Phosphorus removal ceramsite filter material based on carbonaceous mudstone and calcium carbide as well as preparation method and application of phosphorus removal ceramsite filter material

Abstract

The invention discloses a phosphorus removal ceramsite filter material based on carbonaceous mudstone and calcium carbide and a preparation method and application thereof.The preparation method comprises the steps that S1, the carbonaceous mudstone and the calcium carbide are pretreated and then mixed, and a dry material mixture is obtained; s2, mixing the dry material mixture with pure water, granulating to obtain granules, and drying the granules to obtain a ceramsite blank; s3, the ceramsite blank is placed in a muffle furnace to be subjected to high-temperature calcination, and then the phosphorus removal ceramsite filter material based on the carbonaceous mudstone and the calcium carbide is obtained. The phosphorus removal ceramsite filter material based on the carbonaceous mudstone and the calcium carbide can be used for efficiently and stably adsorbing phosphate in a polluted water body, the pollution problem of eutrophication of the water body is solved, and resource utilization of the carbonaceous mudstone and the calcium carbide slag is achieved.

Description

Technical Field

[0001] The present invention relates to the field of carbonaceous mudstone treatment. More specifically, the present invention relates to a phosphorus-removing ceramsite filter material based on carbonaceous mudstone and calcium carbide, and a preparation method and application thereof. Background Art

[0002] The phenomenon of water eutrophication is relatively serious in some local areas of China. The excessive input of phosphorus is the main cause of eutrophication. To reduce the concentration of phosphorus pollutants in water, it is particularly important to seek an economical and efficient phosphorus-removing technology. Based on the difficulties of sewage phosphorus removal, researchers have carried out a large amount of research work. At present, the more common sewage phosphorus-removing technologies mainly include biological phosphorus removal, ecological phosphorus removal, and physicochemical phosphorus removal, etc. Although the biological phosphorus-removing technology has a good removal effect, the system has poor stability, weak anti-shock load capacity, and high operation and maintenance difficulty. The ecological phosphorus-removing technology can make full use of the original ecological system, has the advantages of low investment and operation costs, and is not easy to cause secondary pollution, etc. However, it has a large floor area, and the treatment effect is extremely susceptible to temperature and seasonal changes, and is only suitable for the treatment of small-scale sewage. The adsorption method is a kind of physicochemical phosphorus-removing method, which has the characteristics of high efficiency, low consumption, simple operation, and the adsorbent material can be recycled, etc., and can meet the requirements of low-cost input and high-efficiency phosphorus removal of sewage, which makes it a research hotspot in the field of sewage phosphorus removal in recent years. Substances rich in Ca are often used as adsorbent materials for fixing P.

[0003] Carbonaceous mudstone is widely distributed in the southwestern region of China and the central and western regions of Hunan. It has good mechanical properties under dry conditions and has the relevant characteristics of rock, but it is extremely easy to disintegrate when encountering water and the mechanical properties deteriorate significantly. If carbonaceous mudstone is used for embankment filling, its slope stability is good and the shear strength is high under dry climate, but under the influence of rainfall and repeated dry-wet cycles, the mudstone collapses. Therefore, the general disposal method of mudstone in engineering construction in this area is to abandon it, resulting in the accumulation of mudstone. This treatment method not only occupies a large amount of land resources, but also is not conducive to the recycling of resources, resulting in waste of resources. Calcium carbide slag, as a typical alkaline calcium-rich waste, is the main by-product of the hydrolysis of calcium carbide to produce acetylene. On the one hand, the output of calcium carbide slag as a by-product is large and it still contains a large amount of water after simple dehydration treatment, increasing the cost of transportation and treatment; on the other hand, the slow infiltration of long-term accumulated calcium carbide slag into the surface and underground will pollute the surface soil resources and shallow underground water resources. The CaO content in calcium carbide slag is as high as 80-90%, which gives it great advantages in the adsorption method, but its own special vitreous structure and relatively stable properties make it difficult to achieve a good adsorption effect in solution. Therefore, it is necessary to provide a phosphorus-removing ceramsite filter material based on carbonaceous mudstone and calcium carbide to solve the problem of the accumulation of carbonaceous mudstone and calcium carbide slag while treating phosphorus-containing sewage. Summary of the Invention

[0004] One object of the present invention is to solve at least the above problems and provide at least the advantages described hereinafter.

