Method for regenerating planting soil by dredging silt

Abstract

The present invention relates to a method for regenerating planting soil from dredged silt, comprising the following steps: filtering the dredged silt to reduce its water content and obtain dried silt residue; crushing construction waste with both water absorption and water retention properties, and screening out four main particle size modification materials according to different particle sizes, wherein the particle sizes of the four modification materials are, from small to large, 0.002-0.01 mm, 0.01-0.05 mm, 0.05-0.28 mm, and 0.28-2.00 mm; adding the four particle size modification materials to the silt residue and stirring and mixing to obtain planting adobe soil; adding micro anaerobic compost balls with a slow-release humus function to the planting adobe soil and stirring; and curing the planting adobe soil at room temperature to obtain planting soil. This application has the effect of improving the accuracy of dredged silt particle size modification and ensuring the stability of the humus content in the early stages of regenerating planting soil.

Description

Technical Field

[0001] The present application relates to the technical field of sludge treatment, and in particular to a method for dredging sludge to regenerate planting soil. Background Art

[0002] Bottom sediment pollution is an important factor in river and lake pollution. Dredging will produce a large amount of dredged silt. Ecological dredging is a commonly used engineering method for endogenous pollution control. The resource utilization of dredged silt is the terminal disposal of ecological dredging and a key link restricting the implementation of dredging projects. The abandonment and disorderly landfill of silt will not only cause a waste of land resources, but also easily cause secondary pollution of the environment. The resource utilization of silt is an inevitable choice for sustainable development at this stage and in the future. At present, the resource utilization of dredged silt includes the preparation of building materials, filling materials, planting soil, water storage clay and other directions. River silt is a fine-grained soil that is deposited and enriched with pollutants in a still water and slow-flowing water environment. Its main components are inorganic minerals such as silicate aluminates. Its chemical composition is similar to that of clay. It is rich in nutrients required for plant growth, and the heavy metal content is lower than the standard value. Therefore, the preparation of planting soil is a suitable utilization direction.

[0003] For example, the patent with publication number CN115943869A provides a method for preparing landscaping soil from river silt. The river silt is dehydrated, crushed, and sieved to obtain silt powder. The silt powder is first added with water glass during stirring and stirred for 30 to 50 seconds. Then, a saturated weak acid solution is added and stirred for 60 to 80 seconds to allow the water glass to fully wet the surface of the silt powder. Then, organic acid biocomplex and rice husk carbon are added and stirred at high speed for 80 to 100 seconds to mix them evenly. The mixture is then spread out, air-dried, and cured at room temperature for 24 days to obtain landscaping soil. The shortcomings of this technical solution are that, in order to address the defects of poor texture, poor permeability, and low organic matter content of silt residue, the solution chooses to add a fixed amount of organic acid biocomplex and rice husk carbon at one time for improvement. This results in an insignificant effect on improving the texture and permeability of the regenerated planting soil, poor biodiversity, and a loss of humus in the regenerated product due to the one-time addition of humus supplements. This causes the plants to wilt due to insufficient nutrients required during the growth period.

[0004] For example, the patent with publication number CN116491394A provides a method for preparing planting soil by solidifying and improving silt. The cleaned silt is screened, mechanically crushed, and then pre-dehydrated to obtain pretreated silt; the pretreated silt is mixed with a solidifying matrix and stirred evenly, and then crushed after curing; the crushed particles are collected and mixed with the improved matrix, and after a second curing treatment, regenerated planting soil is obtained. The shortcomings of this solution are: the amount of each material used in the solidifying matrix described in the patent fluctuates within a range, and the amount is not proportioned for specific silt and slag, resulting in an insignificant improvement in the physical properties of the silt and slag; the humus supplement, whose main components are fungus residue and vinegar residue, is added to the silt and slag at one time, and the regenerated product suffers from humus loss, resulting in insufficient nutrients required for the growth period of the plants and a wilting phenomenon.

[0005] For example, patent publication number CN113526822A provides a method for in-situ sludge remediation and sludge planting soil, which involves dehydrating dredged sludge to a moisture content of less than or equal to 60%; crushing the dehydrated sludge into sludge particles; and uniformly mixing the sludge particles with a sludge modifier to produce sludge planting soil. However, this technical solution has the disadvantage of combining river sand, coconut husks, tree branch particles, volcanic rock filter material, and a deodorizer in a fixed ratio and then adding them all at once to the sludge residue to produce the regenerated planting soil. While the soil has a high humus content in the early stages, this humus loss leads to a lack of nutrients for the plants during their growth period, resulting in sludge stagnation.

[0006] According to the standard for Greening Planting Soil (CJT340-2016), dredged silt regenerated planting soil must meet the requirements of pH, salinity, texture, organic matter, soil infiltration rate, and other indicators. However, dredged silt regenerated planting soil faces the following major challenges: (1) The dried dredged silt obtained by dehydration has a high clay content and a low content of silt and sand particles, which is a typical clay soil. Its texture and infiltration rate cannot meet the standard requirements; (2) During the texture improvement process, the amount of improvement material added is fixed, which cannot achieve accurate improvement of soil texture and infiltration rate; (3) After composting, the humus stored in the soil is lost, and its quality is poor in the long term.

[0007] In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a method for dredging silt to regenerate planting soil, aiming to solve the problems in the prior art of humus loss in the soil after composting and the difficulty in accurately improving the infiltration rate and texture of the silt, resulting in the treated silt being unable to meet the requirements of greening planting soil. Summary of the Invention

[0008] In order to solve the problems in the prior art of humus loss in soil after composting and difficulty in accurately improving the infiltration rate and texture of silt, the present application provides a method for dredging silt to regenerate planting soil.

