KR20020088528A - Method and apparatus for pretreating high concentration organic waste water - Google Patents

Abstract

The present invention relates to a method and apparatus for pretreatment of high concentration organic wastewater, and more particularly, to a method for pretreatment of high concentration organic wastewater, in which aeration is carried out so that the temperature of the treated wastewater in the reactor is maintained at 25 to 35 ° C and dissolved oxygen at 1 to 5 ppm. Reacting while making; Transferring the reacted wastewater to a settling tank in which the temperature of the wastewater is maintained at 20 to 30 ° C; Returning the microbial sludge precipitated in the settling tank to the reactor and discharging the supernatant water; And it relates to a method for pretreatment of high concentration organic wastewater comprising the step of performing each step repeatedly and an apparatus to which the method is applicable. The method and apparatus of the present invention not only can handle the high concentration of wastewater compared to the existing methods and apparatus, but also the operation is simple and inexpensive, and no additional process is required, and therefore, there is no additional cost. It is effective because it does not cause problems such as pollution and secondary pollution.

Description

Method and apparatus for pretreating high concentration organic waste water

The present invention relates to a method and apparatus for pretreatment of high concentration organic wastewater, and more particularly, to a method for pretreatment of high concentration organic wastewater capable of treating high concentration organic wastewater generated in various industries with 10 times higher load than a conventional biological treatment process. And to an apparatus.

The general biological wastewater treatment process has a low concentration of organic load in the wastewater is 0.5 ~ 1.0 kg-CODcr / ㎥ · day. The reason why the existing biological wastewater process is operated at such a low load is that microorganisms must dissolve organic matter dissolved in the wastewater, form microbial sludge that easily sinks in the sedimentation tank, and dissolve organic material. This is because most bacteria are broken down by bacteria. However, since the bacteria are small in size, they do not sink easily in the water. When the protozoans inhabiting the bacteria live together, the protozoa and the bacteria aggregate to form microbial sludge that easily settles in the water. If the organic material is added to the existing bioprocess at a high load, the first decomposer bacteria will thrive and eventually the microbial ecosystem will be broken, resulting in worsening of the sedimentation of the microbial sludge, resulting in the sludge floating in the sedimentation tank. Water quality deteriorates Related prior arts include Korean Patent Application Nos. 94-10644, 94-26957, 90-13436, 96-1783, 96-28418, and 97-11980.

On the other hand, for the reasons described above, high-concentration organic wastewater having an acidic or basic pH or having a very high salt concentration is usually disposed of after pretreatment by a physicochemical process, or additionally through a biological process to improve water quality.

Commonly used physical and chemical processes include incineration, Fenton, evaporative concentration, or seawater dumping, as shown in Table 1 below. However, incineration has the advantage of oxidizing organic substances most reliably regardless of organic species. In addition to the high investment costs and high operating costs due to fuel, it is difficult to maintain and secondary pollution occurs. In the case of the Fenton process and the evaporation concentration process, the water quality can be met by the legal regulation value only after the wastewater treatment as the pretreatment process and the second treatment as the biological process.The Fenton process has the advantage of low initial investment cost, but the oxidation power to organic matter is weak and the chemical cost It takes a lot of disadvantages. Evaporative concentration has the disadvantage of solving the problem of dealing with the initial investment and fuel cost and the concentrated sludge. In addition, dumping at sea is an undesirable method in terms of preserving the environment and is likely to be prohibited by law. The characteristics of the aforementioned known methods are shown in Table 1 below.

Evaporative concentration Liquid incinerator Fenton oxide Biological process initial investment versus versus small medium Driving cost versus versus versus small Miscellaneous problem Waste Sludge Secondary pollution Large sludge generation Microbial sludge

As mentioned above, the conventional physicochemical processes for known high concentration organic wastewater treatment each have their own problems, and thus there is a need for an improved method.

As a result of extensive research by the present inventors, the method and apparatus according to the present invention are used to treat high concentration organic wastewater, and as a result, it is possible to treat organic matter using a biological process at a load 10 times higher than that used in conventional organic matter treatment. It has been confirmed that the present invention has been completed based on this.

