Incubation method of granular sludge for water treatment

Abstract

The present invention discloses a method for incubating granular sludge for water treatment, comprising the following steps: step 1, inoculating flocculent sludge into a body, and injecting wastewater to be treated into the body through a water inlet; step 2, driving a stirring rod and a stirring blade thereon in a stirring zone to rotate at a first speed, so that the sludge interface is kept below an overflow tank; step 3, when the stirring blade rotates at a constant first speed for a period of time and the sludge interface begins to decrease, gradually increasing the rotation speed of the stirring blade until the sludge interface remains stable, and at this time, the stirring blade rotates at a second speed; step 4, driving the stirring rod and the stirring blade thereon in the stirring zone to rotate at a constant second speed until a number of granular sludges are formed in the stirring zone. The present invention can gradually improve the density and sedimentation performance of the final granulated sludge, and can ensure the stability of the sludge particles during long-term use while ensuring the compactness of the sludge particles.

Description

Technical Field

[0001] The invention relates to a method for incubating granular sludge for water treatment, belonging to the technical field of sewage treatment. Background Art

[0002] Aerobic granular sludge is an aggregate formed by the coagulation of microorganisms under the action of a certain hydraulic shear force. It is a special biofilm that does not require a carrier, has good sedimentation performance, and has a fast mud-water separation speed. Aerobic granular sludge is structurally divided into anaerobic zone, anoxic zone, and aerobic zone from the inside to the outside. It is mainly composed of functional colonies such as aerobic heterotrophic bacteria, nitrifying bacteria, denitrifying bacteria, polyphosphate bacteria, and polysaccharide bacteria, so as to achieve the effect of simultaneous carbon, nitrogen, and phosphorus removal. Based on the various characteristics of aerobic granular sludge, in practical applications, the process flow can be simplified, the floor space and operating energy consumption can be saved, and it has obvious advantages over the ordinary activated sludge method, and has broad application prospects in sewage treatment.

[0003] However, there are not many actual engineering applications of aerobic granular sludge at present, mainly because the cultivation cycle is long, the particles are easy to disintegrate during long-term operation, and the sludge return pumping process is easy to cause damage to the granular sludge. Therefore, the inventors have developed a method for incubating granular sludge for water treatment based on the difficulties of the prior art to solve the above problems. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a method for incubating granular sludge for water treatment, which can gradually improve the density and sedimentation performance of the final granulated sludge, while ensuring the density of the sludge particles and the stability of the sludge particles during long-term use.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: a method for incubating granular sludge for water treatment, based on an incubator, the incubator comprising: a body, a water inlet arranged at the upper part of the left wall of the body and a water outlet arranged at the upper part of the right wall of the body, a first guide plate and a second guide plate are arranged in the body along the direction of water flow, the first guide plate and the second guide plate are respectively connected to the front and rear walls of the body, an aeration zone is formed between the first guide plate with gaps between the upper and lower ends and the body and the left wall of the body, and a circulation zone is formed between the lower part of the second guide plate connected to the body at the upper end and the first guide plate;

[0006] A baffle connected to the front and rear walls of the body is arranged on the side of the second guide plate opposite to the first guide plate, a stirring rod is arranged in the stirring zone between the baffle and the second guide plate, a stirring blade is installed at the lower end of the vertically arranged stirring rod, a sedimentation zone is formed between the baffle connected to the body at the lower end and the right side wall of the body, a horizontally arranged top plate is connected between the upper end of the baffle and the second guide plate, and a plurality of overflow grooves connecting the stirring zone and the sedimentation zone are opened on the top plate;

[0007] The incubation method comprises the following steps:

[0008] Step 1: Inoculate the flocculent sludge into the body, and inject the wastewater to be treated into the body through the water inlet;

[0009] Step 2: driving the stirring rod and the stirring blades thereon in the stirring zone to rotate at a first speed so that the sludge interface is kept below the overflow tank;

[0010] Step 3: When the stirring blade rotates at a constant first speed for a period of time and the sludge interface begins to decrease, the rotation speed of the stirring blade is gradually increased until the sludge interface remains stable, and the stirring blade rotates at a second speed;

[0011] Step 4: driving the stirring rod and the stirring blades thereon in the stirring zone to rotate at a constant second speed until a number of granular sludges are formed in the stirring zone.

[0012] The further improved scheme in the above technical scheme is as follows:

[0013] 1. In the above scheme, the stirring blade is a rectangular blade perpendicular to the liquid surface.

[0014] 2. In the above solution, a plurality of particle reinforcement columns are arranged at intervals in the stirring zone.

[0015] 3. In the above solution, a third guide plate whose upper end is connected to the main body is provided in the sedimentation area.

