatment tank together with the live manure. By performing such a screen and sedimentation process, a moving tube is blocked during the movement of the manure wastewater. It is possible to remove substances that obstruct the flow of waste water. In addition, the anaerobic digestion process decomposes proteins, carbohydrates, fats, and other large molecular substances in the manure into small, simple, low molecular weight organic matter by anaerobic methane fermentation, and finally, inorganic substances such as water, carbon dioxide, methane, and ammonia. Conversion to primarily reduce organic concentration, ie BOD.

In the present invention, other extinguishing processes other than the anaerobic digestion process may be used, but the anaerobic digestion process is most preferred because of low operation and maintenance costs and easy operation in the primary treatment method. In the present invention, the above chemical treatment process is a process for treating suspended solids (SS: Suspended Solid) present in the anaerobic digestion treatment water, and in general, the treated water undergoing anaerobic digestion includes 15,000 ppm or more of suspended solids. In order to perform the biological treatment directly, the capacity of the treatment facility must be large and the treatment efficiency is also lowered. In the present invention, chemical treatment, in particular, a method using aluminum sulfate and a polymer flocculant as a flocculant, is precipitated by such flocculation. It is desirable to lower the amount of suspended solids to less than 4,000ppm. At this time, the addition amount is preferably 300-500ppm for aluminum sulfate and 1000-2500ppm for cationic polymer material. If the amount of flocculent is less than the above amount, there is no sufficient flocculation effect. If the amount of flocculant exceeds the above amount, the amount of flocculant is excessively retained in the dehydration solution, which may affect the biological treatment, and the operation cost is high. .

The present invention as described above may further include a step of precipitating photosynthetic bacteria and symbiotic bacteria to precipitate the optical bacteria in the discharged water after the main treatment.

In another aspect, the present invention is an active sludge treatment step of precipitating and separating photosynthetic bacteria and symbiotic bacteria and treating supernatant in an activated sludge tank, a catalytic oxidation process connected to the activated sludge treatment tank, and the effluent water of the catalytic oxidation process. And a post-treatment process that includes a flocculation precipitation step of precipitating the precipitate within and releasing the discharged water. In the post-treatment process, the activated sludge process and the catalytic oxidation process finally completely process the organic matter remaining in the treated water, and the suspended solids process finally removes the sludge generated by the activated sludge tank and the catalytic oxidation process.

In addition, the present invention is an organic nutrition microbial tank having a microorganism for converting the organic matter of the manure to an organic acid or a low molecular weight molecule, photosynthetic bacteria and photosynthetic bacteria having a photosynthetic bacterium and a symbiotic bacteria to treat the organic matter of the manure flowed from the organic nutrition microbial tank It provides a manure treatment device comprising a bacterial tank. In the present invention described above, the organic nutrient microorganisms to treat the manure to produce organic acids and low-molecular substances used as a substrate of photosynthetic bacteria, the photosynthetic microorganisms using organic acids and inorganic substances as a substrate to grow the organic matter in the manure to remove the manure Lower my BOD. And it is preferable that this photosynthetic bacterium further contains a symbiotic bacterium. When symbiotic bacteria of photosynthetic bacteria are present together, organic matter removal efficiency in manure can be greatly improved. The symbiotic bacteria of such photosynthetic bacteria include Bacillus, Pseudomonas, Nocardia, Streptococcus, and the like. In addition, it is preferable to provide a photosynthetic seed tank for supplying photosynthetic bacteria to the photosynthetic bacteria tank of the manure treatment device. As photosynthetic bacteria are released together with excess sludge removal and treated water, the concentration of photosynthetic bacteria in the photosynthetic bacteria tank decreases, and the photosynthetic bacteria are constantly supplied to prevent the decrease of photosynthetic bacteria and to keep the concentrations of photosynthetic bacteria constant. Photosynthetic spawning is required.