Accordingly, an object of the present invention is to provide a wastewater treatment method capable of treating wastewater having high organic load, low investment cost and operation cost, and no secondary pollution problem.

Another object of the present invention is to provide a wastewater treatment apparatus to which the method is applicable.

Waste water treatment method of the present invention for achieving the above object is a pre-treatment method of high concentration organic waste water, the step of reacting while maintaining the temperature of the treated waste water in the reaction tank to maintain a 25 to 35 ℃ and dissolved oxygen at 1 to 5ppm; Transferring the reacted wastewater to a settling tank in which the temperature of the wastewater is maintained at 20 to 30 ° C; Returning the microbial sludge precipitated in the settling tank to the reactor and discharging the supernatant water; And a step in which each step is repeatedly performed.

Wastewater treatment apparatus of the present invention for achieving the above another object comprises a reactor and a settling tank, the blower for supplying air in the reaction tank, the acid pipe for making the air supplied from the blower into a fine air bubble, and pH, A reaction tank for dissolving organic matters by microorganisms including a sensor for measuring dissolved oxygen, temperature, and electrical conductivity; A first cooling device installed outside the reactor to prevent the temperature rise of the wastewater due to the metabolic heat of the microorganisms in the reaction tank, the wastewater treated from the reaction tank is introduced to precipitate the microorganisms, and the sludge is returned to the reactor. Settling tank to discharge the supernatant; And a second cooling device installed outside the settling tank to maintain the temperature of the wastewater in the settling tank at 20 to 30 ° C.

1 is a view schematically showing a wastewater treatment apparatus according to the present invention.

2 is a view schematically showing a process of treating wastewater using the wastewater treatment apparatus of the present invention.

Figure 3a is a cross-sectional view schematically showing an aeration device used in the sedimentation tank of the wastewater treatment apparatus according to the present invention.

Figure 3b is a plan view schematically showing an aeration device used in the sedimentation tank of the wastewater treatment apparatus according to the present invention.

Figure 4 is a graph showing the results of measuring the daily COD value and the change in treatment efficiency after the inflow of wastewater into the wastewater treatment apparatus of the present invention.

* Brief description of the main symbols in the drawings

10: reaction tank QBR11: wastewater supply pipe,

12: blowa, 13: diffuser,

14: first cooling device, 15: pH sensor

16: dissolved oxygen sensor 17: temperature sensor

18: electrical conductivity sensor 19: acid tank

20: base tank 21: nutrient tank

22: moving tube 23: second cooling device

100: QCF101: discharge pipe

102 conveying pipe 103 sludge conveying pump

104: scraper 105: drawing pump

111: QCF diffuser

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

Referring to Figure 1, the wastewater treatment apparatus of the present invention is largely composed of the reaction tank QBR (Quick Bio Reactor; 10) and the settling tank QCF (Quick Clarifier; 100), more specifically the reaction tank QBR (10), the A wastewater supply pipe 11 for supplying wastewater to QBR, a blower 12 for supplying air to the QBR, a diffuser 13 for making fine air bubbles from the blower, and QBR due to metabolic heat A separate first cooling device 14 for preventing a temperature increase, a sensor for measuring the pH of the QBR (15), the dissolved oxygen (16), the temperature (17), and the electrical conductivity (18), by the sensor According to the measured results, the acid tank (19) and base tank (20) necessary for automatically adjusting the pH of the reaction tank to the appropriate range, the nutrient tank (21) for storing nutrients necessary for the growth of microorganisms, Transfer pipe 22 for moving to the settling tank QCF, wastewater moved to the QCF through the moving pipe The second cooling device 23 for cooling the water, the QCF (100) for sedimenting the sludge in the waste water moved from the QBR, the discharge pipe 101 for discharging the remaining supernatant after the sludge is settled, the sludge precipitated in the QCF To the reaction tank to maintain a high concentration of microorganisms in the QBR, the conveying pipe 102, the sludge precipitated in the QCF sludge conveying pump 103 to cause the microorganisms to be transferred into the QBR through the conveying pipe, microbial sludge in the QCF It consists of a scraper 104 (Scraper 104), a draw pump 105 for drawing the collected sludge, the diffuser 111 for aeration of the QCF.