[0009] The present application provides a method for regenerating planting soil from dredged silt using the following technical solutions:

[0010] A method for regenerating planting soil by dredging silt comprises the following steps:

[0011] S1. Filter-pressing the dredged sludge to reduce its water content and obtain dried sludge soil;

[0012] S2. Crushing construction waste with both water absorption and water retention properties, and screening out four main particle size modified materials according to different particle sizes. The particle sizes of the four modified materials are 0.002-0.01mm, 0.01-0.05mm, 0.05-0.28mm, and 0.28-2.00mm, respectively.

[0013] S3, adding the four particle size-modified materials into the silt and slag, stirring and mixing to obtain planting adobe soil;

[0014] S4, adding micro anaerobic compost balls with slow-release humus function into the planting adobe soil and stirring;

[0015] S5. Place the planting adobe soil at room temperature for curing to obtain planting soil.

[0016] By adopting the above technical scheme, the dried dredged silt after filter pressing and dehydration has a high clay content and a low silt and sand content, and the texture and infiltration rate cannot meet the standard requirements. Four types of improved materials are prepared by crushing construction waste, 0.002-0.01mm and 0.01-0.05mm corresponding to two different coarse and fine particle sizes of clay and silt, 0.05-0.28mm corresponding to silt, and 0.28-2.00mm corresponding to silt and sand. When added to the dried slag, it can effectively supplement the clay, silt and sand components in the silt and slag, solve the problem of low accuracy in traditional particle size improvement methods, and on the other hand, effectively solve the problem of the disposal of the two solid wastes; by adding compost balls with slow-release humus function, the problem of having to compost first in the traditional composting regeneration planting soil process is solved, the process time of regeneration planting soil is shortened, and the humus content in the early stage of regeneration planting soil work is guaranteed to be stable.

[0017] Optionally, in step S2, the added mass of the four particle size modifying materials is calculated as follows:

[0018] The modified material with a particle size of 0.002-0.01 mm is called modified material A, the modified material with a particle size of 0.01-0.05 mm is called modified material B, the modified material with a particle size of 0.05-0.28 mm is called modified material C, and the modified material with a particle size of 0.28-2.00 mm is called modified material D;

[0019] Specify the ideal particle size distribution d 10 =0.002mm, d 20=0.01mm, d 30＝ 0.02mm, d 45 =0.05mm, d 60 =0.075mm, d 75 =0.28mm and d 90 =2mm, specified variable d 10 =d1,d 20 =d2,d 30 =d3,d 45 =d4,d 60 =d5,d 75 =d6 and d 90 =d7; measure the d of dried sludge 10 d 30 d 60 d 90 , which is denoted as d 1x d 3x d 5x d 7x ;

[0020] For dried silt residue with different masses m, the corresponding added masses of the four improved materials are m A 、m B 、m C and m D , solve formulas such as (1.1) to (1.5):

[0021]

[0022] Where: w1 = 0.2, w3 = 0.25, w5 = 0.3, w7 = 0.25;

[0023] i=1,3,5,7;

[0024] d1=d0=0.002mm, d8=d7=2mm;

[0025] Add the improved materials A, B, C and D into the dried silt slag according to the obtained masses, stir and mix to obtain planting adobe soil.

[0026] By adopting the above technical solution, the specific mass of the supplementary improvement materials of the four main particle sizes is calculated by the above method, which further improves the accuracy of the sludge and soil improvement. First, the ideal particle size classification d is specified. 10 d 20 d 30 d 45 d 60 d 75 and d 90 , four groups of deviation intervals were divided according to the four main particle size modified materials, and the d of silt residue was measured. 10 d30 d 60 d 90 According to formula (1.1), the deviation of the content of four main particle sizes of silt residue is calculated respectively, where w i The weight values ​​are assigned artificially. The added masses of the improved materials A, B, C, and D are determined according to formulas (1.2) to (1.5).

[0027] Optionally, in step S3, the micro anaerobic composting ball with the function of slow-releasing humus comprises a biological egg ball, a composting layer, a polyethylene microporous membrane and a polyethylene-polypropylene porous shell;

[0028] The bio-egg ball is composed of earthworm eggs wrapped in a polylactic acid membrane, which contains 1 to 2 earthworm eggs. The polylactic acid membrane can be decomposed by earthworms. The compost layer is wrapped around the outside of the bio-egg ball. The compost layer includes anaerobic complex bacteria mainly composed of yeast, crushed materials such as straw and grass, manganese dioxide active catalyst powder, and a small amount of nutrients.

[0029] The polyethylene microporous membrane and the polyethylene-polypropylene porous shell are wrapped in sequence on the outside of the compost layer; the polyethylene microporous membrane can be decomposed by earthworms.

[0030] By adopting the above technical solution, biological egg balls are placed inside the micro anaerobic compost balls. The hatched earthworms can degrade the plastic components in the compost balls and subsequently enter the planting soil, solving the problem that the plastic shell of the compost balls is difficult to degrade after the work is completed, and at the same time replenishing beneficial organisms in the soil.

[0031] Optionally, the method for preparing the biological egg ball is to prepare a PLA solution with a mass fraction of 8% using CHCl3, take 1 to 2 earthworm eggs and place them in the PLA with a mass fraction of 8%, soak them and then take them out with tweezers, repeat 2 to 3 times, then place them on a glass slide and air-dry them at room temperature to obtain the biological egg ball.

[0032] By adopting the above technical solution, biological egg balls that automatically decompose after a certain period of time can be produced; after being loaded into the compost ball, the hatching time of the earthworm eggs is consistent with the end point of anaerobic composting, and the plastic shell of the compost ball can be decomposed and enter the soil to enhance biodiversity, thereby solving the problem of recycling the plastic shell of the compost ball.

