A drainage gradient dynamic adsorption organic matter and heavy metal blocking water filtration bird habitat brick and its preparation method

Abstract

The present invention relates to the technical field of preparation of bird perch bricks, specifically a drainage gradient dynamic adsorption of organic matter and heavy metal blocking water filtration bird perch brick and its preparation method, the preparation method comprising: S1. demolding the photocatalytic purification layer, biological filtration layer, and adsorption stabilization layer after forming, and performing anti-seepage treatment on the remaining surfaces except the upper surface of each brick body; S2. splicing in the order of photocatalytic purification layer, biological filtration layer, and adsorption stabilization layer from top to bottom, accurately docking the ceramic tube buckles of each layer, and splicing the three layers of bricks into an integral ecological combination brick, thus obtaining a drainage gradient dynamic adsorption of organic matter and heavy metal blocking water filtration bird perch brick. The present invention can effectively treat pollutants flowing into the brick body through the synergistic effect of gradient pores, the large pores on the surface intercept large particle pollutants, the pores in the biological filtration layer adsorb decomposed organic matter, and the adsorption stabilization layer fixes dissolved pollutants, such as heavy metal ions.

Description

Technical Field

[0001] The present invention relates to the technical field of preparation of bird perch bricks, specifically a drainage gradient dynamic adsorption of organic matter and heavy metal retardation filtration bird perch brick and its preparation method, involving the use of solid waste such as fly ash, slag, potassium-zinc complex metallurgical dust and other materials to prepare an ecological combination bird perch brick with photocatalytic self-cleaning, gradient pore interception of pollutants, and directional micro-pressure diversion characteristics. The technical solution of the bird perch brick is to achieve functional optimization with the help of a pH response mechanism through an innovative physical and chemical combination of materials and a three-layer distribution and diversion assembly structure. The combination brick is mainly used in the special geographical environment where birds inhabit fragile ecological lakes and wetlands in the north. The ecological combination brick realizes the integrated functions of purification of rainwater + bird droppings mixture, physical interception of pollutants during infiltration, and adsorption of heavy metal ions. This combination brick has good advantages for water environment restoration in some areas represented by the Wulansuhai Wetland. Background Art

[0002] Located in Urad Front Banner, Bayannur City, Inner Mongolia, Wulansuhai Lake is the largest freshwater lake in the Yellow River Basin and a vital wetland ecosystem. It plays a crucial role in regulating the Yellow River's water flow, purifying its water quality, and preventing ice and flooding. It serves as a confluence of multiple ecological functions in northern my country. Furthermore, Wulansuhai Lake is a key habitat along a migratory bird route, hosting millions of birds of over 200 species and breeding each year.

[0003] However, the special properties of Wulansuhai Lake have led to a series of environmental problems, mainly reflected in the fact that the water replenishment of Wulansuhai Lake mainly comes from the drainage of the Bayannur Hetao Irrigation District. Specifically, after the Yellow River water passes through the main canal to irrigate the Hetao Irrigation District for agriculture, the excess water in the cultivated land (this part of the water is rich in fertilizers and other substances) is collected through the drainage area to the main drainage, and then the main drainage transports these excess polluted water to Wulansuhai Lake. After being collected by Wulansuhai Lake, it is discharged into the Yellow River. Wulansuhai Lake has gradually transformed from a "stinking lake" to an ecological wetland with relatively beautiful scenery. However, the special properties of Wulansuhai Lake determine the natural fragility of its ecological village. With the increase of bird habitats, the accumulation of bird droppings is washed into the lake by rainwater, and the degree of eutrophication increases. In fact, the impact of bird droppings on ordinary lakes can be ignored, but Wulansuhai Lake itself is the drainage lake of the Hetao Irrigation District. The ecology is fragile, and the impact of bird droppings after a large number of bird habitats is more prominent.

[0004] In addition, as the amount of water supplied by the Yellow River to the Hetao Irrigation District decreased, the Wulansuhai Wetland was caught in the double dilemma of water quality deterioration and habitat degradation due to industrial and agricultural non-point source pollution, reduced water inflow into the lake, and increased concentrations of various substances such as heavy metals after agricultural irrigation drainage entered the lake. The excessive nitrogen and phosphorus concentrations caused eutrophication of the water body.

