KR200190720Y1 - Equipment for wastewater treatment - Google Patents

Abstract

The present invention is a technique related to a device for biologically purification or biochemical purification of wastewater using microorganisms and air.

An object of the present invention is to purify wastewater in a short time by mixing wastewater, microorganisms and air by using the characteristics of the ideal perfusion flow and the stirring action in the reaction tank.

An object of the present invention is to provide an internal circulation pipe in a reaction tank, install a circulating water nozzle at a position coinciding with the upper end of the internal circulation pipe, and force the air by setting the cross-sectional ratio of the air nozzle and the circulating water nozzle to at least one to one or more. By inflow.

The company minimizes the oxygen supply and wastewater treatment time required for microorganisms, and has the effect of minimizing operation stability, operation efficiency and operation cost.

The present application can be widely used for the purification of organic and inorganic substances contained in wastewater using microorganisms and water treatment using ozone.

Description

Equipment for wastewater treatment and water purification {Equipment for wastewater treatment}

The present invention relates to a technique for biologically or biochemically purifying wastewater using microorganisms and air.

The purpose of the present application is to mix wastewater, microorganisms and air in the reaction tank by using the characteristics of ideal perfusion flow and agitation in a fast time to purify the wastewater, minimize the oxygen supply and wastewater treatment time required for the microorganisms, and operating cost The present invention relates to a wastewater treatment and a purified water treatment apparatus using ozone.

6 (Ref .: Dr. Thesis, Name; Burkhard Lohrengel, 1990) and FIG. 7 (Ref .: DE-Z (German journal) Chemie) as prior art for efficient wastewater treatment Ingenieur-Technik 42 (1970) Nr. 7, 474-479) shows the type of circulation reactor that has been developed.

As shown in Figure 6, the circulation reactor is largely divided into three as follows.

First, the mammoth circulation reactor

This reactor uses the principle that the fluid is naturally circulated through the difference of Gas Hold-Up by injecting gas into the inner circulation tube installed inside the reactor or injecting gas into the exterior, but this reactor can introduce a lot of gas. Even though there is a disadvantage that does not break the lock of the microorganism.

Second, jet type circulation reactor

This reactor is designed to force the flow of gas and liquid by installing a nozzle at the bottom, and it has the advantage of breaking microbial flock, but it requires more flow of operating energy than forced flow from the top because liquid and gas must be forced in the bottom. There are disadvantages to using it.

Third, propeller circulation reactor

This reactor has the advantage of forcibly circulating the fluid by installing a propeller in the mammoth reactor, but has the disadvantage of not breaking the Flock of microorganisms.

8 (reference: DE-Z (German journal) Verfahrenstechnik 6 (1972) Nr. 2, 50-57) shows an example of using a specific type of jet circulating reactor, the type of jet of the 70's It is the initial form of the food circulation reactor.

This is because the circulating water nozzle is located at the bottom and the static pressure (between the water surface and the nozzle) , here Density, g: gravitational acceleration, h: height) has the disadvantage that the operating energy increases.

After that, in order to overcome the disadvantage, Korean Patent Application Publication No. 97-20982 installs a circulating water nozzle below a portion of the upper end of the inner circulation pipe.

However, there is a risk that the internal circulation pipe that is fixed after a certain time due to the vibration caused by the strong flow of fluid shakes the internal circulation pipe. This phenomenon occurs because the fluid escape zone occurs at the upper end of the endogenous circulation tube. Because cavitation occurs in this region, the sound pressure is formed.

9 (Ref .: DE-Z (German Journal) Chemie-Ingenieur-Technik 58 (1986) Nr. 11, 906-907) shows a reactor developed by BASF, Germany in the 1980s.

The reactor is equipped with a circulating water nozzle in the center and an air nozzle is installed outside the circulating water nozzle. When operating with such a nozzle, the air required for wastewater treatment must be operated at least 20 m / s in order to achieve natural suction by negative pressure. In such a case, it is impossible to apply because a huge operating cost is used when driving a large apparatus.

As shown in b of FIG. 9, when the excess air is introduced into the reactor, the air cannot be circulated.

The present invention is devised to solve the above-mentioned problems of the prior art.

