Honeycomb-shaped slow release fertilizer based on water supply sludge and preparation method of honeycomb-shaped slow release fertilizer
By preparing honeycomb slow-release fertilizer, the problems of difficult water sludge treatment and unstable fertilizer were solved, the stable slow release of ammonia nitrogen and total phosphorus was achieved, plant growth was promoted and the preparation process was simplified.
Patent Information
- Application Number
- CN202510964519.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-14
- Publication Date
- 2025-09-30
AI Technical Summary
Water supply sludge is difficult to treat, traditional sludge composting has a long cycle and poses a risk of secondary pollution, the release of nutrients from chemical fertilizers is unstable, and the preparation of existing slow-release fertilizers is complex and costly.
By optimizing the ratio and molding process of water supply sludge, monoammonium phosphate, attapulgite clay, organic fertilizer and xanthan gum, and combining physical adsorption and chemical bonding mechanisms, a honeycomb slow-release fertilizer is prepared to achieve stable slow release of ammonia nitrogen and total phosphorus, and improve soil structure.
It realizes the resource utilization of water supply sludge, provides a simple and fast method for preparing slow-release fertilizer, has excellent slow-release performance of ammonia nitrogen and total phosphorus, and promotes plant growth.
Smart Images
Figure CN120717850A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the field of fertilizer technology, and specifically relates to a honeycomb slow-release fertilizer based on water supply sludge and a preparation method thereof. The method produces a slow-release fertilizer with both ammonia nitrogen (NH4 + ) and total phosphorus (PO4 3- )’s slow-release properties and its growth-promoting effect on plants. Background Art
[0002] The production of water supply sludge has increased with urbanization. Its high moisture content, heavy metal content, and organic matter content have limited traditional disposal methods. Existing sludge composting technology also has long processing times, risks of secondary pollution, and unstable nutrient release. Traditional chemical fertilizers release nutrients quickly, have low utilization rates, and are prone to eutrophication. Existing slow-release fertilizer preparation processes are complex and costly. Summary of the Invention To address these issues, the present invention provides a honeycomb-shaped slow-release fertilizer based on water supply sludge and its preparation method. By optimizing the ratio and molding process of water supply sludge, monoammonium phosphate, attapulgite clay, organic fertilizer, and xanthan gum, and combining physical adsorption with chemical bonding mechanisms, the invention achieves a stable, slow-release of ammonia nitrogen and total phosphorus. The organic fertilizer and attapulgite clay are then used to improve soil structure and promote plant growth.
[0003] The present invention provides a honeycomb slow-release fertilizer based on water supply sludge and a preparation method thereof, which adopts the following technical solutions: In one aspect of the present invention, a honeycomb slow-release fertilizer based on water supply sludge is provided. The honeycomb slow-release fertilizer is formed by mixing water supply sludge and monoammonium phosphate that provide ammonia nitrogen and total phosphorus, attapulgite clay and organic fertilizer that improve soil structure and promote plant growth, and xanthan gum for water retention, and is used for the slow release of ammonia nitrogen and total phosphorus. The organic fertilizer is rich in fulvic acid and has an organic matter content of ≥35%.
[0004] Another aspect of the present invention provides a method for preparing a honeycomb slow-release fertilizer based on water supply sludge, comprising the following steps: Step 1): Collect water sludge, dehydrate it to a moisture content of 30%-50%, crush it to a particle size of <2mm, take 50-150g of the crushed sludge powder, and perform electron irradiation treatment of 1-5kGy to obtain harmless product A; Step 2): The harmless product A obtained in step 1) is placed in a stirring container, 50-150 mL of 0.25% xanthan gum is added, and the mixture is stirred at 30° C. and 200 r / min for 10 minutes, mixed thoroughly, and allowed to stand for 30 minutes to obtain a water-retaining product B; Step 3): According to the physicochemical properties of each component, 10-30g of attapulgite clay and 10-30g of monoammonium phosphate powder (nitrogen content ≥20%, total phosphorus content ≥52%, particle size <2mm) are added to the water-retaining product B prepared in step 2) in sequence, and stirred at 30°C and 200r / min for 30min. Then, 30-90g of organic fertilizer is slowly added and stirring is continued for 30min to obtain a uniformly mixed mixture C; Step 4): Take 150-450g of the mixture C obtained in step 3) and press it into a honeycomb mold (the mold height is 10cm, the diameter is 30cm, and there are cylinders in the mold, the number of cylinders is ≥4, and the cylinder diameter is 3cm) to obtain a water sludge-based honeycomb slow-release fertilizer D.
[0005] Preferably, in step 3), the attapulgite clay is microwave-treated for 8-10 minutes.
[0006] Preferably, in step 3), the monoammonium phosphate and organic fertilizer need to be ground and crushed to a particle size of less than 2 mm.
[0007] Compared with the prior art, the present invention has the following beneficial effects: 1. The honeycomb slow-release fertilizer based on water supply sludge of the present invention realizes the simple and efficient resource utilization of water supply sludge.
[0008] 2. The honeycomb slow-release fertilizer based on water supply sludge of the present invention has excellent slow-release performance of ammonia nitrogen and total phosphorus and a growth-promoting effect on plants.