[0033] Optionally, the ratio of the additives in the compost layer is as follows: the volume of the mixture of straw and grass particles is 3 to 5 cm 3 , composite bacteria 1~2g / cm 3 , manganese dioxide powder 1~1.2g / kg, trace nutrient mixture (glucose, vitamin B1) 1~2g / cm 3 .

[0034] By adopting the above technical solution, compost materials mainly composed of straw and grass solid waste are added to micro anaerobic composting balls, and catalytic manganese dioxide particles are added to achieve resource utilization of agricultural solid waste such as straw and grass, while ensuring the stability of the anaerobic composting slow release rate.

[0035] Optionally, the method for preparing the micro anaerobic compost balls includes placing a polyethylene microporous membrane on the surface of a porous polyethylene-polypropylene, repeatedly compacting to obtain a composite material, making the composite material into a circular material with a diameter of 1.3 to 1.5 cm, placing the obtained circular material with one side resting on the polyethylene microporous membrane on a round iron ball with a surface temperature of 50 to 60°C, and after softening, laminating and stretching it to a semi-spherical shape to obtain a compost ball shell blank, filling the semi-spherical shell blank with compost filler and biological eggs until dense, and then using another group of shell blanks to cover and form a micro anaerobic compost ball.

[0036] By adopting the above technical solution, the obtained plastic shell has certain strength and toughness, and its durability can be guaranteed under long-term use; and the preparation process will not produce waste due to secondary processing of plastic products.

[0037] Optionally, the construction waste having both water absorption and water retention properties may be porous fired bricks, waste bricks from building demolition, or concrete blocks from building demolition.

[0038] By adopting the above technical solution, the above-mentioned construction waste particles have many edges and corners and a rough surface, and the components contain hardened cement mortar. They have the characteristics of large porosity, high water absorption rate, low bulk density, high crushing index, high surface inertness, and high mud content. The water absorption rate is between 4 and 10%.

[0039] Optionally, in step S1, the dredged sludge is filtered by a filter press device, the filter press device includes a body, the body is provided with a crossbeam, the crossbeam is provided with a filter plate group, the filter plate group is provided with multiple along the length direction of the crossbeam, the filter plate group slides on the crossbeam, and the sliding direction of the filter plate group is the length direction of the crossbeam, the body is provided with a driving member 1, the driving member 1 drives the filter plate group to slide and makes adjacent filter plate groups conflict with each other; the filter plate group is provided with a limit member, and the limit member limits excessive separation of the filter plate group.

[0040] Existing filter presses often need to move the filter plates in sequence to separate adjacent filter plates in order to discharge the sludge from between the adjacent filter plates. The discharge of the sludge is relatively inconvenient. Through the above technical solution, a limiter is provided. When the driving member drives the filter plate group to move and move away from each other, the limiter drives the movement of the adjacent filter plate groups to limit the excessive separation of the adjacent filter plate groups. In this case, the movement of the filter plate group drives the movement of the adjacent filter plate groups in turn, so that moving one filter plate group can move all the filter plate groups and maintain a spacing for discharging the sludge, making the sludge discharge operation more convenient.

[0041] The filter plate of claim 1, wherein the filter plate is secured to a position adjacent to the filter plate and the filter plate is secured to a position adjacent to the filter plate when the filter plate is in a closed position.

[0042] Through the above technical solution, limiting plate one and limiting plate two are set, and filter plate one and filter plate two are connected through limiting plate one, and adjacent filter plate groups are connected through limiting plate two, so that when the staff operates, they can move the outermost filter plate group to separate the adjacent filter plate groups and separate filter plate one and filter plate two, which is convenient for the discharge of sludge after liquid separation and makes the overall operation more convenient.

[0043] Optionally, the body is provided with a second driving member and a rotating rod, the rotating rod is located on the side wall of the body, and the second driving member drives the rotating rod to rotate; the rotating rod is connected to a rotating plate, and the end of the rotating plate away from the rotating rod is connected to a vibration plate, and the vibration plate is provided with a vibration groove, and a side wall of the filter plate located close to the rotating rod is provided with a vibration rod, and the vibration rod slides in the vibration groove.

[0044] Through the above technical solution, a second driving member and a rotating rod are provided, and the rotation of the rotating rod drives the rotation of the rotating plate, and the rotation of the rotating plate causes the vibration plate to move. The movement of the vibration plate causes the two side walls in the extension direction of the vibration trough to continuously contact and drive the filter plate to swing. Due to the presence of the limit member, the filter plate swings and the filter plate group swings together, which is convenient for removing the silt attached to the filter plate group; and the runner rotates when the filter plate group swings, reducing the obstruction to the swing of the filter plate group.

[0045] In summary, this application includes at least one of the following beneficial technical effects:

[0046] 1. This invention adds four types of modifying materials with different main particle sizes to low-organic matter dried sludge and slag, fully replenishing the clay, silt and sand components in the sludge and slag, thus solving the problem of poor accuracy of traditional particle size modification methods;

[0047] 2. The present invention solves the problem of the traditional composting and regeneration of planting soil that requires composting first by adding a micro anaerobic compost ball that can slowly release humus to the regeneration planting adobe soil, shortens the regeneration planting soil process time, and ensures that the humus content in the early stage of the regeneration planting soil is stable;

[0048] 3. The filter press device is provided with a limiter. When the driving member drives the filter plate groups to move and move away from each other, the limiter drives the movement of the adjacent filter plate groups to limit excessive separation of the adjacent filter plate groups. In this case, the movement of the filter plate groups drives the movement of the adjacent filter plate groups in turn, so that moving one filter plate group can move all the filter plate groups and maintain a spacing for discharging sludge, making the sludge discharge operation more convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 A process flow chart for preparing planting soil using dredged silt for this application;

[0050] Figure 2 It is a schematic diagram showing the deviation range of the measured particle size distribution relative to the ideal particle size distribution;

[0051] Figure 3 This is a schematic diagram of the structure of a micro anaerobic composting ball;

[0052] Figure 4 Schematic diagram of the overall structure of the filter press device;

[0053] Figure 5 Schematic diagram of the explosion of filter plate 1;

[0054] Figure 6 for Figure 4 A magnified schematic diagram of point A in the middle;

[0055] Figure 7 Exploded view of the cleaning assembly.