An object of the present invention is to provide an internal circulation pipe in a reaction tank, install a circulation water nozzle at a position coinciding with the upper end of the internal circulation pipe, and force inflow of air by setting the area ratio of the circulation water nozzle to the air nozzle at least one to one or more. This is to minimize the stability of operation, the efficiency of operation and the cost of operation.

Another object of the present application is to shorten the treatment time by increasing the contact probability of the biochemical reaction between bacteria and organic matter in the wastewater.

1 is a view showing the use of the three-phase (microbial, waste water and air) or two-phase (liquid and gaseous) nozzles used in the present invention

2 is an embodiment of an apparatus for wastewater treatment and water treatment according to the present invention

3 is an embodiment of a device for wastewater treatment (anoxic bath) according to the present invention

4 is a phenomenon in which microbial floc is broken through a circulating water nozzle after inoculating microorganisms into sludge in a sewage treatment plant according to the present invention.

5 is a phenomenon in which all of the higher microorganisms (protozoa) and filamentous bacteria except bacteria are removed by water pressure in the wastewater treatment according to the present invention.

6 and 7 is a prior art form of the circulation reactor

8 illustrates a specific use of a jet circulation reactor as a prior art.

9 is a reactor developed by BASF, Germany as a prior art.

10 is a flow rate of gas according to the cross-sectional area ratio (circulating water nozzle / air nozzle)

11 is a flow rate of air in the air nozzle according to the fluid velocity in the circulating water nozzle

12 and 13 show the microbial sedimentation status with or without secondary degassing in the wastewater treatment system.

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

1: Reactor 2: Internal circulation tube

3: circulating water nozzle 4: primary degassing tank

5: external circulation pipe 6: circulation pump

7: Wastewater injection pipe 8: Return sludge injection pipe

9: Blower (Air forced inflow) 10: Compressor (Air forced inflow)

11: diffuser 12: air nozzle

13: treated water discharge pipe 14: obstruction plate

Q _T : Circulating water flow rate Q _{G, Pr} : Air flow rate

Q _{L, um} : Internal circulating water flow rate Q _{G, um} : Internal circulating gas flow rate

w _{L, U} : Circulating water flow rate in the inner circulation pipe w _{G, RR} : Gas flow rate in the appearance

w _{L, RR} : Circulating water flow rate in appearance w _{G, U} : Gas flow rate in internal circulation pipe

w _T : Circulating water flow rate w _{L, U} : Circulating water flow rate in the inner circulation pipe

H _ZU : Liquid level on the inner circulation pipe d _T : Circulating water nozzle diameter

e: the diving depth of the air nozzle d _G: air nozzle diameter

: Relative speed

Ei: reduced area Ab: fluid escape area

Fr: Jetflow Boundary Line (Freistrahlgrenze)

Pr: Primary Air Dispersion

Se: Secondary air dispersion

In order to achieve the above object of the present invention, as shown in Figure 1 the end of the nozzle is installed to match the upper end of the inner circulation tube.

In addition, in order to maximize the amount of air introduced, the area ratio of the air nozzle and the circulating water nozzle should be one to one. This is because the sound pressure is at maximum under these conditions. Experimental data for this is shown in FIG. 10. 10, the most air is sucked in the energy 5.0 kW / m ³ and the cross-sectional ratio of 1: 1. Therefore, in order to inhale air by the negative pressure, it is possible to make the circulating water flow rate very fast. 11 shows the air inflow rate in the air nozzle according to the fluid velocity in the circulating water nozzle. If the reaction tank size is 100 Liter, the minimum air inflow rate is about 6 m / s. At 25 m ³ , the minimum air inflow rate is about 11 m / s. This result has the disadvantage of maintaining a minimum fluid velocity once the necessary air is introduced into the reactor.

This has the disadvantage of limiting the operation cost and maintaining at least constant operating energy in the existing system to introduce air by negative pressure. In fact, when operating this reactor in large size, the flow velocity in the circulating water nozzle is operated at 14-15 m / s. If operated in this state, too much pressure loss at the end of the circulating water nozzle will cause energy loss. And if the fluid inlet speed in the circulating water nozzle is operated below the minimum speed there is a disadvantage that the waste water can not be treated because air is not introduced by the negative pressure.

