KR100443068B1 - Microbial Agent for Waste Water Treatment - Google Patents

Abstract

The present invention relates to a microbial material used for wastewater treatment, and it is a microorganism that decomposes proteins and lipids . Bacillus sp. And hydrogen sulfide (H ₂ S) or sulfur (S) are oxidized to odor. Acid generating microorganisms to be removed are Thiolcillus sp. , Alcaligenes sp. , Flavobactrium sp. , Purple sulfur bacteria , carbohydrates, ABS and hexane. (hexane), phenol (phenol), hydrocarbons (organic) and other microorganisms that decompose hardly decomposable substances, such as red non-sulfur bacteria ( Pseudomonas sp. ), the genus Coomamonas ( Comamonas sp. ), And nitrifying microorganisms include 10 genus and 27 natural microorganisms of Nitrosomonas sp. , Nitrobacter sp. And Nitrococcus sp. Sewage and wastewater, characterized in that configured For relates to a microorganism.

The microbial agent for wastewater treatment according to the present invention has the effect of increasing the extinguishing efficiency of an anaerobic digester by using a natural microbial agent to cope with the decrease in efficiency due to insufficient capacity of the existing digester.

In addition, by introducing the microbial material of the present invention, the effect of eliminating dead zones in the digester and sedimentation of the two-stage digester is improved, and water quality is improved by reducing the concentration of COD and SS in the digester's supernatant. Due to the organic removal rate, the reduction of organic matters increases the dehydration rate, reduces the use of polymer coagulant, and reduces the sludge land and sea treatment costs.

In particular, the microbial agent of the present invention has the advantage of reducing the final sludge generation of waste water, waste gas increases the amount of gas to be used as an energy source.

Description

Microbial Agent for Waste Water Treatment

The present invention relates to a microbial material for wastewater treatment, and more particularly, to a microbial material for wastewater treatment, characterized in that to increase the extinguishing efficiency by using a natural microbial material in an anaerobic digester for treating sewage sludge. It is about.

The general anaerobic digestion process is the main treatment technology for stabilization and high concentration of organic wastewater and wastes for the final disposal of sewage sludge from sewage treatment plant, and has less secondary pollution problems than other physical and chemical treatments. Despite the advantages, the processing time is long, and due to the disadvantages such as the generation of odors are used in a limited situation. In addition, it is expected that the capacity of the existing digester will be insufficient due to the increase of the total amount of inflow due to the expansion of the detention house, the increase of the inflow of living sewage, and the inflow of manure of nearby new apartments.

The digester that is widely used in anaerobic digestion process, low oil tank type called Anglo-American, and egg type digester called Egg-shaped which is rapidly increasing in use. Digestion efficiency is reduced because the stirring efficiency is lowered due to the increase of dead volume and scum in the digester. In this paper, “Slurry Digester Performance Diagnosis Using Radioisotope Tracer” (3) published by Sung-Hee Chung and others (1999. Journal of Environmental Engineering, 21 (12)), ⁴⁶ Sc-EDTA solution of about 13mCi as a radioisotope tracer. As a result of measuring the change in radiometric value by introducing into the digester, it has been found that there is a significant dead volume inside the digester.

Therefore, as a way to solve the above problems, many studies on microorganisms for wastewater treatment and patents have been filed, but the process of converting organic substrates to methane by microorganisms in the digester is a very complicated process. Numerous microbial communities are involved, and their own substrate and specificity of products are related to each other, so they are sensitive to the surrounding environment. Therefore, the sludge's physical and chemical characteristics must be considered for efficient operation of the digester. The concentration and composition of the substance, the moisture content of the sludge, the nutrients, the presence and concentration of toxic substances, the operating temperature, the alkalinity, the pH and the content of biodegradable substances should be determined.

The present invention is to improve the above problems, to provide a microbial agent for wastewater treatment, characterized in that to increase the digestive efficiency of the anaerobic digester using a natural microbial agent.

Another object of the present invention is to improve the effect of removing the dead volume in the digester and the sedimentation of the two-stage digester, the chemical oxygen demand (COD) of the digester supernatant and suspended solids (SS) It is to provide a microbial material for wastewater treatment, characterized in that the water quality improvement effect according to the decrease in concentration.

Another object of the present invention is to show a higher removal rate of organic matter as the microbial agent is added, dehydration increases due to the reduction of organic matter, reducing the amount of polymer coagulant used, and the sludge land and marine treatment costs, characterized in that the effect of reducing costs To provide a microbial material for wastewater treatment.

Still another object of the present invention is to provide a microbial material for wastewater treatment, characterized in that the final sludge generation amount is reduced, and the gas generation amount is increased to be utilized as an energy source.

Figure 1a is a graph showing the pH change when no microbial agent added during the pilot plant operation

Figure 1b is a graph showing the pH change when the microbial material input during the pilot plant operation

Figure 2a is a graph showing the change in alkalinity when no microbial agent added during the pilot plant operation

Figure 2b is a graph showing the change in alkalinity during the introduction of microbial material during the pilot plant operation

Figure 3a is a graph showing the change in VS / TS (%) when no microbial agent was added during the pilot plant operation

Figure 3b is a graph showing the change in VS / TS (%) when the microbial material input during the pilot plant operation period

4 is a graph showing changes in organic matter removal amount during a pilot plant operation period.

FIG. 5A is a graph showing the change in actual gas generation amount per inflowed organic matter during pilot plant operation

FIG. 5B is a graph showing the change of theoretical gas generation amount per inflowed organic matter during pilot plant operation

6 is a graph showing the change of the CO ₂ gas ratio during the pilot plant operation period

7 is a graph showing changes in fire extinguishing efficiency during a pilot plant operation period.

8 is a graph showing the change in the concentration of COD _Mn during the pilot plant operation period

9 is a graph showing the change in SS concentration during the pilot plant operation

The present invention relates to a microbial agent for wastewater treatment, characterized in that the digestion efficiency can be increased by introducing a natural microbial agent into the anaerobic digester for treating sewage sludge.