[0005] To achieve these objects and other advantages in accordance with the present invention, there is provided a phosphorus-removing ceramsite filter material based on carbonaceous mudstone and calcium carbide. The preparation raw materials of the phosphorus-removing ceramsite filter material based on carbonaceous mudstone and calcium carbide include: a dry material mixture with a mass percentage of 63% - 70% and pure water with a mass percentage of 30% - 37%; the dry material mixture is a mixture of carbonaceous mudstone and calcium carbide, wherein the mass percentage of carbonaceous mudstone is 70% - 75% and the mass percentage of calcium carbide is 25% - 30%.

[0006] Another object of the present invention is to provide a method for preparing a phosphorus-removing ceramsite filter material based on carbonaceous mudstone and calcium carbide, comprising the following steps: S1. Mix the carbonaceous mudstone and calcium carbide after pretreatment to obtain a dry material mixture; S2. Mix the dry material mixture with pure water and granulate to obtain granular materials, and dry the granular materials to obtain ceramsite embryos; S3. Place the ceramsite embryos in a muffle furnace for high-temperature calcination to obtain the phosphorus-removing ceramsite filter material based on carbonaceous mudstone and calcium carbide.

[0007] Preferably, the pretreatment in step S1 includes: S11. Crush the broken carbonaceous mudstone blocks and sieve them through a 80 - 100 mesh sieve; S12. Grind the calcium carbide and sieve it through a 80 - 100 mesh sieve.

[0008] Preferably, in step S2, a disk granulator is used for granulation, and the disk inclination angle of the disk granulator is 45° - 55°, and the rotation speed is 50 rpm - 60 rpm.

[0009] Preferably, the drying temperature of the granular materials is 80°C - 105°C, and the drying time is 8 h - 10 h.

[0010] Preferably, the ceramsite embryos are preheated and kept warm in a muffle furnace in sequence, and then cooled to room temperature to obtain the phosphorus-removing ceramsite filter material of carbonaceous mudstone and calcium carbide; wherein, the preheating temperature is 400°C - 500°C, and it is kept for 10 min - 20 min; the calcination temperature is 1050°C - 1150°C, and it is kept for 20 min - 25 min.

[0011] Another object of the present invention is to provide an application of the phosphorus-removing ceramsite filter material based on carbonaceous mudstone and calcium carbide for treating phosphorus-containing wastewater.

[0012] Preferably, the application of the phosphorus-removing ceramsite filter material based on carbonaceous mudstone and calcium carbide includes the following steps: Add the phosphorus-removing ceramsite filter media based on carbonaceous mudstone and calcium carbide into the phosphorus-containing wastewater at a dosage of 0.5 g / L to 1.5 g / L, and shake and process it at 25 °C to 30 °C for 20 h to 25 h to complete the treatment of the phosphorus-containing wastewater.

[0013] The present invention has at least the following beneficial effects: The present invention uses carbonaceous mudstone and carbide slag to jointly prepare the phosphorus-removing ceramsite filter media based on carbonaceous mudstone and calcium carbide, converting carbonaceous mudstone and carbide slag into high-value-added products, realizing the resource utilization of mudstone and carbide slag, and providing a new way for the treatment of mudstone and carbide slag. And through the mixture design, the property of carbide slag rich in CaO is used to adjust the shortage of calcium element in the raw materials, so that more liquid phase is produced during the preparation of ceramsite to wrap the generated gas, forming more voids, and at the same time calcium-containing minerals are generated. The obtained phosphorus-removing ceramsite filter media based on carbonaceous mudstone and calcium carbide meets CJ / T 299—2008 "Artificial Ceramsite Filter Media for Water Treatment" and has excellent phosphorus adsorption effect.

