High-temperature active carbide material, preparation method and application of high-temperature active carbide material in promoting sludge sedimentation
The high-temperature activated carbide materials prepared through high-temperature carbonization and water vapor activation solve the problem of high cost of chemical agents in sludge treatment, and achieve rapid settlement and cost reduction of sludge.
Patent Information
- Application Number
- CN202411901105.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-23
- Publication Date
- 2025-03-28
AI Technical Summary
In the existing sludge treatment technology, the use of chemical agents increases the operating costs of sewage treatment plants, and the treatment costs of municipal sludge are relatively high, and in-situ utilization has not been achieved.
High-temperature activated carbide materials are prepared by performing high-temperature carbonization and water vapor activation to assist in promoting sludge settlement. The material is prepared by drying, crushing, heating and steam treatment.
This material can effectively promote the rapid settlement of sludge, reduce the use of traditional chemicals by 10 to 30%, reduce the operating costs of sewage treatment plants, and realize the in-situ application of sludge treatment products.
Smart Images
Figure CN119706834A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of sludge settling, and in particular to a high-temperature activated carbide material and a preparation method thereof, and application thereof in promoting sludge settling. Background Art
[0002] At present, the more mature sludge treatment and disposal methods include sanitary landfill, incineration power generation, building materials utilization and composting fermentation, but none of the above methods can achieve in-situ utilization of municipal sludge, thereby increasing the treatment cost of municipal sludge.
[0003] Sludge sedimentation is a process involving the separation of solids and liquids, which is common in the sludge treatment process of sewage treatment plants. In order to improve the sedimentation performance of sludge, some chemical agents are usually added, which can change the properties of sludge and promote its flocculation and sedimentation. The following are some common sludge sedimentation agents: Polyaluminium chloride (PAC): a commonly used inorganic polymer flocculant that can quickly form flocs and increase the sedimentation rate. Polyferric sulfate (PFS): also an inorganic flocculant, suitable for various water qualities, which helps flocculation and sedimentation of sludge. Aluminium sulfate: a traditional flocculant, suitable for removing suspended matter and some dissolved matter in water. Polyacrylamide (PAM): an organic polymer, as a coagulant, it can significantly improve the flocculation effect and make sludge easier to settle. Bone glue: a natural polymer coagulant that can increase the density and strength of flocs. Lime (CaO): used to adjust the pH value of sludge, and can also promote flocculation and sedimentation of sludge. Sodium sulfite: In some cases, it can be used to reduce certain components in sludge and improve sedimentation performance. When using these agents, it is necessary to select and proportion them according to the specific characteristics and treatment requirements of the sludge to ensure the treatment effect and avoid adverse effects on the environment. At the same time, attention should also be paid to the dosage and operation safety of the agents, and comply with relevant regulations and standards.
[0004] Although the addition of chemicals can effectively promote sludge sedimentation, the use of chemicals will significantly increase the cost of sewage treatment. Therefore, a low-cost alternative with the same effect is needed to reduce the operating cost of sewage treatment plants. Summary of the invention
[0005] The purpose of the present invention is to provide a high temperature activated carbide material and a preparation method thereof and use thereof in promoting sludge sedimentation in order to overcome the deficiencies of the prior art.
[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:
[0007] The present invention provides a method for preparing a high temperature active carbide material, comprising the following steps:
[0008] 1) The sludge is dried, crushed and sieved in sequence to obtain sludge particles;
[0009] 2) heating the sludge particles to a target temperature under a protective atmosphere, keeping the temperature at the target temperature and then introducing water vapor;
[0010] 3) After the introduction of water vapor is stopped, the mixture is naturally cooled to room temperature under a protective atmosphere to obtain a high-temperature activated carbide material.
[0011] Preferably, the drying temperature in step 1) is 95-115° C., the drying time is 20-28 hours, and the particle size of the sludge particles is ≤40 mesh.
[0012] Preferably, in step 2), the target temperature is 600-900° C., and the target temperature is maintained for 0.3-0.7 h.
[0013] Preferably, the flow rate of the water vapor in step 2) is 100-1000 mL / min, and the time for introducing the water vapor is 0.5-2 h; the water vapor is introduced into the sludge particles at the target temperature.
[0014] Preferably, in step 2), the heating rate for heating to the target temperature is 2-10°C / min.
[0015] Preferably, the protective atmosphere in step 2) and step 3) is a nitrogen atmosphere, and the flow rate of the nitrogen is 50 to 200 mL / min.
[0016] The invention also provides a high-temperature active carbide material prepared by the preparation method.
[0017] The invention also provides application of the high-temperature activated carbide material in promoting sludge sedimentation.