The microorganisms contained in the microbial agent for wastewater treatment according to the present invention include microorganisms that decompose undissolved protein, microorganisms that degrade lipids, carbohydrates and organic compounds, and nitrided microorganisms that fix nitrogen in air and water. Microorganisms that decompose hardly decomposable substances in wastewater, etc. These microorganisms may be used as a single species depending on their application, but usually, microorganisms in which several kinds of microorganisms are adsorbed and cultured, and preferably all of them are mixed and cultured simultaneously. Culture materials can be used.

The above-mentioned microorganisms are all known strains, and microorganisms that degrade proteins and lipids are Bacillus macerans of Bacillus sp. , Bacillus subtilus , Bacillus rickenformis ( Bacillus licheniformis ), Bacillus polymyxa , and acid-producing microorganisms that remove odors by oxidizing hydrogen sulfide (H ₂ S) or sulfur (S). Thiobacillus , a purple sulfur bacterium. sp.) of the thio Bacillus Novellus (Thiobacillus novellus), thio Bacillus thio oxy residence (Thiobacillus thiooxidans), thio Bacillus dinayi tree pecan switch (Thiobacillus denitrificans), thio Bacillus thio wave Ruth (Thiobacillus thioparus), alkali jeneseu in (Alcaligenes sp. ) of alkali jeneseu dinayi pecan tree's (Alcaligenes denitrificans), Plastic Plastic bobak beam bacterium of the genus Solarium (Flavobactrium sp.) Terry Organic compounds, such as Aqua-butyl (Flavobactrium aquatile), Flavobacterium okay cyano Cedi lactofermentum (Flavobactrium oceanosedimentum) and carbohydrate and ABS, hexane (hexane), phenol (phenol), a hydrocarbon (hydrocarbon) and I to decompose the decomposable material also of a microorganism scarlet non-sulfur bacteria (Purple non-sulfur bacteria) Pseudomonas irregularities disk (Rhodopseudomonas viridis), also Pseudomonas Palouse tris (Rhodopseudomonas palustris), also RY rilrum Molly ski annuum (Rhodospirillum molischianum), also RY rilrum pulbum (Rhodospirillum fulvum ), Rhodospirillum centenum , Rhodospirillum rubrum , Rhodobacter sphaeroides , Pseudomonas sp. ) Of Pseudomonas fluorescein sense (Pseudomonas fluorescens), Nello lease (Pseudomonas citronellolis) as Pseudomonas sheet, Pseudomonas seutut jjeri (Pseudomonas stutzeri), Pseudomonas footage is (Pseudomonas putida), Pseudomonas siring Guy (Pseudomonas syringae), coma Pseudomonas genus (Comamonas sp. coma Pseudomonas Testo Ste Ronnie (Comamonas testosteroni) a), a nitride microorganisms nitro consumption eggplant passage paeah of consumption eggplant in (Nitrosomonas sp.), nitro, (Nitrosomonas europaea), in bakteo nitro (Nitrobacter sp.) may consist of natural microorganisms in the 10 species of the cock 27 kusu Mobilis (Nitrococcus mobilis) nitro, a nitro bakteo wino Grad ski (Nitrobacter winogradskyi), pinto kusu in (Nitrococcus sp.) nitro.

The microbial agent of the present invention acts on all microorganisms, including aerobic or anaerobic bacteria, regardless of the presence of light, acid or alkaline, and without the supply of oxygen in the aeration tank or the nutrition of nitrogen (N), phosphorus (P) It works well, is not affected by rapid temperature changes, works well in organic compounds, biological oxygen demand (BOD, hereinafter called 'BOD'), chemical oxygen demand (COD, `` COD '') and suspended The reduction of materials (SS, hereinafter referred to as 'SS') as well as the odor can be quickly decomposed.

The basic process of removing the sludge of the microbial material of the present invention is as follows. In the process of accumulating organic matter dissolved in the wastewater and wastewater in the body, microorganisms produce carbon dioxide and water as shown in the following equation (1).

BOD + N + P + O ₂ → CO ₂ ↑ + H ₂ O + Cells (1)

Here, dissolved organic matter is expressed as BOD, and when nitrogen (N) and phosphorus (P) necessary for energy transfer are accumulated in the body of bacteria, and the organic material is not enough to feed the bacteria, the following equation (2) Digestion process such as will occur.

Cells + O ₂ → CO ₂ ↑ + H ₂ O + N + P (2)

In a batch system such as sludge pits or reservoirs, bacteria grow and breathe internally, exhaling carbon dioxide and leaving only minerals in the water. This process is often called "mineralization".

The amount of sludge produced relative to the total amount of organics treated throughout the digestive system is also known as the yield coefficient (Yc), or the food-microorganism rate. The total amount of BOD / biological total solids in the system at that day is defined as the concentration of activated sludge (MLSS) / concentration of BOD in the mixture.

In a fully mixed activated sludge digestion system, the F (Food) organic concentration is uniform throughout the aeration tank and equals the effluent organic concentration. The equilibrium concentration of organic matter refers to the amount of organic matter that must be decomposed in the environment in which the microorganisms are located. Since the concentration of organic matter in the effluent is close to 1 ppm, the microorganisms have little energy to maintain their lives. The minimum energy required to keep a microorganism intact is called 'cell maintenance energy', which is the energy the microorganism needs to control entropy (the tendency to escape as much as possible). Microorganisms need energy to perform the digestion process, and when more energy is available for microbial preservation, the microorganisms can synthesize and reproduce new materials.

In wastewater treatment plants such as sewage treatment plants, there is a direct relationship between the organic equilibrium concentrations and production yield coefficients. Lowering the equilibrium F / M ratio reduces sludge production.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited by Examples.

