KR102094020B1 - Device and Method for continuous feeding andintermittent discharge in sewage and wastewater treatment plant - Google Patents

Abstract

The present invention relates to a sewage and wastewater treatment apparatus and a method thereof, capable of simultaneously removing nutrient salt such as nitrogen, phosphorus and the like as well as an organic material in a biological treatment method of sewage and wastewater and being suitable for large capacity treatment. The present invention provides a sewage and wastewater treatment apparatus and a method thereof, capable of effectively performing continuous inflow of inflow water and intermittent discharge of treated water by installing each of an anaerobic tank and an anoxic tank, which are a phosphorus and nitrogen removal apparatus, and alternately operating two SBRs separately which are an organic material removal and nitrogen oxidation tank, and maximizing removal of nitrogen and phosphorus of an entire system by returning sludge to the anaerobic tank during a continuous inflow and intermittent discharge process. In addition, the present invention has an effect of increasing a total nitrogen (TN) removal rate by injecting raw water in a predetermined pattern unlike a conventional method of continuously injecting raw water in a predetermined amount.

Description

Device and method for continuous feeding and intermittent discharge in sewage and wastewater treatment plant}

The present invention relates to a continuous inflow and intermittent discharge-type wastewater treatment apparatus and method. More specifically, the present invention relates to a sewage and wastewater treatment apparatus and method capable of simultaneously removing not only organic matter but also nutrients such as nitrogen and phosphorus in a biological treatment method of wastewater and wastewater, and suitable for large-scale treatment. .

The treatment facility of the conventional batch processing method is mainly composed of an equalization tank and a biological processing reaction tank. The equalization tank functions to store the wastewater generated daily, and in the biological treatment reaction tank, the wastewater stored in the equalization tank is introduced in an amount to be treated and discharged after aeration and sedimentation processes. The wastewater is treated by intermittent inflow and intermittent discharge methods that repeat the discharge process.

However, such an intermittent inflow and intermittent discharge method of batch processing is possible only in small-scale treatment of a farming and fishing village where the generation of wastewater is non-uniform, and practically not applicable in a large-scale generation region.

Accordingly, the treatment method is being converted into a continuous inflow and intermittent discharge method as a method to be applied to a large-scale treatment facility.

As an example, in U.S. Patent Nos. 4,663,044, 4,693,821 and 4,891,128, multiple partitions are installed in a biological treatment reactor as a continuous inflow and intermittent discharge method, and the amount of pollutant removal increases according to the length of the reactor from the inlet. It has been proposed to design a reactor in the form of a plug flow to finalize it at the end of the reactor, and to discharge the final treated water by a decanter when the water level rises due to the influent flow.

As another example, in Korean Patent Registration No. 10-0242042 (Invention name "Wastewater treatment method using intermittent discharge type long-term aeration process"), the biological treatment reactor is designed in a complete-mix reactor flow method, and the influent is It has been proposed to discharge the treated water by a decanter after injecting it through the perforated tube installed at the bottom of the reactor to move it upwardly, and to make the treated water pushed to the inlet flow to be transported upward.

However, the continuous inflow of the influent by the reaction tank in the form of a flow in accordance with the above-mentioned patent document and the inflow of the influent by the perforated pipe into the upstream type may be mixed with the influent by the treated water. In addition, the discharge of treated water relies on an arm type or curtain wall type decanter that can be moved by a mechanical device, and this decanter has a complicated device and a high price. .

In order to improve this, the applicant's Republic of Korea Patent Registration No. 10-0463631 (invention name "continuous inflow and intermittent discharge type sewage and wastewater treatment apparatus and method") while the influent flows continuously while the influent flows into the anaerobic tank ( 16), one of the two aeration tanks while being alternately injected at regular intervals (usually 180 minutes) into the first aeration tank 12 and the second aeration tank 13 by the valves 19 and 20 after passing through the anaerobic tank 18 The aeration tank (12 or 13) was intermittently discharged by a decanter.

