Ozone oxidation sedimentation tank sludge coagulant aid and its preparation method and application

Abstract

The present invention belongs to the technical field of sewage treatment, and specifically discloses a method for preparing an ozone oxidation sedimentation tank sludge coagulant, comprising the following steps: S1: loading a catalyst into a barrel of a coagulant preparation device and installing the barrel, then opening the one-way solenoid valve of the water inlet pipe to inject the sedimentation tank sludge water into the ozone oxidation tank; S2: opening the ozone aeration head and driving the barrel to rotate to perform ozone aeration oxidation treatment; S3: after the ozone aeration oxidation treatment is completed, opening the one-way solenoid valve of the water outlet pipe to discharge the sludge water; S4: filtering and dehydrating the sludge water after the ozone aeration oxidation treatment to obtain sludge; S5: drying the dehydrated sludge, grinding and sieving it to obtain a powdered coagulant. The coagulant prepared by the present invention after oxidation treatment of sedimentation tank sludge water with a catalyst and ozone is added to the coagulation-sedimentation process, thereby improving the treatment effect of low-turbidity water, reducing the amount of sludge in the sedimentation tank, and realizing sludge recycling.

Description

Technical Field

[0001] The present invention relates to the technical field of sewage treatment, and in particular to an ozone oxidation sedimentation tank sludge coagulant aid, a preparation method thereof, and an application thereof. Background Art

[0002] The effectiveness of the coagulation-sedimentation process in conventional water treatment processes is crucial for the final effluent quality. Using reservoir water as a source can result in low-turbidity water, leading to poor coagulation and sedimentation treatment results. Low-turbidity water, because it contains fewer negatively charged colloidal particles, has strong dynamic and aggregation stability. To improve the treatment effect of low-turbidity water, large coagulant dosages are often required, resulting in increased operating costs and difficulties in sludge treatment.

[0003] The sludge water from sedimentation tanks contains a large amount of underutilized coagulants and inorganic particles. Dehydrating, drying, and transporting the sludge not only pollutes the environment but also wastes the chemicals that are not fully utilized in the sludge. The sludge water from sedimentation tanks contains high levels of aluminum and iron hydroxides and suspended colloidal particles. If it is directly returned to the sedimentation tank before the coagulation-sedimentation process, it may lead to the enrichment of some free metal ions and toxic organic matter. However, it is safer to oxidize and stabilize the sludge water before adding it back to the coagulation-sedimentation process to enhance the coagulation treatment of low-turbidity water. Ozone, one of nature's most powerful oxidants, has excellent oxidation, deodorization, decolorization, and sterilization effects in water treatment. Ozone-treated sludge water has improved stability, reduced pollution to the raw water, and also changes the surface properties of the sludge particles, enhancing the interaction between the sludge and raw water impurity particles.

[0004] Chinese patent CN111302452B provides a method for preparing a magnetic coagulant from metal-containing sludge, its application, and a method for enhancing pollutant removal. The method for preparing the magnetic coagulant comprises the following steps: (1) drying the metal-containing sludge to obtain a sludge material; (2) carbonizing the sludge material obtained in step (1) to obtain a magnetic material; and (3) grinding the magnetic material obtained in step (2) to obtain the magnetic coagulant. This method utilizes the metal-containing sludge as a resource, and prepares the magnetic coagulant material through high-temperature carbonization, which is used to degrade pollutants, thereby achieving waste resource utilization.

[0005] The above patent prepares magnetic coagulant aids from metal sludge to achieve resource utilization and protect the ecological environment, but it is not used to solve the problems of poor treatment effect of low-turbidity reservoir raw water and large amount of coagulant addition in current conventional water treatment processes, as well as the problem of pollutant enrichment when directly reusing sedimentation tank sludge for enhanced coagulation. Therefore, there is an urgent need for a coagulant aid that can be added in conjunction with a coagulant before the coagulation and sedimentation process to solve the problems of poor treatment effect and large amount of coagulant addition. Summary of the Invention

[0006] In view of the shortcomings of the existing technology, the purpose of the present invention is to propose an ozone oxidation sedimentation tank sludge coagulant aid and its preparation method and application, which are used to solve the problems of poor treatment effect of conventional water treatment processes in the existing technology on low-turbidity reservoir raw water and large amount of coagulant addition, as well as the problem of possible pollutant enrichment when directly reusing sedimentation tank sludge for enhanced coagulation.