[0005] Since the water source of Wulansuhai comes from the main drainage canal of the Hetao Irrigation District, the water quality is complicated. After years of environmental governance, it has achieved certain results. At present, Wulansuhai wetland is a relatively concentrated typical wetland system in central Inner Mongolia. However, the ecology of the Wulansuhai area is still very fragile, with a large concentration of birds. A large amount of bird droppings has a certain impact on the fragile ecosystem of Wulansuhai. The excrement contained in the droppings directly enters the Wulansuhai water body with surface rainwater and surface water, resulting in patchy pollution areas in the fragile ecological zone of Wulansuhai. Therefore, it is necessary to carry out targeted harmless collection and treatment of bird droppings in the special ecological wetland area of ​​Wulansuhai, and to develop adaptable Wulansuhai bird habitat bricks. The present invention fully understands the characteristics of representative bird droppings in Wulansuhai, and invents a harmless bird habitat brick body. Non-toxic and harmless minerals and various materials are selected. Even after 10 years, when the brick body reaches its life limit, it can be crushed and reused, without causing secondary pollution to the water and soil environment.

[0006] After long-term observation and a large number of preliminary tests, it was found that laying composite bricks has great advantages. It can also attract birds to roost by changing the surface shape in the later stage, and at the same time, it can better sewer polluted water bodies. Secondly, the use of three-layer composite bricks + micro-pressure diversion clay pipes can effectively control the water permeability and intensity of each layer, and adopt appropriate filtration mechanisms to effectively adsorb organic matter in stages and layers, thereby improving the interception efficiency of pollutants and solving problems such as low adsorption capacity and easy desorption after saturation. In addition, material recycling after the service life is reached is easier and simpler than ordinary brick materials. Summary of the Invention

[0007] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a drainage gradient dynamic adsorption organic matter and heavy metal blocking water filtration bird habitat brick and its preparation method. In order to better and more environmentally friendly solve the bird habitat environmental problems in the ecologically fragile area of ​​Wulansuhai Lake, the present invention innovatively adopts a three-layer distribution and diversion assembly structure to combine bricks. The pore size of each layer of bricks is different, from top to bottom, they are large pores, medium pores, and small pores, forming a three-layer gradient pore structure design. The three-layer pore structure will carry out graded treatment of pollutants, and has the functions of intercepting solid particles, adsorbing colloidal organic matter, and adsorbing heavy metal ions respectively. The ecological combination brick designed by the present invention has the functions of dynamic adsorption and self-cleaning. The surface of the brick is loaded with TiO2@wheat husk photocatalytic material, which can degrade organic matter under sunlight and delay pore clogging. In addition, modified attapulgite embedded with pH-sensitive hydrogel microspheres is used in the biological filtration layer and the adsorption stabilization layer, which can be used as a pH-responsive dynamic adsorption material to release Ca when the brick body is in an acidic environment. 2+ Replace the adsorbed heavy metals, expand in alkaline environment to expose adsorption sites, increase PO4 3-Adsorption capacity. Traditional adsorbents dispersed within the bricks are difficult to effectively recover. By adding magnetic biochar to the adsorption stabilization layer, the adsorbent can be quickly recovered using external magnetic separation equipment. The three-layer brick structure eliminates the need for complete replacement during maintenance, reducing the cost of manual cleaning or replacement. Furthermore, the bricks can be recycled after disposal.

[0008] The research and development ideas and structural diagram of the present invention are shown in the attached Figure 9 and attached Figure 10 shown.

[0009] To achieve the above object, the present invention provides the following technical solutions:

[0010] A drainage gradient dynamic adsorption organic matter and heavy metal blocking water filtration bird habitat brick, comprising a photocatalytic purification layer, a biological filtration layer, and an adsorption stabilization layer;

[0011] The functions of each component are as follows: the base slurry is made of industrial solid wastes such as fly ash, blast furnace slag, potassium-zinc complex metallurgical dust and mud as the main raw materials, which replaces traditional cement and reduces carbon emissions by more than 80%. The initial pore structure is formed by adding hemp fiber and wheat husks to provide physical support for the subsequent functional layer. As the matrix material of the composite brick, the above solid waste is activated by sodium hydroxide and water glass alkali to form a geopolymer skeleton to provide overall mechanical strength. The macroporous structure in the photocatalytic purification layer can intercept suspended particles washed down by rainwater, which can reduce the difficulty of subsequent treatment. The TiO2@wheat husk composite material can excite titanium dioxide nanoparticles under ultraviolet irradiation, and photocatalytically degrade large particles on the surface of the brick to form organic matter. The biological filtration layer is a mesoporous structure, which mainly intercepts soluble organic matter and colloidal particles, and converts NH 4+ Converted to NO3 - The adsorption stabilization layer has a microporous structure. By adding zeolite and attapulgite to form a geopolymer network, heavy metal ions and difficult-to-degrade pollutants are encapsulated, deeply purifying the water inside the brick and stabilizing the overall structure.

