Preparation and application of high-performance bamboo charcoal composite ceramsite water treatment filter material

Abstract

The invention relates to the technical field of water treatment, and particularly discloses preparation and application of a high-performance bamboo charcoal composite ceramsite water treatment filter material, the high-performance bamboo charcoal composite ceramsite water treatment filter material comprises the following raw material components: clay and bamboo charcoal according to a mass ratio of (3-9): 1; the adhesive accounts for 1-10% of the total mass of the clay, the bamboo charcoal material and the adhesive; the adhesive is selected from bamboo tar, a cellulose adhesive or a starch adhesive; the bamboo charcoal composite ceramsite filter material provided by the invention is prepared by uniformly mixing the clay, the bamboo charcoal and the adhesive and then calcining at high temperature under a limited oxygen condition. In the preparation process, the clay with good plasticity effectively coats and combines the bamboo charcoal particles, then the composite ceramsite filter material with a stable structure and developed pores is formed, and the specific surface area of the composite ceramsite filter material is remarkably increased.

Description

Technical Field

[0001] This invention belongs to the field of water treatment technology, specifically relating to the preparation and application of a high-performance bamboo charcoal composite ceramic granule water treatment filter media. Background Technology

[0002] Biological filters remove pollutants from water bodies through mechanisms such as adsorption, biodegradation, and transformation, and are widely used in drinking water treatment, wastewater purification, and constructed wetlands. As the carrier of the biofilm, the adsorption performance and biofilm formation capacity of the filter media directly affect the purification efficiency of the biological filter. Ceramsite, due to its low cost and stable performance, has become one of the most commonly used filter media for biological filters. However, traditional ceramsite mainly uses clay, shale, and fly ash as raw materials, which have limited specific surface area, resulting in insufficient adsorption capacity and low biofilm formation efficiency, thus restricting further improvements in water treatment effects.

[0003] Bamboo charcoal, with its unique honeycomb microporous structure, large specific surface area, strong adsorption capacity, and favorable environment for microbial attachment, is considered an ideal filter media material. However, its high price makes it difficult to directly apply to large-scale water treatment projects. Currently, there is a lack of efficient resource utilization methods. If these bamboo charcoal waste materials are prepared as filter media separately, not only are there technical bottlenecks such as difficulties in granulation and molding, but the supply of raw materials is also limited, making it difficult to meet the application needs of large-scale water treatment. Summary of the Invention

[0004] The purpose of this invention is to provide a high-performance bamboo charcoal composite ceramic granule water treatment filter material for preparation and application, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A high-performance bamboo charcoal composite ceramsite water treatment filter media comprises the following raw material components:

[0007] The mass ratio of clay to bamboo charcoal is (3-9):1;

[0008] Adhesive, comprising 1 to 10% of the total mass of clay, bamboo charcoal materials and adhesive;

[0009] The adhesive is selected from bamboo tar, cellulose adhesives or starch adhesives.

[0010] Preferably, the bamboo charcoal material also includes bamboo charcoal processing waste, which includes crushed charcoal or charcoal powder.

[0011] A method for preparing the high-performance bamboo charcoal composite ceramsite water treatment filter media according to any one of the above claims includes the following steps:

[0012] (1) Mix the dried and pulverized clay and bamboo charcoal materials with the adhesive, add water and stir until it becomes a viscous consistency that can be kneaded and shaped.

[0013] (2) Granulate the mixture into small balls with a diameter of 1-20 mm and dry them at 105℃ for 2-5 h;

[0014] (3) Calcine the dried pellets under oxygen-limited conditions at a temperature of 800-1000℃ for 2-6 hours and then cool them down to obtain the product.

[0015] Preferably, in step (1), the clay and bamboo charcoal materials are crushed and then passed through a 100-mesh sieve.