1. Experimental Materials

end. Microbial agent of the present invention

The bacteria constituting the microorganism preparation of the present invention are composed of 10 genus 27 kinds of natural microorganisms, and the number is 350 million per 1 milliliter (3.5 × 10 ⁸ CFU / mL = 3.5 × 10 ¹¹ CFU / L) The above exist, the type of bacteria of the microbial agent of the present invention is as shown in Table 1 below. The microbial agent of the present invention contains Pseudomonas sp. , Which is mainly found in general ecosystems, and also contains nitrifying bacteria that oxidize nitrogen.

TABLE 1

Bacterial colony Genus and species Purple non-sulfur bacteria Rhodopseudomonas viridis Rhodopseudomonas palustris Rhodospirillum molischianum Rhodospirillum molischianum Rhodospirillum fulvum Rhodospirillum duldoil thoril rumil rum rubrum ) Rhodobacter sphaeroides Purple sulfur bacteria Thiobacillus novellus Thiobacillus thiooxidans Thiobacillus denitrificans Thiobacillus thioparus Pseudomonas (Pseudomonas) Pseudomonas fluorescens Pseudomonas citronellolis Pseudomonas stutzeri Pseudomonas putida Pseudomonas putida Pseudomonas syringae Alcaligenes Alcaligenes denitrificans Flavobactrium Flavobactrium aquatile Flavobactrium oceanosedimentum Nitrobacter Nitrobacter winogradskyi Nitrosomonas Nitrosomonas europaea Nitrococcus Nitrococcus mobilis Comamonas Comamonas testosteroni Bacillus (Bacillus) Bacillus macerans Bacillus subtilus Bacillus licheniformis Bacillus polymyxa

The properties and compositional test and heavy metal test results of the microbial agent of the present invention used in the experiment are shown in [Table 2] and [Table 3], respectively. The number of microorganisms in the microbial agent is 5.0 × 10 ¹¹ CFU / L (microbial colonies per liter), smells of hydrogen sulfide and reddish purple. pH was 7.15 and specific gravity was 1.002, respectively.

TABLE 2

division Microbial Count (CFU / L) smell color pH importance Volatile Volume (%) The present invention 5.0 × 10 ¹¹ Hydrogen sulfide Fuchsia 7.15 1.002 96.3

TABLE 3

(Unit: mg / L)

division Cu Mn CD Zn Fe Pb As Hg The present invention ND ¹⁾ 0.010 N.D 0.260 N.D N.D N.D N.D

* 1) N.D (Not detected): Not detected

I. Sewage sludge used in the present invention

Sludge used in the present invention was used sewage sludge transported to the digestion tank in the concentration of the sewage treatment plant in Busan Metropolitan City, the characteristics of the sewage sludge is shown in [Table 4]. The pH ranged from 6.0 to 6.5, with weak acidity and alkalinity ranging from 460.0 to 860.0 mg / L. According to McCarty and McKinney, ammonia nitrogen during anaerobic digestion was reported to have no effect in the concentration range of 50-200 mg / L, since ammonia nitrogen was 73.2 to 92.4. In the range of mg / L, the effect on ammonia toxicity was minimal.

TABLE 4

division unit Concentration (range) pH - 5.94-6.52 Alkalinity mg / L as CaCO ₃ 460.0 to 860.0 TS % 2.72 ~ 4.14 VS % 1.73-2.82 VS / TS % 64.1-71.0 TCOD mg / L 8,976.0-10,220.0 SCOD mg / L 165.2-185.2 TBOD mg / L 6,879.2-9,154.4 SBOD mg / L 561.7-629.7 Cl ^- mg / L 166.6-606.2 NH ₄ ⁺ -N mg / L 73.2-92.4

* TS (Total Solids): Total Solids

VS (Volatile Solids): Volatile Solids

Total Chemical Oxygen Demand (TCOD): Total COD

Solution Chemical Oxygen Demand (SCOD): COD of filtered filtrate

Total Biochemical Oxygen Demand (TBOD): Total BOD

Solution Biochemical Oxygen Demand (SBOD): BOD of filtered filtrate

2. Experiment apparatus

Anaerobic batch test apparatus for the selection of microbial agents and pilot plant experimental apparatus were used to test the anaerobic digestion efficiency of selected microbial agents. In a lab-scale experiment, 1,000 mL of sewage sludge and 10 mL of microbial material were injected into a 2 L mass flask with an effective capacity, and the top of the reactor was sealed with a silicone stopper to maintain anaerobic conditions. The gas was removed by saturation in water. Stirring was performed about 3 to 4 times / day using a magnetic stirrer. To maintain a constant temperature digestion condition of 35 ± 1 ℃ was placed in an incubator (Incubator), the experiment was performed for 20 days. In addition, agitation was performed for 15 days, and left for natural precipitation without stirring for 5 days, and then a part of the lower sludge precipitated was collected and used for the experiment.

The pilot plant experimental apparatus was installed in the form of a two-stage anaerobic digester, which is the same as the digester in the Busan Sewage Treatment Plant, which is treating sewage sludge, and the sewage sludge and the microorganism material of the present invention are installed in a mixed storage tank having an effective capacity of 1.3 m ³ . Injected. 1 and 2 is a standards body of the digester diameter 2.2m, 3.2m high, 9.5m ³ effective dose circular tank material was manufactured by using a steel plate, and the processing method to prevent corrosion of the iron plate was inside. The digestion method was maintained at 35 ± 1 ℃ as a medium temperature high rate two-stage anaerobic digestion tank, and the one-stage digestion tank was attached with a stirrer for smooth mixing of microorganisms and substrates in the reactor, and the stirrer was operated at 120rpm to be completely mixed in the reactor. Drive to lose. In the two stage digester, stirring was not performed to separate the digested sludge and the supernatant. In addition, in order to maintain at 35 ± 1 ℃, which is a medium temperature digestion condition, the outside of the reactor was wrapped with glass fiber and the heating wire was wound around the inside of the reactor to be heated. The influent sewage sludge was allowed to be continuously injected into the reactor using a mono pump. A gas meter was installed at the top of each digester to measure the amount of digested gas, and a gas collecting port was installed at the top for gas analysis. A water sealing device was attached to the stirrer shaft to prevent leakage of generated gas and inflow of air between the stirrer shafts.