In order to overcome this disadvantage, the present invention is driven by forced inflow of air rather than driven by negative pressure. At this time, the operating cost of the blower used is 10 Watt per 1 m ³ of the reactor. This energy is virtually negligible when the actual reactor is installed and used on site. However, the fundamental problem of reducing operating costs is the area ratio of the liquid nozzles.

In order to overcome the above problem, as shown in FIG. 2, one or more internal circulation pipes are installed and the area ratio of the air nozzle and the circulation water nozzle is 1: 1 or more through the circulation pump to inflow into the internal circulation pipe. The bigger the is, the better. This is because the larger the area ratio, the smaller the pressure loss at the tip of the circulating water nozzle. The smaller the pressure loss, the lower the operating cost. And the reactor can be operated regardless of the minimum fluid velocity.

At this time, since the air sucked by the negative pressure is minute, install a blower to force the air inlet. Completely mixed fluid flows uniformly through the reaction tank through a nozzle installed on the inner circulation tube. The fluid that flows upward from the bottom of the reactor through the appearance has a lot of microbubbles in the sludge because of the ideal mixing at the nozzle. If the microbubbles are introduced into the circulation pump through the external circulation pipe without removing the microbubbles, the efficiency of the pump is reduced. In addition, if the circulating water containing microbubbles is introduced into the inner circulation pipe through the circulating water nozzle, bubbles may be generated in the reaction tank. If a lot of bubbles are generated, the sludge in the reaction tank is discharged in a short time, it can lose the function of the reaction tank. Therefore, in order to eliminate these drawbacks in advance, as shown in Figure 2 to make the primary degassing tank on the top of the reaction tank to remove the microbubbles. As shown in FIG. 2, the fluid has a characteristic of treating wastewater through a circulating action that is mixed while repeating an internal circulation and an external circulation.

Raw water and conveying sludge are mixed inflow into the outer circulation pipe naturally by installing inflow pipes at regular intervals in the outer circulation pipe connected to the bottom of the primary degassing vessel as shown in FIG. To do that. In some cases, as shown in FIG. 2, raw water and return sludge inlet pipes may be directly installed in the external circulation pipe.

If the air forced through the nozzle is insufficient, to increase the amount of additional air, if necessary, install a ring nozzle (acid engine) at the same position as the lower end of the inner circulation pipe as shown in FIG. Preferably, it is effective to install the ring nozzle at a height of at least 1/5 from the bottom of the reactor.

In addition, the present invention shows the effect of breaking the floc when bacteria are introduced at high speed through the circulating water nozzle.

In microbial reactors, bacteria have a characteristic of forming a flock and must be broken as soon as possible. This is because the smaller the Folck of the bacteria, the greater the probability of contact between oxygen and organics in the wastewater, resulting in a much faster biochemical reaction. Fast biochemical reactions can shorten treatment time.

These conditions are absolute conditions that increase the efficiency of the aerobic reactor using microorganisms.

The characteristics thereof are shown in FIG. 4. Sludge shown in FIG. 4 is a photodeveloped phenomenon in which microbial flock is broken through a circulating water nozzle when a sludge (microorganism) is taken from a sewage terminal treatment plant and microbial inoculation is carried out to test the reactor. If the reactor is operated for about one day, all microorganisms (protozoa) and filamentous bacteria except bacteria are removed by hydraulic pressure. This is illustrated in FIG. 5.

Because the bacteria are 2-3 microns in size and the microorganisms are hundreds of microns in size. Therefore, it is difficult to survive the high microorganisms and filamentous fungi by hydraulic pressure as it flows through the circulating water nozzle at high speed. Therefore, only small bacteria survive in the reactor. The microorganisms that actually treat wastewater are bacteria. Other higher microbes are bacteria-eating organisms and cannot actually process organic matter. Moreover, the higher the number of these higher microbes, the more difficult it is to settle the sludge in the settling tank. Thus, the reactor is made up of nearly 100% bacteria. In the general activated sludge process, it is difficult for the bacteria to exceed 50%.

In contrast to the above conditions and the wastewater treatment purification apparatus of the present application, the following description will determine the performance and efficiency of the subject innovation.