[0056] Explanation of reference numerals: 1. compost ball; 12. biological egg ball; 121. earthworm egg; 122. polylactic acid membrane; 13. compost layer; 14. polyethylene microporous membrane; 15. polyethylene-polypropylene porous shell; 21. body; 22. crossbeam; 23. filter plate group; 231. filter plate 1; 232. filter plate 2; 24. driving member 1; 25. driving plate; 26. feed channel; 27. liquid outlet channel; 28. connecting part; 29. ​​rotor; 210. filter cloth; 211. plate body; 212. filter tank; 213. air inlet channel ; 214, limit member; 2141, limit plate one; 2142, limit plate two; 215, connecting rod one; 216, connecting rod two; 217, sliding bar hole one; 218, sliding bar hole two; 219, rotating rod; 220, rotating plate; 221, vibration plate; 222, vibration groove; 223, vibration rod; 224, cleaning component; 2241, driving member three; 2242, cleaning plate; 225, mounting groove; 226, reset spring; 227, sliding plate; 228, inclined surface; 229, infusion channel; 230, cleaning tube. DETAILED DESCRIPTION

[0057] The following is combined with Figure 1-7 The present application is further described in detail. The present application discloses a method for regenerating planting soil from dredged silt.

[0058] Reference Figure 1 A method for regenerating planting soil from dredged silt comprises the following steps:

[0059] S1, impurity removal and filter press

[0060] First, the dredged sludge is cleaned to remove household garbage such as plastics, cans, and clothes. Then, the dredged sludge is filtered to obtain low-organic matter dried sludge soil with a water content between 40% and 50%.

[0061] S2. Preparation of improved materials

[0062] S2-1. Construction waste with both water absorption and water retention properties is crushed. This waste can be porous sintered bricks, demolition waste bricks, or demolition concrete blocks. After crushing, the waste is screened to produce four main particle sizes of modified materials. The particle sizes of the four modified materials, from smallest to largest, are 0.002-0.01mm, 0.01-0.05mm, 0.05-0.28mm, and 0.28-2.00mm.

[0063] S2-2. Calculate the added mass of the four particle size modifying materials as follows:

[0064] The modified material with a particle size of 0.002-0.01 mm is called modified material A, the modified material with a particle size of 0.01-0.05 mm is called modified material B, the modified material with a particle size of 0.05-0.28 mm is called modified material C, and the modified material with a particle size of 0.28-2.00 mm is called modified material D. The curvature coefficient range of the four modified materials is controlled as follows: 1<C c <3;

[0065] Specify the ideal particle size distribution d 10 =0.002mm, d 20 =0.01mm, d 30＝ 0.02mm, d 45 =0.05mm, d 60 =0.075mm, d 75 =0.28mm and d 90 =2mm, specified variable d 10 =d1,d 20 =d2,d 30 =d3,d 45 =d4,d 60 =d5,d 75 =d6 and d 90 =d7; measure the d of dried sludge 10 d 30 d 60 d 90 , which is denoted as d 1x d 3x d 5x d 7x For dried silt residue with different masses m, the corresponding added masses of the four improved materials are m A 、m B 、m C and m D , solve formulas such as (1.1) to (1.5):

[0066]

[0067] Where: w1 = 0.2, w3 = 0.25, w5 = 0.3, w7 = 0.25;

[0068] i=1,3,5,7;

[0069] d1=d0=0.002mm, d8=d7=2mm;

[0070] m is the mass of silt and debris, in kg;

[0071] m A 、m B 、m C and m DThey are the masses of the four improved materials, in kg.

[0072] First, the ideal particle size classification d is specified 10 d 20 d 30 d 45 d 60 d 75 and d 90 , corresponding to the four main improved materials A, B, C, D, which are divided into d 10 -d 20 d 20 -d 45 d 45 -d 75 and d 75 -d 90 Four groups of intervals, measured d of silt and slag 10 d 30 d 60 d 90 ,like Figure 2 shown.

[0073] It should be noted that in order to facilitate calculation and improve the aesthetics of the formula, the variable d is specified. 10 =d1,d 20 =d2,d 30 =d3,d 45 =d4,d 60 =d5,d 75 =d6 and d 90 =d7, measured d of silt and slag 10 =d 1x , d 30 =d 3x d 60 =d 5x d 90 =d 7x Formula (1.1) is used to calculate the measured value d ix and the corresponding ideal value d i The difference between the two, divided by the length of the corresponding interval, is d ix The corresponding deviation b i .

[0074] In formulas (1.2) to (1.5), b i Divide by b i The accumulation of is used to evaluate the deviation ratio of one set of measured gradation when there is a deviation between multiple sets of measured particle size gradation and the ideal gradation, reflecting the relative degree of deviation. i is the weight value of the four measured particle sizes, among which the particle size <0.075mm is often used to evaluate the quality of soil texture, so d is assigned 5xThe corresponding weight w5 = 0.3. For the silt soil mentioned in this application, the clay content is high d 10 The importance is relatively low, so the remaining weight is selected as w1 = 0.2, and the remaining w3 and w7 are divided equally, that is, w3 = 0.25, w7 = 0.25.

[0075] The four main particle sizes of improved materials correspond to four groups of deviation intervals. The relative deviation degree of their added mass determines the corresponding added mass. After the improved materials are added to the dried sludge and slag, they can cover the particle size of the corresponding deviation interval and bring the particle size gradation of the interval closer to the ideal gradation value, thereby achieving the purpose of improving the particle size gradation of the dried sludge and slag.

