KR20020080285A - Method for advanced wastewater treatment without excess sludge using sludge disintegration - Google Patents

Abstract

PURPOSE: A sludge disintegration method is provided which effectively improves removing efficiency of nutrient by reducing and utilizing as a carbon source the sludge discharged from advanced biological treatment process, and advanced sewage treatment method and apparatus without sludge discharging using the same are provided. CONSTITUTION: The advanced biological sewage treatment system without sludge discharging using the sludge disintegration method comprises a sludge integration unit(23) for physically and/or chemically treating sludge; a transfer unit for transferring the sludge disintegrated in the sludge integration unit(23) to the biological reactors(20,21); an anaerobic/anoxic biological reactor(20); and an aerobic biological reactor(21), wherein the advanced biological sewage treatment system further comprises a centrifugal inorganic solid separator(22) for separately removing inorganic solids in sludge by using the centrifugal force.

Description

Method for advanced wastewater treatment without excess sludge using sludge disintegration}

The present invention relates to a method and apparatus for utilizing sludge as a carbon source for advanced treatment, and more particularly, to reduce sludge by physically and / or chemically decomposing sludge discharged from a biological advanced treatment process, The present invention relates to a sludge decomposition and solubilization method for reducing sludge and utilizing it as a carbon source that can be utilized as a carbon source for phosphorus release and ultimately effectively improve nutrient removal efficiency.

In addition, the present invention relates to an advanced biological sewage treatment method, and more particularly, by using the solubilized sludge as a food for the microorganism through the sludge decomposition solubilization method for reducing the sludge and utilizing as a carbon source, the discharge of excess sludge is reduced. The present invention relates to a sludge-free sewage altitude treatment method and apparatus using a sludge decomposition solubilization method.

Sewage treatment has been rapidly developed with the development of activated sludge process using microorganisms, mainly for the purpose of removing organic matter and suspended solids, and now, various developments have been developed as it has been developed as an advanced treatment process capable of removing nitrogen and phosphorus. Considering the principle of the presently developed biological advanced treatment process, nitrogen removal is performed by nitrifying microorganisms that convert NH ₄ ⁺ into NO ₂ ^- or NO ₃ ^- and then denitrifying and releasing it into N ₂ gas. Phosphorus removal is achieved by overingesting phosphorus eluted under anaerobic conditions with excess phosphorus by microorganisms under aerobic conditions and then removing sludge. Nitrogen and phosphorus removal methods using this principle include A2 / O, modified Bardenpho, Virgin Initiative Plant (VIP) and the University of Cape Town (UCT) process.

In order to successfully operate such biological advanced treatment processes, a bioreactor with anaerobic, anaerobic and aerobic conditions must be constructed, and a sufficient carbon source is required for phosphorus release and denitrification under anaerobic and anaerobic conditions. A high level of technical know-how is required, such as the discharge of a certain amount of sludge. In addition, as shown in FIG. 1, a facility for concentrating, dewatering, and storing the excess sludge discharged from the process, and final disposal of incineration, landfill, etc., is required.

Looking at the problems of sewage treatment currently installed in Korea, most of the domestic sewage treatment facilities are activated sludge process to remove organic matter and suspended solids, but the removal of nitrogen and phosphorus, which is the eutrophic cause, is poor and largely untreated. It is discharged and causes eutrophication of lakes and streams, causing serious problems in securing quality water resources and preserving natural ecosystems. Therefore, the government has strengthened the regulation of nitrogen and phosphorus in the discharged water quality standards, and has been intensively developing and distributing sewage treatment processes for nitrogen and phosphorus removal.

However, looking at the influent quality of domestic sewage treatment plants, the reality is that almost all sewage treatment plants have a very low concentration of carbon sources necessary for biological denitrification and phosphorus release, or make the biological treatment process difficult to operate at all. Therefore, in order to efficiently operate the domestic biological advanced treatment process, organic matters lacking in influent should be supplemented with external carbon source such as methanol. However, since carbon sources such as methanol are difficult to use because of their high price, there is a lot of research using organic acid, sludge and food waste acid fermentation liquid.

In addition, sludge is inevitably discharged in the biological sewage treatment process, and domestic sludge treatment technology is mostly dependent on concentration, low-efficiency anaerobic digestion, dehydration, and landfilling. However, such a conventional waste sludge treatment method is expensive because it requires a site for landfilling. In fact, in this case, it is known that the cost of waste sludge treatment is about 40% of the total sewage treatment cost.