[0012] The biological filter layer comprises the following components by mass: 50-55 parts of base slurry, 25-30 parts of modified attapulgite, 10-15 parts of carbonized rice husk powder, 3-5 parts of waste eggshell powder, and 5-8 parts of sodium alginate-bentonite composite gel;

[0013] The modified attapulgite comprises the following raw materials in parts by mass: 100-110 parts of attapulgite, 5-8 parts of epoxypropyltrimethylammonium chloride, 10-15 parts of sodium hydroxide solution, 300 parts of deionized water, 10-15 parts of acrylic acid, 3-5 parts of chitosan, and 2-4 parts of Fe3O4 nanoparticles.

[0014] Preferably, the raw materials of the sodium alginate-bentonite composite gel include the following components in parts by weight: 3-4 parts of sodium alginate, 5-8 parts of calcium chloride powder, 6-8 parts of bentonite, and 200 parts of deionized water; the sodium alginate-bentonite composite gel is prepared by the following steps:

[0015] S111. Sodium alginate was placed in a magnetic stirrer, and 100 parts of deionized water was added. The mixture was stirred in a water bath at 60°C for 2 hours to obtain a transparent adhesive solution. Bentonite was then added to the magnetic stirrer. The magnetic stirrer speed was adjusted to 800 rpm. The mixture was stirred at high speed while adding bentonite for 30 minutes. After stirring, the mixture was moved to an ultrasonic instrument and sonicated for 10 minutes to break up bentonite agglomerates and form a homogeneous suspension.

[0016] S112. Calcium chloride powder was dissolved in 100 parts of deionized water to prepare a crosslinking solution. The homogeneous suspension in step S111 was added dropwise to the crosslinking solution using a syringe. The droplets formed gel balls with a diameter of 2-4 mm at the moment of contact and were allowed to solidify for 30 min.

[0017] S113. Rinse the gel three times with deionized water, and dry the washed gel in a drying oven at 60°C for 12 h to obtain a sodium alginate-bentonite composite gel.

[0018] Specifically, the sodium alginate is in powder form with a particle size of 80-100 mesh.

[0019] Specifically, the calcium chloride is in the form of white granules.

[0020] Specifically, the bentonite is in powder form with a particle size of 400-500 mesh.

[0021] Preferably, the modified attapulgite is prepared by the following steps:

[0022] S121. Add epoxypropyltrimethylammonium chloride to a magnetic stirrer, add 200 parts of deionized water, and stir magnetically until completely dissolved. Adjust the pH to 9.0 with 1 mol / L NaOH solution, add attapulgite to the prepared solution, and transfer it to an ultrasonic instrument. Ultrasonic dispersion is carried out at a frequency of 40 kHz for 10 minutes. Then, the mixture is transferred to a microwave reactor, the power is set to 500 W and the temperature is 60°C. After microwave irradiation for 3 minutes, the mixture is transferred to a centrifuge and the speed is adjusted to 5000 rpm. Centrifuge for 5 minutes, wash with deionized water three times until neutral, and then dry in a drying oven at 60°C for 12 hours to obtain epoxypropyltrimethylammonium chloride-grafted attapulgite.