At this time, the general operation cycle is based on anaerobic / anaerobic conditions 1.5-2.5 hours, inflow / reaction / conveyance 180 minutes, precipitation 90 minutes, and discharge 90 minutes as 1 cycle, 4 cycles per day per day, total 8 cycles. The intermittent discharge method is possible by distributing the aeration tanks into two aeration tanks 12 and 13 every three hours during the continuous inflow of the aeration tanks.

However, when the distribution to the aeration tank is finished, the next process, sedimentation and discharge, proceeds, so that the sewage introduced immediately before distribution ends has little reaction time (aeration time). In other words, it is necessary to have a very short aeration time. Due to this, there is a problem that the nitrification efficiency in the aeration tank is lowered. In addition, since the biological nitrogen removal mechanism is performed through nitrification and denitrification (denitrification), a reduction in nitrification efficiency leads to a reduction in denitrification efficiency, which leads to a decrease in nitrogen removal efficiency.

U.S. Patent No. 4,663,044 U.S. Patent No. 4,693,821 U.S. Patent No. 4,891,128 Republic of Korea Patent Registration No. 10-0242042 (Invention name "Wastewater treatment method using intermittent discharge long-term aeration process") Republic of Korea Patent Registration No. 10-0463631 (Invention name "Continuous inflow and intermittent discharge type sewage and wastewater treatment device and method")

The present invention has been devised to solve the problems of the prior art, and the object of the present invention is to continuously treat the nitrogen in the treated water without lowering the nitrification efficiency in the aeration tank and denitrification efficiency in the oxygen-free tank during intermittent discharge type wastewater treatment. It is to provide a continuous inflow and intermittent discharge-type sewage and wastewater treatment apparatus and method with improved removal efficiency.

In order to achieve the above and other objects, the present invention,

Sludge is settled and finally treated after supplying air to the anaerobic tank and the anoxic tank connected to the anaerobic tank and the effluent passing through the anaerobic tank to be biologically treated by inflow of sewage and wastewater influent containing organic, nitrogen, and phosphorus components. In the sewage and wastewater treatment system consisting of SBR (Sequencing Batch Reactor) to repeat the process of intermittent discharge of water,

An anaerobic tank 16 and an anaerobic tank 18 arranged so that the sludges 14 and 15 conveyed from the inflow water 11 and the SBRs 12 and 13 are continuously introduced and processed after complete mixing;

The anaerobic tank 16 and the anaerobic tank 18 are installed separately, and the inflow water 11 and the return sludge 14 and 15 that have passed through the anaerobic tank and the anaerobic tank are provided in valve means 19 and 20 for controlling the inflow to the SBR. It is composed of two SBRs (13) which are intermittently discharged as aeration and sedimentation occur alternately in each SBR after being introduced into the SBR.

The inflow water 11 flowing into the anaerobic tank 16 is configured to be adjusted and introduced at least in two stage inflow ratios, but the inflow ratio in the first stage is configured to be set higher than the inflow ratios in the second stage. A continuous inflow and intermittent discharge type sewage and wastewater treatment system is provided.

In the present invention, it is characterized in that the first step inflow time and the second step inflow time of the inflow water 11 flowing into the anaerobic tank 16 are set to be substantially the same.

In the present invention, the first step inlet ratio is 60 to 90%, and the second step inlet ratio is adjusted to be 40 to 10%.

In the present invention, the anaerobic tank (16) and the anaerobic tank (18) are characterized in that the sludge from the SBRs (12, 13) is transported and introduced.

In addition, the present invention, after the biological treatment by supplying air to the anaerobic tank connected to the anaerobic tank and the anaerobic tank connected to the anaerobic tank and the anaerobic tank continuously flowing into the wastewater and wastewater inflow containing organic and nitrogen, phosphorus components In the sewage and wastewater treatment system consisting of SBR repeating the process of sedimentation and intermittent discharge of the final treated water,

An anaerobic tank and an anaerobic tank arranged so that the influent and sludge returned from the SBR are continuously introduced and processed after complete mixing; And

It is installed separately from the anaerobic tank and the anaerobic tank, and the influent water and the return sludge that have passed through the anaerobic tank and the anaerobic tank flow into the SBR by valve means for controlling the inflow into the SBR, and then aeration and sedimentation action alternately in each SBR. It includes at least two or more SBRs configured to discharge treated water intermittently while rising,

The inflow water flowing into the anaerobic tank is configured to be adjusted to at least a second-stage inflow ratio, and the first-stage inflow ratio is set to be higher than the second-stage inflow ratio, wherein the first-stage inflow ratio is 60 to 60 Provided is a continuous inflow and intermittent discharge-type sewage and wastewater treatment apparatus, which is configured to be 90% and adjusted so that the second stage inflow rate is 40 to 10%.

