Magnetic sintering-free ceramsite-based sludge rapid dewatering system and method

Abstract

The application discloses a sludge rapid dewatering system and method based on magnetic sintering-free ceramsite. The system comprises an ozone generator, a micro-nano bubble generator, a sludge reactor and a flocculation sedimentation tank connected in sequence through pipelines. The sludge reactor comprises a tank body, an aeration head is arranged at the bottom of the tank body and communicated with the air outlet pipe of the micro-nano bubble generator, a ceramsite supporting layer is arranged on the aeration head, a supporting frame is arranged in the middle of the tank body, a plurality of ultrasonic emission probes are arranged on the supporting frame, an ultraviolet light irradiation head and a sludge scraper are arranged on the upper part of the tank body, and a magnetic sintering-free ceramsite feeding device is arranged on the flocculation sedimentation tank. The application can realize rapid utilization of ozone, release of intracellular water of sludge, sludge concentration and rapid dewatering, so that the volume of sludge is greatly reduced, and the application has the advantages of simple equipment operation, low treatment cost, reuse of waste sludge and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to a sludge rapid dewatering system and method based on magnetic sinter-free ceramsite. BACKGROUND

[0002] The rapid development of industrialization and urbanization makes some large and medium-sized sewage treatment plants need to treat a large amount of wastewater every day, and the sludge production also increases significantly. The treatment and disposal of sludge can account for 30% to 50% of the investment and operating costs of the sewage treatment plant. Sludge reduction is a key step to reduce the burden of sludge transportation and disposal. Therefore, developing a fast and environmentally friendly sludge reduction technology is the primary task of sludge treatment and disposal at present.

[0003] Due to the presence of hydrophilic extracellular polymeric substances (EPS) in sludge, mechanical dewatering alone can only remove free water and part of capillary water in sludge solids, which cannot meet the requirements of subsequent sludge treatment and disposal for water content. The strong oxidation activity of ozone causes the destruction of sludge floc and cell structure, and the denaturation and dissolution of polysaccharides and proteins in microbial cell wall and cell membrane, achieving the purpose of degrading microbial cells and releasing bound water. In addition, the mixture of sludge and sludge treatment agent is treated by ultraviolet light and ultrasonic waves, which can further kill bacteria and viruses in the sludge. However, the problem of low ozone utilization rate has always existed in the ozone aeration oxidation process.

[0004] The pretreated sludge can be concentrated to preliminarily reduce the water content of the sludge and achieve sludge reduction. The common concentration method at present is gravity concentration, but for the residual sludge, due to its high organic matter content and poor settling performance, the gravity concentration effect is not ideal. The water content of the concentrated sludge is high, the concentration equipment occupies a large area, the concentration process is long, and the sludge is prone to anaerobic digestion. The high compressibility of the sludge also causes the deformation and collapse of the cake structure during pressure filtration, resulting in the problems of difficulty in flowing out of water in the sludge and low treatment efficiency. How to harmlessly treat the sludge while rapidly reducing the sludge is an important direction for the development of this field. SUMMARY

[0005] In view of the above problems, the present application provides a sludge rapid dewatering system and method based on magnetic sinter-free ceramsite.

[0006] To achieve the above purpose, the sludge rapid dewatering system based on magnetic sinter-free ceramsite of the present application comprises an ozone generator, a micro-nano bubble generator, a sludge reactor and a flocculation and sedimentation tank connected in sequence through pipelines.

[0007] The sludge reactor comprises a tank body, an aeration head is arranged at the bottom of the tank body and communicated with the air outlet pipe of the micro-nano bubble generator, a ceramic support layer is arranged on the aeration head, a support frame is arranged in the middle of the tank body, a plurality of ultrasonic emission probes are arranged on the support frame, an ultraviolet light irradiation head and a sludge scraper are arranged on the upper part of the tank body.

[0008] The flocculation and sedimentation tank is provided with a magnetic sintering-free ceramic particle adding device.