[0007] In order to achieve the above object, the present invention provides the following technical solutions:

[0008] A method for preparing an ozone oxidation sedimentation tank sludge coagulant aid comprises the following steps:

[0009] S1: Load the catalyst into the barrel of the coagulant aid preparation device, install the barrel, and then open the one-way solenoid valve of the water inlet pipe to inject the sludge water in the sedimentation tank into the ozone oxidation tank; the sludge water is the sludge water from the sludge pool of the water plant, and its solid content is 0.5%-1%;

[0010] S2: Open the ozone aeration head and drive the barrel to rotate to perform ozone aeration oxidation treatment;

[0011] S3: After the ozone aeration oxidation treatment is completed, the one-way solenoid valve of the outlet pipe is opened and the sludge water is discharged from the outlet pipe;

[0012] S4: filtering and dehydrating the sludge water after ozone aeration oxidation treatment to obtain sludge;

[0013] S5: The dehydrated sludge is dried and then ground and sieved to obtain a powdered coagulant aid.

[0014] Preferably, in step S1, the method for preparing the catalyst comprises the following steps:

[0015] (1) Mix sepiolite powder, attapulgite and water to form a suspension, then add urea and stir for 2-5 hours;

[0016] The suspension is dried and ground at 80-100° C., and the dried powder is then calcined at 350-500° C. for 3-6 hours, and then cooled to obtain a sepiolite powder-attapulgite-C3N4 composite;

[0017] A mixed solution of lanthanum nitrate and cobalt nitrate is prepared, and then a sepiolite powder-attapulgite-C3N4 complex is added to the mixed solution and stirred for 1-2 hours, followed by drying at 80-100°C, and then calcining at 350-550°C for 2-4 hours to obtain the catalyst powder;

[0018] The obtained catalyst powder is spheronized using a spheronizer to form a spherical catalyst with a particle size of 5-10 mm.

[0019] Preferably, in step S2, the ozone concentration in the ozone aeration oxidation treatment is 500 mg / L-1500 mg / L, the ozone gas flow rate is 1 L / min-2 L / min, and the ozone aeration oxidation time is 10 min-20 min.

[0020] Preferably, in step S5, the dehydrated sludge is dried by natural air drying or oven drying, the drying temperature is room temperature 60°C-100°C, and the mesh size of the ground and sieved sludge is 200 mesh.

[0021] Preferably, the mass ratio of the sepiolite powder, attapulgite and water in step (1) is (1-2): (1-2): (100-500), and the amount of urea added is 0.2-0.5 times the total mass of the sepiolite powder and attapulgite.

[0022] Preferably, the mass concentration of the lanthanum nitrate and cobalt nitrate in step (3) is 10-30 mg / mL, and the amount of lanthanum nitrate and cobalt nitrate used is 5-20% of the sepiolite powder-attapulgite-C3N4 composite.

[0023] Preferably, the granulation is performed using a spheronizer in step (4), comprising the following steps: adding the catalyst powder to the disc of the spheronizer, spraying mist water as a binder, so that the catalyst powder forms spheres, wherein the rotation speed of the disc of the spheronizer is 30-50 rpm, and then adding the spheres and catalyst powder to the disc of the spheronizer at the same rotation speed, spraying mist water as a binder, so that the spheres form spherical catalysts with a diameter of 5-10 mm.