3. Analysis method

The analytical method of the present invention is shown in [Table 5]. The injected samples were analyzed every 2 to 3 days. To evaluate the operating characteristics of each operation, samples were collected in the reaction tank, and total solids (TS, hereinafter referred to as 'TS') and volatile solids (VS, hereinafter referred to as 'VS'). "referred _{to), pH, COD Mn, Cl} -, to measure the alkalinity (alkalinity). pH The pH was measured by a metadata (meter), TS, VS, COD Mn, Cl -, alkalinity (Alkalinity) were analyzed by standard methods (Standard methods) and waste process test.

TABLE 5

division unit Analytical Method pH - pH meta Alkalinity mg as CaCO ₃ / L Base titration COD _Mn mg / L KMnO ₄ law SS mg / L GF / C Decompression Filtration TS mg / L Total solids dried at 103-105 ℃ VS mg / L Volatile solids heated at 550 ° C Cl ^- mg / L Proper law NH ₄ ⁺ -N mg / L Indo-Phenol Method gas % Gas count meta

4. Operation condition

The operating conditions of the present invention are shown in [Table 6]. In fact, pilot plant experiments were conducted with the same number of days of extinguishing and the temperature of digestion at Suyoung sewage treatment plant in Busan.

TABLE 6

division Pilot plant Days of digestion 1 stage digester 15 2-stage digester 5 Digestion temperature (℃) 35 ± 1 Sewage sludge inflow (m ³ / day) 0.65 Microbial injection amount (L / day) 0.5 Stirring speed of 1-stage digestion tank (rpm) 120

(Example 1)

27 strains of microbial strains were purely isolated using 500 sludge samples collected from soils and streams in Busan. 0.1 g of the sample was suspended in 9.9 mL of physiological saline (NaCl 0.85%), diluted 105-fold, plated on a nutritious agar medium, and incubated at 30 ° C. for 48 hours. And subcultured to select strains excellent in material resolution. The results of measuring the material degradation ability of the selected microbial group are shown in the following [Table 7].

TABLE 7

＼ Degradable strain ＼ Protein, lipolytic ability Carbohydrate Degradation Ability Nitriding ability H ₂ , CH ₃ CH magnetization Hardly degradable substance Red non-sulfur bacteria + ++ - - - Red sulfur bacteria + - - ++ - Pseudomonas genus + ++ - - - Alkalins - - - ++ - In the Flavobacterium - - - ++ - Niobacter - - ++ + - Nitrosomonas - - ++ + - Nitrococcus - - ++ + - Comamos genus - - - - ++ Bacillus genus ++ - - - -

* ++: Very good, +: Good,-: No decomposition

(Example 2)

Each microorganism liquid isolated and cultured in Example 1 and the obtained microbial group were placed in a nutrient broth at pH 6.8 for 12 hours with known natural microorganisms (27 species), beef extract 3g, peptone 5g, agar 15g. , 1mL of 1L of distilled water mixed and cultured at 30 ~ 35 ° C was inoculated into sewage with 1,000 ppm of BOD to measure growth activity. The results are shown in the following [Table 8].

TABLE 8

＼ Time Category ＼ 0 One 5 10 20 Mixed culture - ++ +++ +++ +++ Red non-sulfur bacteria - + ++ ++ ++ Red sulfur bacteria - + ++ ++ ++ Pseudomonas genus - + ++ ++ ++ Alkalins - + ++ ++ ++ In the Flavobacterium - + ++ ++ ++ Niobacter - + ++ ++ ++ Nitrosomonas - + ++ ++ ++ Nitrococcus - + ++ ++ ++ Comamos genus - + ++ ++ ++ Bacillus genus - + ++ ++ ++

* +++: Very good, ++: Good, +: Weak,-: Bad,-: Extremely bad

(Example 3)

In order to determine the proper injection amount of the microbial agent, the experiment was performed while varying the injection ratio of the microbial agent of Example 1 to sewage sludge.

TABLE 9

Injection amount of microbial agent (ratio) Analysis item Microbial material / sewage sludge injection ratio TS (%) VS / TS (%) Digestion efficiency (%) 1 / 2,000 3.75 56.1 43.7 1.0mL / 2L 1 / 1,500 3.86 54.2 47.8 1.3 mL / 2 L 1 / 1,250 4.03 52.8 50.7 1.6mL / 2L 1 / 1,000 3.98 53.7 48.9 2.0mL / 2L 1/500 3.86 54.8 46.5 4.0mL / 2L

As a result of the experiment, the injection ratio of the microbial agent / sewage sludge was the highest at the digestion efficiency of 50.7% at 1 / 1,250. In the pilot plant experiment, the injection amount of the microbial agent of Example 1 was injected with 1.6mL per 2L of sewage sludge. It was.

(Example 4)

Pilot plant test results of microbial preparations according to the present invention

end. pH change

PH changes when the microbial agent was not added and the microbial agent prepared in Example 1 were added are shown in FIGS. 1A and 1B, respectively, and the average values are shown in [Table 10].

When the microbial agent of FIG. 1A was not added, the pH of the influent sewage sludge ranged from 6.1 to 6.6 (average 6.3), and the pHs from the single and two stage digesters were 6.8 to 7.0 (average 6.9) and 6.9 to 6.9. The range of 7.2 (average 7.0) is shown respectively.

On the other hand, when the microbial agent of Example 1 of Figure 1b was added, the pH of the influent sewage sludge showed a range of 6.0 to 6.5 (average 6.1), and the pH of the single-stage digestion tank and the two-stage digestion tank was 7.0-7.3 ( The average range of 7.1) was higher than when the microbial agent was not added.