[0009] 3. The present invention provides a simple and rapid method for preparing slow-release fertilizer. BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Figure 1 The electron microscope images of the microstructure of the honeycomb slow-release fertilizer in Example 1 of the present invention at different magnifications are shown; Figure 2 The ammonia nitrogen (NH4 + ) and total phosphorus (PO4 3- ) sustained-release curve; Figure 3 This is a comparison chart of plant growth indicators (biomass and plant height) after applying the slow-release fertilizer of the present invention in Example 1 of the present invention; Figure 4 This is a diagram of the honeycomb slow-release fertilizer in Example 1 of the present invention and a diagram of its actual application. DETAILED DESCRIPTION
[0011] In order to make the present invention more clear and easy to understand, the present invention is described in detail below with reference to the accompanying drawings and specific embodiments.
[0012] The present invention provides a honeycomb-shaped slow-release fertilizer based on water supply sludge. The fertilizer is formed into a honeycomb by mixing water supply sludge and monoammonium phosphate (MAP) to provide ammonia nitrogen and total phosphorus, attapulgite clay to improve soil structure and promote plant growth, organic fertilizer, and xanthan gum for water retention. The fertilizer is rich in fulvic acid and has an organic matter content of 35% or greater. The slow-release fertilizer is produced by pre-treating the water supply sludge, mixing with xanthan gum as a water-retaining agent, adding the remaining components, and then forming a honeycomb. This slow-release fertilizer combines excellent slow-release properties for ammonia nitrogen and total phosphorus with a plant growth-promoting effect.
[0013] Example 1 The present invention provides a method for preparing a honeycomb slow-release fertilizer based on water supply sludge, comprising the following steps: Step 1): Collect water sludge (physical and chemical indicators as shown in Table 1 include 21% organic matter, 76.3 mg / kg ammonia nitrogen, and 34.0 mg / kg total phosphorus, indicating its potential for resource utilization), dehydrate it to a moisture content of 30% and grind it to a particle size of <2 mm. Weigh 50 g of the ground water sludge powder and perform electron irradiation (dose of 1 kGy, energy of 5 MeV) to obtain a more porous and harmless product A. Step 2): The harmless product A is placed in a stirring container, 50 mL of xanthan gum with a mass fraction of 0.25% is added to the container, and stirred at 30°C and 200 r / min for 10 minutes to fully mix the water sludge powder and the xanthan gum. After standing for 30 minutes, a product B with good water retention is obtained; Step 3): According to the physicochemical properties of each component, 10 g of attapulgite clay after microwave treatment for 8 minutes and 10 g of monoammonium phosphate powder ground to a particle size of <2 mm were added to the product B in sequence, and stirred at 30°C and 200 r / min for 30 minutes. Then, 30 g of organic fertilizer ground to a particle size of <2 mm was slowly added, and stirring was continued for 30 minutes to obtain a uniformly mixed mixture C; Step 4): The mixture C (150 g) obtained in step 3) is pressed into a honeycomb mold (with a height of 10 cm and a diameter of 30 cm, and ≥4 cylinders are provided in the mold and the diameter of the cylinders is 3 cm) to obtain the final product, water sludge-based honeycomb slow-release fertilizer D; Figure 1 The honeycomb slow-release fertilizer shown has a layered structure, which provides a microstructural basis for the slow-release performance of the fertilizer; Figure 2 As shown, the fertilizer has an excellent slow-release performance of 68.8% ammonia nitrogen and 73.6% total phosphorus; Figure 3 、 4 As shown, the final product, sewage sludge-based honeycomb slow-release fertilizer, was applied to the soil surface at a rate of 100 g per pellet at a distance of 10 cm from the roots of the plants (lettuce). The yield of the cultivated plants increased by 2100 g (30 plants) compared to the unfertilized plants.
[0014] Table 1 Physical and chemical indicators of water supply sludge in the embodiment of the present invention
[0015] Example 2 The present invention provides a method for preparing a honeycomb slow-release fertilizer based on water supply sludge, comprising the following steps: Step 1): Collect the water sludge, dehydrate it to a moisture content of 30% and grind it to a particle size of <2 mm. Weigh 100 g of the ground water sludge powder and perform electron irradiation (dose of 1 kGy, energy of 5 MeV) to obtain a product A with higher porosity and harmlessness; Step 2): The harmless product A is placed in a stirring container, 100 mL of xanthan gum with a mass fraction of 0.25% is added into the container, and stirred at 30°C and 200 r / min for 10 minutes to fully mix the water sludge powder and the xanthan gum. After standing for 30 minutes, a product B with good water retention is obtained; Step 3): According to the physicochemical properties of each component, 20 g of attapulgite clay treated with microwaves for 9 minutes and 20 g of monoammonium phosphate powder ground to a particle size of <2 mm were added to the product B in sequence, and stirred at 30°C and 200 r / min for 30 minutes. Then, 60 g of organic fertilizer ground to a particle size of <2 mm was slowly added, and stirring was continued for 30 minutes to obtain a uniformly mixed mixture C; Step 4): The mixture C (300 g) obtained in step 3) is pressed into a honeycomb mold (with a height of 10 cm and a diameter of 30 cm, and ≥4 cylinders are provided in the mold and the diameter of the cylinders is 3 cm) to obtain the final product, water supply sludge-based honeycomb slow-release fertilizer D; the obtained water supply sludge-based honeycomb slow-release fertilizer D is applied to the soil surface at a distance of 10 cm from the roots of the plants (lettuce) at a dosage of 300 g / piece. The cultivated plants have an increased yield of 4204 g (30 plants) compared with the unfertilized plants.