[0024] Preferably, the device comprises the following: an ozone oxidation tank, which is cylindrical, the upper end of the ozone oxidation tank is connected to a water inlet pipe, the lower end of the ozone oxidation tank is connected to a water outlet pipe, and a plurality of aeration heads are provided on the inner side wall and bottom wall of the ozone oxidation tank; a shaft seat is provided in the middle of the inner bottom wall of the ozone oxidation tank, a transmission shaft is installed on the shaft seat, and a hole groove is provided on the top of the transmission shaft; a barrel is sleeved on the transmission shaft, the barrel is in the shape of a hollow barrel, a plurality of holes are arranged on the side wall of the barrel, a barrel cover is provided on the upper end of the barrel, the barrel cover is sleeved on the transmission shaft and screwed with the barrel; a pool cover is provided on the ozone oxidation tank, a through hole is provided in the middle of the pool cover, the top of the transmission shaft extends into the through hole of the pool cover, a motor is installed on the pool cover, the rotating shaft of the motor is inserted into the hole groove of the transmission shaft, the transmission shaft and the rotating shaft of the motor are fixed by screws, the motor is provided with a motor flange, and the motor flange is fixed to the pool cover by screws.

[0025] The present invention also protects an ozone oxidation sedimentation tank sludge coagulant aid obtained by the preparation method.

[0026] The third object of the present invention is to provide an application of a coagulant obtained by the method for preparing a coagulant from sludge in an ozone oxidation sedimentation tank, wherein the coagulant is added before the coagulation-sedimentation process in a water treatment process.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] The present invention uses sludge water from a sedimentation tank as a raw material to prepare a coagulant aid, thereby recycling the sludge as a resource, protecting the ecological environment, and having broad application prospects.

[0029] The present invention adopts catalytic ozone oxidation to prepare the coagulant. The prepared catalyst can extremely promote the effect of ozone oxidation. On the one hand, under the action of the catalyst, the effect of ozone oxidation can be enhanced, and the stability of sludge can be enhanced. The formed coagulant is not easy to dissolve in water and pollute the raw water, thereby improving the treatment effect after coagulation and sedimentation. On the other hand, the catalyst can also adsorb and treat aluminum, iron ions, suspended colloidal particles and organic matter in the sludge water, thereby increasing the cleanliness of the treated sludge and avoiding secondary pollution of the water body by the formed coagulant.

[0030] (3) The preparation method of the coagulant aid of the present invention is to use a catalyst and ozone to oxidize the muddy water in the sedimentation tank, dehydrate and dry it, and finally grind it into shape. The production process is simple and easy to operate. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic diagram of the structure of the ozone oxidation device proposed in the present invention;

[0032] Figure 2 It is a partial structural diagram of the ozone oxidation device proposed by the present invention;

[0033] Figure 3 This is a schematic diagram of the appearance and structure of the ozone oxidation device proposed in the present invention;

[0034] Figure 4 This is a schematic diagram of the floc morphology of an ozone oxidation sedimentation tank sludge coagulant and its device, preparation method and application proposed by the present invention;

[0035] Figure 5 This is a schematic diagram of floc fractal dimension values ​​during coagulation of comparative example 3 of an ozone oxidation sedimentation tank sludge coagulant and its device, preparation method and application proposed by the present invention;

[0036] Figure 6 This is a schematic diagram of floc fractal dimension values ​​during coagulation of an ozone oxidation sedimentation tank sludge coagulant aid and its device, preparation method and application according to Example 1 of the present invention;