This is due to the active growth of acid-producing bacteria and methane-producing bacteria when organic matters are ingested due to increased microbial activity.

In the mixed storage tank, the pH was 6.0 and the inflow water for anaerobic digestion was relatively low.However, the pH in the digestion tank mixed with microorganisms was kept neutral so that the pH range of 6.0-8.0 (Benefield, LD and CW Randall., 1992), indicating that there was no adverse effect on pH during operation.

I. Change in alkalinity

When the microbial agent is not added and the microbial agent of Example 1 is added, the alkalinity change of the pilot plant is shown in FIGS. 2A and 2B, respectively, and the average values are shown in [Table 10].

As shown in FIG. 2A, the alkalinity of the influent sewage sludge was found to be in the range of 460 to 840 mg / L (average 611 mg / L) when the microbial agent was not added, and the alkalinity of the 1 and 2 stage digesters was 2,170, respectively. ˜2,400 mg / L (mean 2,277 mg / L) and 2,385 to 2,520 mg / L (mean 2,443 mg / L).

On the other hand, when the microbial preparation of Example 1 was added to the digester of Figure 2b, the alkalinity of the influent sewage sludge appeared in the range of 465 to 860 mg / L (average 548 mg / L), Case alkalinity ranged from 2,560 to 2,940 mg / L (mean 2,718 mg / L) and 2,710 to 3,025 mg / L (mean 2,884 mg / L), respectively.

As a result of treatment, the alkalinity of the microbial agent was increased to about 5.3 times and 4.0 times, respectively.

This phenomenon is seen as an increase in the alkalinity due to the microbial preparation of Example 1, generally 1000 _~ 5,000mg as CaCO ₃ / L, the allowable alkalinity in the anaerobic digestion tank (Ministry of Environment, Design of wastewater treatment facilities, 1995) It appears to be sufficiently satisfactory for the addition of an artificial alkali agent to separate pH drops.

All. Changes in VS / TS

The changes in VS / TS (%) of the microbial products in the inflow sewage sludge, the single stage digester and the two stage digester, and the microbial formulation of Example 1 during the pilot plant operation are shown in FIGS. 3A and 3B, respectively. The average value is shown in [Table 10].

When the microbial agent of FIG. 3A was not added, the VS / TS (%) of the influent sewage sludge showed a range of 64.1 to 66.2% (average 66.3%), and the VS / TS (%) of the single and second stage digesters. The ranges ranged from 52.2 to 55.1% (average 53.7%) and 49.1 to 51.7% (average 50.3%). On the other hand, when the microbial agent of Example 1 was added to the digester of FIG. 3b, the VS / TS (%) of the influent sewage sludge was found to be in the range of 66.7-71.0% (average 68.2%). In the case of two-stage tanks, the VS / TS (%) ranged from 49.1 to 53.3% (average 51.0%) and 47.6 to 51.8% (average 49.5%). Overall, VS / TS (%) of sewage sludge was about 16.0% and 18.7%, respectively, with and without microbial agents. The decrease in organic matter was found to be greater.

la. Organic matter removal amount

The amount of organic matter removal in the digester during the operation period is shown in FIG. 4 and the average value is shown in [Table 10].

When the microbial agent is not added, it is shown as 7.13 ~ 5.39kg / d (average 6.18kg / d), whereas when the microbial agent of Example 1 is added 9.84 ~ 5.95kg / d (average 7.65kg / d), The amount of organic matter removed in the digester when the microbial agent of Example 1 was added was about 1.24 times higher than that when the microbial agent was not added.

hemp. Digestion Gas Generation

The actual gas generation amount and the theoretical gas generation amount per inflow organic matter during the pilot plant operation are shown in FIGS. 5A and 5B, respectively, and the average values are shown in [Table 10].

In anaerobic digestion of sewage sludge, a digestive gas based on methane is obtained. The content of methane in the generated gas is about 60 ~ 70% by volume, and the rest is divided into carbon dioxide and a small amount of nitrogen, minority, and hydrogen sulfide. The specific gravity of the generated gas is about 0.86 compared with air, and the efficiency of extinguishing can be determined based on the amount of gas generated. The gas generated is highly flammable and can be used to obtain useful energy.

In general, the theoretical amount of methane is the methane generation of 0.39m ^3, assuming the standard state temperature of the digester, so that this COD 1kg of 0.35m ³ methane generated when the 100% complete decomposition in (0 ℃, 1 atm) to 35 ℃ do. Since the rate of organic matter conversion to cells is very small, the theoretical gas generation rate / inflow organic matter amount was calculated on the assumption that the digestion efficiency was 50% and the gas generation rate per kg of decomposed organic matter was 0.6m ³ .

If the actual generation amount / incoming organic matter is not turned up to the microorganism 0.28m ³ / kg · d, were found to at least 0.08m ³ / kg · d (average 0.19m ³ / kg · d), Example 1 in the case where the microorganism found to be up to 0.30m ³ / kg · d, at least 0.24m ³ / kg · d (average 0.28m ³ / kg · d). Accordingly, the amount of digestive gas generated was about 1.47 times higher than that of the microbial agent, which was increased by the injection of the microbial agent of Example 1. This is due to the increase in gas generation through organic matter removal. When comparing the actual gas generation / inflowed organic matter and theoretical gas generation / inflowed organic matter, the actual gas generation when no microbial agent was added occurred about 65.5% of theoretical gas generation. The actual gas generation amount was about 84.8% of theoretical gas generation amount.

bar. CO ₂ Ratio in Digestive Gases

The ratio of CO ₂ in the extinguishing gas during the pilot plant operation is shown in FIG. 6, and the average value is shown in [Table 10].