[0016] The application of the high-performance bamboo charcoal composite ceramic granule water treatment filter media described in any one of the above claims in water treatment. This filter media has a well-developed pore structure, mainly composed of micropores (pore size less than 2 nm) and mesopores (pore size 2–50 nm). The micropore volume accounts for more than 70% of the total pore volume, and the specific surface area can reach 50–500 m². 2 / g; This filter media has excellent adsorption performance for pollutants such as ammonia nitrogen and organic matter, with an adsorption capacity of ≥100mg / Kg for ammonia nitrogen. It also has good biofilm formation performance, which is conducive to the rapid formation and stable operation of biofilm.

[0017] It is used in biological filters, including but not limited to biological filters in drinking water plants, aerated biological filters in sewage treatment plants, and artificial ecological wetlands;

[0018] Its typical application process mainly includes the following steps:

[0019] (1) Provide the bamboo charcoal composite ceramic filter media, the particle size can be selected according to the water treatment target, with a single gradation (e.g., 3-5 mm) or multiple gradations (e.g., 3-6 mm for the upper layer and 6-10 mm for the lower layer);

[0020] (2) Lay filter media in the reactor or filter bed. The filter layer can be set to 1 to 3 layers. The height of each layer of filter media is determined according to the treatment requirements. The preferred range is 0.1 to 1 m, and a structure configuration of coarse particles in the lower layer and fine particles in the upper layer is preferred.

[0021] (3) Start up, operate and maintain the water treatment process; the start-up method includes natural biofilm formation or artificial inoculation biofilm formation; during operation, the empty bed residence time is determined according to the influent pollutant load and effluent water quality requirements, preferably 10 to 30 minutes, and under the conditions of successful biofilm formation and sufficient dissolved oxygen (≥2 mg / L), the effluent ammonia nitrogen concentration is basically ≤0.5 mg / L;

[0022] The maintenance methods mainly include backwashing or sludge removal operations, the cycle of which is determined according to the influent water quality and operating parameters. Regular or irregular maintenance can be adopted, with regular maintenance being preferred.

[0023] Compared with the prior art, the beneficial effects of the present invention are:

[0024] (1) The bamboo charcoal composite ceramic filter media provided by the present invention is prepared by uniformly mixing clay, bamboo charcoal and binder and then calcining at high temperature under limited oxygen. During the preparation process, the clay with good plasticity effectively coats and binds the bamboo charcoal particles, and after calcination, a composite ceramic filter media with stable structure and well-developed pores is formed, and its specific surface area is significantly increased.

[0025] (2) The bamboo charcoal composite ceramic granule filter media provided by this invention has a large specific surface area, exhibiting excellent adsorption capacity for pollutants. Simultaneously, its abundant pore structure provides ample attachment space for microorganisms, effectively improving biofilm biomass and the biodegradation and transformation efficiency of pollutants. In an upflow biological filter, a biofilm formation start-up experiment was conducted, demonstrating that the filter media successfully formed a biofilm and operated stably, exhibiting excellent performance in water purification. Furthermore, this filter media is environmentally friendly, causing no secondary pollution to the water quality, and has a wide range of applications, especially suitable for drinking water treatment and other applications with high water quality safety requirements.

[0026] (3) This invention uses readily available and inexpensive clay as the main raw material, supplemented by waste byproducts such as charcoal powder and charcoal fragments from bamboo charcoal processing. The proportion of bamboo charcoal added is small, allowing for complete supply from bamboo charcoal waste, avoiding dependence on commercial bamboo charcoal and effectively reducing the cost of filter material preparation. Furthermore, bamboo tar from the bamboo charcoal burning process can be used as a binder, allowing for local sourcing and further cost reduction. The entire preparation process achieves high-value utilization and resource recovery of byproducts from the bamboo charcoal industry, resulting in significant economic and environmental benefits. Attached Figure Description

[0027] Figure 1 This is a schematic diagram illustrating the ammonia nitrogen removal effects of the bamboo charcoal composite ceramsite filter and the ordinary ceramsite filter in Embodiment 2 of the present invention.