[0009] Further, a tail gas collecting device is arranged above the tank body.

[0010] Further, a sludge collecting groove is arranged on the outer side wall of the tank body corresponding to the sludge scraping device, and the bottom of the sludge collecting groove is connected with the flocculation and sedimentation tank through a pipeline.

[0011] Further, a stirring device is arranged in the flocculation and sedimentation tank.

[0012] To achieve the above-mentioned purpose, the sludge rapid dewatering method based on magnetic sintering-free ceramic particles comprises the following steps: (1) pumping the residual sludge of a sewage treatment plant into a sludge reactor, and fully aerating the sludge by using ozone micro-nano bubbles;

[0013] (2) assisting the sludge with ultrasonic action to perform wall breaking reaction, irradiating the sludge with ultraviolet light to kill pathogenic microorganisms, and concentrating the sludge by air flotation to the upper part of the sludge reactor under the action of micro-nano bubbles, and partially returning the generated biodegradable clear liquid to a biochemical reaction tank through a reflux system (9);

[0014] (3) conveying the sludge after air flotation concentration to a flocculation and sedimentation tank (14), adding magnetic ceramic particles, stirring and standing, and conveying the settled sludge to a sludge filter press to form a sludge cake.

[0015] Further, the method comprises the following steps: the magnetic ceramic particles are prepared by using municipal sludge, fly ash and cement as basic materials through a sintering-free method; the mass ratio of the municipal sludge, fly ash and cement is 2:1:3, the water-cement ratio is 60%, the curing time is 7d, and the ceramic particles are magnetized and modified by using a hydrophobic magnetization method.

[0016] Further, the particle size of the magnetic ceramic particles ranges from 2mm to 5mm.

[0017] Further, in step (1), the moisture content of the sludge entering the sludge reactor is less than 99%, and the dry matter concentration of the sludge is greater than 20g / L.

[0018] Further, in step (3), the standing and settling time is 1.5-3h; and the sludge filter press is one or more of a plate and frame filter press, a vertical filter press and a belt filter press.

[0019] Furthermore, the moisture content of the sludge after pressure filtration is reduced to 41%-43%.

[0020] Furthermore, the hydrophobic magnetization method involves partially dissolving the non-sintering ceramic particles in an alkaline solution, adding a surfactant, fatty acid soap, and a magnet, and reacting on the particle surface to form a thin film of fatty acid iron, which is then directionally magnetized in a magnetic field.

[0021] Compared with the prior art, the present invention has the following obvious advantages:

[0022] 1. During the flocculation process, before mechanical dewatering, non-sintering ceramic-based particles made from municipal sludge, fly ash, etc., are added as skeleton particles after magnetization modification. This not only greatly improves the sludge settling efficiency and achieves rapid sludge reduction, but also prevents the collapse of sludge flocs during compression, further improving the sludge dewatering rate. At the same time, it conforms to the treatment concept of "using waste to treat waste" and reduces the addition of other chemical agents, which can better meet the requirements of subsequent sludge treatment.

[0023] 2. This invention uses a combination of ozone, ultrasound, and ultraviolet light to pretreat excess sludge, achieving cell lysis of microbial cells in the sludge, releasing internal bound water and soluble organic matter, which can promote the sludge's water release capacity during subsequent mechanical dewatering. It also reacts with bacteria, viruses, and insect eggs in the sludge, breaking down their cell walls to achieve effective killing and adsorption sedimentation. Furthermore, the clear liquid containing soluble organic matter is returned to the biochemical reaction tank to supplement the carbon source for microorganisms, promoting their growth.

[0024] 3. Ozone comes into contact with sludge in the form of micro-nano bubbles, which can significantly increase the solubility of ozone in sludge and maintain a high mass transfer efficiency. At the same time, the ceramic granule layer in the reactor can ensure uniform distribution of ozone micro-nano bubbles. Micro-nano bubbles also have the effect of air flotation concentration. With their large specific surface area, micro-nano bubbles increase the contact area with sludge particles. Compared with gravity concentration, this method can obtain concentrated sludge with lower water content, and the equipment occupies less space and has a shorter concentration time. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the process of the rapid sludge dewatering method based on magnetic non-sintering ceramsite of the present invention.