[0023] S122. Acrylic acid and chitosan were added to a magnetic stirrer, followed by 100 parts of deionized water. The mixture was stirred for 2 h until completely dissolved. The mixture was then transferred to an ultrasonicator, and Fe3O4 nanoparticles were added. Ultrasonic dispersion was performed at 40 kHz for 30 min. Nitrogen was introduced into the solution for 30 min and then placed under a microscope at 360 nm and 10 mW / cm 2 Irradiate under UV light for 2 h to form pH-sensitive hydrogel microspheres;

[0024] S123. The pH-sensitive hydrogel microspheres obtained in step S122 were placed in a magnetic separation rack for magnetic separation, washed three times with deionized water, freeze-dried for 24 h, and stored sealed and protected from light;

[0025] S124. The attapulgite grafted with epoxypropyltrimethylammonium chloride obtained in step S121 and the pH-sensitive hydrogel microspheres obtained in step S123 are put into a three-dimensional mixer at a ratio of 9:1, the speed is adjusted to 30 rpm and low-speed mixing is carried out for 15 minutes, a 5% sodium alginate solution is prepared, and magnetic stirring is carried out for 20 minutes until it becomes transparent. The solution is evenly sprayed onto the surface of the mixture with a sprayer at a spraying amount of 10 ml / 100 g. The treated mixture is spread flat on a tray and placed in a forced air drying oven at 60°C for 2 hours to obtain modified attapulgite.

[0026] Preferably, the method for preparing the biological filtration layer comprises the following steps:

[0027] S11. The modified attapulgite, carbonized rice husk powder, and discarded eggshell powder were placed in a blender, the blender speed was adjusted to 200 rpm, and dry mixed for 2 min. The base slurry was then added to the mixture, the blender speed was adjusted to 60 rpm, and stirred at low speed for 5 min. The sodium alginate-bentonite composite gel was slowly added to the blender, the blender speed was adjusted to 120 rpm, and stirred at medium speed for 3 min.

[0028] S12. The mold is cleaned and sprayed with a silicone solvent-based release agent. 20 mm diameter ceramic tubes are embedded above and below the mold. The surfaces of the ceramic tubes are drilled, wrapped with a layer of gauze, and filled with hemp fibers. The mixture obtained in step S11 is then filled into the mold and vibrated and compacted. An acrylic anti-seepage liquid is sprayed on all surfaces except the top surface to form an 80 mm thick biofiltration layer.

[0029] Specifically, the waste eggshell powder is in powder form with a particle size of 500-550 meshes.

[0030] Specifically, the carbonized rice husk powder has a particle size of 25-40 mesh.

[0031] Specifically, the attapulgite is in powder form with a particle size of 200-300 meshes.

[0032] Specifically, the functions of each material in the biological filtration layer are as follows: Attapulgite can only adsorb cations and has a weak adsorption capacity for anions. After modification, the attapulgite is grafted with epoxypropyltrimethylammonium chloride, so that the modified attapulgite also has a certain adsorption capacity for anions. In addition, the modified attapulgite is further processed by adding pH-sensitive hydrogel microspheres to achieve pH dynamic responsive adsorption. Under acidic conditions, the gel microspheres expand and release Ca 2 + , can replace the adsorbed heavy metals, neutralize acidity, and prevent soil acidification. Under alkaline conditions, the gel microspheres shrink to enhance the adsorption capacity of phosphate ions, expose the modified attapulgite cation adsorption sites, enhance the coordination bond, and adsorb NH 4+ , Pb 2+ Carbonized rice husk powder has a specific surface area greater than or equal to 300m² / g, which can intercept organic matter through physical adsorption, and contains silanol (Si-OH) on the surface, which can inhibit the erosion of acidic substances on bricks by maintaining the pH value. In addition, the rough surface forms capillary channels, which cooperates with the pores of the base slurry to improve the water conduction efficiency. Waste eggshell powder can provide Ca 2+ , released Ca 2+ With PO4 3- The combination forms hydroxyapatite, which fixes phosphorus. The sodium alginate-bentonite composite gel forms a three-dimensional network structure, optimizing the pore structure and preventing the loss of effective ingredients. The negatively charged surface of the bentonite absorbs cationic pollutants through electrostatic interaction.

[0033] Preferably, the raw materials of the photocatalytic purification layer include the following components in parts by mass: 60-65 parts of base slurry, 15-20 parts of TiO2@wheat husks, 20-30 parts of rice husk ash, and 10-15 parts of expanded perlite powder.