[0028] Figure 2 This is a schematic diagram illustrating the ammonia nitrogen removal effect of the bamboo charcoal composite ceramsite filter in landscape water bodies according to Embodiment 3 of the present invention.

[0029] Figure 3 This is a schematic diagram illustrating the effect of bamboo charcoal composite ceramic granule filter on the removal of organic matter in landscape water bodies in Embodiment 3 of the present invention. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Example 1:

[0032] Please see Figure 1-3 As shown, the preparation of a high-performance bamboo charcoal composite ceramic granule water treatment filter media includes:

[0033] A bamboo charcoal composite ceramic granule filter media, the raw material composition and content of which are as follows:

[0034] 75g clay, 25g bamboo charcoal, 1g binder;

[0035] In one embodiment of the present invention, both the clay and bamboo charcoal undergo drying and pulverizing pretreatment. The drying is performed at 105°C for 2 hours, and the pulverized material is passed through a 100-mesh sieve.

[0036] In one embodiment of the present invention, the clay used is from Wuyishan area of ​​Nanping City, Fujian Province, the bamboo charcoal used is from a bamboo charcoal processing enterprise in Nanping City, Fujian Province, and the binder used is sodium carboxymethyl cellulose.

[0037] The XRF results of the clay and bamboo charcoal used are shown in Table 1:

[0038] Table 1: XRF results of the clay and bamboo charcoal used

[0039]

[0040]

[0041] The preparation method of the above-mentioned bamboo charcoal composite ceramic filter material includes the following steps:

[0042] (1) Weigh 75g of clay, 25g of bamboo charcoal and 1g of adhesive, mix them evenly and then add water and stir to obtain a viscous mixture; the amount of water added should be such that the clay, bamboo charcoal and adhesive can be kneaded into shape after mixing.

[0043] (2) Prepare the viscous mixture obtained in step (1) into small balls of 2-4 mm, and dry them in an oven at 105°C for 2 hours;

[0044] (3) The small balls obtained in step (2) are calcined in a muffle furnace with limited oxygen at a temperature of 900°C for 2 hours. After calcination, they are cooled to room temperature to obtain the bamboo charcoal composite ceramic filter material.

[0045] The bamboo charcoal composite ceramic filter media obtained above has a rich microporous-mesoporous pore structure, and its specific surface area is significantly increased, as shown in Table 2;

[0046] Table 2: Specific surface area and total pore volume of bamboo charcoal composite ceramic filter media

[0047]

[0048] Example 2:

[0049] This embodiment illustrates the application of the bamboo charcoal composite ceramic filter media of the present invention in the treatment of slightly polluted water sources;

[0050] Upflow biological filters were constructed using ordinary clay ceramsite and bamboo charcoal composite ceramsite filter media prepared in Example 1, respectively. No aeration device was installed, and the filter was started by natural biofilm formation. The empty bed retention time was 10 minutes.

[0051] The influent was artificially simulated slightly polluted water source, with an ammonia nitrogen concentration of 1.5–2 mg / L and a dissolved oxygen concentration of 7–9 mg / L. After successful biofilm formation, the ammonia nitrogen concentration in the influent and effluent was determined using the salicylic acid spectrophotometric method according to the "Standard Examination Methods for Drinking Water" (GB / T 5750.1–5750.13—2023). Figure 1 As shown;

[0052] contrast Figure 1 The ammonia nitrogen removal efficiency of the two types of filters shows that the ammonia nitrogen removal efficiency of the bamboo charcoal composite ceramsite filter is significantly improved compared with that of ordinary ceramsite, with an ammonia nitrogen removal rate of more than 90% and an effluent ammonia nitrogen concentration of less than 0.2 mg / L, which meets the requirements of the "Standards for Drinking Water Quality" (GB 5749-2022).

[0053] Furthermore, the bacterial biomass attached to the filter media was detected using the R2A plate culture method, and the results are shown in Table 3.