The aeration device is radially installed at the bottom of the settling tank and may be six or eight branches depending on the settling tank size. Since the scraper must scratch the bottom, the aerator is positioned slightly above the scraper so as not to interfere with the rotation of the scraper. The air inlet pipe in the center part where the air enters should also be installed slightly off center, unlike the rotary shaft of the scraper. The incoming air is branched in the reactor blower and the aeration time is controlled using a valve operated by a timer.

Aeration time is preferably carried out once a day, 30 minutes at a time, and adjust the time and time according to the situation with a timer.

According to a preferred embodiment of the present invention, the capacity of the QBR 10 is about 350 m 3 to a maximum of 400 m 3, and the size is 10,000 × 10 × 10 × 4,200 (mm) in height. The type of the blower 12 is an underwater blower for supplying the aeration tank air, and six units having a capacity of about 400 m 3 / h are used and the power is about 22 Kw. The first and second cooling devices are bioreactor coolers (plate type), which use a separate refrigerant such as groundwater to cooler and microbial fluid to exchange heat. Cooling tower system that is in contact with the heat radiating can be used. The cooling device is largely composed of a cool side (Cool Side) and a hot side (Hot Side), the flow rate of the low temperature portion is about 60 ㎥ / hr, inlet temperature is about 21 ℃, discharge temperature is about 30 ℃, Firefighters are used. The flow rate of the high temperature part of the cooling device is about 150 m 3 / hr, the inlet temperature is about 32 ° C., the discharge temperature is about 28 ° C., and the contents are the microbial liquid of the reactor. A circulation pump is present in the cooling device to circulate the microbial fluid, with a capacity of 150 m 3 / h and a power of about 45 Kw. The cooling device 23 installed in the moving tube 22 in which the wastewater moves from the QBR to the QCF is installed for the purpose of cooling the microbial fluid flowing into the QCF even more than the reaction tank temperature, and the temperature of the microbial liquid through the cooling water. Will drop. The reason why the temperature of the sedimentation tank is lower than that of the reaction tank is because in the sedimentation tank, when the dissolved oxygen is operated for a long time, anaerobic bacteria inhabit and decay inside the sedimentation tank.

The volume of the QCF is 70 m 3, the size is 5,000 × diameter 3,450 (mm) in height. The capacity of the conveying pump 103 which returns the sludge precipitated in the settling tank to the reaction tank has a value of 10 m 3 / h and used two as a spare concept, and the power is 2.2 Kw and is continuously operated. The capacity of the drawing pump for drawing the sludge is the same as that of the conveying pump, but the operation cycle is operated as needed unlike the conveying pump. The cycle is usually about once an hour once a week. The scraper installed in the settling tank rotates at a rotational speed of about 0.1 rpm, and the power is about 0.75 Kw.

Looking at the wastewater treatment method according to the invention with reference to Figure 1 and 2 as follows.

First, the wastewater is introduced into the QBR 10 and stays for a predetermined time, and the microorganisms inhabiting the QBR 10 decompose, oxidize, and multiply organic matter dissolved in the wastewater. During the oxidation and propagation of the microorganisms, QBR 10 is acutely aerated with oxygen supplied in large quantities through the blower 12 and the diffuser 13, and the aeration provides the oxygen necessary for the microorganisms to oxidize the organic matter. In addition, the entire QBR 10 is homogenized. The amount of aeration at this time is determined so that dissolved oxygen (DO) concentration is maintained at 1 to 5ppm. The reason is that if the dissolved oxygen concentration is too high, the utilization of oxygen is lower than the blower capacity, which is uneconomical. On the contrary, if the dissolved oxygen concentration is too low, the efficiency of treatment of waste water is reduced due to insufficient oxygen necessary for microorganisms to decompose waste water. to be.

In this process, organics are converted to carbon dioxide and microbial sludge. If the temperature in the QBR rises due to the increase in the reaction rate due to the large amount of oxygen input, some of the reacting wastewater is sent to the first cooling unit to cool and circulate to prevent excessive temperature rise. At this time, the temperature of the microbial liquid in the reaction tank is maintained at 25 to 35 ° C, but up to 40 ° C is acceptable. The reason is that if the temperature is too low, the microbial activity is lowered and the treatment efficiency of the waste water is lowered. On the contrary, if the temperature is high, the activity is improved, but if the temperature is exceeded, the activity is rapidly reduced and the microorganism is irreversibly killed.