[0026] Figure 2 This is a schematic diagram of the sludge rapid dewatering system based on magnetic non-sintering ceramsite of the present invention;

[0027] Figure 3 The diagram shows the ceramic-based particles of the present invention, (a) before magnetization and (b) after magnetization.

[0028] In the diagram: 1. Ozone generator 2. Micro / nano bubble generator 3. Aeration head 4. Aeration pipeline 5. Sludge inlet pipe 6. Ultrasonic emission probe 7. Exhaust gas collection device 8. Ceramsite support layer 9. Return system 10. Sludge collection tank 11. Sludge scraper 12. Ultraviolet light irradiation head 13. Agitator 14. Flocculation sedimentation tank Detailed Implementation

[0029] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0030] In the description of this invention, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0031] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0032] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0033] This invention aims to provide a magnetic non-sintered ceramic-based particle and process equipment for rapid sludge reduction. The magnetic non-sintered ceramic-based particle is based on non-sintered ceramic granules, modified by incorporating magnetic seeds through a hydrophobic magnetization method. This transforms ordinary non-sintered ceramic-based particles into magnetic non-sintered ceramic-based particles, which are then mixed with pretreated sludge, significantly improving flocculation efficiency and shortening flocculation and sedimentation time. The ceramic-based particles are hydrophobic, meaning they do not readily bind with water. When added to sludge, they tend to aggregate or distribute in certain areas of the sludge, forming hydrophobic channels or networks within the sludge. These channels facilitate water drainage during filtration, providing a pathway for water to escape the sludge system. Furthermore, the ceramic-based particles form a robust skeletal structure within the sludge. Due to their high hardness and stability, this skeleton supports the sludge structure during filtration, preventing collapse or deformation under pressure. This support ensures the sludge maintains a relatively stable morphology during filtration, facilitating water removal.

[0034] The hydrophobic magnetization method involves partially dissolving non-sintering ceramic particles in an alkaline solution, then adding surfactants such as fatty acid soaps and magnets to form a thin film of fatty acid iron on the particle surface, which is then directionally magnetized in a magnetic field.

[0035] Example 1

[0036] This invention relates to a system for rapid sludge dewatering based on magnetic non-sintering ceramsite, such as... Figure 2 As shown.

[0037] After ozone is generated by ozone generator 1, ozone micro-nano bubbles are generated by micro-nano bubble generator 2. The ozone micro-nano bubbles are introduced into the sludge reactor through aeration pipe 4 and aeration head 3, and then further evenly distributed by the ceramsite support layer 8 at the bottom of the sludge reactor, and make full contact with the sludge transported by sludge inlet pipe 5 in the reactor. The ceramsite support layer is laid at the bottom of the sludge reactor and has a thickness of 35-40cm. The aeration pipe is provided at the end of the aeration pipe and the aeration head is located in the ceramsite support layer.

[0038] Meanwhile, the sludge reactor is equipped with an ultrasonic transmitting probe, which is located above the ceramsite layer and connected to the ultrasonic transmitter; the ultrasonic action generated by the ultrasonic transmitting probe 6 works in conjunction with ozone to complete cell wall disruption.

[0039] The sludge reactor is equipped with a clear liquid reflux system in the middle. The biodegradable clear liquid generated by ozone and ultrasound is partially refluxed back to the biological reaction tank via this system, with a reflux ratio of 35%–45%.