[0076] S3. Add the four particle size improvement materials into the silt and slag according to the obtained mass, which can supplement the components of clay particles, silt particles and sand particles. The accuracy of the silt and slag particle size improvement can be achieved after sufficient stirring and mixing to obtain planting adobe soil.

[0077] S4. Quality Improvement

[0078] The micro anaerobic composting balls with slow-release humus function are placed at 10 to 15 per dm 3 Add to the planting adobe soil and stir thoroughly for 1 to 2 hours. Figure 3 The micro anaerobic composting ball 1 includes, from the inside to the outside, a biological egg ball 12, a composting layer 13, a polyethylene microporous membrane 14 and a polyethylene-polypropylene porous shell 15.

[0079] The biological egg ball 12 is composed of earthworm eggs 121 wrapped in a polylactic acid film 122, with a diameter of 2 to 3 mm. It contains 1 to 2 earthworm eggs 121 and can be hatched within 30 to 35 days. The polylactic acid film 122 can be decomposed by earthworms.

[0080] The preparation method of biological egg ball 12 is as follows: prepare a PLA solution with a mass fraction of 8% with CHCl3, take 1 to 2 earthworm eggs 121 and place them in the PLA with a mass fraction of 8%, soak for 20 to 30 seconds, then take them out with tweezers, repeat 2 to 3 times, then place them on a glass slide and air-dry them at room temperature of 25°C to obtain biological egg ball 12.

[0081] The compost layer 13 is wrapped around the outer side of the biological egg ball 12. The compost layer 13 includes anaerobic complex bacteria mainly composed of yeast, crushed straw and grass with a particle size range of 1 to 5 mm, manganese dioxide active catalyst powder and a small amount of nutrients. The volume of the entire compost layer 13 is 3 to 5 cm 3 .

[0082] The proportion of each additive in the compost layer 13 is as follows: the volume of the mixture of straw and grass particles is 3 to 5 cm 3 , composite bacteria 1~2g / cm 3, manganese dioxide powder 1~1.2g / kg, trace nutrient mixture (glucose, vitamin B1) 1~2g / cm 3 .

[0083] The polyethylene microporous membrane 14 and the polyethylene-polypropylene porous shell 15 are wrapped around the outside of the compost layer 13 in sequence. The polyethylene microporous membrane 14 allows a passage radius of 0.01 mm and can be decomposed by earthworms. The polyethylene-polypropylene porous shell 15 has a diameter of 1 to 1.2 cm.

[0084] The preparation method of the micro anaerobic composting ball 1 is as follows: a polyethylene microporous membrane 14 is placed on the surface of a porous polyethylene-polypropylene, and a composite material is obtained by repeated compaction. The composite material is made into a circular material with a diameter of 1.3 to 1.5 cm. The obtained circular material is placed on the upper part of a standard round iron ball (1 to 1.2 cm) with a surface temperature of 50 to 60° C. with one side of the polyethylene microporous membrane 14 in contact. After softening, the material is stretched to a semi-spherical shape to obtain a shell blank of the compost ball 1. After the compost filler and the biological egg ball 12 are filled into the semi-spherical shell blank until dense, another group of shell blanks are used to cover and form the micro anaerobic composting ball 1.

[0085] S5. Place the planting adobe soil at room temperature and cure for 1 day to obtain planting soil.

[0086] Taking the silt produced by river dredging in a certain area of ​​Hangzhou City, Zhejiang Province as an example, its basic properties and particle size distribution in its original state are shown in Tables 1 and 2, and its basic properties after impurity removal and dehydration are shown in Table 3.

[0087] Table 1 - Basic characteristics of dredged sludge

[0088]

[0089] Table 2 - Particle size gradation

[0090] <![CDATA[d 10 ’]]> <![CDATA[d 30 ']]> <![CDATA[d 60 ’]]> <![CDATA[d 90 ’]]> Inhomogeneous Cu Curvature coefficient Cc Clay content / % 0.002 0.011 0.032 0.547 16 0.89 20.12

[0091] Table 3- Basic characteristics of silt and slag

[0092] <![CDATA[Specific gravity G s > <![CDATA[Heavy Υ (kN / m 3 )]]> Initial moisture content / % <![CDATA[Liquid limit w L / %]]> <![CDATA[Plastic limit w P / %]]> <![CDATA[Plasticity index I P > 1.65 12.2 45.3 64.9 22.7 42.2

[0093] The obtained low-organic matter dried silt residue was mixed with four kinds of particle size improvement materials to obtain planting adobe soil. The addition amount of the four kinds of particle size improvement materials was determined as follows:

[0094] Specified standard particle size: d 10 =0.002mm, d 20 =0.01mm, d 30＝ 0.02mm, d 45 =0.05mm, d 60 =0.075mm, d75 =0.28mm and d 90 =2mm, specified variable d 10 =d1,d 20 =d2,d 30 =d3,d 45 =d4,d 60 =d5,d 75 =d6 and d 90 =d7. The d of dried sludge is specified 10 =d 1x d 30 =d 3x d 60 =d 5x d 90 =d 7x According to Table 2, we can know that d 10 =d 1x =0.002, d 30 =d 3x =0.011, d 60 =d 5x =0.032, d 90 =d 7x =0.547, and the added mass of the corresponding four improved materials is solved according to formulas (1.1) to (1.5):

[0095]

[0096] Where: w1 = 0.2, w3 = 0.25, w5 = 0.3, w7 = 0.25;

[0097] i=1,3,5,7;

[0098] d1=d0=0.002mm, d8=d7=2mm.