In addition, the present invention, the step of releasing the phosphorus by continuously flowing into the anaerobic tank and wastewater influent containing organic, nitrogen, and phosphorus components, denitrification of nitrate nitrogen in the anoxic tank connected to the anaerobic tank to further nitrogen In the method of removing wastewater, the sludge is settled and the final treated water is intermittently discharged after the biological treatment is performed while supplying air to the SBR by sending the influent flowing through the anaerobic tank and the anaerobic tank to SBR.

Continuously introducing the influent water and the sludge returned from the SBR into the anaerobic tank and the anaerobic tank; A step of alternately operating the two SBR inflow valves through the intake water and the return sludge that has passed through the anoxic tank to two SBRs installed on both sides so that biological treatments alternate in the SBRs; And by repeatedly operating the above steps, the sludge is precipitated, and then returned to the anaerobic tank and the anaerobic tank, and the treated water is intermittently discharged.

At this time, the inflow water flowing into the anaerobic tank is configured to be adjusted to at least two-stage inflow ratio, and the inflow ratio of the first stage is higher than the inflow ratio of the second stage. · Provide wastewater treatment methods.

In the present invention, the first step inflow time and the second step inflow time of the influent flowing into the anaerobic tank are characterized by being substantially the same.

In the present invention, the first step inlet ratio is 60 to 90%, and the second step inlet ratio is characterized in that 40 to 10%.

In the construction of the wastewater treatment system as in the present invention, in the case of a small scale (small capacity), one anaerobic tank and an anaerobic tank, which are phosphorus and nitrogen removal devices, are installed one by one, and the organic matter removal and nitrogen oxidation tank, SBR, are divided into two and alternately By allowing the furnace to operate, continuous inflow of influent water and intermittent discharge of treated water can be effectively performed, and in the process of continuous inflow and intermittent discharge, sludge is returned to the anaerobic tank to maximize the removal of nitrogen and phosphorus throughout the system. In the case of large-scale (large-capacity), the anaerobic tank and anaerobic tank are two, and the aeration tank is two, so that the entire system can be configured.

 In addition, the nitrogen removal rate increased as the TN removal efficiency increased as the inflow rate of the first half (0-90 minutes) was increased compared to the constant inflow rate.

1 is a schematic diagram of a continuous inflow and intermittent discharge-type wastewater treatment apparatus according to the present invention.
Figure 2 is a conceptual diagram showing the change in the amount of inflow with the inflow time during the injection time (generally 180 minutes) alternately in SBR (12, 13), respectively.

Hereinafter, the present invention will be described in more detail with reference to the accompanying exemplary drawings. In describing the present invention, descriptions of already known functions or configurations will be omitted to clarify the gist of the present invention. In addition, the same reference numbers throughout the specification indicate the same components.

1 of the accompanying drawings in the present invention schematically shows a continuous inflow and intermittent discharge-type sewage and wastewater treatment apparatus according to the present invention, and FIG. 2 shows a time (generally 180 minutes) alternately injected into SBRs 12 and 13, respectively. ) Is a conceptual diagram showing the change of the inflow water volume according to the inflow time.

As shown in Fig. 1, the sewage and wastewater treatment apparatus according to the present invention includes sludge (14, 15) in which sewage and wastewater inflow water (11) containing components of organic matter, nitrogen, and phosphorus is returned from the SBR (12, 13). ) Is mixed and introduced into the anaerobic tank 16, the complete mixing of the influent 11 and the return sludge 14, 15 by the agitator 17 in the anaerobic tank 16 occurs, and the carbon source contained in the influent 11 is used. Therefore, some of the nitrate nitrogen components contained in the phosphorus release and return sludge liquid in the microbial cells are reduced to nitrogen gas and removed.