[0016] 4. In the above scheme, the right side wall of the main body further includes a first vertical portion with a mud discharge port, a second vertical portion with a water outlet, and an inclined portion connecting the first vertical portion and the second vertical portion, and the inclined portion whose lower end is connected to the first vertical portion is inclined toward a side away from the baffle.

[0017] 5. In the above solution, the lower end of the third guide plate extends above the inclined portion.

[0018] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0019] The incubation method of granular sludge for water treatment of the present invention realizes gradual granulation of sludge while performing preliminary treatment on wastewater. Multi-directional shearing force is provided for the mud-water mixture by setting up aeration zone, circulation zone and stirring zone layer by layer, and sludge with poor sedimentation property can be discharged in time, thereby shortening the sludge granulation time and improving the density of granulated sludge. Sludge reflux is not required, thereby avoiding the destruction of sludge reflux pumping process. Furthermore, by adjusting the stirring speed, the waste of sludge in the initial stage of operation can be avoided, and the density and sedimentation performance of the final granulated sludge can be gradually improved, thereby ensuring the density of sludge particles and the stability of sludge particles during long-term use. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Attached Figure 1 A front view of the structure of the incubator on which the present invention is based;

[0021] Attached Figure 2 The figure is a top view of the structure of the incubator on which the present invention is based.

[0022] In the above drawings: 100, main body; 1, water inlet; 2, aeration zone; 3, circulation zone; 4, stirring zone; 5, overflow trough; 6, sedimentation zone; 7, baffle; 8, top plate; 9, water outlet; 10, mud outlet; 11, aerator; 12, stirring motor; 13, stirring rod; 14, stirring blade; 15, particle reinforcement column; 16, first guide plate; 17, second guide plate; 18, third guide plate. DETAILED DESCRIPTION

[0023] In the description of this patent, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention; the terms "first", "second", and "third" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance; in addition, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this patent can be understood according to specific circumstances.

[0024] Embodiment 1: A method for incubating granular sludge for water treatment, based on an incubator, the incubator comprising: a body 100, a water inlet 1 arranged at the upper part of the left wall of the body 100, and a water outlet 9 arranged at the upper part of the right wall of the body 100, wherein a first guide plate 16 and a second guide plate 17 are arranged in the body 100 along the direction of water flow, the first guide plate 16 and the second guide plate 17 are respectively connected to the front and rear walls of the body 100, and the first guide plate 16 and the second guide plate 17 are respectively connected to the front and rear walls of the body 100, and the first guide plate 16 and the second guide plate 17 are respectively provided with a gap between the upper and lower ends and the body 100. An aeration zone 2 is formed between a guide plate 16 and the left side wall of the body 100, and a circulation zone 3 is formed between the lower part of the second guide plate 17 whose upper end is connected to the upper wall of the body 100 and the first guide plate 16. The first guide plate and the second guide plate separate the aeration zone, the circulation zone, and the stirring zone to realize the circulation flow state of the mixed liquid under the aeration plug flow. Under the aeration plug flow, the aeration zone and the circulation zone have a high flow velocity in the vertical direction to provide shear force, which is conducive to the entanglement and aggregation of sludge flocs and promotes sludge granulation.

[0025] A baffle plate 7 connected to the front and rear walls of the body 100 is disposed on the side of the second guide plate 17 opposite to the first guide plate 16. A stirring rod 13 is disposed in the stirring zone 4 between the baffle plate 7 and the second guide plate 17. A stirring blade 14 is installed at the lower end of the vertical stirring rod 13. A sedimentation zone 6 is formed between the baffle plate 7 connected to the lower wall of the body 100 at the lower end and the right side wall of the body 100. A horizontally disposed top plate 8 is connected between the upper end of the baffle plate 7 and the second guide plate 17. A plurality of overflow troughs 5 connecting the stirring zone 4 and the sedimentation zone 6 are provided on the top plate 8 located below the upper wall of the main body 100. The sludge flocs with poor sedimentation properties gradually rise to the supernatant area above the sludge interface, overflow to the overflow trough with the supernatant and then enter the sedimentation zone, thereby being washed out and eliminated. The floc sludge with good sedimentation properties is screened and retained, and gradually granulated in the incubator. The concentrated sludge at the bottom of the sedimentation zone only needs to be discharged from the system regularly, and no sludge reflux is required, so as to avoid the sludge reflux pumping process from destroying the integrity of the granular sludge.

