A tetracycline sewage treatment device with tea dregs biochar as filter element and a use method thereof

Abstract

The application discloses a tetracycline sewage treatment device with tea dregs biological carbon as a filter core and a use method thereof. First, the application uses tea dregs as raw materials, carries out carbonization by doping sulfur elements and sodium alginate polyvinyl alcohol coating to prepare tetracycline adsorbents; second, the application also designs a matching sewage treatment device, which can complete harmless separation of livestock and poultry manure, and can use the prepared tea dregs adsorbents to complete the adsorption of tetracycline in sewage, and the adsorbents can be regularly replaced. The tetracycline sewage pretreatment device with tea dregs biological carbon as the core constructed by the application eliminates the pollution and series harm of tetracycline residues in livestock and poultry industry wastewater to the environment, processes tea dregs into adsorbents, reduces the cost and environmental pressure of tea dregs garbage treatment, improves the utilization rate and added value of tea dregs, promotes the rational utilization of resources and solves the environmental pollution problem.

Description

Technical Field

[0001] This invention relates to a technology for the pretreatment of tetracycline wastewater from livestock and poultry industries, and more particularly to a device for the pretreatment of tetracycline wastewater from livestock and poultry industries that utilizes waste tea residue to prepare an adsorption filter element. Background Technology

[0002] In recent years, my country has generated as much as 5 million tons of waste tea leaves annually from tea production and brewing, of which 90% is landfilled or incinerated as garbage. This not only wastes resources but also causes significant pollution, so there is an urgent need for a technology to reuse tea leaves.

[0003] In livestock and poultry farming, large amounts of tetracycline are used to enhance disease resistance and prevent disease transmission. However, most of this tetracycline is not metabolized by the animals and is released into the environment. This not only affects the effectiveness of animal manure composting but also causes serious pollution of soil and water bodies, ultimately harming plants and humans. Currently, many livestock and poultry wastewater treatment devices are available on the market, but they primarily address traditional issues such as dry-wet separation of manure and wastewater and nitrogen, phosphorus, and potassium pollution, and mostly utilize biodegradation technology. These devices lack the ability to treat tetracycline, and due to tetracycline's bactericidal and bacteriostatic effects, their composting and biodegradation functions are significantly reduced. Therefore, a wastewater pretreatment device for livestock and poultry farming needs to be designed.

[0004] Adsorbent adsorption is a traditional method for separating and purifying substances in chemical and environmental engineering. However, currently available adsorbents lack sufficient active adsorption sites for organic matter, cannot selectively adsorb tetracycline, and have poor regeneration performance, lacking recycling capabilities. Furthermore, used adsorbents can easily cause secondary pollution. Therefore, it is necessary to develop and improve new adsorbents to meet the separation requirements of tetracycline in livestock and poultry wastewater. Summary of the Invention

[0005] To address the pollution hazards caused by tetracycline-containing wastewater from livestock and poultry industries, this invention designs a tea residue biochar adsorbent prepared from tea residue, its preparation method, and its application, which can be used in tetracycline wastewater pretreatment devices.

[0006] The tea residue biochar adsorbent provided by this invention is sulfur-doped tea residue biochar particles coated with sodium alginate.

[0007] This invention also provides a method for producing tea residue biochar adsorbent, the specific steps of which are as follows:

[0008] (1) Take the waste tea residue from the tea production process or after brewing tea, dry it at 70-90℃, and then grind it into fine powder of 30-60 mesh.

[0009] (2) Mix sodium thiosulfate pentahydrate with the fine powder from step (1) at a mass ratio of 1-2:1, and then place at 200-240℃.

[0010] The tea residue was carbonized using a hydrothermal method in a forced-air drying oven, and then washed with deionized water through a suction filter to obtain sulfur-doped tea residue biochar.

[0011] (3) Take the tea residue biochar from step (2), mix it with a coating agent composed of sodium alginate and polyvinyl alcohol, add deionized water and mix thoroughly. Then slowly drip it into CaCl2 solution. The resulting particles are sodium alginate-coated sulfur-doped tea residue biochar adsorbent.

[0012] Furthermore, in step (3), the weight ratio of sodium alginate to polyvinyl alcohol in the coating agent is 1:1-2.

[0013] Furthermore, in step (3), the weight ratio of tea residue biochar to coating agent is 1:0.8-1.2.

[0014] This invention also provides the application of tea residue biochar adsorbent in the adsorption and removal of tetracycline in livestock and poultry wastewater.

[0015] Furthermore, it also includes methods for treating tetracycline-containing wastewater from livestock and poultry industries, comprising the following steps:

[0016] (1) Fill the adsorption tank of the wastewater treatment equipment with tea residue biochar adsorbent to form a filter element;

[0017] (2) Discharge the livestock and poultry wastewater into the primary settling tank of the treatment equipment and adjust the pH value of the wastewater to below 3. Tetracycline will be converted into a free state. At the same time, the solid manure settles to achieve solid-liquid separation. The solid manure is discharged from the solid discharge port, and the liquid phase carries the tetracycline into the secondary settling tank.