The wastewater treated in the QBR 10 is transferred to the QCF 100 together with the sludge, and is separated into the sludge and the supernatant in the QCF 100. The microorganisms that sink in sludge form in the QCF (100) are collected in the bottom of the sedimentation tank and returned to the QBR (10), and the returned microorganisms participate in the process of decomposing wastewater again. The temperature of the precipitation tank at this time is preferably in the range of 10 to 20 ° C, but it is almost impossible to maintain the temperature at that level in the field. The reason for lowering the temperature of the settling tank is because the microorganisms having the maximum activity in the reactor are introduced into the settling tank, and the settling tank is always kept at a dissolved oxygen concentration of "0". Because. When this phenomenon occurs, the aerobic microorganisms of the reactor introduced into the settling tank are dissolved by the attack of anaerobic microorganisms, resulting in the inability of the settling tank to function.

Through this process, the wastewater treatment method of the present invention can maintain a high microbial concentration (MLSS; mixed liquor suspended solid). The supernatant separated from the microbial sludge in the QCF 100 becomes treated water having a significantly reduced organic concentration, and then proceeds to the next process (general activated sludge biological treatment process).

According to the present invention, the method of the present invention can maintain the pH, dissolved oxygen, electrical conductivity (salt concentration), etc. of the waste water in an appropriate range to increase the treatment efficiency of the waste water. The loading amount (kg.CODCr / m 3 · day) of wastewater suitable for the method of the present invention is 20 or less, preferably 5.0 to 15, and pH is 6.5 to 7.5. In addition, the nutrient is preferably supplied so that the ratio of TOC: N: P is maintained at about 100: 5: 1, and the influent wastewater limit concentration (TOC-ppm) is preferably maintained at about 20,000 ppm or less.

In addition, in the present invention, the high concentration dye wastewater was treated using the method of the present invention. As a result, the dissolved oxygen concentration was drastically reduced from the start of the wastewater supply, and after about 7 days after the wastewater supply, the CODcr value was 670-490. ppm was shown, and the wastewater treatment efficiency was found to be stable at 97%.

As a result, the wastewater treatment method and apparatus of the present invention are similar to the activated sludge which is a conventional biological process in terms of using aerobic microorganisms, but in terms of efficiency, they show many differences from known apparatus and methods. The difference is the high organic load.

Unlike the activated sludge method, which is a conventional biological process as described above, the reason why the organic material can be treated under high load is as follows.

First, in the present invention, the capacity of the blower and the type and quantity of the diffuser were also increased in order to increase the oxygen supply capacity. Second, there is a separate chiller in the apparatus of the present invention that is not present in conventional bioreactors. In the case of wastewater with a high organic load, metabolic heat is generated a lot, so that the temperature in the reaction vessel is increased and the purpose of preventing the activity of the microorganism is reduced by the temperature rise. Third, in addition to the thermometer and pH sensor existing in most existing biological processes, the wastewater treatment apparatus of the present invention is provided with a dissolved oxygen sensor and an electrical conductivity sensor in the reactor, and the sensors maintain a range of input values of the solution in the reactor. Automatically operate other supplementary facilities to enable For example, pH is automatically adjusted by adding acid or base from the acid tank 19 and the base tank 20 according to the pH of the reaction tank input to the sensor, and in the case of salt (TDS: Total Dissolved Solid) It automatically maintains the salt concentration below the set value by automatically adjusting the flow rate of the dilution water flowing in according to the electrical conductivity of the reactor input to. In addition, the dissolved oxygen concentration is controlled by adjusting the operating time of the blower or the amount of aerated air. Fourthly, in the existing apparatus, the sedimentation tank is not aerated or emptied, but in the present invention, a separate aeration apparatus is installed in the sedimentation tank to periodically aeration and sometimes empty the sedimentation tank to prevent anaerobic microorganisms from inhabiting.