[0018] The beneficial effects of the present invention include:
[0019] Based on the low utilization rate of municipal sludge treatment and disposal products and the demand of sewage treatment plants for new and cheap sludge sedimentation-promoting agents, the present invention obtains a municipal sludge high-temperature activated carbonized material by high-temperature carbonization and water vapor activation of municipal sludge, which is used to assist in promoting sludge sedimentation, so as to improve the effect of sludge treatment and disposal, and achieve the goal of in-situ application of sludge treatment and disposal products. After being crushed, the municipal sludge high-temperature activated carbonized material of the present invention can assist in promoting the rapid sedimentation of municipal sludge, thereby reducing the use of traditional chemical agents by 10-30% and reducing the operating costs of municipal sewage treatment plants. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 is a scanning electron microscope image of the MSB of Example 1;
[0021] Figure 2 is the X-ray powder diffraction pattern of MSB of Example 1;
[0022] Figure 3 is the Fourier infrared spectrum of the MSB of Example 1;
[0023] Figure 4 The MSB in Example 1 was used to replace 10% PAC in the sedimentation experiment of municipal sludge. DETAILED DESCRIPTION
[0024] The present invention provides a method for preparing a high temperature active carbide material, comprising the following steps:
[0025] 1) The sludge is dried, crushed and sieved in sequence to obtain sludge particles;
[0026] 2) heating the sludge particles to a target temperature under a protective atmosphere, maintaining the temperature at the target temperature, and then introducing water vapor;
[0027] 3) After the introduction of water vapor is stopped, the mixture is naturally cooled to room temperature under a protective atmosphere to obtain a high-temperature activated carbide material.
[0028] In the present invention, the drying temperature in step 1) is preferably 95-115°C, more preferably 100-110°C, more preferably 105°C, and the drying time is preferably 20-28h, more preferably 22-26h, more preferably 24h; the particle size of the sludge particles is preferably ≤40 mesh.
[0029] In the present invention, the sludge is preferably municipal sludge.
[0030] In the present invention, the target temperature in step 2) is preferably 600-900°C, more preferably 700-850°C, and more preferably 750-800°C. The target temperature is preferably kept for 0.3-0.7h, and more preferably for 0.5h.
[0031] In the present invention, the flow rate of the water vapor in step 2) is preferably 100-1000 mL / min, more preferably 150-800 mL / min, more preferably 200-600 mL / min, and the time for the water vapor to be introduced is preferably 0.5-2 h, more preferably 1-1.5 h; the water vapor is introduced into the sludge particles at the target temperature.
[0032] In the present invention, the heating rate of heating to the target temperature in step 2) is preferably 2 to 10°C / min, more preferably 4 to 9°C / min, and more preferably 5 to 8°C / min.
[0033] In the present invention, the protective atmosphere in step 2) and step 3) is preferably a nitrogen atmosphere, and the flow rate of the nitrogen is preferably 50 to 200 mL / min, more preferably 80 to 160 mL / min, and more preferably 120 to 150 mL / min.
[0034] The invention also provides a high-temperature active carbide material prepared by the preparation method.
[0035] In the present invention, the high temperature activated carbonized material is municipal sludge high temperature activated carbonized material.
[0036] The invention also provides application of the high-temperature activated carbide material in promoting sludge sedimentation.
[0037] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.
[0038] Municipal sludge was taken from the municipal sewage treatment plant in Jingkou District, Zhenjiang City, Jiangsu Province. The sewage treatment plant adopts the UCT process. PAC is added to the municipal sludge before it is discharged from the water treatment system to achieve flocculation and sedimentation of the sludge. The main parameters of municipal sludge are: water content of 85-87% and organic matter content of 70-72%.
[0039] Example 1
[0040] The municipal sludge was placed in an electric blast drying oven and dried at 105°C for 24 hours. The dried municipal sludge was crushed and sieved (40 mesh). 50g of the sieved sludge was transferred to a clean porcelain boat and placed in a high-temperature tube furnace. In a nitrogen atmosphere (the flow rate of nitrogen was 150mL / min, and nitrogen was introduced at a fixed flow rate until the cooling was completed), the sieved sludge was heated to 800°C at a heating rate of 10°C / min and kept at 800°C for 0.5h. After that, the temperature of the tube furnace was kept at 800°C, the steam generator was turned on and connected to the tube furnace, the flow rate of water vapor was 200mL / min, and the water vapor was introduced for 1h. Subsequently, the introduction of water vapor was stopped, the heating was stopped, and the mixture was naturally cooled to room temperature under a nitrogen atmosphere to obtain a municipal sludge high-temperature activated carbon material (MSB).
[0041] Example 2
[0042] The municipal sludge was placed in an electric blast drying oven and dried at 100°C for 26 hours. The dried municipal sludge was crushed and sieved (40 mesh). 50g of the sieved sludge was transferred to a clean porcelain boat and placed in a high-temperature tube furnace. In a nitrogen atmosphere (the flow rate of nitrogen was 120mL / min, and nitrogen was introduced at a fixed flow rate until the cooling was completed), the sieved sludge was heated to 750°C at a heating rate of 8°C / min and kept at 750°C for 0.7h. After that, the temperature of the tube furnace was kept at 750°C, the steam generator was turned on and connected to the tube furnace, the flow rate of water vapor was 150mL / min, and the water vapor was introduced for 1.5h. Subsequently, the introduction of water vapor was stopped, the heating was stopped, and the mixture was naturally cooled to room temperature under a nitrogen atmosphere to obtain a municipal sludge high-temperature activated carbon material (MSB).