[0018] (3) In the secondary settling tank, the pH value is adjusted to 4-9 and further settling is carried out to perform solid-liquid separation again;

[0019] (4) After the wastewater undergoes sedimentation treatment in step (2), it flows into the adsorption tank and passes through the tea residue biochar adsorbent filter. Tetracycline is adsorbed by the filter, and the wastewater after removing tetracycline is discharged in compliance with standards.

[0020] The present invention also discloses a wastewater treatment device for livestock and poultry industries, including a primary sedimentation tank and a secondary sedimentation tank connected in series in the liquid phase. The primary sedimentation tank and the secondary sedimentation tank have a dosing port at the top and a slag discharge port at the bottom. The liquid phase outlet of the secondary sedimentation tank is connected to an adsorption tank, and the adsorption tank is filled with a filter element formed by the tea residue biochar adsorbent.

[0021] Furthermore, the filter element is tubular in shape.

[0022] The present invention has the following beneficial effects:

[0023] (1) Tea dregs are processed into adsorbents, which reduces the cost of tea dregs waste disposal and environmental pressure, and improves the utilization rate and added value of tea dregs;

[0024] (2) It eliminates the pollution and series of hazards to the environment caused by the residual tetracycline in livestock and poultry wastewater. Attached Figure Description

[0025] Figure 1 This invention describes the preparation process of the tea residue biochar adsorbent.

[0026] Figure 2 This is the wastewater pretreatment device of the present invention.

[0027] In the diagram, 1. Solid height infrared monitoring and pH monitoring device, 2. Pressure plate, 3. Water pump, 4. pH monitoring device, 5. Filter residue discharge port, 6. Filter screen, 7. Filter element, 8. Chemical outlet, I. Primary settling tank, II. Secondary settling tank, III. Adsorption tank.

[0028] During use, wastewater is first discharged into the primary settling tank (Ⅰ). The wastewater settles on the upper side of the pressure plate (2). When the height of the animal feces in the wastewater reaches the monitor (1), the pressure plate (2) will automatically open, allowing the animal feces to be separated to the lower side of the pressure plate. At the same time, the agent is added through the agent port (8) to adjust the pH value of the primary settling tank. Finally, all tetracycline is released into the upper waste liquid of this part.

[0029] The upper waste liquid is pumped to the secondary settling tank (II) using a water pump (3). The pH value of the waste liquid is adjusted by adding reagents through the reagent inlet (8), and further settling is completed.

[0030] The secondary settling tank (II) and the adsorption tank (III) are connected by five pipes, each with a filter screen (6) at its opening. 5×5=25 replaceable filter elements (7) are inserted into the adsorption tank (III), and a loop-shaped fluid path is designed so that the waste liquid repeatedly passes through the filter elements for tetracycline adsorption. The final treated liquid flows out from the drain outlet at the top of the adsorption tank (III). Detailed Implementation

[0031] The technical solution of the present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0032] Example 1

[0033] (4) Take the waste tea residue from the tea production process or after brewing tea, dry it at 70°C, and then grind it into a fine powder of 30 mesh.

[0034] (5) Sodium thiosulfate pentahydrate and the fine powder in step (1) are mixed at a mass ratio of 2:1, and then placed in a blast drying oven at 200°C for hydrothermal carbonization. After being taken out, the mixture is washed with deionized water through a suction filter to obtain sulfur-doped tea residue biochar.

[0035] (6) Take the tea residue biochar from step (2), mix it with a coating agent composed of sodium alginate and polyvinyl alcohol, add deionized water and mix thoroughly. Then slowly drip it into CaCl2 solution. The resulting particles are sodium alginate-coated sulfur-doped tea residue biochar adsorbent.

[0036] Furthermore, in step (3), the weight ratio of sodium alginate to polyvinyl alcohol in the coating agent is 1:1.

[0037] Furthermore, in step (3), the weight ratio of tea residue biochar to coating agent is 5:4.

[0038] This invention also provides the application of tea residue biochar adsorbent in the adsorption and removal of tetracycline in livestock and poultry wastewater.

[0039] Furthermore, it also includes methods for treating tetracycline-containing wastewater from livestock and poultry industries, comprising the following steps:

[0040] (1) Fill the adsorption tank of the wastewater treatment equipment with tea residue biochar adsorbent to form a filter element;

[0041] (2) The livestock and poultry wastewater is discharged into the primary settling tank of the treatment equipment, and the pH value of the wastewater is adjusted to 3. Tetracycline is converted into a free state. At the same time, the solid manure settles to achieve solid-liquid separation. The solid manure is discharged from the solid discharge port, and the liquid phase carries tetracycline into the secondary settling tank.

[0042] (3) In the secondary settling tank, the pH value is adjusted to 6 and further settling is carried out to perform solid-liquid separation again;

[0043] (4) After the wastewater undergoes sedimentation treatment in step (2), it flows into the adsorption tank and passes through the tea residue biochar adsorbent filter. Tetracycline is adsorbed by the filter, and the wastewater after removing tetracycline is discharged in compliance with standards.