[0037] In the figure: Among them: 5, transmission shaft; 6, barrel cover; 7, tank cover; 8, motor flange; 9, motor; 10, water inlet pipe; 11, water outlet pipe; 12, positioning plate; 13, limit piece; 14, limit hole; 15, small cover; 16, barrel; 17, ozone oxidation tank; 18, aeration head; 19, shaft seat. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0039] The ozone aeration oxidation treatment device used in the preparation method of the ozone oxidation sedimentation tank sludge coagulant of the present invention includes an ozone oxidation tank 17, the ozone oxidation tank 17 is cylindrical, the upper end of the ozone oxidation tank 17 is connected to the water inlet pipe 10, the lower end of the ozone oxidation tank 17 is connected to the water outlet pipe 11, and the inner side wall and bottom wall of the ozone oxidation tank 17 are provided with a plurality of aeration heads 18; a shaft seat 4 is provided in the middle of the inner bottom wall of the ozone oxidation tank 17, a transmission shaft 5 is installed on the shaft seat 4, and a hole groove is provided on the top of the transmission shaft 5; a barrel 16 is sleeved on the transmission shaft 5, and the barrel 16 is a hollow barrel, and a plurality of holes are arranged on the side wall of the barrel 16. A barrel cover 6 is provided on the upper end of the barrel 16. The barrel cover 6 is sleeved on the drive shaft 5 and screwed to the barrel 16; the ozone oxidation tank 17 is provided with a pool cover 7, and a through hole is provided in the middle of the pool cover 7. The top of the drive shaft 5 extends into the through hole of the pool cover 7, and a motor 9 is installed on the pool cover 7. The rotating shaft of the motor 9 is inserted into the hole groove of the drive shaft 5. The drive shaft 5 and the rotating shaft of the motor 9 are fixed by screws. The motor 9 is provided with a motor flange 8, and the motor flange 8 is fixed to the pool cover 7 by screws.

[0040] The aeration head 18 emits ozone. One-way solenoid valves are installed on both the water inlet pipe 10 and the water outlet pipe 11. A positioning plate 12 is located below the drive shaft 5, and a stopper 13 is mounted on the positioning plate 12. A stopper hole 14 is located at the bottom of the barrel 16, and the stopper 13 fits in the stopper hole 14. A small, movably connected cover 15 is provided on the pool cover 7.

[0041] The diameter of the spherical catalyst is larger than the diameter of the hole on the side wall of the barrel 16. Example 1

[0042] A method for preparing an ozone oxidation sedimentation tank sludge coagulant aid comprises the following steps:

[0043] S1: The catalyst is loaded into the barrel 16 of the ozone oxidation device, the barrel 16 is installed, and then the one-way solenoid valve of the water inlet pipe 10 is opened to inject the sludge water in the sedimentation tank into the ozone oxidation tank 17;

[0044] The preparation steps of the catalyst are as follows: 5g of sepiolite powder, 5g of attapulgite and 700g of water are mixed to form a suspension, and then 2g of urea is added and stirred for 2h; drying and grinding at 80°C, and then calcining the dried powder at 350°C for 6h, and then cooling to obtain a sepiolite powder-attapulgite-C3N4 complex; preparing a mixed solution with a mass concentration of 10mg / mL of lanthanum nitrate and cobalt nitrate, and the amount of lanthanum nitrate and cobalt nitrate is 5% of the sepiolite powder-attapulgite-C3N4 complex respectively, and then adding sepiolite powder to the suspension. The powder-attapulgite-C3N4 complex is added to the mixed solution and stirred for 1 hour, then dried at 80°C, and then calcined at 350°C for 4 hours to obtain the catalyst powder; the catalyst powder is added to the disc of the spheronizer, and mist water is sprayed as a binder to form the catalyst powder into balls, wherein the rotation speed of the disc of the spheronizer is 30rpm, and then at the same rotation speed, the balls and catalyst powder are added to the disc of the spheronizer, and mist water is sprayed as a binder to form a spherical catalyst with a diameter of 5mm.

[0045] S2: Open the ozone aeration head 18 and drive the barrel 16 to rotate to perform ozone aeration oxidation treatment; the ozone aeration oxidation treatment concentration is 500 mg / L, the ozone gas flow rate is 1 L / min, and the ozone aeration oxidation time is 10 minutes;

[0046] S3: After the ozone aeration oxidation treatment is completed, the one-way solenoid valve of the outlet pipe 11 is opened, and the sludge water is discharged from the outlet pipe 11;

[0047] S4: filtering and dehydrating the sludge water after ozone aeration oxidation treatment to obtain sludge;

[0048] S5: The dehydrated sludge is naturally air-dried and then ground, and sieved using a 200-mesh sieve to obtain a powdered coagulant aid. Example 2