[0026] The stirring blade 14 is a rectangular blade perpendicular to the liquid surface, so that the upper part of the incubator body can still achieve solid-liquid separation during the stirring process; the two strip-shaped overflow grooves 5 are respectively located on both sides of the stirring rod 13; the height of the water outlet 9 is lower than the overflow groove 5;

[0027] A plurality of particle strengthening columns 15 are arranged at intervals in the stirring zone 4 to promote the continuous collision and aggregation of flocculent sludge to gradually form dense particles during the stirring and mixing process; a third guide plate 18 is arranged in the sedimentation zone 6, the upper end of which is connected to the upper wall of the body 100; a mud discharge port 10 connected to the sedimentation zone 6 is arranged at the lower part of the right side wall of the body 100;

[0028] The right side wall of the body 100 further includes a first vertical portion with a mud discharge port 10, a second vertical portion with a water outlet 9, and an inclined portion connecting the first vertical portion and the second vertical portion, wherein the inclined portion connected to the first vertical portion at the lower end is inclined toward a side away from the baffle 7; the lower end of the third guide plate 18 extends to above the inclined portion;

[0029] At least one aerator 11 is installed at the bottom of the aeration zone 2. The upper end of the stirring rod 13 extends to the outside of the main body 100 and is connected to the output shaft of a stirring motor 12. The four particle reinforcement columns 15 are vertically arranged outside the stirring blade 14 and located at the four corners of the stirring zone 4.

[0030] Embodiment 2: A method for incubating granular sludge for water treatment, comprising the following steps:

[0031] Step 1: Inoculate the flocculent sludge in the body 100, and inject the wastewater to be treated into the body 100 through the water inlet 1, so that the liquid levels in the aeration zone, the circulation zone, and the stirring zone are all at the overflow tank position, the liquid level in the sedimentation zone is flush with the water outlet, the height of the sludge surface is located in the middle and upper position of the body, the sludge concentration in the initial state is 5 g ~ 8g / L, open the water outlet to keep the water inlet flow rate the same as the water outlet flow rate, and the hydraulic retention time, i.e., the effective HRT, is 4 h ~ 8h;

[0032] Step 2: driving the stirring rod 13 and the stirring blades 14 in the stirring zone 4 to rotate at a first speed so that the sludge interface is kept below the overflow tank 5;

[0033] Step 3: When the stirring blade 14 rotates at a constant first speed for a period of time and the sludge interface begins to decrease, the rotation speed of the stirring blade 14 is gradually increased in a stepwise manner until the sludge interface remains stable, and the stirring blade 14 rotates at a second speed;

[0034] Step 4: driving the stirring rod 13 and the stirring blades 14 thereon in the stirring zone 4 to rotate at a constant second speed until a plurality of granular sludges are formed in the stirring zone 4 .

[0035] Further explanation of Example 2 is as follows:

[0036] The inlet water enters the incubator body from the water inlet, and enters the circulation zone and the stirring zone together with the mud-water mixture under the action of aeration flow. Under the action of aeration lifting, the mixed liquid in the stirring zone enters the aeration zone from the bottom of the first guide plate, thereby forming a mixed liquid circulation process in the aeration zone, the circulation zone, and the stirring zone;

[0037] The muddy-water mixture in the stirring zone is mixed under the stirring of the stirring blades. The sludge concentration in each area is the same at the same liquid level in the horizontal direction, but there are differences in the sludge concentration at different liquid levels in the vertical direction.

[0038] Since the stirring blades are located at the lower part of the incubator body, the sludge at the lower part of the incubator body is in a suspended state under the stirring action of the stirring blades. As the liquid level depth decreases, the stirring and mixing intensity decreases, and the sludge begins to settle. When the liquid level depth decreases to a certain extent, the sludge settling effect and the stirring and mixing effect reach a balance state. The liquid level depth is the sludge interface position.

[0039] Above the sludge interface, there are mainly supernatant and a small amount of sludge flocs with poor sedimentation. Below the sludge interface, as the liquid level increases, the sludge sedimentation becomes better and the sludge concentration becomes higher.

[0040] At the beginning of the incubator startup, due to the poor settling properties of the inoculated flocculent sludge, the stirring motor is set to run at a lower speed to ensure that the upper sludge interface remains below the overflow tank to avoid sludge loss;

[0041] In the stirring area, the flocculent sludge with poor settling property gradually rises above the sludge interface under the stirring action, overflows to the overflow tank with the supernatant, and then flows to the sedimentation area to be washed out and eliminated, and the settling property of the sludge in the incubator gradually increases;

[0042] In addition, as the degree of sludge granulation increases, the sludge settling properties in the incubator also gradually increase.

[0043] Under the same stirring speed conditions, the sludge interface gradually decreases. At this time, the stirring motor speed can be appropriately increased to increase the stirring intensity, increase the shear force, increase the granular sludge density and the sedimentation performance of the granular sludge, and at the same time further wash out and eliminate the flocculent sludge to increase the degree of sludge granulation.

[0044] As the incubator runs longer, the speed of the stirring motor can be gradually increased.

[0045] After the incubator has been running for a certain period of time, the sludge granulation degree reaches the predetermined target, the sludge interface in the incubator is located at a suitable position below the overflow tank and remains stable, and the speed of the stirring motor is no longer adjusted.