[0014] Other advantages, objectives and features of the present invention will be partially reflected by the following description and partially understood by those skilled in the art through the research and practice of the present invention. Detailed implementation manners

[0015] The following further detailed description of the present invention is made in conjunction with embodiments, so that those skilled in the art can implement it according to the description in the specification.

[0016] It should be noted that the experimental methods in the following implementation schemes are all conventional methods unless otherwise specified, and the reagents and materials can be obtained from commercial channels unless otherwise specified.

[0017] The present invention provides a phosphorus-removing ceramsite filter media based on carbonaceous mudstone and calcium carbide. The preparation raw materials of the phosphorus-removing ceramsite filter media based on carbonaceous mudstone and calcium carbide include: a dry material mixture with a mass percentage of 63% to 70% and pure water with a mass percentage of 30% to 37%; the dry material mixture is a mixture of carbonaceous mudstone and calcium carbide, wherein the mass percentage of carbonaceous mudstone is 70% to 75% and the mass percentage of calcium carbide is 25% to 30%.

[0018] In the above technical solution, through the recycling of carbonaceous mudstone and carbide slag, granulation is carried out by adding water with different mixing ratios and calcined at high temperature to generate ceramsite filter media for the efficient and stable adsorption of phosphate in polluted water bodies, which not only solves the pollution problem of water eutrophication but also realizes the resource utilization of carbonaceous mudstone and carbide slag.

[0019] The preparation method of the phosphorus-removing ceramsite filter media based on carbonaceous mudstone and calcium carbide includes the following steps: S1. Pretreat the carbonaceous mudstone and calcium carbide and then mix them to obtain a dry material mixture; S2. Mix the dry material mixture with pure water and granulate to obtain granular materials, and dry the granular materials to obtain ceramsite embryos; S3. Place the ceramsite embryos in a muffle furnace and calcine them at high temperature to obtain the phosphorus-removing ceramsite filter media based on carbonaceous mudstone and calcium carbide.

[0020] Further, the pretreatment in step S1 includes: S11. Crush the crushed carbonaceous mudstone blocks and sieve them through a 80-100 mesh sieve; S12. Grind calcium carbide and sieve it through a 80-100 mesh sieve; Further, in step S2, granulation is carried out using a disk granulator, and the disk inclination angle of the disk granulator is 45°-55°, and the rotation speed is 50 rpm-60 rpm.

[0021] Further, the drying temperature of the granular materials is 80°C-105°C, and the drying time is 8 h-10 h.

[0022] Further, the ceramsite embryos are preheated and kept warm in a muffle furnace in sequence, and then cooled to room temperature to obtain the phosphorus-removing ceramsite filter media based on carbonaceous mudstone and calcium carbide; wherein, the preheating temperature is 400°C-500°C, and it is kept for 10 min-20 min; the calcination temperature is 1050°C-1150°C, and it is kept for 20 min-25 min.

[0023] The present invention also provides an application of the phosphorus-removing ceramsite filter media based on carbonaceous mudstone and calcium carbide, which is used for the treatment of phosphorus-containing wastewater, and includes the following steps: Add the phosphorus-removing ceramsite filter media based on carbonaceous mudstone and calcium carbide to the phosphorus-containing wastewater, and the addition amount is 0.5 g / L-1.5 g / L, and shake and process at 25°C-30°C for 20 h-25 h to complete the treatment of the phosphorus-containing wastewater. Preferably, the phosphate concentration of the phosphorus-containing wastewater is 2 mg / L.

