WO2022225300A1

WO2022225300A1 - Sewage and wastewater treatment apparatus using algae granules

Info

Publication number: WO2022225300A1
Application number: PCT/KR2022/005595
Authority: WO
Inventors: 황호재; 이정준; 성수영
Original assignee: 주식회사 부강테크
Priority date: 2021-04-19
Filing date: 2022-04-19
Publication date: 2022-10-27
Also published as: KR102436828B1

Abstract

Disclosed is a sewage and wastewater treatment apparatus using algae granules. One aspect of the present embodiment provides an algae granule reaction tank which removes organic matter and nitrogen from sewage using algae granules.

Description

Sewage and wastewater treatment device using algae granules

The present invention relates to an apparatus for treating sewage and wastewater using algae granules.

The content described in this section merely provides background information for the present embodiment and does not constitute the prior art.

In the case of a biological treatment process that treats sewage and wastewater, an appropriate concentration of dissolved oxygen is required to treat organic matter and induce a nitrification reaction. In a commonly used activated sludge process, it is known that the energy used as aeration for oxygen supply accounts for about 40 to 60% of the total energy consumption of the sewage treatment plant. In order to reduce the energy consumed in aeration, there is a method of removing pollutants using algae, a microorganism that can replace the aeration process.

The method of using algae can significantly reduce the power required for sewage treatment facilities. Since microalgae require nitrogen and phosphorus to grow and have excellent heavy metal adsorption capacity, they have a high removal rate in treating organic matter, nutrients and heavy metals.

Conventional microbial treatment processes have removed contaminants by using an open or closed reactor to remove organic contaminants. In the case of an open reactor, it has the advantages of low installation cost and easy design and operation, while the upper part is open, so there are major disadvantages such as deterioration of water quality due to the inability of photosynthesis due to the weather. In addition, a large site is required, the HRT (Hydraulic Retention Time) is long, and the water treatment efficiency is low. In the case of a closed reactor, it is mainly operated with various types of photobioreactors (PBRs), which are difficult to operate as large-scale plants and have low economic feasibility.

Due to these problems, there is an increasing demand for a more efficient treatment method in treating sewage and wastewater.

An embodiment of the present invention has an object to provide an algae granule reactor for removing organic matter and nitrogen in sewage using algae granules.

In addition, an embodiment of the present invention, in removing organic matter and nitrogen in sewage using algae granules, it is an object to provide an algae granule reactor capable of continuously removing organic matter and nitrogen regardless of time. .

According to one aspect of the present invention, in the algae granule reactor for receiving sewage and wastewater to remove organic matter or nitrogen in the sewage and wastewater, the introduced sewage and wastewater are stored, and the microbes in the sewage or sludge granules formed from microorganisms A reaction tank that induces algae to adhere to generate algae granules, a stirring unit that circulates in the opposite direction to the direction in which sunlight is incident into the reaction tank, and agitates the sewage and wastewater, and the flow rate of sewage and wastewater introduced into the reaction tank, lower Located at the bottom of the reactor and a measuring unit that measures some or all of suspended solids concentration (MLSS) in wastewater, turbidity of sewage and wastewater, dissolved oxygen in sewage and wastewater, carbon dioxide in sewage and wastewater, and flow rate of sewage and wastewater Thus, the granule outlet for discharging the precipitated algae granules to the outside, the supernatant outlet for discharging the supernatant water after the algae granules are settled to the outside, which is located at a preset height of the reaction tank, and a control unit for controlling the operation of the stirring unit. It provides an algal granule reactor, characterized in that.

According to one aspect of the present invention, it characterized in that it further comprises a light source for irradiating light to the reaction tank.

According to an aspect of the present invention, the light source unit receives sunlight and stores it as energy.

According to an aspect of the present invention, a filter for filtering a wavelength band of sunlight incident to the reaction tank or light irradiated from the light source unit is further included between the light source unit and the reaction tank.

According to one aspect of the present invention, the filter is characterized in that it passes a wavelength band that allows the preset microalgae in the reaction tank to dominate, and filters the remaining wavelength band.

According to one aspect of the present invention, the preset microalgae are Aphanizomenon sp., Oscillatoria sp. and Phormidium sp. It is characterized by some or all of.

According to one aspect of the present invention, it is disposed on the bottom of the reaction tank, it characterized in that it further comprises an inclined portion for guiding the algal granules to be precipitated to the granule outlet.

According to one aspect of the present invention, the inclined portion is characterized in that it has an inclination toward the granule outlet from the opposite side of the granule reactor.