[0046] During long-term operation, the aged granular sludge is gradually hollowed out and disintegrated. The suspended fine sludge flocs in the mixed liquor use the granular sludge fragments as crystal nuclei to promote biological aggregation through adsorption bridging, collision entanglement, and further form new aerobic granular sludge, ensuring the long-term and stable operation of the system.

[0047] During the continuous water inlet process, a small amount of flocculent sludge with poor settling properties is discharged from the overflow trough at the top of the stirring zone to the sedimentation zone along with the supernatant, and the main part of the sludge is still retained in the mechanical stirring zone. In the sedimentation zone, the supernatant after mud and water separation is discharged from the incubator body through the outlet. The concentrated sludge at the bottom of the sedimentation zone only needs to be discharged from the system regularly, and no sludge reflux is required, so as to avoid the sludge reflux pumping process destroying the integrity of the granular sludge.

[0048] When the above-mentioned method for incubating granular sludge for water treatment is adopted, the sludge is gradually granulated while the wastewater is preliminarily treated. The aeration zone, the circulation zone and the stirring zone are arranged layer by layer to provide multi-directional shearing force for the mud-water mixture, and the sludge with poor sedimentation performance can be discharged in time, thereby shortening the sludge granulation time and improving the density of the granulated sludge. There is no need for sludge reflux, thus avoiding the destruction of the sludge reflux pumping process. Furthermore, by adjusting the stirring speed, it is possible to avoid the waste of sludge in the initial stage of operation, and gradually improve the density and sedimentation performance of the final granulated sludge, thereby ensuring the density of the sludge particles and the stability of the sludge particles during long-term use.

[0049] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for incubating granular sludge for water treatment, based on an incubator, the incubator comprising: A body (100), a water inlet (1) arranged at the upper part of the left side wall of the body (100), and a water outlet (9) arranged at the upper part of the right side wall of the body (100), characterized in that: a first guide plate (16) and a second guide plate (17) are arranged in the body (100) along the direction of water flow, the first guide plate (16) and the second guide plate (17) are respectively connected to the front wall and the rear wall of the body (100), an aeration zone (2) is formed between the first guide plate (16) with a gap between the upper and lower ends and the body (100), and a circulation zone (3) is formed between the lower part of the second guide plate (17) connected to the body (100) at the upper end and the first guide plate (16); A baffle plate (7) connected to the front and rear walls of the body (100) is arranged on the side of the second guide plate (17) opposite to the first guide plate (16); a stirring rod (13) is arranged in the stirring zone (4) between the baffle plate (7) and the second guide plate (17); a stirring blade (14) is mounted on the lower end of the vertically arranged stirring rod (13); a sedimentation zone (6) is formed between the baffle plate (7) connected to the body (100) at the lower end and the right side wall of the body (100); a horizontally arranged top plate (8) is connected between the upper end of the baffle plate (7) and the second guide plate (17); a plurality of overflow grooves (5) connecting the stirring zone (4) and the sedimentation zone (6) are provided on the top plate (8); The incubation method comprises the following steps: Step 1: inoculate flocculent sludge into the body (100), and at the same time inject wastewater to be treated into the body (100) through the water inlet (1); Step 2: driving the stirring rod (13) and the stirring blades (14) thereon in the stirring zone (4) to rotate at a first speed so that the sludge interface is kept below the overflow tank (5); Step 3: when the stirring blade (14) rotates at a constant first speed for a period of time and the sludge interface begins to decrease, gradually increasing the rotation speed of the stirring blade (14) until the sludge interface remains stable, at which time the stirring blade (14) rotates at a second speed; Step 4: driving the stirring rod (13) and the stirring blades (14) thereon in the stirring zone (4) to rotate at a constant second speed until a plurality of granular sludges are formed in the stirring zone (4).

2. The method for incubating granular sludge for water treatment according to claim 1, characterized in that: The stirring blade (14) is a rectangular blade perpendicular to the liquid surface.

3. The method for incubating granular sludge for water treatment according to claim 1, characterized in that: A plurality of particle reinforcement columns (15) are arranged at intervals in the stirring zone (4).

4. The method for incubating granular sludge for water treatment according to claim 1, characterized in that: A third guide plate (18) whose upper end is connected to the main body (100) is provided in the sedimentation area (6).

5. The method for incubating granular sludge for water treatment according to claim 4, characterized in that: The right side wall of the body (100) further comprises a first vertical portion with a mud discharge port (10), a second vertical portion with a water outlet (9), and an inclined portion connecting the first vertical portion and the second vertical portion, wherein the inclined portion, whose lower end is connected to the first vertical portion, is inclined toward a side away from the baffle (7).

6. The method for incubating granular sludge for water treatment according to claim 5, characterized in that: The lower end of the third guide plate (18) extends above the inclined portion.

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