The aeration device is radially installed at the bottom of the settling tank and may be six or eight depending on the size of the settling tank. Since the scraper must scratch the bottom, the aerator is positioned slightly above the scraper so as not to interfere with the rotation of the scraper. The air inlet pipe in the center part where the air enters should also be installed slightly off center, unlike the rotary shaft of the scraper. The incoming air is branched in the reactor blower and the aeration time of the settling tank is controlled using a valve operated by a timer. Aeration time is preferably carried out once a day, 30 minutes at a time, and according to the situation, the number and time of the timer is adjusted. Emptying the settling tank stops the flow into the settling tank and keeps the return pump running. This usually takes about 10 hours, so it is a good idea to do this once a month. In addition, most of the excess volume of the reaction tank is possible because it sufficiently covers the volume of the settling tank.

Therefore, the wastewater treatment method of the present invention can not only treat high concentration wastewater as compared to the existing apparatus, but also be simple in operation, low in cost, and do not require additional processing, and thus do not incur additional costs. There is no problem of secondary pollution.

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

Example 1

First, in order to screen microorganisms that best degrade wastewater, a minimum medium containing nitrogen, phosphorus, and inorganic salts was made in the wastewater, followed by culturing 25 microorganisms on solid and liquid media and observing the results.

For a solid medium experiment, commercial agar (Bacto-Agar, Difco Co., Ltd.) was added to the minimum medium to sterilize and then solidified to make a solid medium, and 25 kinds of microorganisms were streaked thereto. After culturing for 24 hours after smearing, the three largest microorganisms were selected by comparing the size of colonies formed on the solid medium.

In addition, in this embodiment, since a large amount of microorganisms are used to initially inoculate the microorganisms in the QBR reactor, wastewater decomposition rate was tested using standard activated sludge in the field. Experiments were conducted on activated sludge in standard activated sludge and in six other plants.

As a result, in the solid medium experiment, the SK Evertech standard activated sludge was shown to grow much faster than the standard activated sludge collected from six other plants. In detail, about 7 kinds of microorganisms were observed on the SK Evertec standard activated sludge. Among them, the fastest growth rate was two kinds of microorganisms, the growth rate of which was 1 mm / 24 hr.

Staining of standard activated sludges from six different plants also produced a variety of microbial communities, and the growth rate was about 0.5 mm / 24h, even when compared to the fastest growing community.

The liquid medium experiment was performed by measuring the absorbance and chemical oxygen demand (hereinafter referred to as COD) every 24 hours after inoculating the activated sludge of each plant into the final medium at a concentration of 2%. As a result, it was confirmed that the activated sludge of the Ulsan plant of SK Evertech Co., Ltd. showed a significantly faster microbial growth and COD reduction rate than the other six plants.

Based on the results, in the present invention, 350 m3 of activated sludge inhabiting the standard activated sludge tank of the SK Evertec Ulsan plant was planted in a QBR reactor containing wastewater. After activated sludge planting, sufficient nutrients (500 kg of urea and 80 L of 85% phosphoric acid solution) were added, and then phenol was added to multiply the microorganisms, and at the same time, 1.0 m 3 of wastewater was newly added to the reactor to adapt to the wastewater. Since phenol is toxic to microorganisms at once, phenol concentration is 50 in QBR reactor by adding 20 liters of 80% phenol solution every time phenol is decomposed and the dissolved oxygen concentration in the QBR reactor increases. Do not exceed ppm. After 7 days after active sludge planting, phenol supply was stopped and only wastewater was supplied. The load was gradually increased as follows. From day 15, in order to dilute the concentration of the wastewater, a mixed solution of the wastewater and the clean water 1: 1 was supplied to the reactor. The change in the solution in the reaction tank according to the above-described experimental procedure is shown in Table 2 below, the operating conditions of the apparatus according to the invention used in the present embodiment is shown in Table 3.