In this application, the wastewater introduced through the circulating water nozzle installed in the upper part of the reactor, the air and the return sludge (microorganism) are completely ideally mixed. At this time, since microbubbles are present between the microbial flocks and bubbles are generated due to the appearance of waste water, a primary degassing tank is installed in the upper part of the reaction tank as shown in FIG. 2. This ensures that only liquids containing little bubbles are introduced into the circulation pump. This increases the efficiency of the pump and blocks bubbles from forming in the reactor. Secondary degassing tank (not shown) creates a tank of a certain size before the treated wastewater enters the sedimentation tank to have a certain residence time, removes microbubbles contained in the microorganisms, and enters the sedimentation tank. Allow to settle. If the secondary degassing tank is not installed, it is difficult to treat the wastewater because the microorganisms are floated and released from the settling tank and the amount of microorganisms in the reaction tank is greatly reduced. 12, when the secondary degassing vessel is made, it can be seen that after 30 minutes, the sludge (microbial) and the treated water are clearly separated. However, if the secondary degassing tank is not made, as shown in FIG. 12, after 30 minutes, the microorganisms are separated into the upper and lower ends, and the microorganisms at the upper end are discharged from the settling tank, and the microorganisms in the reaction tank are almost leaked out as time passes. Figure 13 a) shows the microorganisms and microbubbles tangled due to the strong turbulent mixing of the circulating water nozzle. But as you go through the secondary degassing vessel as shown in b) all microbubbles are released and the microbial precipitation is improved. 4, 5, and 12 this fact is shown in the picture of the actual state of the microorganisms.

In addition, the existing wastewater treatment device is to mix the raw waste water to be purified and mixed with the circulating water discharged from the reaction tank in a predetermined ratio before the injection of the reaction tank, but if the device becomes complicated in operation, the return sludge stays inside the reaction tank for some time. Microorganisms are crushed in the circulating water nozzle through the circulation pump.

However, in the present application, as shown in FIG. 2 without mixing the circulated water and the waste water at a predetermined ratio, the introduction of the upper portion of the outer circulation pipe connected to the bottom of the primary degassing vessel is installed in the upper part of the reaction sludge (microorganism) and raw water as shown in FIG. If it simply flows into the pipe (8, 7) at regular intervals, it is introduced through the circulation water nozzle installed in the upper portion of the inner circulation pipe through the circulation pump, and mixed with the raw waste water, the return sludge (microorganism) and the treated water in the reactor. Is done. As the microbial flock passes through the liquid nozzle tube and flows into the inner circulation tube, it breaks below 50 µm. This position can be directly connected to the outer circulation tube (8, 7) as shown in FIG.

The above objects, features and advantages of the present invention will become more apparent from the following description of the accompanying drawings which illustrate in detail a preferred embodiment of the invention.

<Example 1>

(Wastewater treatment and purification device under aerobic conditions)

A first embodiment of the present application is described below in conjunction with FIGS. 1 and 2.

FIG. 1 shows an example showing the use state of three-phase (microbial, wastewater and air) or two-phase (liquid and gaseous) nozzles (3 in FIG. 2) installed on top of the waste water purification treatment apparatus. As shown, it must be installed in line with the upper end of the inner circulation pipe.

Primary air dispersion occurs when circulating water (Q _T ) introduced from the outside through negative pressure or forced air inflow is introduced through the circulating water nozzle, and the density of water is about 1000 times heavier than that of air. Attempts to distract occur. As a result of this phenomenon, when a reduced area is created and the sunlight is collected in one place using a magnifying glass, as the black paper is burned, as shown in the figure, the circulating water collides under the air nozzle tube (12 in FIG. Crush). Secondary air dispersion is caused by internal circulating water flow rate (Q _{L, um} ), which is the driving force of friction. In other words, even if the circulating water (Q _T ) is introduced at 15 m / s, the expansion occurs suddenly as it exits the circulating water nozzle (3 in Figure 2), suddenly the speed is significantly reduced. The speed at this time is much less than the flow rate (W _{L, U in} FIG. 1) generated by the internal circulation flow rate (Q _{L, um} ). Therefore, at this time, the relative velocity is generated and large bubbles of internal circulating gas (Q _{G, um} ) introduced by the internal circulating water flow rate (Q _{L, um} ) due to frictional force are rubbed like palms, causing secondary air dispersion. Done. The boundary line where the primary and secondary air dispersion is strongly formed is called a jet flow boundary line, and this boundary line is clearly visible on the inner circulation pipe where the circulating water nozzle (3 in FIG. 2) is installed. Since the limit is shown in Fig. 2, it is kept constant.