[0049] A method for preparing an ozone oxidation sedimentation tank sludge coagulant aid comprises the following steps:

[0050] S1: The catalyst is loaded into the barrel 16 of the ozone oxidation device, the barrel 16 is installed, and then the one-way solenoid valve of the water inlet pipe 10 is opened to inject the sludge water in the sedimentation tank into the ozone oxidation tank 17;

[0051] The preparation steps of the catalyst are as follows: 10g of sepiolite powder, 10g of attapulgite and 1500g of water are mixed to form a suspension, and then 6g of urea is added and stirred for 5h; drying and grinding at 100°C, and then calcining the dry powder at 500°C for 3h, and then cooling to obtain a sepiolite powder-attapulgite-C3N4 complex; preparing a mixed solution with a mass concentration of lanthanum nitrate and cobalt nitrate of 20mg / mL, and the amount of lanthanum nitrate and cobalt nitrate is 10% of the sepiolite powder-attapulgite-C3N4 complex respectively, and then adding sepiolite powder to the suspension. The stone powder-attapulgite-C3N4 complex is added to the mixed solution and stirred for 2 hours, then dried at 100°C, and then calcined at 550°C for 2 hours to obtain the catalyst powder; the catalyst powder is added to the disc of the spheronizer, and mist water is sprayed as a binder to form the catalyst powder into balls, wherein the rotation speed of the disc of the spheronizer is 50rpm, and then at the same rotation speed, the balls and catalyst powder are added to the disc of the spheronizer, and mist water is sprayed as a binder to form the balls into spherical catalysts with a diameter of 10mm.

[0052] S2: Open the ozone aeration head 18 and drive the barrel 16 to rotate to perform ozone aeration oxidation treatment; the ozone concentration of the ozone aeration oxidation treatment is 1000 mg / L, the ozone gas flow rate is 2 L / min, and the ozone aeration oxidation time is 20 min.

[0053] S3: After the ozone aeration oxidation treatment is completed, the one-way solenoid valve of the outlet pipe 11 is opened, and the sludge water is discharged from the outlet pipe 11;

[0054] S4: filtering and dehydrating the sludge water after ozone aeration oxidation treatment to obtain sludge;

[0055] S5: The dehydrated sludge is naturally air-dried and then ground, and sieved using a 200-mesh sieve to obtain a powdered coagulant aid. Example 3

[0056] A method for preparing an ozone oxidation sedimentation tank sludge coagulant aid comprises the following steps:

[0057] S1: The catalyst is loaded into the barrel 16 of the coagulant aid preparation device, the barrel 16 is installed, and then the one-way solenoid valve of the water inlet pipe 10 is opened to inject the sludge water from the sedimentation tank into the ozone oxidation tank 17;

[0058] The catalyst preparation steps are as follows: 7.5g of sepiolite powder, 7.5g of attapulgite and 2000g of water are mixed to form a suspension, and then 4.5g of urea is added and stirred for 3.5h; drying and grinding at 90°C, and then calcining the dried powder at 425°C for 4.5h, and then cooling to obtain a sepiolite powder-attapulgite-C3N4 complex; preparing a mixed solution with a mass concentration of lanthanum nitrate and cobalt nitrate of 20mg / mL, and the amount of lanthanum nitrate and cobalt nitrate is 13% of the sepiolite powder-attapulgite-C3N4 complex, respectively; and then adding the sepiolite powder-attapulgite-C3N4 complex to the mixture. The C3N4 complex is added to the mixed solution and stirred for 1.5 hours, then dried at 90°C, and then calcined at 450°C for 3 hours to obtain the catalyst powder; the catalyst powder is added to the disc of the spheronizer, and mist water is sprayed as a binder to form the catalyst powder into balls, wherein the rotation speed of the disc of the spheronizer is 40rpm, and then at the same rotation speed, the balls and catalyst powder are added to the disc of the spheronizer, and mist water is sprayed as a binder to form the balls into spherical catalysts with a diameter of 8mm.

