KR100432321B1 - Method for advanced wastewater treatment without excess sludge using sludge disintegration - Google Patents

Abstract

The sludge decomposition solubilization method for reducing sludge and utilizing it as a carbon source according to the present invention is a sludge decomposition solubilization method for reducing sludge and utilizing it as a carbon source in a high biological treatment process, using an inorganic solids separation device using centrifugal force. (A) separating and removing the inorganic solid having a high specific gravity in the sludge generated in the biological sewage treatment process and the advanced sewage treatment process; Treatment of the sludge generated in the biological sewage treatment process and the advanced sewage treatment process by mechanical crushing, heat treatment at 60 ° C to 150 ° C, or freezing and thawing at 20 ° C to 60 ° C Step (b); And injecting ozone in a range of 0.1 to 1.0 gO ₃ / gSS sequentially or in parallel with step (b) to treat ozone.

Description

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

The present invention relates to a method of utilizing sludge as a carbon source for advanced treatment, and more particularly, to reduce sludge by physically treating the sludge discharged from the biological advanced treatment process and chemically decomposing the treated sludge using ozone. The present invention relates to a sludge decomposition and solubilization method for reducing sludge and utilizing it as a carbon source, which can be effectively utilized as a carbon source for denitrification and phosphorus release and ultimately effectively improve nutrient removal efficiency.

In addition, the present invention relates to a biological sewage advanced treatment method, and more particularly, by using the solubilized sludge as a food for the microorganism through the sludge decomposition solubilization method to reduce the sludge and utilize as a carbon source, the discharge of excess sludge is reduced. The present invention relates to a sludge-free sewage altitude treatment method 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, VIP (Virginia Initiative Plant) and UCT (University of Cape Town) processes.

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 physical treatment, such as mechanical crushing, heating or freeze thaw, which is inevitably generated in the biological sewage treatment process and chemical treatment using ozone By treating the sludge sequentially or in parallel, the microorganisms are killed and the tissue is decomposed to reduce the sludge, and the decomposed sludge can be effectively used as a carbon source for denitrification and phosphorus release. It is to provide a sludge decomposition solubilization method for reducing sludge 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 It is to provide a sludge-free discharge sewage treatment method 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 method 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 according to the present invention and utilizing it as a carbon source is a sludge decomposition solubilization method for reducing sludge and utilizing it as a carbon source in a biologically advanced process. (A) 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 using the inorganic solids separation device; Treatment of the sludge generated in the biological sewage treatment process and the advanced sewage treatment process by mechanical crushing, heat treatment at 60 ° C to 150 ° C, or freezing and thawing at 20 ° C to 60 ° C Step (b); And injecting ozone in a range of 0.1 to 1.0 gO ₃ / gSS sequentially or in parallel with step (b) to treat ozone.

In the sludge decomposition solubilization method for reducing sludge and utilizing as a carbon source according to the present invention, the step (c) is a protease (Protease) and cellulase (Cellulase) in the range of 0.3g / L ~ 3g / L Injecting in an amount may further comprise the step of enzyme treatment.

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, acid or alkali is injected to adjust the pH to improve sludge decomposition efficiency.

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, biological sewage treatment process and sewage altitude treatment using an inorganic solids separation device using centrifugal force. (A) separating and removing the inorganic solid having a high specific gravity in the sludge generated in the process; Treatment of the sludge generated in the biological sewage treatment process and the advanced sewage treatment process by mechanical crushing, heat treatment at 60 ° C to 150 ° C, or freezing and thawing at 20 ° C to 60 ° C Step (b); (C) ozone treatment by injecting ozone in a range of 0.1 to 1.0 gO ₃ / gSS sequentially or in parallel with step (b); And (d) using the decomposed sludge as a carbon source for denitrification and phosphorus release by inputting the anaerobic / anoxic bioreactor in the biological sewage treatment process.

In the sludge free discharge sewage treatment method using the sludge decomposition solubilization method according to the present invention, the step (c) is a protease (Protease) and cellulase (Cellulase) in the range of 0.3g / L ~ 3g / L Injecting in an amount may further comprise the step of enzyme treatment.

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

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.

In the present invention, as the physical treatment method, ultrasonic irradiation can be used in addition to mechanical crushing, heating or freeze thawing. In addition, in the present invention, an acid-alkali treatment or a hydrogen peroxide treatment method can be used in addition to the ozone treatment method.

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 FIG. 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 21 is relatively concentrated using a centrifugal inorganic solids separator 22. The large inorganic solids are separated and removed, and decomposed and solubilized using a sludge decomposition device 23 using ozone to be sent to the anaerobic / oxygen-free bioreactor 20. Decomposed sludge sent to the anaerobic / anoxic bioreactor 20 is used as a carbon source for denitrification and phosphorus release under anaerobic / anoxic conditions, and the remainder is used as microbial feed in the aerobic bioreactor 21.

This will be described in more detail as follows.