Meanwhile, the tightening of regulations will prohibit the introduction of waste sludge in waste landfills, requiring a new method for waste sludge treatment. Therefore, if the organic sludge from the biological treatment process can be pretreated and reused as a carbon source for advanced treatment, it will be the most efficient use of the sludge, and the environmental and economic problems that can occur when the sludge is landfilled or incinerated. It is expected to be solved.

The present invention is to solve the conventional problems as described above, an object of the present invention, the mechanical treatment, such as mechanical decomposition, heating and freezing, ultrasonic and sludge generated in the biological sewage treatment process, ozone, acid Chemical treatment such as alkali and hydrogen peroxide alone or in combination to treat sludge, kill microorganisms and decompose tissues to reduce sludge primarily, and utilize the decomposed sludge as a carbon source for denitrification and phosphorus release. It is to provide a sludge decomposition solubilization method for reducing sludge that can increase the removal efficiency and utilizing it as a carbon source.

In addition, another object of the present invention, by utilizing the sludge subjected to the physical and / or chemical sludge decomposition solubilization treatment as a carbon source for the advanced biological treatment, the excess sludge is hardly generated, there is no problem such as landfill, low concentration The present invention provides a sludge-free sewage altitude treatment method and apparatus using sludge decomposition solubilization method that can be efficiently applied to influent.

1 is a representative process diagram of a typical sewage treatment plant using a conventional biological sewage treatment method.

Figure 2 is a diagram illustrating an embodiment of the sludge-free biological sewage treatment system using the sludge decomposition solubilization method according to the present invention.

Figure 3 shows the result of applying the sludge decomposition solubilization method to the sewage treatment to reduce the sludge of the present invention and to utilize as a carbon source.

4 is another embodiment in which the sludge decomposition solubilization method for reducing sludge of the present invention and utilizing it as a carbon source is applied to a sewage advanced treatment process employing a continuous ash reactor.

Explanation of symbols on the main parts of the drawings

20: anaerobic / oxygen-free bioreactor 21: aerobic bioreactor

22: centrifugal inorganic solid separation device 23: sludge decomposition device using ozone

In order to achieve the above object, the sludge decomposition solubilization method for reducing sludge and utilizing it as a carbon source according to the present invention is to reduce sludge and utilize it as a carbon source of a biological advanced treatment process. A method of decomposing sludge generated in a process by performing physical treatment and / or chemical treatment alone or in combination, wherein the physical treatment is selected from mechanical decomposition, heating, freeze thawing, or ultrasonic irradiation, and the chemical treatment is ozone. At least one selected from acid, alkali, hydrogen peroxide, and enzyme treatment.

In the sludge decomposition solubilization method for reducing sludge according to the present invention and utilizing it as a carbon source, the sludge decomposition solubilization method is a biological sewage treatment process using an inorganic solids separation device using centrifugal force before physical treatment and / or chemical treatment. And separating and removing the inorganic solid having a high specific gravity in the sludge generated in the sewage treatment process.

In the sludge decomposition solubilization method for reducing sludge according to the present invention and utilizing it as a carbon source, when the chemical treatment is ozone or hydrogen peroxide treatment, an acid or an alkali is injected to adjust the pH to improve sludge decomposition efficiency. do.

In the sludge decomposition solubilization method for reducing sludge according to the present invention and utilizing it as a carbon source, the method is a conventional advanced treatment process, an advanced treatment process using a continuous batch reaction tank, an intermittent discharge continuous inlet continuous batch reactor. It is characterized in that the advanced treatment process, or the influent water quality is applied to the low load treatment plant lower than the design reference value.

Sludge-free sewage altitude treatment method using the sludge decomposition solubilization method according to the present invention is a biological sewage altitude treatment method that does not generate excess sludge, and physical treatment and / sludge generated in biological sewage treatment process and sewage altitude treatment process Or (a) degrading the chemical treatment alone or in combination; And (b) injecting the sludge decomposed in step (a) into an anaerobic / anaerobic bioreactor of a biological sewage treatment process as a carbon source for denitrification and phosphorus release, wherein step (a) The physical treatment of is characterized in that at least one selected from mechanical decomposition, heating, freeze thaw, or ultrasonic irradiation, the chemical treatment is characterized in that at least one selected from ozone, acid alkali, hydrogen peroxide, or enzyme treatment.

In the sludge-free sewage altitude treatment method using the sludge decomposition solubilization method according to the present invention, the sludge-free sewage altitude treatment method is an inorganic solid using centrifugal force before the step (a) of physically treating and / or chemically treating the sludge. And separating and removing the inorganic solids having a high specific gravity in the sludge generated in the biological sewage treatment process and the sewage advanced treatment process by using the separation device.