[0044] The preparation and usage method of Example 1 improves the pore size of the adsorbent and creates a milder working environment, under which better adsorption effects can be achieved. It is suitable for working scenarios with slow flow rates and high tetracycline concentrations.

[0045] Example 2

[0046] (7) Take the waste tea residue from the tea production process or after brewing tea, dry it at 90°C, and then grind it into a fine powder of 60 mesh.

[0047] (8) Sodium thiosulfate pentahydrate and the fine powder in step (1) are mixed at a mass ratio of 1:1, and then placed in a blast drying oven at 240°C for hydrothermal carbonization. After being taken out, the mixture is washed with deionized water through a suction filter to obtain sulfur-doped tea residue biochar.

[0048] (9) Take the tea residue biochar from step (2), mix it with a coating agent composed of sodium alginate and polyvinyl alcohol, add deionized water and mix thoroughly. Then slowly drip it into CaCl2 solution. The resulting particles are sodium alginate-coated sulfur-doped tea residue biochar adsorbent.

[0049] Furthermore, in step (3), the weight ratio of sodium alginate to polyvinyl alcohol in the coating agent is 1:2.

[0050] Furthermore, in step (3), the weight ratio of tea residue biochar to coating agent is 5:6.

[0051] This invention also provides the application of tea residue biochar adsorbent in the adsorption and removal of tetracycline in livestock and poultry wastewater.

[0052] Furthermore, it also includes methods for treating tetracycline-containing wastewater from livestock and poultry industries, comprising the following steps:

[0053] (1) Fill the adsorption tank of the wastewater treatment equipment with tea residue biochar adsorbent to form a filter element;

[0054] (2) The livestock and poultry wastewater is discharged into the primary settling tank of the treatment equipment, and the pH value of the wastewater is adjusted to 1. The tetracycline is converted into a free state. At the same time, the solid manure settles to achieve solid-liquid separation. The solid manure is discharged from the solid discharge port, and the liquid phase carries the tetracycline into the secondary settling tank.

[0055] (3) In the secondary settling tank, the pH value is adjusted to 4 and further settling is carried out to perform solid-liquid separation again.

[0056] (4) After the wastewater undergoes sedimentation treatment in step (2), it flows into the adsorption tank and passes through the tea residue biochar adsorbent filter. Tetracycline is adsorbed by the filter, and the wastewater after removing tetracycline is discharged in compliance with standards.

[0057] Example 2 increases the particle size of the adsorbent and the proportion of coating agent used. This allows the adsorbent to maintain high mechanical strength even under harsh operating conditions, enhancing its recyclability. It is suitable for scenarios requiring the treatment of large quantities of low-concentration wastewater in a short period.

[0058] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method of using a tetracycline wastewater treatment device with tea residue biochar as the filter element, characterized in that, The specific steps are as follows: Waste tea leaves from tea production or brewing are dried at 70-90℃ and then ground into a fine powder of 30-60 mesh. Sodium thiosulfate pentahydrate is mixed with the fine powder at a mass ratio of 1-2:1, and then carbonized using a hydrothermal method in a forced-air drying oven at 200-240℃. After removal, the mixture is washed with deionized water using a suction filter to obtain sulfur-doped tea residue biochar. The tea residue biochar, sodium alginate, and polyvinyl alcohol are thoroughly mixed with deionized water and then slowly dripped into a CaCl2 solution. The resulting particles are sodium alginate-coated sulfur-doped tea residue biochar adsorbents. These adsorbents are then filled into the adsorption tank of a wastewater treatment device to form a filter element. The wastewater treatment device includes a primary settling tank and a secondary settling tank connected in series in the liquid phase. Both the primary and secondary settling tanks have chemical dosing ports at the top. The system has a slag discharge port at the bottom. The liquid phase outlet of the secondary settling tank is connected to the adsorption tank, which is filled with a filter element formed by the tea residue biochar adsorbent. Livestock and poultry wastewater is discharged into the primary settling tank of the treatment device, and the pH value of the wastewater is adjusted to below 3. Tetracycline is converted into a free state, and at the same time, solid manure settles, achieving solid-liquid separation. The solid manure is discharged from the solid discharge port, and the liquid phase carries tetracycline into the secondary settling tank. In the secondary settling tank, the pH value is adjusted to 4-9, and further settling is carried out to achieve solid-liquid separation again. The wastewater after the second settling treatment flows into the adsorption tank and passes through the tea residue biochar adsorbent filter element. The tetracycline is adsorbed by the filter element, and the wastewater after removing tetracycline meets the standards and is discharged.

2. The method of use as described in claim 1, characterized in that: The filter element is tubular in shape.

3. The method of use as described in claim 1, characterized in that: The primary settling tank also includes a solid phase level sensor, a solid phase discharge port, and a baffle plate installed at the discharge port. The sensor controls the opening and closing of the baffle plate through a controller and a baffle plate drive mechanism controlled by the controller.

4. The method of use as described in claim 1, characterized in that: A filter is also installed in the liquid phase connection passage between the secondary settling tank and the adsorption tank.

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