Method for preparing green planting soil from bottom mud of aquaculture pond

Abstract

The invention discloses aquaculture pond bottom mud planting soil and a preparation method thereof. The aquaculture pond bottom mud planting soil is prepared from aquaculture pond bottom mud, coconut shreds, vermiculite and perlite. The method has the advantages of short preparation period, better performance than existing green planting soil and the like, and can reduce the stockpiling and disposal burden of bottom mud, reduce the culture non-point source pollution risk and save soil replacement resources.

Description

Technical Field

[0001] This invention belongs to the field of planting soil technology, specifically relating to a method for preparing greening planting soil using mud from the bottom of aquaculture ponds. Background Technology

[0002] The rapid development of aquaculture, while boosting the economy and ensuring food supply, has also led to the accumulation of large amounts of bottom sediment in aquaculture ponds. This sediment mainly originates from feed residues, fish and shrimp feces, dead algae, and flocculent matter, and is characterized by high water content, strong viscosity, and a tendency to emit foul odors. Disturbing or improperly disposing of it can easily release nutrients such as ammonia nitrogen and phosphorus, causing blackening and odor of the water and secondary pollution, affecting the stability of aquaculture water quality and the safety of the surrounding ecological environment. Currently, the removal and disposal of pond sediment mainly involves on-site stockpiling, off-site landfilling, or drying and disposal. However, these methods generally suffer from problems such as large land occupation, high transportation and disposal costs, high risk of leachate overflow, and easy backflow pollution during the rainy season. Furthermore, the high organic matter content, high soluble nitrogen and phosphorus content, and potential exceedances of pathogenic microorganisms and parasite eggs in the sediment limit its direct agricultural use, making it difficult to achieve a balance between reduction, harmlessness, and resource utilization.

[0003] Meanwhile, the demand for imported topsoil continues to grow in urban and landscaping construction, while high-quality topsoil resources are becoming increasingly scarce. The external procurement of topsoil brings negative impacts such as ecological damage and carbon emissions. How to transform aquaculture pond sediment into planting soil that can be directly used for landscaping, achieving "replacing soil with waste and cultivating greenery with sediment," has become an urgent engineering and environmental problem to be solved. Existing research and engineering on the resource utilization of dredged sludge or urban sludge mainly focus on solidification / stabilization, brick-making, or simple composting, but these approaches have two major shortcomings: First, it is difficult to systematically regulate the characteristics of aquaculture pond sediment, such as "high organic matter content, high ammonia odor and volatile reducing substances, fine and dense particles, and high water content." Second, existing methods for preparing planting soil from sediment have problems such as long cycles (composting requires 30-60 days) and arbitrary mixing ratios. The impact of different ratios on soil physicochemical properties and plant growth has not been systematically studied, leading to unstable product performance and hindering the rapid reduction and on-site resource utilization of dredged materials from aquaculture farms.

[0004] Therefore, there is an urgent need for a method to prepare greening planting soil using mud from the bottom of aquaculture ponds, so as to realize the scientific concept, environmental protection needs and industrial value of "using waste to replace soil and using mud to cultivate greenery". Summary of the Invention

[0005] The main objective of this invention is to provide a planting soil for aquaculture pond bottom sediment and its preparation method, which has significant technical advantages such as reducing the burden of bottom sediment storage and disposal, reducing the risk of non-point source pollution from aquaculture, and saving imported soil resources.

[0006] In a first aspect, the present invention provides a planting soil for aquaculture pond bottom mud, which is made from the following raw materials: aquaculture pond bottom mud powder, coconut shreds, vermiculite, and perlite.

[0007] In some implementations, the volume ratio of the aquaculture pond bottom mud powder: the coconut fiber: the vermiculite: the perlite is 4-6:1-3:1-3:0.5-1.5.

[0008] Preferably, the volume ratio of the aquaculture pond bottom mud powder: the coconut fiber: the vermiculite: the perlite is 4-6:1-3:1-3:1.

[0009] More preferably, the volume ratio of the aquaculture pond bottom mud powder: the coconut fiber: the vermiculite: the perlite is 5:1-3:1-3:1.

[0010] Most preferably, the volume ratio of the aquaculture pond bottom mud powder: the coconut fiber: the vermiculite: the perlite is 5:2:2:1.