[0040] The sludge reactor is equipped with an ultraviolet light irradiation probe 12 at the top, which emits ultraviolet light to irradiate the upper layer of sludge, killing bacteria, viruses, etc. in the sludge. During aeration, the sludge in the reactor floats to the top of the reactor to complete the concentration. The concentrated sludge has a water content of 94%-95%. It is scraped into the sludge collection tank 10 by the sludge scraper 11 at the top of the reactor. The exhaust gas is treated by the collection device 7 at the top of the reactor. The sludge in the collection tank is transported to the flocculation sedimentation tank 14. Magnetic ceramic particles are added to the flocculation sedimentation tank and react fully with the sludge under the stirring of the stirring device 13. Finally, the sludge that has been settled is transported to the sludge filter press for dewatering. The final sludge water content is 41%-43%.

[0041] Specifically, the ozone dosage is 10–35 mg / g dry weight of sludge, the ultrasonic power is 100 W, the frequency is 100 kHz, the duration is 5–10 min, the wavelength of ultraviolet light is 50 nm, the intensity is 500 W, the thickness of the ceramsite layer is 35–40 cm, the sludge return ratio is 30%–65%, the dosage of magnetic non-sintering ceramic-based particles is 30%–45% of the dry weight of sludge, and the optimal stirring and settling times are 0.2 h and 2.5 h, respectively.

[0042] The non-sintering ceramic-based granules added to the flocculation sedimentation tank are made from municipal sludge, cement, and fly ash. The ceramic-based granules are partially dissolved in an alkaline solution. By adding surfactants such as fatty acid soaps and magnets, a thin film of fatty acid iron is formed on the surface of the granules. After being directionally magnetized in a magnetic field, magnetic ceramic-based granules are produced.

[0043] The sludge treated by the magnetic non-sintering ceramic-based particles and process flow of this invention, which enables rapid sludge reduction, releases bound water and soluble organic matter from its interior. The clarified liquid containing soluble organic matter, after being recycled, can compensate for the insufficient organic carbon source in the biological reaction tank, while simultaneously reducing the production of residual sludge during the reaction process, achieving the goal of in-situ sludge reduction. The sludge after air flotation concentration has a lower water content than that after gravity concentration. Adding magnetized ceramic-based particles made from waste materials during the dewatering process not only rapidly achieves flocculation and sedimentation but also effectively prevents the sludge flocs from collapsing during compression, further improving the sludge dewatering rate.

[0044] Example 2

[0045] The method of the present invention includes the following steps:

[0046] Step 1: After being pressurized, the sludge is pumped into the sludge reactor through the sludge conveying pipe. The sludge entering the sludge reactor is required to have a moisture content of less than 99% and a dry matter concentration of greater than 20 g / L.

[0047] The ozone generated by the ozone generator is passed through a micro-nano bubble generator to produce ozone micro-nano bubbles. These bubbles are then transported to the aeration heads via aeration pipes. After being evenly distributed through the ceramsite support layer, the ozone reacts fully with the sludge, promoting the degradation of organic matter and achieving the purpose of preservation and deodorization. The reactor interior is further enhanced by ultrasonic cell disruption and ultraviolet irradiation, which further releases bound water from within the cells, killing pathogenic microorganisms in the sludge. Simultaneously, the biodegradable soluble substances released after cell disruption enter the clarified liquid and are returned to the biological reaction tank.

[0048] Step 2: After the ozone micro-nano bubbles come into contact with the sludge, in addition to participating in the reaction in Step 1, they can also adhere to the surface of the sludge particles and produce a floating effect, thereby concentrating the sludge to the top of the reactor. The concentrated sludge is scraped into the sludge collection tank by the sludge scraper and then transported to the flocculation sedimentation tank. The exhaust gas is safely treated after entering the exhaust gas collection device.

[0049] Step 3: Add magnetic non-sintering ceramic matrix granules to the flocculation sedimentation tank. Under the stirring of the stirring device, they react fully with the sludge in the flocculation sedimentation tank, effectively achieving rapid flocculation and sedimentation of the sludge and preventing the sludge flocs from collapsing during the compression process. Finally, the sludge that has been allowed to settle is transported to the sludge filter press for dewatering.