[0024] Example 1 Preparation of phosphorus-removing ceramsite filter media based on carbonaceous mudstone and calcium carbide: S1. Pretreatment of mudstone: Crush the crushed carbonaceous mudstone blocks and sieve them through a 100-mesh sieve to obtain mudstone; Pretreatment of calcium carbide: Grind calcium carbide and sieve it through a 100-mesh sieve to obtain calcium carbide; S2. Mix the mudstone and calcium carbide in step S1 at a ratio of 4:1 to obtain a dry material mixture; Pour 1 / 3 of the pure water accounting for the total solid mass and mix it with the dry material mixture evenly, and then pour it into a disk granulator with a disk inclination angle of 45° and a rotation speed of 50 rpm; Take out the granular materials and dry them in an oven at 80°C for 8 h to obtain ceramsite embryos; S3. Place the ceramsite embryo in a muffle furnace, raise the temperature to the preheating temperature of 500 °C at a heating rate of 10 °C / min, hold for 10 min, then raise the temperature to the calcination temperature of 1050 °C at the same rate, hold for 20 min, take it out after cooling, and obtain the phosphate-removing ceramsite filter media A.

[0025] Example 2 The difference from Example 1 is that in step S3, the calcination temperature is 1075 °C, and finally the phosphate-removing ceramsite filter media B is obtained.

[0026] Example 3 The difference from Example 1 is that in step S3, the calcination temperature is 1100 °C, and finally the phosphate-removing ceramsite filter media C is obtained.

[0027] Comparative Example 1 The difference from Example 2 is that in step S2, the ratio of mudstone to calcium carbide is 4:0.6, and finally the phosphate-removing ceramsite filter media D is obtained.

[0028] Comparative Example 2 The difference from Example 2 is that in step S2, the ratio of mudstone to calcium carbide is 4:0.7, and finally the phosphate-removing ceramsite filter media E is obtained.

[0029] Comparative Example 3 The difference from Example 2 is that in step S2, the ratio of mudstone to calcium carbide is 4:0.9, and finally the phosphate-removing ceramsite filter media F is obtained.

[0030] Comparative Example 4 The difference from Example 2 is that in step S2, the ratio of mudstone to calcium carbide is 4:0.96, and finally the phosphate-removing ceramsite filter media G is obtained.

[0031] For the phosphate-removing ceramsite filter media obtained in Examples 1 to 3 and Comparative Examples 1 to 4, conduct the phosphate adsorption test according to the following steps respectively: Pass the phosphate-removing ceramsite filter media through an 80-mesh sieve, weigh the product according to a solid-liquid ratio of 1 g / L, mix it thoroughly with 30 mL of potassium dihydrogen phosphate solution, place it in a gas bath oscillator at 25 °C, react for 24 h, and set the rotation speed of the oscillator to 150 r / min. After the adsorption is completed, filter it with a 0.45-μm PES filter head to obtain a clear supernatant. Determine the phosphate concentration of the supernatant according to the "Molybdate Ammonium Spectrophotometric Method for the Determination of Total Phosphorus in Water Quality" (GB 11893-89), and calculate the phosphate adsorption capacity of the phosphate-removing ceramsite filter media according to the formula. The calculation results are shown in the following table: Table 1 Calculation Results of Phosphate Adsorption Capacity Phosphorus-removing ceramsite filter media A Phosphorus-removing ceramsite filter media B Phosphorus-removing ceramsite filter media C Phosphorus-removing ceramsite filter media D Phosphorus-removing ceramsite filter media E Phosphorus-removing ceramsite filter media F Phosphorus-removing ceramsite filter media G Phosphate adsorption capacity 1.84mg / g 1.64mg / g 0.77mg / g 1.03mg / g 1.53mg / g 1.80mg / g 1.83mg / g From the results of the above phosphate adsorption test, it can be seen that the phosphorus-removing ceramsite filter media based on carbonaceous mudstone and calcium carbide provided by the present invention comply with the specifications of CJ / T 299-2008 "Artificial Ceramsite Filter Media for Water Treatment". The maximum adsorption capacity of the phosphorus-removing ceramsite filter media based on carbonaceous mudstone and calcium carbide for phosphate can reach 1.84 mg / g, and the adsorption efficiency for phosphorus in water body reaches more than 98%, showing excellent phosphorus adsorption effect.