[0011] Secondly, the present invention provides a method for preparing planting soil from the bottom mud of aquaculture ponds as described in the first aspect, comprising the following steps:

[0012] (1) Dehydration: Dehydrating the mud from the bottom of aquaculture ponds in a centrifuge;

[0013] (2) Sun exposure: Spread the dehydrated bottom mud evenly and expose it to the sun;

[0014] (3) Crushing: Crush the sun-dried bottom mud to obtain bottom mud powder;

[0015] (4) Mixing: Mix the bottom mud powder with coconut shreds, vermiculite and perlite in volume ratio, stir, and ensure that each component is evenly distributed to obtain greening planting soil.

[0016] In some implementation schemes, the dewatering speed in step (1) is 5000-5500 r / min, the moisture content of the pond bottom mud after dewatering is ≤20%, the sun exposure time in step (2) is 5-7 days, the particle size of the bottom mud powder in step (3) is ≤1 cm, and the stirring time in step (4) is 10-15 min.

[0017] Thirdly, the present invention provides the application of the aquaculture pond bottom mud planting soil described in the first aspect and the aquaculture pond bottom mud planting soil prepared by the preparation method described in the second aspect for plant cultivation.

[0018] Compared with the prior art, the advantages of the present invention are:

[0019] 1. The preparation method is simple and the cycle is short (7-10 days), which can realize the rapid reduction of the bottom mud of aquaculture ponds on-site.

[0020] 2. Achieve resource utilization of aquaculture bottom sediment, reduce disposal costs, and the preparation cost (51-64.5 yuan / m³) is far lower than that of commercially available ordinary planting soil (100-200 yuan / m³).

[0021] 3. Through optimized formulation, the planting soil exhibits stable physical and chemical properties, and excellent water retention, air permeability, and slow nutrient release performance.

[0022] 4. Significantly improves plant growth indicators, with seed germination rate and biomass superior to ordinary greening planting soil. Detailed Implementation

[0023] To enable those skilled in the art to better understand the technical solutions of the present invention, some non-limiting embodiments are further disclosed below to provide a more detailed description of the present invention.

[0024] The specific material ratios, process conditions, and results described in this invention are for illustrative purposes only and should not, and will not, limit the invention as described in the claims.

[0025] Experimental Description: Ryegrass was used as the test plant in all examples. The planting environment was a natural open-air environment. The planting containers were seedling pots. Each group had 3 replicates. The test methods were carried out in accordance with "Green Planting Soil" (CJ / T 340-2016) and "Experimental Guide for Plant Physiology".

[0026] The experimental materials are as follows:

[0027] Aquaculture pond bottom mud: Freshwater aquaculture pond bottom mud, containing 15-20g / kg of organic matter, pH 5.0-5.5;

[0028] Coconut flakes: Organic matter ≥90%;

[0029] Vermiculite: particle size 2-5mm, porosity ≥70%;

[0030] Perlite: Particle size 1-3 nm, bulk density 0.1-0.2 g / cm³ 3 .

[0031] Example 1

[0032] Preparation process

[0033] 1. Pretreatment of bottom mud in aquaculture ponds: Dewatering speed 5000 r / min, dewatering to a moisture content of 18%; spread to a thickness of 10 cm, sun-dry for 5 days; after crushing, the particle size of the bottom mud powder is ≤1 mm;

[0034] 2. Mixing ratio: Base clay powder: coconut flakes: vermiculite: perlite = 5:2:2:1 (volume ratio), mix and stir for 10 min;

[0035] Test Results

[0036] - Plant growth indicators: 92% seed germination rate in 7 days, and average plant growth rate of 0.8 cm / day in 30 days;

[0037] - Soil physicochemical properties: pH 5.55, water retention 46%, total porosity 55%;

[0038] - Cost accounting: The cost of preparing 1m³ of planting soil is 51 yuan.

[0039] Example 2

[0040] Preparation process

[0041] 1. Pretreatment of bottom mud in aquaculture ponds: Dewatering speed 5000 r / min, dewatering to a moisture content of 18%; spread to a thickness of 10 cm, sun-dry for 5 days; after crushing, the particle size of the bottom mud powder is ≤1 mm;

[0042] 2. Mixing ratio: Base clay powder: coconut flakes: vermiculite: perlite = 5:1:3:1 (volume ratio), mix and stir for 10 minutes;

[0043] Test Results

[0044] - Plant growth indicators: 86% seed germination rate in 7 days, and average plant growth rate of 0.65 cm / day in 30 days;

[0045] - Soil physicochemical properties: pH 5.42, water retention 49%, total porosity 58%;

[0046] - Cost accounting: The cost of preparing 1m³ of planting soil is 47 yuan.