[0034] Preferably, the photocatalytic purification layer is prepared by the following steps:

[0035] S31. The TiO2@ wheat husk, rice husk ash, expanded perlite powder was placed in a blender, the blender speed was adjusted to 200 rpm, dry mixed for 5 min, then the base slurry was added, the blender speed was adjusted to 500 rpm, and wet mixed for 10 min until the slurry was uniform without agglomeration;

[0036] S32. Clean the mold and spray a silicone solvent-based release agent. Pre-buried Φ20mm ceramic tubes under the mold, drilled the surface of the ceramic tubes, and wrapped the surface of the ceramic tubes with a layer of gauze to prevent mortar from clogging the pores. The interior of the ceramic tubes was filled with hemp silk for further purification. The mixture obtained in step S31 was filled into the mold and vibrated to compact it. Six 20mm deep retention ditches were pressed out on the upper surface using a mold to form a 50mm thick primary photocatalytic purification layer.

[0037] S33. Except for the upper surface, the remaining surfaces were sprayed with acrylic acid anti-seepage liquid, dried at 50 ° C for 2 hours, and then sprayed with 365nm, intensity 30mW / cm 2 The UV lamp was irradiated for 48 hours to obtain a photocatalytic purification layer.

[0038] Specifically, the rice husk ash is in the form of black powder with a particle size of 30-40 mesh.

[0039] Specifically, the expanded perlite powder is in powder form with a particle size of 100-200 meshes.

[0040] Specifically, the functions of each material in the photocatalytic purification layer are as follows: TiO2@wheat husk mainly improves the photocatalytic efficiency. After the wheat husk is degraded, pores are formed inside the slurry. The porous structure and high specific surface area of ​​the wheat husk can provide a uniform loading platform for TiO2 nanoparticles, reduce agglomeration, increase the exposure of active sites, and thus improve the efficiency of the photocatalytic reaction. The carbonaceous components in the wheat husk can serve as an electron transfer medium. The porosity and surface functional groups (such as hydroxyl and carboxyl) of the wheat husk can adsorb organic pollutants (such as formaldehyde, phenol, etc.) in water or air, enriching them near the TiO2 active sites, shortening the photochemical degradation path, and improving the overall purification efficiency. Rice husk ash provides active sites and adsorption capacity. Rich in inorganic components such as silica, potassium, and phosphorus, its porous structure can adsorb pollutants such as heavy metal ions, creating an enriched environment for photocatalytic reactions and improving purification efficiency. Furthermore, the microporous structure of rice husk ash serves as a carrier for the photocatalyst, promoting the dispersion of active components and preventing aggregation. Furthermore, the metal oxides in rice husk ash may participate in redox reactions, creating a synergistic effect with the photocatalyst and enhancing free radical generation. Expanded perlite, with its porous properties and high specific surface area, provides a stable loading platform for the photocatalyst, increasing the exposure of active sites. Its tubular or spherical morphology also improves mass transfer efficiency. The chemical inertness of expanded perlite reduces photocatalyst loss during the reaction, extending the material's lifespan and enhancing photocatalytic stability. The combined use of rice husk ash and expanded perlite exhibits a synergistic enhancement mechanism: after pollutants are adsorbed by the rice husk ash, the expanded perlite-loaded photocatalyst rapidly degrades them.

[0041] Preferably, the preparation method of TiO2@wheat husk comprises the following steps:

[0042] S311. The wheat husks were soaked in deionized water and ultrasonically cleaned for 20 minutes to remove surface dust and impurities. The husks were then placed in a drying oven and dried at 60°C for 12 hours. After drying, the husks were crushed into 0.5-1 mm particles, passed through a 20-mesh sieve, and placed in a crucible. The crucible was placed in a muffle furnace and heated at 5°C / min to 400°C under a nitrogen atmosphere. The mixture was kept at this temperature for 1 hour and then naturally cooled to room temperature to obtain carbonized wheat husks.

[0043] S312. 100 parts of anhydrous ethanol were placed in a magnetic stirrer, 10 parts of tetrabutyl titanate were added, the magnetic stirrer speed was adjusted to 800 rpm, magnetic stirring was performed for 30 min, 3 parts of 10% citric acid was mixed with 10 parts of deionized water and added dropwise to the magnetic stirrer, stirring was continued for 2 h, and the pH value of the sol was adjusted to 2.5-3.0 to obtain a titanium dioxide sol;

[0044] S313. The carbonized wheat husks prepared in step S311 are immersed in the titanium dioxide sol obtained in step S312 at a solid-to-liquid ratio of 1:10. The husks are then treated in an ultrasonic cleaner for 30 minutes to promote penetration of the sol into the pores of the rice husks. The ultrasonically treated material is then transferred to a vacuum drying oven and dried at 60°C for 12 hours to remove any residual solvent. This step is repeated twice to obtain the loaded wheat husks.