As described above, according to one aspect of the present invention, organic matter and nitrogen can be removed using algae granules, and organic matter and nitrogen can be continuously removed regardless of time in removing organic matter and nitrogen. there are advantages to

1 is a diagram showing the configuration of an algae granule reactor according to an embodiment of the present invention.

Figure 2 is a view showing a cross-section of the algae granule reactor according to an embodiment of the present invention.

Figure 3 is a view showing a cross-section of the algae granules according to an embodiment of the present invention.

Since the present invention can have various changes and can have various embodiments, specific embodiments are illustrated in the drawings and described in detail. However, this is not intended to limit the present invention to a specific embodiment, it should be understood to include all modifications, equivalents and substitutes included in the spirit and scope of the present invention. In describing each figure, like reference numerals have been used for like elements.

Terms such as first, second, A, and B may be used to describe various elements, but the elements should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, a first component may be referred to as a second component, and similarly, a second component may also be referred to as a first component. and/or includes a combination of a plurality of related listed items or any of a plurality of related listed items.

When a component is referred to as being “connected” or “connected” to another component, it may be directly connected or connected to the other component, but it is understood that other components may exist in between. it should be On the other hand, when it is said that a certain element is "directly connected" or "directly connected" to another element, it should be understood that no other element is present in the middle.

The terms used in the present application are only used to describe specific embodiments, and are not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. It should be understood that terms such as “comprise” or “have” in the present application do not preclude the possibility of addition or existence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification in advance. .

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

Terms such as those defined in a commonly used dictionary should be interpreted as having a meaning consistent with the meaning in the context of the related art, and should not be interpreted in an ideal or excessively formal meaning unless explicitly defined in the present application. does not

In addition, each configuration, process, process or method included in each embodiment of the present invention may be shared within a range that does not technically contradict each other.

1 is a view showing the configuration of the algal granule reactor according to an embodiment of the present invention, Figure 2 is a view showing a cross-section of the algae granule reactor according to an embodiment of the present invention.

1, the algae granule reactor 100 according to an embodiment of the present invention includes a light source unit 110, agitation unit 120, a measurement unit 130, an inclined unit 140, a granule outlet 150, and supernatant water. It includes an outlet 160 , a reaction tank 170 , and a control unit (not shown).

The algae granule reactor 100 receives sewage and wastewater from which suspended substances or solids are primarily removed, and generates algae granules with microalgae attached to microorganisms or sludge granules. The algae granule reactor 100 removes organic matter and nitrogen in sewage using algae granules.

Algae granule reactor 100 forms sludge granules and breeds microalgae. Most microorganisms in the sewage introduced into the algae granulation tank 100 are present without being granulated in the sludge. These microorganisms aggregate with each other in the algal granule reactor 100 to form sludge granules. On the other hand, microalgae existing in the sewage in the algae granule reactor 100 receives light incident to the algae granule reactor 100 and reproduces. The light incident to the algae granule reaction tank 100 may be sunlight or artificial light from a separate light source. Microalgae reproduce by receiving sunlight or artificial light. At this time, the algae granule reaction tank 100 may include a filter or a screen that transmits a specific wavelength band, so that only a specific wavelength band is incident into the reaction tank. When only light of a specific wavelength band is incident to the algae granule reaction tank 100 , a specific type of microalgae may dominate and propagate in the reaction tank. Here, the microalgae that dominate and reproduce are cyanobacteria or cyanobacteria with high cohesion of the alga itself and excellent cohesion with sludge granules, for example, Aphanizomenon sp., Oscillatoria sp. or Phormidium sp. can be The algae granule reaction tank 100 may use a filter or a screen to filter so that, for example, only light of a wavelength band of 450 to 650 nm is incident, to predominate the above-mentioned types of microalgae.

The algal granule reactor 100 generates algal granules with microalgae attached to the sludge granules. When the algae granule reaction tank 100 provides a preset environment, the microalgae are attached to the surface of the sludge granules formed in the first settling tank 110 or formed in the algae granule reaction tank 100 . When the microorganisms form sludge granules and microalgae reproduce in a sufficient amount, the surface of the sludge granules releases a substance that allows the microalgae to adhere, so the microalgae are attached to the sludge granules, and algae granules are formed. . The algae granule reactor 100 provides a preset environment necessary for the formation of algae granules. The preset environment includes the temperature in the reaction tank, the amount of light incident to the reaction tank, or the flow rate of sewage in the reaction tank. The algal granule reaction tank 100 provides the temperature in the reaction tank, the amount of light incident into the reaction tank, or the flow rate of the sewage in the reaction tank as optimal conditions for forming the algae granules. Compounds may be added to the algal granules reactor 100 for smooth algal granules. The compound to be added corresponds to a substance that provides a cation, such as a calcium ion, a magnesium ion, a potassium ion, a copper ion, or a zinc ion. As the compound is added and the cations are supplied to the algae granule reactor 100, the supplied cations affect the promotion of biofilm immobilization of microorganisms or sludge granules. The amount of the compound to be added may be 0.5 to 3 g per 1 m ³ of sewage introduced into the algae granule reactor 100 . As such, microalgae are attached to the sludge granules to generate algal granules in the algal granule reactor 100, and the generated algal granules are shown in detail in FIG. 3 .