[0099] According to formula (1.1), the deviation is calculated and b1 = 0, b3 = 0.225, b5 = 0.187, b7 = 0.845. According to formulas (1.2) to (1.5), the addition amount m of the four particle size improvement materials is determined one by one. A 、m B 、m C and m D , take silt m = 1kg for field test, and calculate the addition amount of four particle size improvement materials: m A =0, m B =0.1738kg, m C = 0.1734 kg and m D =0.6528kg.

[0100] The calculated amount was taken and mixed with silt and soil for 1 to 2 hours. After standing and curing for 1 day, the particle size composition was measured as shown in Table 4. The particle sizes were close to the standard values ​​and Cu and Cc met the requirements. It was found that the addition values ​​of the four particle size improvement materials for every 1 kg of low organic matter dried silt and soil were mA = 0, mB = 0.1738 kg, mC = 0.1734 kg and mD = 0.6528 kg.

[0101] Table 4 - Particle size distribution

[0102] <![CDATA[d 10 ']]> <![CDATA[d 30 ']]> <![CDATA[d 60 ']]> <![CDATA[d 90 ’]]> Inhomogeneous Cu Curvature coefficient Cc Clay content / % 0.002 0.023 0.082 1.89 15 1.95 10.12

[0103] The micro anaerobic compost balls 1 with slow-release humus function were mixed with planting adobe soil at a rate of 10 to 15 balls / dm3. After being fully stirred for 1 to 2 hours, they were placed in a 25°C curing box and cured continuously for 7 days. Samples were taken every day to measure the humus content, and the values ​​were recorded as shown in Table 5. The humus content increased slowly in the first two days, suddenly increased on the third day, and then increased evenly to obtain regenerated planting soil.

[0104] The embodiment of the present application also discloses a filter press device for the above-mentioned dehydration and drying of dredged sludge, which solves the problem in the prior art that, since the filter press is generally provided with multiple groups of filter plates, the filter plates need to be moved sequentially after the sludge and liquid are separated, and the sludge between the adjacent filter plates must be moved away from each other before it can be discharged, which reduces the discharge speed of the sludge and affects the filtration efficiency of the dredged sludge.

[0105] See also Figure 4 The filter press device includes a body 21, which is provided with a crossbeam 22, the length direction of which is horizontal. The crossbeam 22 is provided with a filter plate group 23, and multiple filter plate groups 23 are provided along the length direction of the crossbeam 22. The filter plate group 23 slides on the crossbeam 22, and the sliding direction of the filter plate group 23 is the length direction of the crossbeam 22. The body 21 is provided with a driving member 24 and a driving plate 25. The driving plate 25 is located between the driving member 24 and the filter plate group 23, and the driving plate 25 is connected to the filter plate group 23. The driving member 24 is connected to the driving plate 25, and the driving member 24 drives the driving plate 25 to move to push the filter plate group 23 to slide along the length direction of the crossbeam 22 and cause adjacent filter plate groups 23 to conflict with each other. In actual use, the driving member 24 can be a cylinder. Alternatively, the driving member 24 can also be a motor and a screw.

[0106] See also Figure 4 and Figure 5The filter plate assembly 23 includes a first filter plate 231 and a second filter plate 232. The first filter plate 231 is located on the side of the second filter plate 232 away from the drive plate 25. The filter plate assembly 23 is provided with a feed channel 26 and a liquid outlet channel 27. The feed channel 26 passes through the first filter plate 231 and the second filter plate 232, while the liquid outlet channel 27 passes through the first filter plate 231 and the second filter plate 232. The feed channel 26 extends parallel to the length of the crossbeam 22, while the liquid outlet channel 27 extends parallel to the length of the crossbeam 22. Both the first filter plate 231 and the second filter plate 232 are provided with a connecting portion 28. The connecting portion 28 is provided with a rotating wheel 29. The rotating wheel 29 rotates on the connecting portion 28 and contacts the crossbeam 22. The rotation axis of the rotating wheel 29 is horizontal and eccentrically perpendicular to the length of the crossbeam 22.

[0107] Filter plate 232 has the same structure as filter plate 1 231. Filter plate 1 231 includes two filter cloths 210 and a plate body 211 disposed between the filter cloths 210. Filter grooves 212 are located on either side of the plate body 211, and the filter cloths 210 cover the filter grooves 212. Filter plates 1 and 2 are spaced apart. When filter plate 1 231 abuts filter plate 232, sludge flows through the filtration channel into the gap formed by the filter cloths 210 of filter plate 1 231 and filter cloths 210 of filter plate 232. Plate body 211 is provided with an air inlet channel 213, one end of which communicates with the outside and the other end communicates with the filter grooves 212. In actual use, air entering through the air inlet channel 213 pushes the filter cloths 210, helping to squeeze the sludge and discharge the liquid contained therein.

[0108] See also Figure 6The filter plate assembly 23 is provided with a stopper 214, which is used to prevent the filter plate assembly 23 from excessively separating. The stopper 214 includes a stopper plate 1 2141 and a stopper plate 2 2142, which have identical structures. Filter plate 1 231 is provided with a connecting rod 1 215, and filter plate 2 232 is provided with a connecting rod 2 216. Stopper plate 1 2141 is located on the side wall of filter plate 1 231. Stopper plate 1 2141 is provided with a sliding bar hole 1 217. Connecting rod 216 slides in sliding bar hole 1 217, and stopper plate 1 2141 is rotatably connected to connecting rod 1 215. When filter plate 1 231 contacts filter plate 2 232, connecting rod 216 contacts the side wall of sliding bar hole 1 217 near connecting rod 1 215. When filter plate 232 moves away from filter plate 1 231 and drives filter plate 1 231 to move, connecting rod 216 contacts the sidewall of sliding bar hole 1 217 away from connecting rod 1 215. Positioning plate 2142 is located between two adjacent filter plate assemblies 23 and is provided with sliding bar hole 218. Positioning plate 2142 is rotatably connected to connecting rod 216 of one filter plate assembly 23, while connecting rod 1 215 of the other filter plate assembly 23 slides on sliding bar hole 218.