[0043] Example 3
[0044] The municipal sludge was placed in an electric blast drying oven and dried at 110°C for 22 hours. The dried municipal sludge was crushed and sieved (40 mesh). 50g of the sieved sludge was transferred to a clean porcelain boat and placed in a high-temperature tube furnace. In a nitrogen atmosphere (the flow rate of nitrogen was 160mL / min, and nitrogen was introduced at a fixed flow rate until the cooling was completed), the sieved sludge was heated to 850°C at a heating rate of 9°C / min and kept at 850°C for 0.3h. After that, the temperature of the tube furnace was kept at 850°C, the steam generator was turned on and connected to the tube furnace, the flow rate of water vapor was 600mL / min, and the water vapor was introduced for 1h. Subsequently, the introduction of water vapor was stopped, the heating was stopped, and the mixture was naturally cooled to room temperature under a nitrogen atmosphere to obtain a municipal sludge high-temperature activated carbon material (MSB).
[0045] Figure 1 is a scanning electron microscope image of the MSB of Example 1, Figure 1 It can be seen that the microscopic surface of the municipal sludge high-temperature activated carbon material is distributed with a complete pore structure that penetrates the interior of the material. The pore structure of the plant-based biochar material produced at high temperature is very easy to collapse, while the microstructure of the MSB material of the present invention remains stable, which is attributed to the difference in the proportion of inorganic components such as SiO2 and organic components in the sludge raw material.
[0046] Figure 2 is the X-ray powder diffraction pattern of MSB of Example 1, Figure 2It can be seen that there are significant characteristic peaks at positions such as 21.06°, 26.86°, 36.73°, 39.71°, 40.45°, 42.67°, 46.01°, 50.32°, 55.14° and 60.20°, corresponding to the (100), (101), (110), (102), (111), (200), (201), (112), (202) and (211) crystal planes of SiO2 (JCPDS 46-1045).
[0047] Figure 3 is the Fourier infrared spectrum of the MSB of Example 1, Figure 3 It can be seen that at 3424.40cm -1 and 3697.87cm -1 The characteristic peaks at are caused by the stretching vibrations of -OH and -OH, proving the presence of hydrogen-bonded functional groups (such as water, carboxylic acid, etc.) in the MSB material. The peaks caused by the stretching vibrations of -C=C in the aromatic ring appear at 1649.58-1605.42 cm -1 .1058.49cm -1 The peak is attributed to the asymmetric stretching vibration of -Si-O and the absorption of -CO; 480~800cm -1 It is the fingerprint region of SiO2, in which there are a large number of peaks generated by -Si-O functional groups.
[0048] Figure 4 The MSB in Example 1 was used to replace 10% polyaluminium chloride (PAC) for the sedimentation experiment of municipal sludge. The specific process is: take 100mL of sludge sewage and place it in a measuring cylinder with a volume of 100mL, and continue stirring to prevent the sludge from settling naturally. Add 0.0g of flocculation material (10% MSB + 90% PAC) into the measuring cylinder. After adding the above substances, continue stirring for 5s, then stop stirring, observe the sludge sedimentation effect and record the sludge sedimentation distance. As can be seen from the figure, after adding 10% municipal sludge high temperature activated carbon + 90% PAC, the municipal sludge settles rapidly. In addition, the addition of MSB accelerates the hydrolysis of PAC, which is conducive to reducing the loss of PAC caused by its own agglomeration and further reducing the use of chemical flocculants.
[0049] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.
Claims
1. A method for preparing a high temperature active carbide material, characterized in that: The following steps are included: 1) The sludge is dried, crushed and sieved in sequence to obtain sludge particles; 2) heating the sludge particles to a target temperature under a protective atmosphere, keeping the temperature at the target temperature and then introducing water vapor; 3) After the introduction of water vapor is stopped, the mixture is naturally cooled to room temperature under a protective atmosphere to obtain a high-temperature activated carbide material.
2. The preparation method according to claim 1, characterized in that: Step 1) The drying temperature is 95-115° C. and the drying time is 20-28 hours; the particle size of the sludge particles is ≤40 mesh.
3. The preparation method according to claim 1, characterized in that: Step 2) The target temperature is 600-900° C. and the temperature is maintained at the target temperature for 0.3-0.7 h.
4. The preparation method according to claim 1 or 3, characterized in that: Step 2) The flow rate of the water vapor is 100-1000 mL / min, and the time for the water vapor to be introduced is 0.5-2 h; the water vapor is introduced into the sludge particles at the target temperature.
5. The preparation method according to claim 4, characterized in that: In step 2), the heating rate for heating to the target temperature is 2 to 10°C / min.
6. The preparation method according to claim 5, characterized in that: The protective atmosphere in step 2) and step 3) is a nitrogen atmosphere, and the flow rate of the nitrogen is 50 to 200 mL / min.
7. The high temperature active carbide material prepared by the preparation method according to any one of claims 1 to 6.
8. Use of the high temperature activated carbide material according to claim 7 in promoting sludge sedimentation.