[0059] S2: Open the ozone aeration head 18 and drive the barrel 16 to rotate to perform ozone aeration oxidation treatment; the ozone concentration of the ozone aeration oxidation treatment is 800 mg / L, the ozone gas flow rate is 1.5 L / min, and the ozone aeration oxidation time is 15 minutes;

[0060] S3: After the ozone aeration oxidation treatment is completed, the one-way solenoid valve of the outlet pipe 11 is opened, and the sludge water is discharged from the outlet pipe 11;

[0061] S4: filtering and dehydrating the sludge water after ozone aeration oxidation treatment to obtain sludge;

[0062] S5: The dehydrated sludge is dried at 80° C. and then ground, and sieved using a 200-mesh sieve to obtain a powdered coagulant aid.

[0063] Comparative Example 1:

[0064] A method for preparing a coagulant aid comprises the following steps:

[0065] S1: Open the one-way solenoid valve of the water inlet pipe 10 to inject the sludge water in the sedimentation tank into the ozone oxidation tank 17;

[0066] S2: Open the ozone aeration head 18 and drive the barrel 16 to rotate to perform ozone aeration oxidation treatment; the ozone concentration of the ozone aeration oxidation treatment is 10 mg / L, the ozone gas flow rate is 1 L / min, and the ozone aeration oxidation time is 10 min.

[0067] S3: After the ozone aeration oxidation treatment is completed, the one-way solenoid valve of the outlet pipe 11 is opened, and the sludge water is discharged from the outlet pipe 11;

[0068] S4: filtering and dehydrating the sludge water after ozone aeration oxidation treatment to obtain sludge;

[0069] S5: The dehydrated sludge is naturally air-dried and then ground, and sieved using a 200-mesh sieve to obtain a powdered coagulant aid.

[0070] The difference between Comparative Example 1 and Example 1 is that no catalyst was used when preparing the coagulant aid in Comparative Example 1;

[0071] Comparative Example 2

[0072] A method for preparing a coagulant aid comprises the following steps:

[0073] S1: The catalyst is loaded into the barrel 16 of the coagulant aid preparation device, the barrel 16 is installed, and then the one-way solenoid valve of the water inlet pipe 10 is opened to inject the sludge water from the sedimentation tank into the ozone oxidation tank 17;

[0074] S2: driving the barrel 16 to rotate and process;

[0075] S3: After the catalytic treatment is completed, the one-way solenoid valve of the outlet pipe 11 is opened, and the sludge water is discharged from the outlet pipe 11;

[0076] S4: filtering and dehydrating the catalytically treated sludge water to obtain sludge;

[0077] S5: The dehydrated sludge is naturally air-dried and then ground, and sieved using a 200-mesh sieve to obtain a powdered coagulant aid.

[0078] The difference between Comparative Example 2 and Example 1 is that no ozone oxidation treatment was performed when preparing the coagulant aid in Comparative Example 2.

[0079] The performance of the coagulant aids prepared in Examples 1-3 and Comparative Examples 1-2 was evaluated:

[0080] Take 1L of raw water from the water plant and use a six-way mixing device to conduct a coagulation and sedimentation experiment on the raw water from the water plant. The turbidity of the raw water is 9.77NTU, pH is 7.46, and COD Mn 4.81 mg / L, UV 254 The coagulant is 0.058cm-1, and the coagulant is a composite aluminum iron bisulphate ([Al2(OH) n Cl(SO4) b-6 ] m ·[Fe2(OH) n Cl 6-n (SO4) b-6 ] m), the coagulant aids prepared in Examples 1-3 and Comparative Examples 1-3 were added to the raw water of the water plant and a coagulation-sedimentation test was performed using a six-joint stirring device, and an organic matter analyzer was used to detect UV 254 The numerical test results are shown in the following table:

[0081] Group Coagulant dosage (mg) Coagulant dosage (mg) Turbidity of treated water (NTU) <![CDATA[UV 254 (cm -1 )]]> <![CDATA[COD Mn (mg / L)]]> Example 1 20 25 0.379 0.024 3.23 Example 2 20 25 0.375 0.027 3.28 Example 3 20 25 0.381 0.025 3.21 Comparative Example 1 20 25 2.04 0.045 3.99 Comparative Example 2 20 25 3.15 0.038 3.48

[0082] At the same time, at the end of the six-joint stirring experiment precipitation in Example 1 and Comparative Example 1, flocs with better morphology were sampled from the coagulation stirring cup and placed on a glass slide. The floc images were collected by a microscope camera system, and the flocs were analyzed and calculated using ImageJ image processing software.

[0083] Depend on Figure 4 It can be seen that the flocs of Example 1(b) are denser than those of Comparative Example 1(a). Figure 5 and Figure 6 It can be seen from the floc fractal dimension value that in low turbidity raw water, the coagulant in Example 1 can improve the floc particle size and fractal dimension value (D), and the floc particles formed are large, firm, and sink quickly. From the analysis of the floc fractal dimension value, it can be seen that the coagulant has a more obvious effect on the morphological characteristics of the flocs. The floc fractal dimension value of Comparative Example 1 is D=1.63, and the fractal dimension value of Example 1 is D=1.72. It can be seen that the addition of the coagulant prepared by containing a catalyst and ozone oxidation allows for more sufficient penetration and filling between particles, small flocs and flocs in the dynamic process of continuous fragmentation-flocculation of the flocs, making the flocs stronger and less prone to breakage. Therefore, the flocs can grow larger, the fractal dimension value is improved, and they can settle quickly, thereby improving the coagulant efficiency.

[0084] While the basic concepts have been described above, it will be apparent to those skilled in the art that the detailed disclosure is merely illustrative and does not limit this specification. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements, and variations to this specification. Such modifications, improvements, and variations are suggested in this specification and remain within the spirit and scope of the exemplary embodiments of this specification.

[0085] It should be noted that if the descriptions, definitions, and / or usage of terms in the accompanying materials of this specification are inconsistent or conflicting with the contents of this specification, the descriptions, definitions and / or usage of terms in this specification shall prevail.

[0086] Finally, it should be understood that the embodiments described in this specification are intended only to illustrate the principles of the embodiments of this specification. Other variations are also possible and fall within the scope of this specification. Therefore, by way of example and not limitation, alternative configurations of the embodiments of this specification may be considered consistent with the teachings of this specification. Accordingly, the embodiments of this specification are not limited to the implementations explicitly described and illustrated in this specification.

Claims

1. A method for preparing an ozone oxidation sedimentation tank sludge coagulant aid, characterized in that: The steps include: S1: The catalyst is loaded into the barrel (16) of the ozone oxidation device, the barrel (16) is installed, and then the one-way solenoid valve of the water inlet pipe (10) is opened to inject the sludge water in the sedimentation tank into the ozone oxidation tank (17); the sludge water is the sludge water from the sludge pool of the water plant; S2: Open the ozone aeration head (18) and drive the barrel (16) to rotate to perform ozone aeration oxidation treatment; S3: After the ozone aeration oxidation treatment is completed, the one-way solenoid valve of the outlet pipe (11) is opened, and the sludge water is discharged from the outlet pipe (11); S4: filtering and dehydrating the sludge water after ozone aeration oxidation treatment to obtain sludge; S5: drying the dehydrated sludge, grinding and screening it to obtain a powdered coagulant aid; In step S1, the method for preparing the catalyst comprises the following steps: (1) Mix sepiolite powder, attapulgite and water to form a suspension, then add urea and stir for 2-5 hours; The suspension is dried and ground at 80-100° C., and the dried powder is then calcined at 350-500° C. for 3-6 hours, and then cooled to obtain a sepiolite powder-attapulgite-C3N4 composite; A mixed solution of lanthanum nitrate and cobalt nitrate is prepared, and then a sepiolite powder-attapulgite-C3N4 complex is added to the mixed solution and stirred for 1-2 hours, followed by drying at 80-100°C, and then calcining at 350-550°C for 2-4 hours to obtain the catalyst powder; The obtained catalyst powder is spheronized using a spheronizer to form a spherical catalyst with a particle size of 5-10 mm.