In the sludge-free sewage treatment method using the sludge decomposition solubilization method according to the present invention, when the chemical treatment is ozone or hydrogen peroxide treatment, it is characterized in that the pH is adjusted by injecting acid or alkali to improve the sludge decomposition efficiency. do.

In the sludge-free sewage altitude treatment method using the sludge decomposition solubilization method according to the present invention, the method is a conventional high-treatment process, an advanced treatment process using a continuous ash reactor, an intermittent discharge continuous inlet continuous ash reactor It is characterized in that the advanced treatment process, or the influent water quality is applied to the low load treatment plant lower than the design reference value.

The sludge-free biological sewage treatment system using the sludge decomposition solubilization method according to the present invention comprises: a sludge decomposition apparatus for physically treating sludge and / or chemically treating the sludge; A device for transferring the sludge decomposed in the sludge digestion apparatus to a bioreactor; Anaerobic / anoxic bioreactor; And an aerobic bioreactor.

In the sludge-free biological sewage altitude treatment system using the sludge decomposition solubilization method according to the present invention, the sludge-free biological sewage altitude treatment system is a centrifugal inorganic solids separation device that separates and removes inorganic solids in the sludge using centrifugal force. It characterized in that it further comprises.

Hereinafter, the sludge-free sewage treatment method and apparatus using the sludge decomposition solubilization method according to the present invention will be described in detail with reference to the accompanying drawings. However, it is to be understood that the drawings described below are provided only for the purpose of illustration in order to facilitate understanding of the present invention, and the scope and scope of the present invention are not limited thereto.

Figure 2 is a process diagram including a sludge decomposition solubilization method using ozone as an embodiment of the sludge-free sewage altitude treatment method using the sludge decomposition solubilization method according to the present invention.

As shown in Figure 2, according to the sludge-free biological sewage advanced treatment method according to the present invention, a portion of the sludge from the aerobic bioreactor 20 using a centrifugal inorganic solids separation device 21 relative gravity The large inorganic solids are separated and removed, decomposed and solubilized using a sludge decomposition device 22 using ozone, and sent to an anaerobic / oxygen-free bioreactor 23. The decomposed sludge sent to the anaerobic / anoxic bioreactor 23 is used as a carbon source for denitrification and phosphorus release under anaerobic / anoxic conditions, and the rest is used as a food for microorganisms in the aerobic bioreactor 20.

This will be described in more detail as follows.

The centrifugal inorganic solids separating device 21 separates and removes relatively large inorganic solids from sludge by using centrifugal force to suppress the accumulation of inorganic solids in the bioreactor, thereby ultimately enabling the organic sludge to be discharged.

The sludge decomposing apparatus using ozone decomposes the microorganisms in the excess sludge by using the strong oxidizing power of ozone, so that it can be decomposed biologically faster and easier. The destruction of microorganisms is achieved by contacting ozone, a powerful oxidant, with microorganisms in surplus sludge and damaging and destroying the cell membrane. The microorganisms destroyed by this process are the carbon source for denitrification and phosphorus release in the anaerobic / anoxic bioreactor 23 It is utilized as, the rest is transferred to the aerobic bioreactor 20 is used as food for aerobic microorganisms.

Figure 3 shows the elution of carbon source when treated by ozone treatment, ultrasonic treatment, heat treatment at a temperature of 30-150 ° C., enzyme treatment and freeze thaw as ozone injection amount 0.1-5.0 gO ₃ / gSS as a result of sludge decomposition according to the present invention. It can be seen that a large amount of sludge is eluted as organic matter. Among the above-mentioned methods used in the sludge decomposition apparatus 22, physical treatment methods such as ultrasonic wave, heating, freeze thaw, and mechanical fracturing do not cause any problems in the biological treatment process. It is strong and effectively decomposes sludge, but it has little residual, so it is suitable to be combined with biological treatment process, and there is no toxicity because residual ozone in water after reaction is converted to oxygen.

The sludge decomposition solubilization method for reducing the sludge of the present invention and utilizing it as a carbon source can be applied to a poor load treatment plant. In general biological sewage treatment processes, microorganisms and food must be operated at an appropriate ratio in order to obtain stable treatment efficiency. However, there is a case that the biological treatment process is difficult because the water quality of the inflow water in the domestic sewage treatment plant is much lower than the design reference value. This is referred to as a poor load treatment plant. In this case, if the sludge decomposition solubilization method for reducing sludge according to the present invention and utilizing it as a carbon source is applied for stable biological treatment, it is possible to supplement the food of the microorganisms lacked in raw water. I can solve it.