Algae granules 300 are formed by attaching microalgae 320 to the outside of the sludge granules 310 . Microorganisms are granulated and formed into sludge granules 310 in the algal granule reactor 100 . And as the microalgae are attached to the surface of the sludge granules 310 after being propagated in the algae granule reactor 100 , the algae granules 300 are generated in the algae granules reactor 100 . The generated algae granules 300 use oxygen generated by microalgae without a separate oxygen supply device, and the sludge granules 310 can remove organic matter and nitrogen. In addition, since the algae granules 300 are in a state in which the sludge granules 310 and the microalgae are combined, the sedimentation speed of the algae granules 300 from which organic matter and nitrogen are removed increases the processing speed, and the processing speed of sewage from which organic matter and nitrogen are removed It has the advantage of remarkably shortening the time until it is discharged for post-processing.

Referring back to FIGS. 1 and 2 , the algal granule reactor 100 performs a denitrification reaction or a photosynthetic reaction and a nitrification reaction depending on whether light is incident using the generated algal granules. Algal granules perform different reactions depending on whether or not light is incident into the reactor. When sunlight or artificial light is incident, the microalgae in the algae granules perform a photosynthetic reaction to generate oxygen, and the nitrifying microorganisms in the sludge granules perform a nitrification reaction. On the other hand, in a situation in which sunlight or artificial light is not incident, the denitrification microorganisms in the sludge granules perform the denitrification reaction. The generated algal granules remove organic matter and nitrogen depending on whether light is incident on or not.

The algae granule reaction tank 100 may be operated by being disposed at a place where sunlight is incident. Accordingly, sunlight is incident on the reaction tank 170 during the time when the sun is rising. However, in order to induce photosynthesis of algal granules even during the time when the sun is not rising, the light source unit 110 is additionally disposed. The light source unit 110 may receive power from a separate power supply device (not shown) to irradiate light, and may additionally include an energy storage device (not shown) that receives sunlight and generates and stores energy. It is also possible to irradiate light using the energy stored from the

The aforementioned filter or screen (not shown) is disposed between the light source unit 110 and the reaction tank 170 . A filter or screen (not shown) converts the wavelength band of the incident light into a preset wavelength band. Here, as described above, the preset wavelength band may be a wavelength advantageous for the propagation of microalgae having a high cohesive force of the algae and excellent cohesion with sludge granules.

The agitator 120 is mounted at one position of the reaction tank 170 and stirs the sewage and wastewater introduced into the reaction tank 170 up and down (the y-axis direction in FIG. 1 ). The stirring unit 120 may be implemented as any device capable of generating a water flow, such as a gas-type stirrer, an impeller-type stirrer, or a water flow motor. The agitator 120 is mounted in a direction to generate a water flow up and down, and stirs the waste water in the up and down directions in the reaction tank 170 . The reason why the stirring unit 120 stirs the sewage and wastewater in the vertical direction is as follows.

Oxygen is absolutely required for the nitrification reaction required for nitrogen removal, and this oxygen is generated by photosynthesis of microalgae. The photosynthesis process proceeds with the following light reactions and dark reactions.

In the presence of water and NADP ⁺ under light irradiation, microalgae perform a light reaction to produce energy (ATP), oxygen (O ₂ ) and NADPH. On the other hand, when carbon dioxide and NADPH are present in a situation where light is not irradiated, microalgae consume energy to produce glucose, water and NADP ⁺ . That is, in order for microalgae to perform a light reaction to produce oxygen, NADP ⁺ , a product of the dark reaction, must exist. That is, it can be seen that in order for the light reaction to be continuously performed, the dark reaction must also occur continuously.