As shown above, the inflow water 11 and the return sludges 14 and 15 that have passed through the anaerobic tank 16 flow in the direction of the arrow indicated by the dotted line in FIG. 1 and are sent to the anoxic tank 18, and in the anoxic tank 18, nitric acid nitrogen occurs at the same time. The removal of nitrogen is further maximized.

In the anoxic tank 18, the reacted influent 11 and the return sludges 14 and 15 flow in the direction of the arrow through the first SBR solenoid valve 19 installed in the anoxic tank 18 to perform the A reaction process. (12), and in the first SBR (12), while supply of air occurs, oxidation of organic substances contained in the influent water, nitrification of nitrogen components contained in the influent water, and absorption of more phosphorus than the amount of phosphorus released from the anaerobic tank Excess absorption of phosphorus occurs. After the air supply is finished in the first SBR (12), a sedimentation process in which the treated water and the sludge are separated into a solid liquid is performed, and after the precipitation is completed, the treated water is discharged through the discharge device 30 by the principle of siphon.

For example, when the method of the present invention is divided into an A reaction process in the first SBR 12 and a B reaction process in the second SBR 13, the anaerobic tank 16 and the anaerobic tank are illustrated as illustrated in FIG. 1. (18) is one for each, so it is used jointly in the A and B processes, and because the SBR (12,13) is two, the A and B reactions proceed separately. That is, as shown in Table 1, the progress of the A and B reactions varies with time.

Therefore, if the aeration process is completed after the anoxic tank 18 through the anaerobic tank 16 and the influent 11 and the return sludge 14, 15 in the reaction process A, precipitation and discharge are already completed in the reaction process B, and the reaction process A When precipitation and discharge are completed, the aeration process is completed in the second SBR (13) of the B reaction process. When precipitation starts again in the first SBR 12 of the A reaction process, the inflow water 11 and the return sludges 14 and 15 are introduced into the anaerobic tank 16 in the B reaction process.

Eventually, the anaerobic tank 16 and the anaerobic tank 18 are installed and used one by one, respectively, and the first and second SBRs 12 and 13 are separately used, so that the inflow water 11 passes through the anaerobic tank 16 to be anaerobic tank 18 ), The first and the second SBR (12,13) can be continuously flown, and the first and second SBRs (12,13) where aeration, sedimentation and discharge occur alternately can be intermittently discharged.

According to the present invention, as shown in FIG. 1, the inlet solenoid valve is provided with two inlet solenoid valves 18, and for the reaction process A, the first SBR inlet solenoid valve 19 located on the left side of the anoxic tank 18 ) Is opened, and the influent and return sludge passed through the anoxic tank 18 flow into the first SBR 12, whereas in the B reaction process, the influent and return sludge that has already passed through the anaerobic and anoxic processes are transferred to the second SBR 13. Since the reaction proceeds due to the inflow, the second SBR inlet solenoid valve 20 located on the right side is locked.

After all, the progress of the alternating reaction in the SBR depends on the alternating action of the solenoid valves 19 and 20 installed in the anoxic tank 18, and the treatment water after aeration and sedimentation in the SBR (12, 13) uses the head difference. Discharge is performed through the discharging device 30 according to the phone principle.

Accordingly, according to the present invention, the sludge return from the SBR to the anaerobic tank is carried out for replenishment of sludge in the anaerobic tank 16 and the anaerobic tank 18, release of phosphorus from the sludge, and denitrification of nitrated nitrate nitrogen in the SBR, A, B In each reaction process, sludge return to the anaerobic tank 16 is continuously performed until the aeration ends.

In addition, one anaerobic tank 16 and one anaerobic tank 18 are installed, and two SBRs 12 and 13 are installed to alternately discharge the aeration process, so that the discharge is intermittent and the inflow can be continuously performed. . And by using the SBRs (12, 13) alternately, there is room to cope with mechanical failures or other emergency situations. On the other hand, two or more anaerobic tanks, anaerobic tanks, and SBRs are installed in medium and large treatment plants, allowing complete integration.