[0109] See also Figure 4 and Figure 7 The body 21 is equipped with a second driving member and a rotating rod 219. The rotating rod 219 is located on the side wall of the body 21. The second driving member is used to drive the rotating rod 219 to rotate. The rotating rod 219 is connected to a rotating plate 220. The end of the rotating plate 220 away from the rotating rod 219 is rotatably connected to a vibration plate 221. The vibration plate 221 has a vibration groove 222. A vibration rod 223 is installed on the side wall of the filter plate 1 231 near the rotating rod 219. The vibration rod 223 slides in the vibration groove 222. In actual use, the second driving member is a motor.

[0110] When the driving member 2 drives the rotating rod 219 to rotate, the rotating rod 219 rotates and drives the rotating plate 220 to rotate. The movement of the rotating plate 220 drives the vibration plate 221 to move and causes the vibration rod 223 to drive the filter plate 1 231 to swing. The limiting member 214 causes the filter plate group 23 to swing together, so as to facilitate the falling off of the silt attached to the filter cloth 210.

[0111] See also Figure 4 and Figure 7A cleaning assembly 224 is located above the filter plate assembly 23. This cleaning assembly 224 is used to clean sludge adhered to the filter cloth 210. The cleaning assembly 224 includes a third driver 2241 and a cleaning plate 2242. The driver 2241 drives the cleaning plate 2242 to move vertically. The cleaning plate 2242 has two mounting slots 225 located on either side of the cleaning plate 2242. A return spring 226 is located at the bottom of the mounting slot 225. A sliding plate 227 is located at the end of the return spring 226 away from the bottom of the mounting slot 225. The elastic force of the return spring 226 restricts the sliding plate 227 from moving toward the bottom of the mounting slot 225. The end of the sliding plate 227 away from the bottom of the mounting slot 225 protrudes from the surface of the cleaning plate 2242. The sliding plate 227 has an inclined surface 228 located at its lower end, extending downward away from the bottom of the mounting slot 225.

[0112] The cleaning plate 2242 is provided with a liquid infusion channel 229, which is used to supply liquid to clean sludge adhered to the filter cloth 210. A cleaning pipe 230 is provided at the bottom of the mounting groove 225, connecting to the liquid infusion channel 229. The sliding plate 227 slides along the cleaning pipe 230, sliding along the length of the cleaning pipe 230. When the sliding plate 227 contacts the bottom of the mounting groove 225, the distance between the end of the cleaning pipe 230 away from the bottom of the mounting groove 225 and the end of the sliding plate 227 away from the bottom of the mounting groove 225 is the same as the distance between the end of the sliding plate 227 away from the bottom of the mounting groove 225. In actual use, the third driving member 2241 is a pneumatic cylinder; alternatively, the third driving member 2241 may be an oil cylinder.

[0113] The working principle of this embodiment is as follows: the driving member 1 24 drives the driving plate 25 to move, separating the mutually conflicting filter plate groups 23 and separating the filter plate 1 231 from the filter plate 2 232, thereby discharging the sludge between the filter plate 1 231 and the filter plate 2 232. The limiting member 214 prevents the filter plate group 23 from separating too far, and also prevents the filter plate 1 231 from separating too far from the filter plate 232. When it is necessary to remove the sludge attached to the filter mesh 210, the driving member 2 drives the rotating rod 219 to rotate. The rotating rod 219 rotates and drives the rotating plate 220 to rotate. The movement of the rotating plate 220 drives the vibration plate 221 to move, causing the vibration rod 223 to swing the filter plate 1 231. The limiting member 214 causes the filter plate group 23 to swing together, facilitating the removal of the sludge attached to the filter mesh 210.

[0114] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A method for regenerating planting soil from dredged silt, characterized by: The following steps are included: S1. Filter-pressing the dredged sludge to reduce its water content and obtain dried sludge soil; S2. Crushing construction waste with both water absorption and water retention properties, and screening out four main particle size modified materials according to different particle sizes. The particle sizes of the four modified materials are 0.002-0.01mm, 0.01-0.05mm, 0.05-0.28mm, and 0.28-2.00mm, respectively. S3, adding the four particle size-modified materials into the silt and slag, stirring and mixing to obtain planting adobe soil; S4, adding the micro anaerobic compost balls (1) with slow-release humus function into the planting adobe soil and stirring; S5, curing the planting adobe soil at room temperature to obtain planting soil; The micro anaerobic composting ball (1) with the function of slow-releasing humus comprises a biological egg ball (12), a composting layer (13), a polyethylene microporous membrane (14) and a polyethylene-polypropylene porous shell (15); The biological egg ball (12) is composed of a polylactic acid film (122) wrapping an earthworm egg (121), which contains 1 to 2 earthworm eggs (121). The polylactic acid film (122) can be decomposed by earthworms. The compost layer (13) is wrapped around the outer side of the biological egg ball (12), and the compost layer (13) includes an anaerobic composite bacteria mainly composed of yeast, a mixture of straw and grass particles, manganese dioxide active catalyst powder and a small amount of nutrient mixture; A polyethylene microporous membrane (14) and a polyethylene-polypropylene porous shell (15) are sequentially wrapped around the outside of the compost layer (13); the polyethylene microporous membrane (14) can be decomposed by earthworms; The preparation method of the biological egg ball (12) is as follows: using CHCl3 to prepare a PLA solution with a mass fraction of 8%, taking 1 to 2 earthworm eggs (121) and placing them in the PLA solution with a mass fraction of 8%, soaking them and then taking them out with tweezers, repeating this process 2 to 3 times, and then placing them on a glass slide and air-drying them at room temperature to obtain the biological egg ball (12); The preparation method of the micro anaerobic composting ball (1) comprises: placing a polyethylene microporous membrane (14) on the surface of a polyethylene-polypropylene porous shell (15), repeatedly compacting to obtain a composite material, making the composite material into a circular material with a diameter of 1.3-1.5 cm, placing the obtained circular material with the polyethylene microporous membrane (14) as the side to be attached to a round iron ball with a surface temperature of 50-60°C, and stretching it after softening to a semi-spherical shape to obtain a compost ball (1) shell blank, filling the compost ball (1) shell blank with a compost layer (13) and a biological egg ball (12) until it is dense, and then using another group of compost ball (1) shell blanks to cover and form the micro anaerobic composting ball (1).