H _zu shown in FIG. 1 is a very important design factor when air is introduced by negative pressure or forced air from outside. If the H _zu is too high, the head pressure acts on the inflowing air pipe, so when the air is introduced by the negative pressure, the amount of air is reduced or a lot of energy is used when the forced air is used. On the other hand, if too low, too much air is introduced there is a disadvantage that the fluid is not circulated in the reaction vessel. Therefore, the optimal height should be selected according to the reaction conditions.

In addition, e (air nozzle submersion depth) should be installed as close to the end of the circulating water nozzle as possible. If this part gets longer, the head pressure is applied to the air pipe. Therefore, when the air is introduced by negative pressure, the amount of air is reduced or when the forced air is used, a lot of energy is used. On the other hand, it does not matter if the position of e (air nozzle submersion depth) is located inside the circulating water nozzle. However, the optimal conditions should be slightly projected as shown in FIG.

Figure 2 shows the operation of the overall reaction tank of the wastewater purification treatment apparatus. As shown in the drawing, one or more internal circulation pipes 2 are installed to allow the area ratio of the circulation water nozzle 3 to the air nozzle 12 to be greater than or equal to 1 through the circulation pump 6. Inflow). At this time, since the air sucked by the negative pressure is minute, the blower 9 is installed to force the air inlet. The fluid completely mixed through the circulating water nozzle 3 installed on the inner circulation pipe 2 flows uniformly throughout the reaction tank 1. The fluid flowing out from the bottom of the reactor through the inner circulation pipe outside (between 1 and 2) has a lot of fine bubbles in the sludge because the ideal mixing in the circulating water nozzle (3). In order to remove such microbubbles, a primary degassing tank 4 is installed at the top of the reaction tank.

The fluid is mixed while repeating the internal circulation (Q _{L, um} internal circulating water flow rate and Q _{G, um} internal circulating water flow rate) and external circulation (5, Q _T circulating water flow rate).

Raw water and conveying sludge are mixed and flowed into the external circulation pipe 5 naturally by installing inflow pipes 7 and 8 at regular intervals in the external circulation pipe 5 connected to the primary degassing tank 4. Complete mixing occurs through the circulating water nozzle (3). In some cases, raw water and conveying sludge inflow pipes 7 and 8 may be directly installed in the external circulation pipe 5. If the air (Q _{G, Pr} ) forced inflow through the air nozzle 12 by the blower (9) is insufficient, to increase the amount of additional air if necessary by using the compressor (10) the internal circulation pipe (number 2) A ring nozzle 11 is installed at a position corresponding to the lower end of the lower portion to assist and inflow. The ring nozzle 11 is installed in a straight line at the lower end of the inner circulation tube, and more preferably at a height of 1/5 or more from the bottom of the reactor.

At this time, the speed of the circulating water in the inner circulation pipe (2) is called w _{L, U} , and the speed of the circulating water flowing in the inner circulation pipe (1 and 2) is called w _{L, RR} . The bubble velocity inside the inner circulation tube (number 2) is called w _{G, U} , and the bubble velocity flowing outside the inner circulation tube (between numbers 1 and 2) is called w _{G, RR} . As shown in Fig. 2, the bubble velocity flowing inside the inner circulation pipe should be faster than the circulation water speed w _{L, U.} As an indication of this (Relative speed) is shown. The higher the relative speed, the better.

If there is no relative velocity, i.e. if the air velocity is faster than the liquid velocity, the fluid cannot circulate in the reactor. On the other hand, the bubble velocity (w _{G, RR} ) flowing outside the inner circulation tube is naturally faster than the circulation water velocity w _{L, U.} This is because air tends to rise by buoyancy. As an indication of this (Relative speed). At this time, the higher the relative speed is disadvantageous. Because the bubbles are agglomerated and the bubbles become larger. Larger bubbles reduce the contact probability of biochemical reactions of microorganisms.