When the microbial agent was not added, the result was 22.5-27.0% (average 24.0%), whereas the microbial agent of Example 1 was 17.5-22.5% (average 20.1%). The ratio of CO ₂ in the digestive gas was lower by about 3.9%.

four. Extinguishing efficiency

During the pilot plant operation, the extinguishing efficiency of the microorganism preparation of Example 1 and the case of not injecting is shown in FIG. 7, and the average value is shown in [Table 10].

The digestive efficiency of the digester in anaerobic digestion of sewage sludge was calculated using the following equation.

here,

D: Digestion efficiency of anaerobic digester (%)

FS ₁ : Inorganic Components (%) in the input sludge

VS ₁ : Organic Components (%) in the input sludge

FS ₂ : Inorganic Components in Digestion Sludge (%)

VS ₂ : Organic Components in Digested Sludge (%)

When the microbial agent was not added, the extinguishing efficiency was 46.0 to 50.9% (average 48.6%), whereas when the microbial agent of Example 1 was added, the extinguishing efficiency was 52.8 to 57.3% (average 54.2%). The digestion efficiency of the microbial agent was 1.12 times higher than that of the microbial agent. This is because digestion efficiency is increased because the amount of microorganisms added is higher in the amount and activity of anaerobic microorganisms than in the case of not adding microbial agents.

Ah. Change of COD _Mn Concentration in Overflow Water

The COD _Mn concentration change of the two-stage tank overflow water during the operation period is shown in FIG. 8 and the average value is shown in [Table 10].

When no microbial agent was added, the concentration change of COD _Mn ranged from 1,232 to 2,450 mg / L (average 1,639 mg / L). On the other hand, in the digester in which the microbial agent of Example 1 was added, COD _Mn was found to be in the range of 537-1,390 mg / L (average 859 mg / L). Therefore, the concentration of COD _{Mn in the} effluent was about 1.91 times lower than in the case of adding the microbial agent of Example 1, which was lower than that of the microbial agent. This is because the decomposition of solids occurred more quickly.

character. SS concentration change

The change in SS concentration of the two-stage tank overflow water during the operation period is shown in Figure 9, the average value is shown in [Table 10].

During the operation period, the concentration of SS was found to be in the range of 3,960 to 6,040 mg / L (average 4,888 mg / L) when the microbial agent was not added. SS concentrations ranged from 976 to 3850 mg / L (mean 2,405 mg / L). As a result of anaerobic digestion of sewage sludge, it was found that the addition of microbial agents could improve the effluent quality about 2.0 times than that without microbial agents. This is due to the increase in the decomposition of organic matter due to the injection of the microbial agent of Example 1, the sedimentation of the two-stage tank effluent more increased, the lower the concentration of SS.

TABLE 10

division No microbial material added Microbial input Influent Sewage Sludge 1 stage digester 2-stage digester Influent Sewage Sludge 1 stage digester 2-stage digester pH 6.3 6.9 7.0 6.1 7.1 7.1 Alkalinity (mg / L) 611 2,277 2,443 548 2,718 2,884 VS / TS (%) 66.3 53.7 50.3 68.2 51.0 49.5 Organic matter removal amount (㎏d) - - 6.18 - - 7.65 Gas generation amount (㎥ / ㎏ · d) (actual gas generation amount / inflowed organic matter amount) - - 0.19 - - 0.28 % CO ₂ - - 24.0 - - 20.1 Digestion efficiency (%) - - 48.6 - - 54.2 COD _Mn (mg / L) - - 1,639 - - 859 SS concentration (mg / L) - - 4,888 - - 2,405

car. Comprehensive Comparison of Pilot Plant Experiments

The experimental results of the case of adding the microbial agent of Example 1 and the case of the non-injection of the microorganism during the operation of the pilot plant are shown in [Table 11].

TABLE 11

division No microbial material added Microbial input Digestion tank inflow sludge ¹⁾ (㎥ / d) 1,200 1,200 Digestion Sludge Generation ²⁾ (㎥ / d) 923.1 830.8 Dehydration cake generation amount ³⁾ (water content: 80%) (ton / d) 178.6 122.1 Coagulant input amount ⁴⁾ (Input ratio: 0.55%) (kg / d) 196.5 134.3 Gas generation amount ⁵⁾ (㎥ / d) 4,430.8 9,230.8 Upper quantity ⁶⁾ (㎥ / d) 276.9 369.2 Constant COD Load ⁷⁾ (㎏ / d) 453.8 419.9

As shown in [Table 11], when the microbial preparation of Example 1 was added, the amount of digested sludge and dehydrated cake was significantly reduced as compared with the case where the microbial preparation was not added. In addition, the amount of gas generated increased more than two times, and the amount of supernatant also increased, indicating that the extinguishing efficiency is excellent.

1) Calculation basis for each item

A) Blank test (when microorganisms are not added)

▷ Digestion sludge TS: 3.87%, VS / TS: 47.4%

* 1) Sludge inflow of digester: 1,200㎥ / d

2) Extinguishing Sludge Generation: (0.50㎥ / d × 1,200㎥ / d) /0.65㎥/d = 923.1㎥ / d

3) Dehydration cake generation rate (water content = 80%): (923.1㎥ / d × 3.87) / (100-80) = 178.6ton / d

4) Polymer coagulant input (coagulant input ratio = 0.55%)

: 923.1㎥ / d × 1ton / ㎥ × 0.0387 × 1,000 × 0.0055 = 196.5㎏ / d

5) Extinguishing gas amount: (2.4㎥ / d × 1,200㎥ / d) /0.65㎥/d = 4,430.8㎥ / d

6) Digestion tank top water: (0.15㎥ / d × 1,200㎥ / d) /0.65㎥/d = 276.9㎥ / d

7) COD load of digester supernatant

: 276.9m 3 / d × 1,639mg / L × 10 ^-6 kg / mg × 10 ^3L / m ³ = 453.8kg / d

B) Example 1 test (at the time of introduction of microorganisms)