[0047] Example 3

[0048] Preparation process

[0049] 1. Substrate pretreatment: Dewater at 5000 r / min until moisture content is 18%; spread to a thickness of 10cm and sun-dry for 5 days; after crushing, the particle size of the substrate powder should be ≤1mm;

[0050] 2. Mixing ratio: Base clay powder: coconut flakes: vermiculite: perlite = 5:3:1:1 (volume ratio), mix and stir for 15 minutes;

[0051] Test Results

[0052] - Plant growth indicators: 83% seed germination rate in 7 days, and average plant growth rate of 0.58 cm / day in 30 days;

[0053] - Soil physicochemical properties: pH 5.63, water retention 42%, total porosity 52%;

[0054] - Cost accounting: The cost of preparing 1m³ of planting soil is 55 yuan.

[0055] Comparative Example 1

[0056] Preparation process

[0057] Based on Example 1, no coconut fiber, vermiculite, or perlite were added after the bottom mud pretreatment; only the bottom mud powder was used as the planting soil.

[0058] Test Results

[0059] - Plant growth indicators: Seed germination rate of 52% in 7 days, average plant growth rate of 0.25cm / day in 30 days;

[0060] - Soil physicochemical properties: pH 5.38, water retention 28%, total porosity 32%;

[0061] It is evident that without additives, the soil has poor aeration and water retention, making it difficult to meet the needs of plant growth.

[0062] Comparative Example 2

[0063] Sample source

[0064] Commercially available ordinary planting soil for municipal greening (price: 150 yuan / m³);

[0065] Test Results

[0066] - Plant growth indicators: 55% seed germination rate in 7 days, and average plant growth rate of 0.30 cm / day in 30 days;

[0067] - Soil physicochemical properties: pH 5.80, water retention 40%, total porosity 40%;

[0068] It is evident that the planting soil of Example 1 of this invention is superior to commercially available products in terms of plant growth indicators (germination rate, growth rate, etc.) and soil physicochemical properties (water retention rate, total porosity, etc.), and its cost is only about 1 / 3 of that of commercially available products.

[0069] Finally, it should be noted that the above examples are merely a few specific embodiments of the present invention. Obviously, the present invention is not limited to the above embodiments and many variations are possible. All variations that can be directly derived or conceived by those skilled in the art from the disclosure of the present invention should be considered within the scope of protection of the present invention.

Claims

1. An aquaculture pond bottom mud soil seedling bed, characterized by, The aquaculture pond bottom mud planting soil is made of the following raw materials: aquaculture pond bottom mud powder, coconut fiber, vermiculite and perlite.

2. The aquaculture pond bottom mud planting soil according to claim 1, characterized in that, The volume ratio of the aquaculture pond bottom mud powder, the coconut fiber, the vermiculite and the perlite is 4-6:1-3:1-3:0.5-1.

5.

3. The aquaculture pond bottom mud soil of claim 2, wherein, The volume ratio of the aquaculture pond bottom mud powder, the coconut fiber, the vermiculite and the perlite is 4-6:1-3:1-3:

1.

4. The aquaculture pond bottom mud soil of claim 3, wherein, The volume ratio of the aquaculture pond bottom mud powder, the coconut fiber, the vermiculite and the perlite is 5:1-3:1-3:

1.

5. The aquaculture pond bottom mud soil of claim 3, wherein, The volume ratio of the aquaculture pond bottom mud powder, the coconut fiber, the vermiculite and the perlite is 5:2:2:

1.

6. The preparation method of the aquaculture pond bottom mud planting soil according to any one of claims 1-5, comprising the following steps: (1) dehydration: dehydrating the aquaculture pond bottom mud in a centrifuge; (2) exposure: laying the dehydrated bottom mud and exposing it to the sun; (3) crushing: crushing the bottom mud after exposure to obtain bottom mud powder; (4) mixing: mixing the bottom mud powder with coconut fiber, vermiculite and perlite according to the volume ratio, stirring and ensuring uniform distribution of each component, thereby obtaining the green planting soil.

7. The production method according to claim 6, wherein In the step (1), the dehydration rotation speed is 5000-5500 r / min, and the water content of the pond bottom mud after dehydration is ≤20%; in the step (2), the exposure time is 5-7 days; in the step (3), the particle size of the bottom mud powder is ≤1 cm; and in the step (4), the stirring time is 10-15 min.

8. The application of the aquaculture pond bottom mud planting soil according to any one of claims 1-5 or the aquaculture pond bottom mud planting soil prepared by the preparation method of claim 6 or 7 in plant planting.