[0045] S314. Place the loaded wheat husk obtained in step S313 into a muffle furnace, heat it to 350°C at a rate of 2°C / min, keep it at that temperature for 2 hours, and cool it naturally to room temperature to obtain a TiO2@wheat husk composite material.

[0046] Preferably, the raw materials of the adsorption stabilization layer include the following components in parts by weight: 20-25 parts of zeolite powder, 15-20 parts of biochar, 15-20 parts of modified attapulgite, and 40-50 parts of base slurry; the preparation method of the adsorption stabilization layer includes the following steps:

[0047] S41. The biochar was placed in a magnetic stirrer and an FeCl3 solution was added to the mixture at a solid-to-liquid ratio of 1:5. The stirrer was adjusted to 60°C and magnetic stirring was performed for 6 hours. The biochar was then dried in a drying oven at 105°C for 12 hours to obtain the iron-loaded biomass. The biochar was then placed in a ceramic crucible with a lid, sealed with aluminum foil, and heated directly to 500°C in a muffle furnace for 1 hour. The biochar was then rinsed three times with deionized water to obtain the magnetic biochar.

[0048] S42. Zeolite powder, magnetic biochar, and modified attapulgite were placed in a blender and dry-mixed for 5 minutes until uniform. The base slurry was then added to the blend in three portions. The stirring speed was gradually increased from 60 rpm to 120 rpm and then to 180 rpm for a total of 8 minutes.

[0049] S43. Clean the mold and spray a silicone oil solvent-based release agent. Pre-embed Φ20mm ceramic tubes above and below the mold. Drill holes on the surface of the ceramic tubes, wrap a layer of gauze on the surface of the ceramic tubes, and fill the inside of the ceramic tubes with hemp silk for further purification. Fill the mold with the mixture obtained in step S42, vibrate and compact it, and spray the remaining surfaces except the top surface with an acrylic anti-seepage liquid to form a 120mm thick adsorption stabilization layer.

[0050] Specifically, the functions of each material in the adsorption stabilization layer are as follows: zeolite powder has ion exchange adsorption function, and the silicon-aluminum skeleton structure of zeolite has a negatively charged surface, which captures NH 4+ , K + , Pb 2+ The uniform pores of zeolite powder can selectively adsorb small molecular pollutants. Magnetic biochar can be pyrolyzed to form honeycomb pores, which can adsorb organic pollutants and hydrophobic heavy metals (such as Cd 2+ ), and the oxygen-containing functional groups (-COOH, -OH) on the surface of magnetic biochar promote the oxidative degradation of pollutants.

[0051] Preferably, the raw materials of the base slurry include the following components in parts by mass: 40-45 parts of fly ash, 25-30 parts of blast furnace slag, 10-15 parts of potassium-zinc complex metallurgical dust, 3-5 parts of hemp fiber, 8-15 parts of metakaolin, and 8-10 parts of water glass; the base slurry is prepared by the following steps:

[0052] S21. The potassium-zinc complex metallurgical sludge was mixed with 5% citric acid solution at a solid-liquid ratio of 1:5, stirred at 300-400 r / min at room temperature for 30-60 min to remove soluble contaminants attached to the surface, rinsed with deionized water 1-2 times, heated to 60-80°C, and stirred for 60-70 min. After rinsing with deionized water 5 times, the mixture was placed in a microwave reactor with a microwave power of 500 W. The mixture was stirred at 60°C for 30 min, and then vacuum filtered. The filtered residue was washed with deionized water until neutral, and dried at 60°C to obtain the treated potassium-zinc complex metallurgical sludge.

[0053] S22. The hemp fibers were cut into 3-5 mm short fibers, soaked in a constant temperature water bath with a 3% NaOH solution at a solid-to-liquid ratio of 1:10, and stirred at 60°C for 2 h. The fibers were then washed with deionized water until neutral and dried in a dryer at 60°C to obtain the treated hemp fibers.

[0054] S23. A base-activated solution was prepared by mixing water glass and 8 mol / L NaOH solution in a volume ratio of 3:1. The mixture was stirred on a magnetic stirrer for 30 min at 500 rpm. The SiO2 / Na2O molar ratio was determined to a modulus of 1.3. The resulting base-activated solution was transferred to a sealed polyethylene bottle.