[0054] Table 3 Biomass of Ceramsite Biofilm

[0055] index Bamboo charcoal composite ceramsite Ordinary clay ceramsite Biomass (CFU / g) <![CDATA[5.7×10 6 ]]> <![CDATA[2.1×10 6 ]]>

[0056] As can be seen from the data in Table 3, bamboo charcoal composite ceramsite has more microorganisms attached to it, which is due to its larger specific surface area than that of ordinary clay ceramsite.

[0057] Example 3:

[0058] This embodiment illustrates the application of the bamboo charcoal composite ceramic filter media of the present invention in the water treatment of landscape water bodies in residential communities.

[0059] A biological filter bed is constructed using bamboo charcoal composite ceramic filter media with a clay-to-bamboo charcoal ratio of 4:1 and a particle size of 3-6mm. The flow direction is downward, and an aeration device is installed at the bottom of the filter bed.

[0060] The filter bed was started using a natural biofilm formation method, with an empty bed retention time set to 30 minutes.

[0061] The quality of influent and effluent water is measured, and the test indicators include ammonia nitrogen, nitrite nitrogen, nitrate nitrogen, and total organic matter concentration.

[0062] After successful biofilm formation, the dissolved oxygen concentration in the effluent should be controlled at 2–4 mg / L.

[0063] The water purification effect of the bamboo charcoal composite ceramsite biological filter is as follows: Figure 2 and Figure 3 As shown;

[0064] In the early stage of biofilm formation, the bamboo charcoal composite ceramic granule filter mainly adsorbs pollutants such as ammonia nitrogen and organic matter, with an ammonia nitrogen removal rate of about 30% and an organic matter removal rate of about 15%.

[0065] In the mid-to-late stage of biofilm formation, the bamboo charcoal composite ceramic granule filter mainly removes pollutants such as ammonia nitrogen and organic matter through biological action. The ammonia nitrogen removal rate gradually increases to more than 80%, and the organic matter removal rate gradually stabilizes and is greater than 10%.

[0066] After successful biofilm formation, the filter bed maintains a stable effect on pollutant removal, with ammonia nitrogen removal rate between 95% and 100%, effluent ammonia nitrogen at 0 to 0.2 mg / L, and organic matter removal rate between 10% and 40%.

[0067] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high-performance bamboo charcoal composite ceramsite water treatment filter media, characterized in that, Includes the following raw material components: The mass ratio of clay to bamboo charcoal is (3-9):1; Adhesive, comprising 1 to 10% of the total mass of clay, bamboo charcoal materials and adhesive; The adhesive is selected from bamboo tar, cellulose adhesives or starch adhesives.

2. The high-performance bamboo charcoal composite ceramic granule water treatment filter media according to claim 1, characterized in that: The bamboo charcoal material also includes bamboo charcoal processing waste, which includes crushed charcoal or charcoal powder.

3. A method for preparing the high-performance bamboo charcoal composite ceramsite water treatment filter media according to any one of claims 1-2, characterized in that, Includes the following steps: (1) Mix the dried and pulverized clay and bamboo charcoal materials with the adhesive, add water and stir until it becomes a viscous consistency that can be kneaded and shaped. (2) Granulate the mixture into small balls with a diameter of 1-20 mm and dry them at 105℃ for 2-5 h; (3) Calcine the dried pellets under oxygen-limited conditions at a temperature of 800-1000℃ for 2-6 hours and then cool them down to obtain the product.

4. The preparation method of a high-performance bamboo charcoal composite ceramsite water treatment filter media according to claim 3, characterized in that: In step (1), the clay and bamboo charcoal materials are crushed and then passed through a 100-mesh sieve.

5. The method for preparing a high-performance bamboo charcoal composite ceramsite water treatment filter media according to claim 3, characterized in that: The preferred calcination temperature for step (3) is 900℃, and the preferred holding time is 2h.

6. The application of the high-performance bamboo charcoal composite ceramic water treatment filter media according to any one of claims 1-2 in water treatment.

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