In FIG. 1, reference numeral 25 is a stirrer installed in the anaerobic tank 18, and reference numerals 28 and 29 are a first SBR sludge conveying pump and a second SBR sludge conveying pump, respectively.

Of the accompanying drawings, FIG. 2 shows the change of the inflow water amount according to the inflow time during the alternate injection time (generally 180 minutes) to the SBRs 12 and 13, and the following Table 2 is illustrated. In other words, the ratio of the influent flowing into the anaerobic tank is continuously adjusted to the ratio of two stages. In the case of a, it shows the conventional injection method that flows at a constant rate, and 50% of the total inflow amount was injected up to 90 minutes, which is half of 180 minutes.

On the other hand, b, c, d, and e are injected by 60%, 70%, 80%, and 90%, respectively, up to 90 minutes, and the remaining 40%, 30%, 20%, and 10% are injected for the remaining 90 minutes. Sewage introduced immediately before (at the time of 180 minutes) has almost no reaction time (aeration time), thereby minimizing the reduction in nitrification and denitrification efficiency in SBR.

However, when driving with an extremely large amount introduced in the first half of the inflow time (0-90 minutes), phosphorus emission efficiency in the anaerobic tank 16 and denitrification (denitrification) efficiency in the anoxic tank 18 may be reduced. This is due to various causes (influent flow, influent characteristics, sludge internal conveyance, DO concentration, microbial activity, etc.). Therefore, the percentage (%) of influent to flow in the first half (0-90 minutes) must find the appropriate percentage of influent (%) that satisfies the optimum efficiency at each test run.

Hereinafter, the present invention will be described in more detail based on examples.

Example

Using the actual sewage flowing into the sewage treatment plant as the influent, the plant with a daily treatment capacity of 20 tons / day was operated in a continuous inflow and intermittent discharge method for about 5 months. Operating conditions were anaerobic and anaerobic tank hydraulic residence time of 1 hour each, reaction time of each SBR was 3 hours each, and precipitation and discharge times were 1.5 hours each. In addition, the concentration of microorganisms in each reaction tank was about 3,850 mg / L, and the internal return of the sludge from the SBR to the anaerobic tank was operated at 1.0 to 3.0 times the influent flow rate.

Table 3 below shows the results of experiments by averaging the properties of influent and treated water operated for 5 months.

As can be seen through Table 3, the removal rate of organic substances, that is, the COD and BOD removal efficiency was 93.9-94.6% and 97.5-97.9%, respectively, and there was no change in the treatment efficiency due to the change in inflow volume, and the SS removal efficiency was also 95.5-96.1%. There was no change according to the inflow pattern change. Under the a, b, c, d, and e conditions, the treated water T-P was 2.6, 2.5, 2.5, 2.5, and 2.7 mg / L, respectively.

However, the TN removal efficiency showed a removal rate of 76.9% in the a condition that constantly flows the inflow and the removal efficiency of 80.6, 82.3, 83.9, and 82.4% in the b, c, d, and e conditions, respectively. ) It was confirmed that the nitrogen removal rate increased as the inflow flow rate increased. However, in the e condition (inflow condition of 90% of the inflow amount in the first half), the removal efficiency was rather reduced.

This phenomenon was analyzed to be due to the result of a slight decrease in the denitrification rate under the e condition (the inflow condition of 90% of the total inflow rate in the first half), although the TKN continued to decrease (increased nitrification rate) with the increase in the inflow rate in the first half.

In the above, it has been described with reference to preferred embodiments of the present invention, but those skilled in the art may variously modify and change the present invention without departing from the spirit and scope of the present invention as set forth in the claims below. You will understand that you can.