And the present invention preferably comprises a photosynthetic bacteria precipitation tank for precipitating photosynthetic bacteria in the treated water introduced from the photosynthetic bacteria tank and separating the solid solution. By treating the manure with the treatment apparatus of the present invention as described above, the cell concentration of photosynthetic bacteria flowing out is high, and the cells such as photosynthetic bacteria and microorganisms obtained by sedimenting such photosynthetic bacteria in a precipitation tank can be used as raw materials for organic fertilizers. have.

In another aspect, the present invention is an activated sludge treatment for treating the supernatant of the discharged water discharged from the photosynthetic bacteria settling tank, the contact oxidation tank for contact oxidation of the discharge water discharged from the activated sludge tank, the release released from the contact oxidation tank It may further comprise a float settling tank for precipitating the suspended matter. Thus, by installing the activated sludge tank and the catalytic oxidation tank, the organic matter remaining in the treated water treated by photosynthetic bacteria is finally treated, and the sludge is precipitated by using the flotation tank to discharge the treated water in a more completely treated state. can do.

EXAMPLE

Hereinafter, preferred embodiments and comparative examples of the present invention have been described, and the processing steps are shown in the drawings. However, the following examples are only preferred embodiments of the present invention for demonstrating the constitution and effects of the present invention, and the present invention is not limited to the following examples.

Example

Raw manure with pH 8.5, BOD 23,000, COD _Mn 6000, SS 25,000, Cl 0.55% by weight, TKN 6,500 was removed by screening and sedimentation to remove contaminants and sediments, and by using two tanks in a temperature-digestive manner at a temperature of 35 ° C. The solution was treated in an anaerobic digester for 30 days, pretreated by separating the solid and the liquid by chemical precipitation by administering 500 ppm of aluminum sulfate and 3000 ppm of a polymer flocculent aid as flocculants. 150 treated water from this It is adjusted to pH 7 ~ 8 by agitation in organic nutrient tank and aerated at 1 ~ 5ppm of dissolved oxygen at room temperature for 1 day by aerobic heterotrophic bacteria, starch is sugar, protein is amino acid, fat is acetic acid, pyrionic acid, etc. It was decomposed into organic acids to decompose photosynthetic bacteria and commensal bacteria in an easy-to-treat state.

BOD volume load 0.525-0.975kg / ㎥ / day, F / M ratio 0.11-0.24kg / BOD / kg MLSS D, HRT 1.3-2 days, MLSS 3500-5000mg / , Raw water inflow 40-60 / day, sludge conveyance rate of 100-150% photosynthetic symbiosis in the transport conditions were operated. At this time, the pH of the photosynthetic symbiotic bath was adjusted to pH 7-7.5, and photosynthetic bacteria were added so as to be 10 ppm periodically from the photosynthetic spawn tank. The treated water thus obtained was introduced into the photosynthetic precipitation tank, and a part of the sludge precipitated was returned, and some were sent to a dehydrator to be dehydrated and removed. The supernatant of the settling tank was again activated, and the activated sludge was operated at pH 7-8, dissolved oxygen concentration of 1-5ppm, HRT 1.3-2 Day, and BOD load of 0.094-0.169BOD / ㎥ · day. Final treatment was carried out using microorganisms attached to the contact medium under the same conditions.

When the manure is treated by the above method, the water quality of the treated water discharged after being treated in each step is shown in the following table.

[table]

Comparative example

Raw manure with pH 8.5, BOD 23,000, COD _Mn 6000, SS 25,000, Cl 0.55% by weight, TKN 6,500 was first treated with anaerobic digestion by forced stirring and a large amount of dilution. After diluting 20 times with water, BOD load 20kg / ㎥ · day, water load 100 It was carried out in an actual manure treatment plant under conditions of / m 3 · day.