[0032] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and embodiments. It can be fully applied to various fields suitable for the present invention. For those familiar with the field, additional modifications can be easily made. Therefore, without departing from the general concept defined by the claims and the equivalent scope, the present invention is not limited to the specific details and the embodiments shown and described here.

Claims

1. A phosphorus-removing ceramsite filter material based on carbonaceous mudstone and calcium carbide, characterized in that The raw materials for preparing the phosphorus-removing ceramsite filter material based on carbonaceous mudstone and calcium carbide include: a dry material mixture with a mass percentage of 63% - 70% and pure water with a mass percentage of 30% - 37%; the dry material mixture is a mixture of carbonaceous mudstone and calcium carbide, and the mass ratio of carbonaceous mudstone to calcium carbide is 4:(0.5 - 1.7).

2. A preparation method of the phosphorus-removing ceramsite filter material based on carbonaceous mudstone and calcium carbide as described in claim 1, characterized in that, It includes the following steps: S1. Mix the carbonaceous mudstone and calcium carbide after pretreatment to obtain a dry material mixture; S2. Mix the dry material mixture with pure water and granulate to obtain granular materials, and dry the granular materials to obtain ceramsite embryos; S3. Place the ceramsite embryos in a muffle furnace for high-temperature calcination to obtain the phosphorus-removing ceramsite filter material based on carbonaceous mudstone and calcium carbide.

3. The preparation method of the phosphorus-removing ceramsite filter material based on carbonaceous mudstone and calcium carbide according to claim 2, characterized in that, The pretreatment in step S1 includes: S11. Crush the broken carbonaceous mudstone blocks and sieve them through a 80 - 100 mesh sieve; S12. Grind the calcium carbide and sieve it through a 80 - 100 mesh sieve.

4. The preparation method of the phosphorus-removing ceramsite filter material based on carbonaceous mudstone and calcium carbide as claimed in claim 2, wherein, In step S2, a disk granulator is used for granulation. The inclination angle of the disk of the disk granulator is 45° - 55°, and the rotation speed is 50 rpm - 60 rpm.

5. The phosphorus-removing ceramsite filter material based on carbonaceous mudstone and calcium carbide according to claim 2, characterized in that, In step S2, the drying temperature of the granular materials is 80°C - 105°C, and the drying time is 8 h - 10 h.

6. The phosphorus-removing ceramsite filter material based on carbonaceous mudstone and calcium carbide according to claim 2, characterized in that, In step S3, the ceramsite embryos are preheated and kept warm in a muffle furnace in sequence, and then cooled to room temperature to obtain the phosphorus-removing ceramsite filter material of carbonaceous mudstone and calcium carbide; among them, the preheating temperature is 400°C - 500°C and kept for 10 min - 20 min; the calcination temperature is 1050°C - 1150°C and kept for 20 min - 25 min.

7. Application of a phosphorus-removing ceramsite filter material based on carbonaceous mudstone and calcium carbide. The phosphorus-removing ceramsite filter material is the phosphorus-removing ceramsite filter material based on carbonaceous mudstone and calcium carbide as described in claim 1 or the phosphorus-removing ceramsite filter material prepared by the preparation method described in any one of claims 2-6, and is characterized in that For the treatment of phosphorus-containing wastewater.

8. The application of the phosphorus-removing ceramsite filter material based on carbonaceous mudstone and calcium carbide according to claim 7, characterized in that, It includes the following steps: Add the phosphorus-removing ceramsite filter material based on carbonaceous mudstone and calcium carbide to the phosphorus-containing wastewater, with the addition amount of 0.5 g / L - 1.5 g / L, and shake and treat it at 25°C - 30°C for 20 h - 25 h to complete the treatment of the phosphorus-containing wastewater.