11: Influent 12, 13: SBR
14, 15: return sludge 16: anaerobic tank
17,25: stirrer 18: anoxic tank
19, 20: valve 28, 29: return pump
30: discharge device 31: inlet member
32: inlet 33: valve
34: discharge pipe 35: outlet

Claims (8)

Sludge is settled and finally treated after supplying air to the anaerobic tank and the anoxic tank connected to the anaerobic tank and the effluent passing through the anoxic tank biologically by inflow of sewage and wastewater inflows containing organic, nitrogen and phosphorus components. In the sewage and wastewater treatment system consisting of SBR (Sequencing Batch Reactor) to repeat the process of intermittent discharge of water,
A single anaerobic tank 16 and an anaerobic tank 18 arranged such that the sludges 14 and 15 conveyed from the inflow water 11 and the SBRs 12 and 13 are continuously introduced and processed after complete mixing; And
The anaerobic tank 16 and the anaerobic tank 18 are installed separately, and the inlet water 11 and the conveyed sludge 14 and 15 that have passed through the anaerobic tank 16 and the anaerobic tank 18 are valve means for controlling the inflow to the SBR. After flowing into SBR by (19, 20), each SBR includes two SBRs 13 configured to intermittently discharge the treated water while aeration and sedimentation occur alternately,
Doedoe the incoming water 11 that is continuously flowing into the anaerobic tank 16 is adjusted to the second stage inlet ratio configured to be introduced in succession, and the inflow rate of the first phase is configured to be set higher than the inflow rate of the second stage ,
The first step inflow time of the inflow water 11 flowing into the anaerobic tank 16 and the second step inflow time are configured to be set to be the same,
Continuous inflow and intermittent discharge type wastewater treatment apparatus, characterized in that the first stage inflow ratio is 80% and the second stage inflow ratio is adjusted to be 20%. delete delete According to claim 1,
The anaerobic tank (16) and the anaerobic tank (18) is a continuous inflow and intermittent discharge-type sewage and wastewater treatment device, characterized in that a means is provided in which sludge from the SBR (12, 13) is conveyed and introduced. Sludge is settled and finally treated after supplying air to the anaerobic tank and the anoxic tank connected to the anaerobic tank and the effluent passing through the anoxic tank biologically by inflow of sewage and wastewater inflows containing organic, nitrogen and phosphorus components. In the sewage and wastewater treatment system consisting of SBR repeating the process of intermittent discharge of water,
An anaerobic tank and an anaerobic tank arranged so that the influent and sludge returned from the SBR are continuously introduced and processed after complete mixing; And
It is installed separately from the anaerobic tank and the anaerobic tank, and the influent water and the return sludge that has passed through the anaerobic tank and the anaerobic tank flow into the SBR by valve means for controlling the inflow into the SBR, and then aeration and sedimentation action alternately in each SBR. It includes two or more SBRs that are configured to be discharged intermittently while being treated.
The inflow water flowing into the anaerobic tank is configured to be adjusted to the inflow rate of the second stage, and the inflow ratio of the first stage is set to be higher than the inflow ratio of the second stage.
The first step inflow time of the inflow water 11 flowing into the anaerobic tank 16 and the second step inflow time are configured to be set to be the same,
Continuous inflow and intermittent discharge type sewage and wastewater treatment apparatus, characterized in that the first stage inflow ratio is 80% and the second stage inflow ratio is adjusted to be 20%. A step of continuously flowing into the anaerobic tank and discharging phosphorus into the anaerobic tank containing organic, nitrogen, and phosphorus components, and further removing nitrogen by denitrifying nitrate nitrogen in the anoxic tank connected to the anaerobic tank. And in the sewage and wastewater treatment method consisting of repeating the process of intermittently discharging the final treated water after the biological treatment while supplying air by sending the influent through the anoxic tank to the SBR,
Continuously introducing the influent water and the sludge returned from the SBR into the anaerobic tank and the anaerobic tank; A step of alternately operating the two SBR inflow valves through the intake water and the return sludge passing through the anoxic tank to two SBRs installed on both sides so that biological treatments alternate in the SBRs; And by repeatedly operating the above steps, the sludge is precipitated, and then returned to the anaerobic tank and the anaerobic tank, and the treated water is intermittently discharged.
At this point, the inlet water is continuously flowing into the anaerobic tank is adjusted in two steps inflow rate doedoe configured to be continuously flowing, flowing rate of the first stage is introduced above the inflow rate of the second stage,
The first step inflow time and the second step inflow time of the influent flowing into the anaerobic tank are the same,
Continuous inflow and intermittent discharge type sewage and wastewater treatment method, characterized in that the first stage inflow ratio is 80%, and the second stage inflow ratio is 20%. delete delete

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