As described above, the sludge decomposition solubilization method for reducing sludge according to the present invention and utilizing it as a carbon source is performed by physically and / or chemically degrading the sludge inevitably generated in a biological sewage treatment process. It kills microorganisms and decomposes tissues to reduce sludges first, and decomposes the sludges under anaerobic / anoxic conditions of the biological advanced treatment process to use them as a carbon source for denitrification and phosphorus release to secure organic matter in the treatment system. It can effectively increase nutrient removal efficiency.

In addition, in the sludge-free sewage treatment method using the sludge decomposition solubilization method of the present invention, a problem such as landfilling is generated because almost no excess sludge is generated by effectively removing nitrogen and phosphorus by introducing a secured carbon source into a bioreactor. Instead, it can be efficiently applied to low concentration influent.

Claims (10)

To reduce sludge and use it as a carbon source for advanced biological treatment, As a method of decomposing sludge generated in biological sewage treatment process and advanced sewage treatment process alone or in combination with physical treatment and / or chemical treatment, The physical treatment is selected from at least one from mechanical decomposition, heating, freeze thaw, or ultrasonic irradiation, and the chemical treatment is selected from ozone, acid alkali, hydrogen peroxide, or enzyme treatment to reduce sludge and reduce carbon source. Sludge dissolution solubilization method to utilize The method of claim 1, The sludge decomposition solubilization method separates and removes inorganic solids having a high specific gravity in sludge generated in biological sewage treatment and sewage altitude treatment processes using an inorganic solids separation device using centrifugal force before physical treatment and / or chemical treatment of sludge. Sludge decomposition solubilization method for reducing sludge and utilizing as a carbon source, characterized in that it further comprises the step of. The method according to claim 1 or 2, When the chemical treatment is ozone or hydrogen peroxide treatment, the sludge decomposition solubilization method for reducing sludge and utilizing as a carbon source, characterized in that to adjust the pH by injecting acid or alkali to improve the sludge decomposition efficiency. The method according to claim 1 or 2, The method may be applied to an existing advanced treatment process, an advanced treatment process using a continuous batch reactor, an advanced treatment process using an intermittent continuous inflow continuous batch reactor, or an inert water treatment plant where the water quality of the influent is lower than the design standard. Sludge decomposition solubilization method for reducing sludge and utilizing it as a carbon source. As a biological sewage treatment method that does not generate excess sludge, (A) decomposing sludge generated in a biological sewage treatment process and an advanced sewage treatment process alone or in combination with physical treatment and / or chemical treatment; And The sludge decomposed in step (a) is introduced into an anaerobic / anoxic bioreactor of the biological sewage treatment process, and is used as a carbon source for denitrification and phosphorus release. The physical treatment of step (a) is at least one selected from mechanical decomposition, heating, freeze thaw, or ultrasonic irradiation, and the chemical treatment is at least one selected from ozone, acid, alkali, hydrogen peroxide, or enzyme treatment. Sludge-free sewage treatment using sludge decomposition solubilization. The method of claim 5, The sludge-free sewage treatment method is a sludge produced in biological sewage treatment and sewage treatment process using an inorganic solids separation device using centrifugal force before the step (a) of physically treating and / or chemically treating the sludge. Sludge free discharge sewage treatment method using the sludge decomposition solubilization method characterized in that it further comprises the step of separating and removing the inorganic solids having a high specific gravity. The method according to claim 5 or 6, When the chemical treatment is ozone or hydrogen peroxide treatment, sludge discharge sewage treatment using sludge decomposition solubilization method characterized in that the pH is adjusted by injecting acid or alkali to improve the sludge decomposition efficiency. The method according to claim 5 or 6, The method may be applied to an existing advanced treatment process, an advanced treatment process using a continuous batch reactor, an advanced treatment process using an intermittent continuous inflow continuous batch reactor, or an inert water treatment plant where the water quality of the influent is lower than the design standard. Sludge free discharge sewage treatment method using sludge decomposition solubilization method. Sludge cracking apparatus for physically treating sludge and / or chemically treating the sludge; A device for transferring the sludge decomposed in the sludge digestion apparatus to a bioreactor; Anaerobic / anoxic bioreactor; And Sludge-free biological sewage treatment system using sludge decomposition solubilization method characterized in that it comprises an aerobic bioreactor. The method of claim 9, The sludge-free biological sewage treatment system using a sludge dissolving solubilization method further comprises a centrifugal inorganic solids separating device for separating and removing the inorganic solids in the sludge using centrifugal force. system.