[0050] The present invention has been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described above. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention. Many other changes and modifications made without departing from the concept and scope of the present invention should be considered within the scope of protection of the present invention.

[0051] In the description of this specification, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0052] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A rapid sludge dewatering system based on magnetic non-sintering ceramsite, characterized in that, The system includes an ozone generator, a micro-nano bubble generator, a sludge reactor, and a flocculation sedimentation tank connected in sequence by pipes. The sludge reactor includes a tank body, an aeration head connected to the air outlet pipe of a micro-nano bubble generator is provided at the bottom of the tank body; a ceramic support layer is provided on the aeration head; a support frame is provided in the middle of the tank body, and multiple ultrasonic transmitting probes are provided on the support frame; and an ultraviolet light irradiation head and a sludge scraping device are provided at the top of the tank body. The flocculation sedimentation tank is equipped with a magnetic non-sintering ceramsite dosing device; A sludge collection trough is installed on the outer wall of the tank corresponding to the sludge scraping device, and the bottom of the sludge collection trough is connected to the flocculation sedimentation tank through a pipe.

2. The rapid sludge dewatering system based on magnetic non-sintering ceramsite as described in claim 1, characterized in that, An exhaust gas collection device is installed on top of the tank.

3. The rapid sludge dewatering system based on magnetic non-sintering ceramsite as described in claim 1, characterized in that, The flocculation sedimentation tank is equipped with a stirring device.

4. A method for rapid sludge dewatering based on magnetic non-sintering ceramsite, wherein the method is based on the rapid sludge dewatering system based on magnetic non-sintering ceramsite as described in claim 1, characterized in that... The method includes the following steps: (1) Pump the wastewater treatment plant’s excess sludge into the sludge reactor and aerate the sludge using ozone micro-nano bubbles. (2) The sludge is subjected to ultrasonic action to break the wall reaction of the sludge in the sludge reactor, and the pathogenic microorganisms are killed by ultraviolet light irradiation. The sludge is concentrated by air flotation to the upper part of the sludge reactor under the action of micro-nano bubbles. The generated biochemical clear liquid is partially returned to the biochemical reaction tank through the return system (9). (3) The sludge after being concentrated by air flotation is transported to the flocculation sedimentation tank (14), magnetic non-sintering ceramsite is added, stirred and left to stand, and the sludge after sedimentation is transported to the sludge filter press to be made into sludge cake.

5. The rapid sludge dewatering method based on magnetic non-sintering ceramsite as described in claim 4, characterized in that, The method includes the following steps: the magnetic non-sintering ceramsite is prepared by a non-sintering method using municipal sludge, fly ash and cement as base materials; wherein the mass ratio of municipal sludge, fly ash and cement is 2:1:3, the water-cement ratio is 60%, the curing time is 7 days, and the ceramsite particles are magnetized and modified by a hydrophobic magnetization method.

6. The rapid sludge dewatering method based on magnetic non-sintering ceramsite as described in claim 5, characterized in that, The particle size of the magnetic ceramic particles ranges from 2 to 5 mm.

7. The rapid sludge dewatering method based on magnetic non-sintering ceramsite as described in claim 4, characterized in that, In step (1), the sludge entering the sludge reactor has a water content of less than 99% and a dry matter concentration of more than 20 g / L.

8. The rapid sludge dewatering method based on magnetic non-sintering ceramsite as described in claim 4, characterized in that, The settling time in step (3) is 1.5 to 3 hours; the sludge filter press is one or more of plate and frame filter press, vertical filter press, and belt filter press; the moisture content of the sludge after filtration is reduced to 41%-43%.

9. The rapid sludge dewatering method based on magnetic non-sintering ceramsite as described in claim 5, characterized in that, The hydrophobic magnetization method involves partially dissolving non-sintering ceramic particles in an alkaline solution, adding a surfactant, fatty acid soap, and a magnet, and reacting on the particle surface to form a thin film of fatty acid iron, which is then directionally magnetized in a magnetic field.

Images