[0016] Example 3 The present invention provides a method for preparing a honeycomb slow-release fertilizer based on water supply sludge, comprising the following steps: Step 1): Collect the water sludge, dehydrate it to a moisture content of 30% and grind it to a particle size of <2 mm. Weigh 150 g of the ground water sludge powder and perform electron irradiation (dose of 1 kGy, energy of 5 MeV) to obtain a product A with higher porosity and harmlessness; Step 2): The harmless product A is placed in a stirring container, 150 mL of xanthan gum with a mass fraction of 0.25% is added to the container, and stirred at 30°C and 200 r / min for 10 minutes to fully mix the water sludge powder and the xanthan gum. After standing for 30 minutes, a product B with good water retention is obtained; Step 3): According to the physicochemical properties of each component, 30 g of attapulgite clay treated with microwaves for 10 min and 30 g of monoammonium phosphate powder ground to a particle size of <2 mm were added to the product B in sequence, and stirred at 30°C and 200 r / min for 30 min. Then, 60 g of organic fertilizer ground to a particle size of <2 mm was slowly added, and stirring was continued for 30 min to obtain a uniformly mixed mixture C; Step 4): The product C (450 g) obtained in step 3) is pressed into a honeycomb mold (with a height of 10 cm and a diameter of 30 cm, and ≥4 cylinders are provided in the mold and the diameter of the cylinders is 3 cm) to obtain the final product, water supply sludge-based honeycomb slow-release fertilizer D; the obtained water supply sludge-based honeycomb slow-release fertilizer D is applied on the soil surface at a dosage of 450 g / piece at a distance of 10 cm from the root of the plant (lettuce). The cultivated plants have an increased yield of 5964 g (30 plants) compared with the unfertilized plants.
[0017] In summary, the slow-release fertilizer of the present invention has excellent slow-release performance of ammonia nitrogen and total phosphorus and a growth-promoting effect on plants. The above is only a preferred embodiment of the present invention, and is not any formal or substantial limitation to the present invention. It should be pointed out that ordinary technicians in this technical field can make several improvements and supplements without departing from the present invention, and these improvements and supplements should also be regarded as the scope of protection of the present invention. Any technician familiar with this profession, without departing from the spirit and scope of the present invention, can make some changes, modifications and equivalent changes made by using the technical content disclosed above, which are equivalent embodiments of the present invention; at the same time, any changes, modifications and evolutions of any equivalent changes made to the above embodiments based on the essential technology of the present invention are still within the scope of the technical solution of the present invention.
Claims
1. A honeycomb slow-release fertilizer based on water supply sludge, characterized in that: The honeycomb slow-release fertilizer is formed by mixing water sludge and monoammonium phosphate that provide ammonia nitrogen and total phosphorus, attapulgite clay and organic fertilizer that improve soil structure and promote plant growth, and xanthan gum for water retention into a honeycomb shape, and is used for the slow release of ammonia nitrogen and total phosphorus; the organic fertilizer is rich in fulvic acid and has an organic matter content of ≥35%.
2. A method for preparing a honeycomb slow-release fertilizer based on water supply sludge according to claim 1, characterized in that: The following steps are involved: Step 1): Collect water sludge, dehydrate it to a moisture content of 30-50%, crush it to a particle size of <2mm, take 50-150g of the crushed sludge powder, and perform electron irradiation treatment to obtain harmless product A; Step 2): The harmless product A obtained in step 1) is placed in a stirring container, 50-150 mL of 0.25% xanthan gum is added, and the mixture is stirred at 30° C. and 200 r / min for 10 minutes, mixed thoroughly, and allowed to stand for 30 minutes to obtain a water-retaining product B; Step 3): According to the physicochemical properties of each component, 10-30g of attapulgite clay and 10-30g of monoammonium phosphate powder are added to the water-retaining product B prepared in step 2) in sequence, and after stirring at 30°C and 200r / min for 30min, 30-90g of organic fertilizer is slowly added and stirring is continued for 30min to obtain a uniformly mixed mixture C; Step 4): Take 150-450g of the mixture C obtained in step 3) and press it into a honeycomb mold to prepare a water supply sludge-based honeycomb slow-release fertilizer D.
3. The method for preparing honeycomb slow-release fertilizer based on water supply sludge according to claim 2, characterized in that: In step 3), the attapulgite clay needs to be microwaved for 8-10 minutes.
4. The method for preparing honeycomb slow-release fertilizer based on water supply sludge according to claim 2, characterized in that: In step 3), the monoammonium phosphate and organic fertilizer need to be ground and crushed to a particle size of less than 2 mm.