▷ Digestion sludge TS: 2.94%, VS / TS: 53.0%

* 1) Sludge inflow of digester: 1,200㎥ / d

2) Extinguishing Sludge Generation: (0.45㎥ / d × 1,200㎥ / d) /0.65㎥/d = 830.8㎥ / d

3) Dehydration cake generation rate (water content = 80%): (830.8㎥ / d × 2.94) / (100-80) = 122.1ton / d

4) Polymer coagulant input (coagulant input ratio = 0.55%)

: 830.8㎥ / d × 1ton / ㎥ × 0.0294 × 1,000 × 0.0055 = 134.3㎏ / d

5) Extinguishing gas generation: (5.0㎥ / d × 1,200㎥ / d) /0.65㎥/d = 9,230.8㎥ / d

6) Digestion tank top water: (0.20㎥ / d × 1,200㎥ / d) /0.65㎥/d = 369.2㎥ / d

7) COD load of digester supernatant

: 369.2m 3 /d×1,137.2mg/L×10 ^-6 kg / mg × 10 ^3L / m ³ = 419.9kg / d

(Example 5)

Field plant test results of microbial preparations according to the present invention

end. pH, temperature and alkalinity changes

Table 12 shows the pH, temperature and alkalinity test results when the microbial agent was not added during the field plant operation and when the microbial agent of Example 1 was added. The pH of the case of not adding the microbial agent and of the microbial agent of Example 1 was in the range of 7.18 and 7.23, respectively, indicating that there was no adverse effect of pH.

I. Changes in VS / TS

The average value of VS / TS (%) change when the microbial agent was not added and the microbial agent of Example 1 was added during the field plant operation period is shown in [Table 12]. When no microbial agent was added, the VS / TS ranged from 60.5 to 66.0% (average 62.5%), and when the microbial agent of Example 1 was added to the digester, VS / TS was 51.6 to 55.4% (average 52.9%). ), The removal rate of organic matter was increased by about 9.6% compared to the case of no input.

All. Dehydration Cake Test and Digestion Gas Generation

When the microbial agent was not added during the field plant operation and the microbial agent of Example 1 was added, the dehydration cake moisture content, the digestion gas generation amount, and the gas generation amount are shown in [Table 12], respectively. The cake moisture content was 80.2% and 77.7% when the microorganisms were not added and the microorganisms of Example 1 were added, respectively, and the water content was lower when the microorganisms of Example 1 were added. In addition, when the microbial agent of Example 1 was added also in terms of the flocculant input ratio and the amount of digestion gas generated, the effect was higher than that at the time of no input. These results were obtained by reducing the microbial material of Example 1 in the anaerobic digestion tank to reduce the cake moisture content, the coagulant input cost, the amount of digestion gas generated through the removal of organic matter.

la. Extinguishing efficiency

Table 12 shows the average value of the change in digestion efficiency when the microbial agent was not added during the field plant operation and when the microbial agent in Example 1 was added. Digestion efficiency was 22.6 to 35.0% (average 29.4%) when no microbial agent was added, while digestion efficiency was 54.5 to 63.2% (average 59.5%) when the microbial agent of Example 1 was added to the digester. The range of is shown. When the microbial agent of Example 1 was added, the digestion efficiency was about 30% higher than that of the non-injection.

hemp. Changes in COD _Mn and SS Concentrations in Overflow Water

Table 12 shows the results of the digester supernatant and the COD _Mn concentration of the overflowed water when the microbial agent was not added during the field plant operation and when the microbial agent was added in Example 1, respectively. COD _Mn and SS concentrations were 4,793 mg / L and 16,594 mg / L, respectively, when the microbial agent was not added, whereas the COD _Mn and SS concentrations were 4,016 mg / L and 4, respectively. At 14,813 mg / L, the improvement of the effluent quality of the supernatant was greater than that of no microbial agent.

TABLE 12

division No microbial material added Microbial input Influent Sewage Sludge 1 stage digester 2-stage digester Influent Sewage Sludge 1 stage digester 2-stage digester pH 6.09 7.18 7.38 6.07 7.23 7.41 Alkalinity (mg / L) - 2,880 - - 2,790 3,215 VS / TS (%) - - 62.5 - - 52.9 Cake moisture content (%) - - 80.2 - - 77.7 Coagulant input ratio (%) - - 0.87 - - 0.73 Extinguishing gas generation amount (㎥ / d) - - 8,768 - - 16,125 CH ₄ (%) - - 72.5 - - 73.6 Digestion efficiency (%) - - 29.4 - - 59.5 COD _Mn (mg / L) - - 4,793 - - 4,016 SS concentration (mg / L) - - 16,594 - - 14,813

bar. Overall Comparison of Field Plant Experiments

Table 13 summarizes the experimental results when the microbial preparation was not added and the microbial preparation of Example 1 was added during the field plant operation.

TABLE 13

division No microbial material added Microbial input Digestion tank inflow sludge ¹⁾ (㎥ / d) 1,644 1,644 Digestion Sludge Generation ²⁾ (㎥ / d) 1,398 1,378 Dehydration Cake Generation ³⁾ (ton / d) 154.8 144.8 Coagulant input ⁴⁾ (㎏ / d) 247 219 Gas generation amount ⁵⁾ (㎥ / d) 8,769 16,125 Upper quantity ⁶⁾ (㎥ / d) 246 267 Constant COD Load ⁷⁾ (㎏ / d) 1,179 1,072

As shown in [Table 13], the amount of digested sludge and dehydrated cake was significantly reduced in the case in which the microbial agent of Example 1 was added compared to the case in which the microbial agent was not added. In addition, the amount of gas generated increased more than twice, and the amount of supernatant also increased, indicating that the extinguishing efficiency was excellent.