[0055] S24. The potassium-zinc complex metallurgical dust mud treated in step S21 is put into a blender with fly ash, blast furnace slag, metakaolin and the hemp fiber treated in step S22 for dry mixing. The blender speed is adjusted to 60 rpm and the stirring time is 3 min. The alkali-activated solution obtained in step S23 is then added to the mixed dry materials in stages. In the first stage, the liquid temperature of the alkali-activated solution is preheated to 40°C, 70% of the total amount of the alkali activator is slowly poured in, and the blender is stirred at 30 rpm for 5 min to form a uniform paste; in the second stage, the blender speed is increased to 60 rpm, 20% of the total amount of the alkali activator is added, and the mixture is stirred for 10 min; in the third stage, 10% of the total amount of the alkali activator is added, and the blender is stirred at a high speed of 120 rpm for 2 min. It is observed that there is no bubble accumulation on the surface of the slurry, and the basic slurry is obtained.

[0056] Specifically, the role of each material in the base slurry is as follows: fly ash with a particle size of 325 mesh is an active admixture, which provides volcanic ash activity as a siliceous-aluminous material, reacts with calcium hydroxide produced by the hydration reaction to form hydrated calcium silicate gel, and enhances the later strength of the slurry. Fly ash particles can fill pores, increase the density of the slurry, improve impermeability and durability, reduce the water demand of the slurry, improve workability, and inhibit water seepage and segregation. Blast furnace slag with a particle size of 60-100 mesh is suitable for enhancing sulfate corrosion resistance in the Wulansuhai wetland area, recycling solid waste, reducing carbon emissions from cement production, reducing hydration heat, reducing shrinkage cracks, and combining with alkaline activators to release active ingredients such as CaO and SiO2 to form high-strength hydration products. Potassium-zinc complex metallurgical dust mud provides K + 、Zn 2+ Elements such as iron and steel participate in hydration reactions or microstructure optimization, fix heavy metal ions through physical encapsulation and chemical chelation, reduce leaching toxicity, and achieve heavy metal solidification. Hemp fiber forms a three-dimensional network structure in the slurry, inhibiting crack propagation and improving crack resistance and impact resistance. Metakaolin with a particle size of 4000 mesh has volcanic ash activity. After high-temperature calcination, it forms amorphous SiO2 and Al2O3, accelerating the hydration reaction and improving early strength. Ultrafine particles fill pores, optimize the slurry microstructure, and reduce shrinkage. Water glass and sodium hydroxide work synergistically to create an alkaline environment, activate the potential activity of fly ash and slag, promote geopolymerization reactions, and form a stable silicate network structure.

[0057] A method for preparing a drainage gradient dynamic adsorption organic matter and heavy metal blocking water filtration bird habitat brick, used for preparing the drainage gradient dynamic adsorption organic matter and heavy metal blocking water filtration bird habitat brick, comprising the following steps:

[0058] S1. After the photocatalytic purification layer, biological filtration layer, and adsorption stabilization layer are formed, they are demoulded. Except for the upper surface of each brick layer, the remaining surfaces are treated for anti-seepage;

[0059] S2. The bricks are spliced ​​in the order of photocatalytic purification layer, biological filtration layer and adsorption stabilization layer from top to bottom. The ceramic tube buckles of each layer are precisely docked and the three layers are spliced ​​into a whole ecological combination brick, thus obtaining the drainage gradient dynamic adsorption of organic matter and heavy metal blocking water filtration bird habitat brick.

[0060] Compared with the prior art, the present invention has the following beneficial effects:

[0061] 1. The present invention prepares three layers of bricks by pressing and splicing them together. The bricks are designed with large pores, medium pores and small pores from top to bottom, and the pore structure is diversified. The pollutants flowing into the bricks can be effectively treated through the synergistic effect of gradient pores. The large pores on the surface intercept large particles of pollutants, the medium pores in the biological filtration layer adsorb and decompose organic matter, and the adsorption stabilization layer fixes dissolved pollutants, such as heavy metal ions.