2. The method for preparing an ozone oxidation sedimentation tank sludge coagulant aid according to claim 1, characterized in that: In step S2, the ozone concentration in the ozone aeration oxidation treatment is 500 mg / L-1500 mg / L, the ozone gas flow rate is 1 L / min-2 L / min, and the ozone aeration oxidation time is 10 min-20 min.

3. The method for preparing an ozone oxidation sedimentation tank sludge coagulant aid according to claim 1, characterized in that: In step S5, the dehydrated sludge is dried by natural air drying or oven drying, the drying temperature is room temperature 60°C-100°C, and the mesh size of the ground and sieved sludge is 200 mesh.

4. The method for preparing an ozone oxidation sedimentation tank sludge coagulant aid according to claim 1, characterized in that: The mass ratio of the sepiolite powder, attapulgite and water in step (1) is 1-2:1-2:100-500, and the amount of urea added is 0.2-0.5 times the total mass of the sepiolite powder and attapulgite.

5. The method for preparing an ozone oxidation sedimentation tank sludge coagulant aid according to claim 1, characterized in that: The mass concentration of lanthanum nitrate and cobalt nitrate in step (3) is 10-30 mg / mL, and the amount of lanthanum nitrate and cobalt nitrate is 5-20% of the sepiolite powder-attapulgite-C3N4 composite.

6. The method for preparing an ozone oxidation sedimentation tank sludge coagulant aid according to claim 1, characterized in that: In step (4), granulation is performed using a spheronizer, which comprises the following steps: adding the catalyst powder into the disc of the spheronizer, spraying mist water as a binder, so that the catalyst powder forms spheres, wherein the rotation speed of the disc of the spheronizer is 30-50 rpm, and then adding the spheres and catalyst powder into the disc of the spheronizer at the same rotation speed, spraying mist water as a binder, so that the spheres form spherical catalysts with a diameter of 5-10 mm.

7. The method for preparing the ozone oxidation sedimentation tank sludge coagulant aid according to any one of claims 1 to 6, characterized in that: The ozone oxidation device comprises: an ozone oxidation tank (17), the ozone oxidation tank (17) is cylindrical, the upper end of the ozone oxidation tank (17) is connected to a water inlet pipe (10), the lower end of the ozone oxidation tank (17) is connected to a water outlet pipe (11), and a plurality of aeration heads (18) are provided on the inner side wall and the bottom wall of the ozone oxidation tank (17); a shaft seat (19) is provided in the middle of the inner bottom wall of the ozone oxidation tank (17), a transmission shaft (5) is installed on the shaft seat (19), and a hole groove is provided on the top of the transmission shaft (5); a barrel (16) is sleeved on the transmission shaft (5), and the barrel (16) is in the shape of a hollow cylinder. A plurality of holes are provided on the side wall ring. A barrel cover (6) is provided on the upper end of the barrel (16). The barrel cover (6) is sleeved on the transmission shaft (5) and then screwed to the barrel (16). A pool cover (7) is provided on the ozone oxidation pool (17). A through hole is provided in the middle of the pool cover (7). The top of the transmission shaft (5) extends into the through hole of the pool cover (7). A motor (9) is installed on the pool cover (7). The rotating shaft of the motor (9) is inserted into the hole groove of the transmission shaft (5). The transmission shaft (5) and the rotating shaft of the motor (9) are fixed by screws. A motor flange (8) is provided on the motor (9). The motor flange (8) and the pool cover (7) are fixed by screws.

8. An ozone oxidation sedimentation tank sludge coagulant aid prepared by the preparation method according to any one of claims 1 to 6.

9. Use of the coagulant aid according to claim 8, characterized in that: The coagulant aid is added before the coagulation-sedimentation process in the water treatment process.

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