1) Calculation basis for each item

A) On-site plant (if microorganisms are not added)

▷ Digestion sludge TS: 2.03%, VS / TS: 62.6%

* 1) Sludge inflow of digester: 1,644㎥ / d

2) Extinguishing Sludge Generation: 1,398㎥ / d

3) Dehydration cake generation amount: 143.3㎥ / d × 1.08ton / ㎥ = 154.8ton / d

-Cake Generation: (1,398㎥ / d × 2.03) / (100-80.2) = 143.3㎥ / d

-Cake weight: 1.08ton / ㎥

4) Input of polymer coagulant: 247㎏ / d

5) Extinguishing gas amount: 13,490㎏ / d × 0.65㎥ / removed VS㎏ = 8,769㎥ / d

-Removal VS: 1,644㎥ / d × 0.0397 × 0.703 × 0.294 × 1,000㎏ / ㎥ = 13,490㎏ / d

-Theoretical amount of gas generated: 0.65㎥ / VSkg

6) Digestion tank top volume: 1,644㎥ / d-1,398㎥ / d = 246㎥ / d

7) Digestion tank top water COD load

: 246㎥ / d × 4,793㎎ / L × 10 -6 ㎏ / ㎎ × 10 3L / ㎥ = 1,179㎏ / d

B) On-site plant (Example 1 input)

▷ Digestion sludge TS: 2.17%, VS / TS: 52.6%

* 1) Sludge inflow of digester: 1,644㎥ / d

2) Extinguishing Sludge Generation: 1,378㎥ / d

3) Dehydration cake generation amount: 134.1㎥ / d × 1.08ton / ㎥ = 144.8ton / d

-Cake Generation: (1,378㎥ / d × 2.17) / (100-77.7) = 134.1㎥ / d

-Cake weight: 1.08ton / ㎥

4) Polymer coagulant dose: 219㎏ / d

5) Extinguishing gas amount: 24,832㎏ / d × 0.65㎥ / removed VS㎏ = 16,141㎥ / d

-Removal amount of VS: 1,644㎥ / d × 0.0375 × 0.718 × 0.561 × 1,000㎏ / ㎥ = 24,832㎏ / d

-Theoretical amount of gas generated: 0.65㎥ / VSkg

6) Digestion tank top water: 1,644㎥ / d-1,378㎥ / d = 267㎥ / d

7) COD load of digester supernatant water: 267㎥ / d × 4,016mg / L × 10 ^-6 ㎏ / ㎎ × 10 ^3L / ㎥ = 1,072㎏ / d

Therefore, it can be seen that the microbial agent for wastewater wastewater according to the present invention has excellent digestion efficiency and is significantly superior to the case where the microbial agent is not added as a result of comparing the removal ability of organic matter to the sewage and the amount of gas generation.

The microbial agent for wastewater treatment according to the present invention has the effect of increasing the extinguishing efficiency of an anaerobic digester by using a natural microbial agent to cope with the decrease in efficiency due to insufficient capacity of the existing digester.

In addition, by introducing the microbial material of the present invention, the effect of removing dead volume in the digester and sedimentation of the two-stage digester is improved, and water quality is improved by reducing the concentration of COD and SS in the digester supernatant. Due to the high removal rate of organics, the reduction of organics has the effect of increasing dehydration, reducing the use of polymer coagulant, and reducing the cost of sludge onshore and offshore treatment.

In particular, the microbial agent of the present invention has an advantage in that it can reduce the final sludge generation of the waste water, increase the gas generation amount can be utilized as an energy resource.

Claims (1)

Bacillus macerans of Bacillus sp. , Bacillus subtilus , Bacillus licheniformis , Bacillus polymyxa ) and a thio Bacillus Novellus (Thiobacillus novellus) of hydrogen sulfide (H ₂ S) and sulfur (the thio Bacillus (Thiobacillus sp.) S), the acid generator and scarlet sulfur bacteria, a microorganism (Purple sulfur bacteria) to remove odors by oxidation , Thiobacillus thiooxidans , Thiobacillus denitrificans , Thiobacillus thioparus , Alcaligenes denitrificans of Alcaligenes sp. Flavobactrium aquatile , Flavobactrium sp. Tumefaciens okay cyano Cedi lactofermentum (Flavobactrium oceanosedimentum) and carbohydrate and ABS, hexane (hexane), phenol (phenol), a hydrocarbon (hydrocarbon) organic compound and I scarlet non sulfur bacteria, a microorganism for decomposing the decomposable material (Purple non such as -sulfur bacteria) is also Pseudomonas irregularities disk (Rhodopseudomonas viridis), also Pseudomonas Palouse tris (Rhodopseudomonas palustris), also RY rilrum Molly ski annuum (Rhodospirillum molischianum), also RY rilrum pulbum (Rhodospirillum fulvum), also RY rilrum Centennial num (Rhodospirillum centenum ), Rhodospirillum rubrum , Rhodobacter sphaeroides , Pseudomonas sp. ) Of Pseudomonas fluorescein sense (Pseudomonas fluorescens), Nello lease (Pseudomonas citronellolis) as Pseudomonas sheet, Pseudomonas seutut jjeri (Pseudomonas stutzeri), Pseudomonas footage is (Pseudomonas putida), Pseudomonas siring Guy (Pseudomonas syringae), coma Pseudomonas genus (Comamonas sp. coma Pseudomonas Testo Ste Ronnie (Comamonas testosteroni) a), a nitride microorganisms nitro consumption eggplant passage paeah of consumption eggplant in (Nitrosomonas sp.), nitro, (Nitrosomonas europaea), in bakteo nitro (Nitrobacter sp.) a knight bakteo wino Grad ski (Nitrobacter winogradskyi), consists of a nitro-nitro cock kusu in (Nitrococcus sp.) to cock kusu Mobilis 10 natural microorganism of the genus 27 species (Nitrococcus mobilis), 3.5 × 10 11 CFU A microbial agent for wastewater treatment, characterized in that the microbial colonies of / L to 5.0 × 10 ¹¹ CFU / L at the same time mixed culture.