At this time, as in FIG. 2 , since light can reach only a certain depth in water, whether sunlight or artificial light, the region in the reaction tank 170 is divided into an incident region 200 and a non-incident region 210 . are separated For this reason, only the light reaction may be continuously performed in the region 200 to which the light is incident, and only the dark reaction may be continuously performed in the non-incident region 210 . Accordingly, there may be a problem that the microalgae (or algae granules) in the reaction tank 170 cannot smoothly generate oxygen. In order to solve this problem, the agitator 120 generates and stirs water flow up and down, so that the algae granules in the reaction tank 170 are evenly positioned in the area 200 where light is incident and the area 210 where it is not incident. make it possible When only relying on the incident of light by the sun, since the light reaction time and dark reaction time of the algae granules are clearly different, there is a situation in which organic matter and nitrogen cannot be removed in either case when the sun is rising or when the sun is setting. exist. In addition, since the conventional reaction tank operates with a region to which light is incident and a region not to be incident light, it is not possible to smoothly remove organic matter and nitrogen. The stirring unit 120 solves the above-described conventional problem. Accordingly, the microalgae entering the region 200 to which the light is incident performs a light reaction to react ammonia nitrogen with nitrate nitrogen or nitrite nitrogen, and the microalgae entering the non-incident region 210 are dark reaction and The nitrogen component is removed by performing a denitrification reaction, and a light reaction is prepared later. Since all algae granules can remove organic matter and nitrogen as long as light is incident into the reactor 170 , the algal granule reactor 100 can always operate regardless of the time to remove organic matter and nitrogen.

The measurement unit 130 measures matters necessary for control of the control unit (not shown). The measuring unit 130 measures the flow rate, suspended matter concentration (MLSS), turbidity, dissolved oxygen amount, carbon dioxide amount or flow rate in the sewage and wastewater introduced into the reaction tank 170 and transmits it to the control unit (not shown).

The inclined portion 140 guides the sedimented algal granules to the granule outlet 150 . The inclined portion 140 is formed at the bottom of the reaction vessel 170 , and is inclined from the opposite side of the granule outlet 150 to the granule outlet 150 . Accordingly, when the stirring unit 120 stops stirring and tries to discharge some of the algae granules or algae granules that are too large in size due to photosynthesis or adsorption of suspended substances, the algae granules are generated. is precipitated in the lower part (-y-axis direction) of the reaction tank 170 . The precipitated granules may be discharged to the granule outlet 150 along the inclined portion 140 .

The granule outlet 150 discharges the algae granules traveling along the inclined portion 140 to the outside of the algae granules reaction tank 100 .

The supernatant water outlet 160 is located at a preset height in the reaction tank 170 to discharge supernatant water. When the sedimentation of the algae granules proceeds after the reaction between the introduced sewage and wastewater and the algae granules has sufficiently progressed (in a state in which stirring is stopped), the supernatant water outlet 160 discharges the supernatant water at a position above the height at which the algae granules are maximally settled. do.

The reaction tank 170 stores the incoming sewage and wastewater, so that algae granules can be generated. The reaction tank 170 has a predetermined volume and receives and stores a predetermined amount of sewage and wastewater. Accordingly, the reaction tank 170 allows microalgae to be attached to microbes or sludge granules in sewage and wastewater to generate algae granules.

A control unit (not shown) controls the operation of the stirring unit 120 or the light source unit 110 based on the measurements measured by the measurement unit 130 .

The control unit (not shown) controls the stirring unit 120 to perform the inflow of sewage and wastewater, the growth of algal granules, the reaction of the algal granules, and the sedimentation of the algal granules in the reaction tank 170 . The control unit (not shown) determines whether the sewage has been introduced to a water level sufficient to grow algal granules into the reaction tank 170 by determining the flow rate and the concentration/turbidity of the suspended matter. When the algal granules are sufficiently grown, the controller (not shown) operates the stirring unit 120 so that the algae granules are stirred to continuously perform light and dark reactions, and to remove organic matter and nitrogen in sewage and wastewater. When it is determined that sufficient organic matter and nitrogen have been removed, when the algal granules are too large or the concentration of the algal granules is excessively increased, the control unit (not shown) stops the operation of the stirring unit 120 to induce sedimentation of the algal granules. By repeating the above-described process, the controller (not shown) may continuously remove organic matter and nitrogen without a pause in the agitation unit stopping the agitation in order to generate a product necessary for the reaction.

A control unit (not shown) controls the operation of the stirring unit 120 based on the measurement items of the measuring unit 130 . When the size of the algal granules is excessively large, the surface area (concentration) of the algal granules per area of the reaction tank 170 is rather decreased. A decrease in the surface area (concentration) of algal granules leads to a decrease in photosynthetic amount, so that sufficient oxygen is not generated for nitrogen removal. The most suitable size for algal granules may be 0.5 to 1.0 mm. The controller (not shown) determines the size of the algae granules, and controls the stirring speed of the stirring unit 120 when it is out of the above-described preset range. When the size of the algae granules does not reach the preset range, the control unit (not shown) reduces the stirring speed of the stirring unit 120 . As the agitation speed is decreased, the time for each algae granules to stay in the region 200 on which light is incident increases and may grow. That is, based on one stirring cycle, the time for which the algal granules stay in the region 200 on which light is incident is increased, so that the algal granules can grow sufficiently. Conversely, when the size of the algae granules exceeds the preset range, the control unit (not shown) increases the stirring speed of the stirring unit 120 . As the stirring speed is increased, the time for each algal granules to stay in the region 200 on which light is incident is reduced, thereby inhibiting the growth of the algal granules, and the algal granules may become smaller again.