The waste water purified through the reaction tank of the present application is discharged through the discharge pipe 13 together with the microorganism.

The purified wastewater discharged through the discharge pipe goes through a secondary degassing vessel. The secondary degassing tank is installed before the wastewater treated to remove microbubbles contained in the microorganisms enters the settling tank.

The purified wastewater from the secondary degassing tank and the settling tank is separated from each other in the subsequent equipment (not shown).

The separated microorganisms are returned to the reactor for recycling and the rest are discharged to the excess sludge.

<Example 2>

(Waste water treatment and purification device under denitrification process (oxygen tank))

A second embodiment of the present application is described below in conjunction with FIGS. 1 and 3.

3 is an operation method used when treating wastewater by a denitrification process (anoxic tank), not an aerobic oxidation tank.

In this case, the external air inlet air (Q _{g, Pr in} FIG. 2) should be blocked. Therefore, the air nozzle (12 of FIG. 2) is removed and only the circulating water nozzle 3 is installed. This allows complete mixing of the return sludge, the raw water (7,8) and the treated water in the reactor.

More preferably, as shown in the drawing, a baffle plate 14 is installed at the lower end of the circulating water nozzle and below the water surface to block air from being sucked out of the water surface by the circulating water nozzle flow rate wT. It can be operated as anoxic in the reactor.

At this time, the circulation water speed inside the internal circulation pipe (number 2) is called wL, U, and the circulation water speed flowing outside the internal circulation pipe (between numbers 1 and 2) is called wL, RR.

It is the same as Example 1 except the conditions operated by an oxygen-free tank.

In addition, circulating water nozzles of the same structure can be arranged at regular intervals in large reactors to increase the wastewater throughput.

As described above, the present application can achieve the minimization of oxygen supply and wastewater treatment time required for microorganisms, and by installing the circulating water nozzle coinciding with the upper end of the inner circulation tube, even if a strong fluid flow occurs, There is no risk of overturning, ensuring the stability of the process.

In addition, the operating cost can be reduced by setting the ratio of the liquid nozzle cross section to the gas nozzle cross section to 1 or more.

The present application provides a device for wastewater and water purification treatment that can minimize wastewater treatment time and operation cost, and ensure maximum operation efficiency and process stability.

In addition, the present application can be widely used for the purification of organic and inorganic substances contained in wastewater by using microorganisms and water purification treatment using ozone.

Claims (6)

Inside the reactor, the internal circulation pipe with open top is installed vertically, and the gas and waste water are mixed and descended to the inside of the internal circulation pipe, and then some of the flow rising to the outside of the internal circulation pipe flows back into the internal circulation pipe. In the wastewater treatment apparatus using the action, the wastewater and microorganisms are introduced into the external circulation pipe through the inlet pipe at regular intervals, and are mixed in the gas and the circulating water nozzles introduced by the air forced inlet method through the air nozzle to circulate inside the reactor. It is injected into the upper part of the pipe, the circulating water nozzles are installed in a straight line at the end of the inner circulating pipe, and the waste water purification treatment device, characterized in that the primary degassing tank is installed in the upper portion of the reaction tank The waste water purification treatment apparatus according to claim 1, wherein the ratio of the liquid nozzle cross section to the gas nozzle cross section is at least one. The waste water purification treatment apparatus according to claim 1, wherein an air injector is further provided on a straight line of the lower end of the inner circulation pipe, and is installed at a height of 1/5 or more from the bottom of the reactor. The waste water purification treatment apparatus according to any one of claims 1 to 3, wherein a secondary degassing tank for removing microbubbles containing microorganisms is provided between the reaction tank and the settling tank. The wastewater and microorganisms according to any one of claims 1 to 2, wherein the wastewater and microorganisms which have been removed from the air nozzles and introduced into the circulating water nozzles through the external circulation pipe are completely mixed with the treated water in the reactor and used for the denitrification process (anoxic tank). Waste water purification treatment device The wastewater purification treatment apparatus according to claim 5, wherein an obstruction plate is provided between the upper portion of the circulating water nozzle and the water surface in order to block air inflow from outside the water surface.