Hours Wastewater Flow Rate (t / d) Inflow load (㎏-TOC / ㎥, d) Treated Water TOC (ppm) MLSS (ppm) 8 2 0.17 480 3,500 9 4 0.34 530 3,700 10 8 0.68 580 4,100 11 10 1.3 670 4,700 12 25 2.1 810 5,600 13 35 3.0 1,120 6,300 14 45 3.9 1,250 7,100 15 50 4.3 1,190 7,300

Driving variables Proper range Load amount (㎏.CODCr / ㎥.day) Normal: 5.0 to 15 (Max: 20) pH 6.5 to 7.5 DO (ppm) 1 to 5 ppm Reactor temperature (℃) 30 ° C ± 2 (allowable up to 35 ° C) Sedimentation tank temperature (℃) 20 to 25 ° C (30 ° C or below) Nutrients 100: 5: 1 (TOC: N: P) Influent Wastewater Concentration (TOC-ppm) 20,000 ppm

The degree of purification of the wastewater according to the above process is shown in Table 4 below.

Item Driving results Wastewater After QBR treatment pH 2.0 6.5 to 7.5 density 30,000 ppm-TOC Normal: 500 to 1,000 ppm-TOC Salt concentration 1.5 g / L 3 to 4 g / L Etc H ₂ O ₂ was about 3% and it was incineration wastewater. Dilution of wastewater to 1: 1 with dilution water and treated with QBR 95% treatment efficiency (excluding dilution)

As shown in Table 4, it can be seen that the high concentration wastewater of 15,000 ppm-TOC (Total Organic Carbon) can be treated with 500 to 1,000 ppm-TOC with the apparatus of the present invention.

Excluding the effects of adding dilution water, the treatment efficiency shown in this example was confirmed to be about 95% on average. The treated water of 500 to 1,000 ppm-TOC treated by the above method was further treated by the conventional standard activated sludge method and was discharged to about 30 ppm-TOC which is much lower than the legal limit value.

In addition, the high concentration of wastewater introduced is pH 2.0, which is very strong acidic acid, but the pH of the reactor remains neutral even if it is directly introduced into the QBR reactor without neutralization with a basic solution. It is assumed that the microorganisms used have a unique property of changing pH to alkaline in the process of decomposing organic matter.

Example 2

The high concentration wastewater of Samahwa Island Co., Ltd., the only industrial dye producer in Korea, located in Gumi, Gyeongsangbuk-do, was conducted in a laboratory using the wastewater treatment apparatus of the present invention, and the basic properties of the wastewater used are shown in Table 5 below.

Characteristic Wastewater Content CODcr (ppm) 21,600 TDS (g / L) 32 pH 14 NH ₄ -N (ppm) 4 PO ₄ -P (ppm) 40 Quantity (t / d) 100

In addition to the features shown in Table 5, the wastewater has a pale milky white color with a small amount of white precipitate as the dyeing wastewater.

First, solid medium and liquid medium experiments were carried out in the same manner as in Example 1 using active sludges collected from seven bioprocesses in order to select microorganisms excellent in wastewater resolution. As a result of the solid medium test, the activated sludge in Ulsan-si sewage treatment plant showed the fastest growth rate, and the three microorganisms among the activated sludge showed significantly faster growth rate than other colonies. However, the three types of microorganisms with high growth rates were not dominant in terms of numbers, which means that the microorganisms having high resolution did not necessarily occupy the dominant species. In the results of the liquid culture experiment, the activated sludge collected from the sewage treatment plant in Ulsan showed significantly faster microbial growth and COD reduction rate than the activated sludges of six other plants.

Therefore, using the activated sludge collected in the above-mentioned Ulsan City sewage treatment plant was performed according to the wastewater treatment method of the present invention under the conditions of Table 6, wherein the concentration of the initial wastewater is 2,000 ppm COD, initial microbial inoculation volume Was 10%, and was continuously fed with wastewater after 24 hours of adaptation.

Driving variables Experimental conditions Inflow concentration 20,000 ppm-CODcr Residence time 2 days Inflow load 10 kg-CODcr / t, d Reactor volume 2.0 L Temperature 30 ℃ pH 6.5 to 7.5 DO (dissolved oxygen) 2.0 to 7.0 ppm Nutrients 100: 7: 1 (CODcr: N: P)

After 8 hours of microbial planting, dissolved oxygen began to decrease rapidly, suggesting that the microorganisms could easily adapt to and degrade the wastewater components.