When manure was treated by this method, it was difficult to secure a large amount of dilution water.If proper dilution was not possible, the manure was not loaded properly due to the heavy load of organic matter flowing into the rotating disc. The problem is that even microorganisms are washed away. In addition, when a large amount of microorganisms were attached, a heavy load was applied, which caused frequent failure of the rotating disc, resulting in unstable treatment. As a result, the quality of the final effluent was unstable.

[effect]

As can be seen in the above examples and comparative examples, the treatment method of the manure using the photosynthetic bacteria of the present invention can stably process the manure without requiring a large amount of dilution water, and thus the site area and facility It is possible to reduce installation costs, operation management costs, labor costs, etc. to reduce the cost of manure treatment, and the excess sludge obtained as a by-product is an excellent manure processing method and apparatus that can be used as a useful organic fertilizer containing a large amount of photosynthetic bacteria.

Claims (13)

Anaerobic digestion process for decomposing organic matter in manure under anaerobic conditions, chemical treatment process for separating solids by adding aggregates to the anaerobic digested manure, and decomposing the supernatant of manure after chemical treatment into organic acids and low molecular weight substances using microorganisms. A pretreatment step including an organic material decomposition step of performing; A main treatment step of treating the pretreated manure containing the organic acid and the low molecular weight material using photosynthetic bacteria in a dilution state; Manure treatment method comprising a. The method of claim 1, wherein the photosynthetic bacteria are added periodically to form a symbiotic bacteria system and operated. 3. The method of claim 1 or 2, wherein the photosynthetic bacteria are continuously supplied at this site or supplied by booker feedback to the effluent. The method of claim 3, wherein the amount of photosynthetic bacteria added to the photosynthetic symbiotic cell from the outside is% 5-15 ppm. The method of claim 1, further comprising a screening and precipitation process for removing bulky and heavy suspended solids present in the manure prior to the pretreatment process. The method of claim 6, wherein the amount of flocculant and flocculent aid in the chemical treatment process is 300-500 ppm of aluminum sulfate and 1000-2500 ppm of cationic polymer material. The method of claim 1, wherein the manure treatment method further comprises a first sedimentation step of precipitating photosynthetic bacteria and commensal bacteria in the discharged water after the main treatment. The method of claim 1, wherein the manure treatment method is an activated sludge treatment step of precipitating photosynthetic bacteria and symbiotic bacteria and treating the remaining supernatant in an activated sludge tank, and treating the effluent water treated from the activated sludge tank by catalytic oxidation. And a second precipitation step of precipitating and releasing the precipitate in the effluent of the catalytic oxidation step. Anaerobic digestion tank that decomposes organic matter in the manure under anaerobic conditions, chemical treatment tank separating solid solution by adding flocculant to the manure treated in the anaerobic digestion tank, and decomposing the supernatant of the manure treated in the chemical treatment tank into organic acid and low molecular substance An organic nutrient microbial tank having a microorganism to be treated, and a manure processing apparatus including a photosynthetic symbiotic microbial tank including a photosynthetic bacterium for treating the organic matter of the manure introduced from the nutrient microbial tank. According to claim 10, wherein said photosynthetic symbiotic tank is a photosynthetic symbiotic microorganism treatment apparatus further comprising photosynthetic bacteria and symbiotic bacteria. 11. The manure processing device according to claim 10, wherein the manure processing device further comprises a photosynthetic bacteria bath for supplying photosynthetic bacteria to the photosynthetic symbiotic bacteria. 11. The manure processing device according to claim 10, wherein the manure processing device further comprises a photosynthetic precipitation tank for precipitating photosynthetic bacteria and commensal bacteria in the treated water discharged from the photosynthetic combiotic bath and separating solid solution. The method of claim 13, wherein the manure treatment device is an activated sludge tank for treating the supernatant of the discharged water discharged from the photosynthetic precipitation tank, a contact oxidation tank for contact oxidation of the discharged water discharged from the activated sludge tank, A sedimentation tank further comprising a sedimentation tank of suspended matter discharged from the contact oxidation tank.