The centrifugal inorganic solids separator 22 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 allowing 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 the microorganisms is achieved by contacting ozone, a powerful oxidant, with the microorganisms in the excess 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 / oxygen-free bioreactor 20. And the rest is transferred to the aerobic bioreactor 21 is used as a 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. The ultrasonic treatment in FIG. 3 (a) was performed using an ultrasonic device having a generation power of 49 kW. As a result of the experiment, the solubilization effect was up to 30 minutes. After 30 minutes, there was no difference. The heat treatment of FIG. 3 (b) is a method of heating the sludge to destroy the sludge composed of cells and solubilizing the temperature range during the heat treatment. The treatment time was the same as 30 minutes at each temperature condition. As shown in Figure 3 (b), the solubilization reaction of the waste activated sludge according to the heat treatment has no effect up to 60 ℃ it can be seen that rapidly eluted after that. In addition, the solubilized organic matter increased proportionally as the heat treatment temperature increased to 90 ° C., 120 ° C., and 150 ° C. The enzymatic treatment of FIG. 3 (c) was performed by mixing and administering a protease, a protease, and a cellulase. As a method of reducing the size, as shown in the figure, the elution concentration of the solubilized organic material tended to increase in proportion to the dose. The freeze-thawing treatment of FIG. 3 (d) freezes the microorganisms and thaws solubilizing the sludge. As a method, after freezing under the same conditions of -10 ℃, the thawing temperature was varied from 0 ℃ to 60 ℃, as shown in the figure, it can be seen that the solubilization efficiency is increased in the rapid thawing. In particular, when thawed at a relatively high temperature of 60 ℃, the amount of soluble organics elution (see Figure 3 (b)) was more than when the heat treatment at 60 ℃, it can be seen that the effect of freeze thaw. In freezing and thawing, solubilized organic matter was obtained more when thawed at a high temperature (60 ° C.) than at a low temperature (20 ° C.). FIG. 3 (e) shows an ozone injection amount of 0.05-2.0 gO ₃ /. Ozone treatment was performed by different gSS, and the degree of decomposition of sludge was analyzed. As shown in FIG. 3 (e), the solubilized organic material increased with the change of the ozone injection amount, and a high solubilized organic material was obtained at the ozone injection amount of 0.5gO ₃ / gSS. In addition, no significant change in SCOD was observed until the ozone injection amount of 1.0 gO ₃ / gSS, but when the ozone injection amount was 1.0 gO ₃ / gSS or more, it was confirmed that SCOD, which is an indicator of solubilization, was reduced by ozone oxidation. Among the above methods used in the apparatus 23, physical treatment methods such as ultrasonic wave, heating, freeze thaw and mechanical crushing do not cause any problem in biological treatment process, and in the case of ozone treatment which is chemical treatment, the oxidizing power is strong. It effectively decomposes the sludge, but it is suitable for incorporation into biological treatment processes because it has little residual, and there is no toxicity since residual ozone in water after the reaction is converted into 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 to sequentially or concurrently perform physical and / or chemical decomposition treatment of sludge inevitably generated in a biological sewage treatment process. By killing microorganisms and decomposing tissues, the sludge is firstly reduced and the decomposed sludge is put into anaerobic / anoxic conditions of the biological advanced treatment process to utilize organic carbon as a carbon source for denitrification and phosphorus release. , Can effectively increase the efficiency of nutrient removal.

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)

As a sludge decomposition solubilization method for reducing sludge and using it as a carbon source for a biologically advanced process, (A) separating and removing the inorganic solids having a high specific gravity in sludge generated in the biological sewage treatment process and the sewage advanced treatment process by using an inorganic solids separator using centrifugal force; Treatment of the sludge generated in the biological sewage treatment process and the advanced sewage treatment process by mechanical crushing, heat treatment at 60 ° C to 150 ° C, or freezing and thawing at 20 ° C to 60 ° C Step (b); And Sludge to reduce the sludge and utilize as a carbon source, characterized in that it comprises a step (c) to ozone treatment by injecting ozone in the range of 0.1 ~ 1.0gO ₃ / gSS sequentially or in parallel with the step (b) Decomposition solubilization method. delete delete The method of claim 1, 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) separating and removing the inorganic solids having a high specific gravity in sludge generated in the biological sewage treatment process and the sewage advanced treatment process by using an inorganic solids separator using centrifugal force; Treatment of the sludge generated in the biological sewage treatment process and the advanced sewage treatment process by mechanical crushing, heat treatment at 60 ° C to 150 ° C, or freezing and thawing at 20 ° C to 60 ° C Step (b); (C) ozone treatment by injecting ozone in a range of 0.1 to 1.0 gO ₃ / gSS sequentially or in parallel with step (b); And Sludge free discharge using sludge decomposition solubilization method comprising the step (d) of decomposing sludge into the anaerobic / oxygen-free bioreactor of biological sewage treatment process as a carbon source for denitrification and phosphorus release. Sewage treatment method. delete delete The method of claim 5, 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. delete delete