After 24 hours, the dissolved oxygen in the reactor suddenly started to rise to 7.3 ppm, which means that all of the wastewater added initially was decomposed, and the wastewater was introduced at a rate of 1.0 L / d from this point. The daily COD value was measured and the change in treatment efficiency was calculated based on the wastewater inflow time (see FIG. 4), and the values are shown in Table 7 below.

Date range CODcr (ppm) Processing efficiency memo One 1500 93% Microbial planting 2 450 98% Start of waste water supply 3 860 96% 4 1590 92% 5 1480 93% 6 1360 93% 7 1120 94% 8 830 96% 9 670 97% 10 590 97% 11 560 97% 12 530 97% 13 510 97% 14 520 97% 15 490 98% 16 510 97% 17 530 97% 18 540 97% 19 520 97%

As shown in Table 7, the dissolved oxygen concentration rapidly decreased from the start of the waste water supply, and after about 7 days after the waste water supply, the CODcr value was 670 to 490 ppm, and the wastewater treatment efficiency was stable at 97%. It can be seen that the value.

Since the method and apparatus of the present invention not only increase the blower capacity but also the type and quantity of the diffuser, the oxygen supply capacity per unit volume is 10 times higher than that of the existing apparatus, and thus, wastewater having a very large organic load can be treated. There is a separate cooling device to prevent temperature rise in the reaction tank due to metabolic heat, and dissolved oxygen sensor and electric conductivity sensor are installed in the reaction tank to check the wastewater treatment process quickly and accurately. It is very efficient because the amount of acid or base solution and dilution water added, blower operating time, and amount of air discharged are automatically adjusted. In addition, the sedimentation tank of the present invention is very effective by preventing the incubation of anaerobic microorganisms in the high-temperature state without oxygen by installing aeration device that does not exist in the existing device periodically.

Claims (9)

In the pretreatment method of high concentration organic wastewater, Reacting the aerated tank while maintaining the temperature of the treated wastewater at 25 to 35 ° C. and dissolved oxygen at 1 to 5 ppm; Transferring the reacted wastewater to a settling tank in which the temperature of the wastewater is maintained at 20 to 30 ° C; Returning the microbial sludge precipitated in the settling tank to the reactor and discharging the supernatant water; And Pretreatment method for a high concentration organic wastewater, characterized in that it comprises the step of performing each step repeatedly. The method for pretreatment of a high concentration of organic wastewater according to claim 1, wherein the organic load (kg · CODCr / m 3 · day) of the treated wastewater is 5.0 to 20. The method of claim 1, wherein the sedimentation tank is aerated once a day for 30 minutes at a time of 3 to 8 ppm of dissolved oxygen. The method according to claim 1, wherein the pH, nutrient input amount and salt concentration of the wastewater in the reactor are automatically controlled by a sensor installed in the reactor. The method of claim 1, wherein the temperature of the reaction tank and the settling tank is controlled by a cooling device. Including a reactor and a precipitation tank, A reaction tank for decomposing organic matter by a microorganism including a blower for supplying air into the reaction tank, an acid engine for making air supplied from the blower into fine air bubbles, and a sensor for measuring pH, dissolved oxygen, temperature, and electrical conductivity. ; A first cooling device installed outside the reaction tank to prevent a temperature rise of the wastewater due to metabolic heat of microorganisms in the reaction tank, A settling tank receiving the treated wastewater from the reaction tank to precipitate the microorganisms, returning the sludge to the reaction tank, and discharging the supernatant water; And A wastewater treatment apparatus for performing the method of any one of claims 1 to 5, which is installed outside the sedimentation tank and comprises a second cooling device for maintaining the temperature of the wastewater in the sedimentation tank at 20 to 30 ° C. 7. The apparatus of claim 6, wherein the settling tank further comprises an aeration device for periodically aeration. 7. The apparatus of claim 6, wherein the reactor further comprises a sensor for automatically adjusting the pH, nutrient input and salt concentration of the wastewater. The apparatus of claim 6, wherein the cooling device is a chiller type or a cooling tower method.