In addition, the control unit (not shown) controls the operation of the stirring unit 120 according to the amount of suspended matter in the introduced sewage and wastewater. Algae granules are in physical contact with suspended substances in sewage and wastewater, and are removed by adsorbing suspended substances. When the amount of suspended matter increases, the amount of light incident into the sewage and wastewater decreases, so that the algae granules do not perform photosynthesis smoothly. Accordingly, when the amount of suspended matter is increased, the control unit (not shown) controls the stirring unit 120 to increase the stirring speed. As the stirring speed increases, the contact of the algae granules with the suspended matter increases, and the suspended matter removal rate increases.

A control unit (not shown) controls the operation of the light source unit 110 . When the ratio of the light incident region 200 and the non-incident region 210 in the reaction tank 170 is 1:1, the algae granules can most efficiently remove organic matter and nitrogen. Accordingly, the controller (not shown) may control the light source unit 110 so that the ratio of the area 200 on which the light is incident to the area 210 on which the light is not incident becomes 1:1 in a time period in which the sun is not incident.

The above description is merely illustrative of the technical idea of this embodiment, and various modifications and variations will be possible without departing from the essential characteristics of the present embodiment by those of ordinary skill in the art to which this embodiment belongs. Accordingly, the present embodiments are intended to explain rather than limit the technical spirit of the present embodiment, and the scope of the technical spirit of the present embodiment is not limited by these embodiments. The protection scope of this embodiment should be interpreted by the claims below, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present embodiment.

CROSS-REFERENCE TO RELATED APPLICATION

This patent application claims priority in accordance with U.S. Patent Law Article 119(a) (35 U.S.C § 119(a)) with respect to Patent Application No. 10-2021-0050685 filed in Korea on April 19, 2021. All contents are incorporated into this patent application by reference. In addition, if this patent application claims priority for countries other than the United States for the same reason as above, all contents thereof are incorporated into this patent application by reference.

Claims

In the algae granule reactor for receiving sewage and wastewater to remove organic matter or nitrogen in the sewage and wastewater,

a reaction tank that stores the introduced sewage and wastewater, and induces microalgae to adhere to microorganisms or sludge granules formed from microorganisms in sewage to generate algal granules;

a stirring unit circulating in the opposite direction to the direction in which sunlight is incident to the reaction tank and stirring the wastewater;

A portion of the flow rate of sewage and wastewater introduced into the reactor, the concentration of suspended substances in sewage and wastewater (MLSS), the turbidity of the sewage and wastewater, the amount of dissolved oxygen in the sewage and wastewater, the amount of carbon dioxide in the water and the flow rate of the sewage and wastewater or a measurement unit that measures all;

a granule outlet located at the bottom of the reactor to discharge the precipitated algae granules to the outside;

a supernatant water outlet located at a preset height of the reaction tank and discharging supernatant water after the algae granules are precipitated to the outside; and

A control unit for controlling the operation of the stirring unit

Algae granule reactor comprising a.
According to claim 1,

Algae granule reaction tank, characterized in that it further comprises a light source for irradiating light to the reaction tank.
3. The method of claim 2,

The light source unit,

Algae granule reactor, characterized in that it receives sunlight and stores it as energy.
According to claim 1,

Algae granule reaction tank, characterized in that it further comprises a filter between the light source unit and the reaction tank to filter the wavelength band of the sunlight incident on the reaction tank or the light irradiated from the light source portion.
5. The method of claim 4,

The filter is

Algae granule reaction tank, characterized in that it passes a wavelength band that allows the pre-set microalgae to dominate in the reaction tank and filters the remaining wavelength band.
6. The method of claim 5,

The preset microalgae,

Aphanizomenon sp., Oscillatoria sp. and Phormidium sp. Algae granule reactor, characterized in that some or all of.
According to claim 1,

The algal granule reactor according to claim 1, further comprising an inclined portion disposed at the bottom of the reactor and guiding the precipitated algal granules to the granule outlet.
8. The method of claim 7,

The inclined portion,

Algae granule reactor, characterized in that it has a slope from the opposite side of the granule reactor to the granule outlet.