2. The method for regenerating planting soil from dredged silt according to claim 1, characterized in that: In step S2, the calculation method for the added mass of the four particle size modifying materials is as follows: The modified material with a particle size of 0.002~0.01mm is called modified material A, the modified material with a particle size of 0.01~0.05mm is called modified material B, the modified material with a particle size of 0.05~0.28mm is called modified material C, and the modified material with a particle size of 0.28~2.00mm is called modified material D; Specify the ideal particle size distribution d 10 =0.002mm, d 20 =0.01mm, d 30= 0.02mm, d 45 =0.05mm, d 60 =0.075mm, d 75 =0.28mm and d 90 =2mm, the specified variable d 10 = d 1.d 20 = d 2.d 30 = d 3.d 45 = d 4.d 60 = d 5.d 75 = d 6 and d 90 = d 7; Measuring the d of dried silt and soil 10 d 30 d 60 d 90 , which corresponds to d 1x 、 d 3x 、 d 5x 、 d 7x ; For different qualities m The added mass of the four improved materials for the dried silt and soil is m A 、 m B 、 m C and m D , solve formulas such as (1.1) to (1.5): ； in: w 1=0.2, w 3=0.25, w 5=0.3, w 7=0.25; i =1,3,5,7； d 1= d 0=0.002mm, d 8= d 7=2mm; Add the improved materials A, B, C and D into the dried silt slag according to the obtained masses, stir and mix to obtain planting adobe soil.

3. The method for regenerating planting soil from dredged silt according to claim 1, characterized in that: The ratio of each additive in the compost layer (13) is as follows: the volume of the mixture of straw and grass particles is 3~5cm 3 , anaerobic composite bacteria 1~2g / cm 3 , manganese dioxide active catalyst powder 1~1.2g / kg, nutrient mixture 1~2g / cm 3 , the nutrient mixture is glucose and vitamin B1.

4. The method for regenerating planting soil from dredged silt according to claim 1, characterized in that: The construction waste with both water absorption and water retention properties is porous sintered bricks, waste bricks from building demolition or concrete blocks from building demolition.

5. The method for regenerating planting soil from dredged silt according to claim 1, characterized in that: In step S1, the dredged sludge is filtered by a filter press device, the filter press device includes a body (21), the body (21) is provided with a crossbeam (22), the crossbeam (22) is provided with a filter plate group (23), a plurality of filter plate groups (23) are provided along the length direction of the crossbeam (22), the filter plate group (23) slides on the crossbeam (22), and the sliding direction of the filter plate group (23) is the length direction of the crossbeam (22), the body (21) is provided with a driving member (24), the driving member (24) drives the filter plate group (23) to slide and causes adjacent filter plate groups (23) to conflict with each other; the filter plate group (23) is provided with a limiting member (214), and the limiting member (214) limits the excessive separation of the filter plate group (23).

6. The method for regenerating planting soil from dredged silt according to claim 5, characterized in that: The limiting member (214) includes a limiting plate 1 (2141) and a limiting plate 2 (2142), the filter plate group (23) includes a filter plate 1 (231) and a filter plate 2 (232), the filter plate 1 (231) is provided with a connecting rod 1 (215), the filter plate 2 (232) is provided with a connecting rod 2 (216), the limiting plate 1 (2141) is located on the side wall of the filter plate 1 (231), the limiting plate 1 (2141) is provided with a sliding bar hole 1 (217), the connecting rod 2 (2 16) slides on the sliding bar hole 1 (217), the limiting plate 1 (2141) is rotatably connected to the connecting rod 1 (215), and the limiting plate 1 (2141) limits the excessive separation of the filter plate 1 (231) and the filter plate 2 (232); when the filter plate 2 (232) moves in a direction away from the filter plate 1 (231), the connecting rod 2 (216) slides along the extension direction of the sliding bar hole 1 (217), and the limiting plate 1 (2141) is rotated on the connecting rod 1 (215); The second limiting plate (2142) is located between two adjacent filter plate groups (23), and the second limiting plate (2142) is provided with a second sliding bar hole (218). The second limiting plate (2142) is rotatably connected to the second connecting rod (216) of one filter plate group (23), and the first connecting rod (215) of the other filter plate group (23) slides on the second sliding bar hole (218).

7. The method for regenerating planting soil from dredged silt according to claim 6, characterized in that: The machine body (21) is provided with a second driving member and a rotating rod (219), wherein the rotating rod (219) is located on a side wall of the machine body (21), and the second driving member drives the rotating rod (219) to rotate; the rotating rod (219) is connected to a rotating plate (220), and an end of the rotating plate (220) away from the rotating rod (219) is connected to a vibration plate (221), wherein the vibration plate (221) is provided with a vibration groove (222), and a vibration rod (223) is provided on the side wall of the filter plate (231) located on the side close to the rotating rod (219), and the vibration rod (223) slides in the vibration groove (222).

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