[0062] 2. The photocatalytic purification layer is loaded with TiO2@wheat husk photocatalytic material, which enables large-diameter particulate pollutants intercepted by the macropores to decompose into organic matter under sunlight, filtering to the lower layer of the brick body and delaying pore clogging. TiO2@wheat husk mainly improves photocatalytic efficiency. After the wheat husk is degraded, pores are formed within the slurry. The porous structure and high specific surface area of ​​the wheat husk can provide a uniform loading platform for TiO2 nanoparticles, reduce agglomeration, increase the exposure of active sites, and thus improve the efficiency of the photocatalytic reaction. The carbonaceous components in the wheat husk can serve as an electron transport medium. The porosity and surface functional groups of the wheat husk can adsorb organic pollutants in water or air, enriching them near the TiO2 active sites, shortening the photochemical degradation path, and improving the overall purification efficiency.

[0063] 3. The brick's biological filtration layer and adsorption stabilization layer use modified attapulgite with added pH-sensitive hydrogel microspheres, which can achieve dynamic adsorption and self-cleaning functions. Attapulgite has a high specific surface area and rich pore structure, which can produce a certain adsorption effect on cations. Grafting epoxypropyltrimethylammonium chloride onto the attapulgite gives the attapulgite cation exchange capacity and certain antibacterial properties, which can enable it to adsorb negatively charged ions such as phosphates and organic anions, thereby enhancing the purification effect of the biological filtration layer. The pH-sensitive hydrogel microspheres can dynamically adjust the function of the combined brick when the environmental pH changes. Under acidic conditions, the sensitive hydrogel microspheres expand and release Ca 2+ Replace the adsorbed heavy metals. Under alkaline conditions, the sensitive hydrogel microspheres expand to expose the adsorption sites, the coordination bonds are strengthened, and the PO4 3- adsorption.

[0064] 4. The adsorption and filtration layer uses magnetic biochar as an admixture, loaded with ferroferric oxide nanoparticles, which has a magnetic response function and can be directionally recovered through an external magnet. The bricks can be broken and recycled, and the bricks do not need to be replaced as a whole after they are saturated with adsorption. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Figure 1 This is a process flow chart for preparing the bird habitat bricks with gradient dynamic adsorption of organic matter and heavy metal retardation and filtration according to the present invention;

[0066] Figure 2 This is a process flow chart for preparing the biological filtration layer of the present invention;

[0067] Figure 3 This is a process flow chart for preparing the sodium alginate-bentonite composite gel of the present invention;

[0068] Figure 4 This is a flow chart of the preparation process of the modified attapulgite of the present invention;

[0069] Figure 5 This is a flow chart of the preparation process of the basic slurry of the present invention;

[0070] Figure 6 This is a flow chart of the preparation process of the photocatalytic purification layer of the present invention;

[0071] Figure 7 This is a flow chart of the preparation process of TiO2@wheat husk of the present invention;

[0072] Figure 8 This is a flow chart of the preparation process of the adsorption stabilization layer of the present invention;

[0073] Figure 9 This is a diagram showing the research and development ideas of the bird habitat bricks for the present invention, which can dynamically adsorb organic matter and block heavy metals to filter water;

[0074] Figure 10 This is a schematic diagram of the structure of the bird habitat brick that can dynamically adsorb organic matter and block heavy metals to filter water. DETAILED DESCRIPTION

[0075] The present invention will be described clearly and completely below in conjunction with the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0076] See also Figure 1-10 , the present invention provides a technical solution:

[0077] Example 1

[0078] A drainage gradient dynamic adsorption of organic matter and heavy metal blocking and filtration bird habitat brick:

[0079] First, the base slurry, sodium alginate-bentonite composite gel, modified attapulgite, TiO2@wheat husk, biological filtration layer, photocatalytic purification layer, and adsorption stabilization layer were prepared:

[0080] The base slurry is prepared by the following steps:

[0081] S21. 1000 g of potassium-zinc complex metallurgical sludge was mixed with 5% citric acid solution at a solid-liquid ratio of 1:5, stirred at 300 r / min at room temperature for 30 min to remove soluble contaminants attached to the surface, rinsed once with deionized water, heated to 60°C, and stirred for 60 min. After rinsing five times with deionized water, the mixture was placed in a microwave reactor, the microwave power was adjusted to 500 W, stirred at 60°C for 30 min, and then vacuum filtered. The filtered residue was washed with deionized water until neutral and dried at 60°C to obtain the treated potassium-zinc complex metallurgical sludge.

[0082] S22. 300 g of hemp fiber was cut into 3 mm short fibers, soaked in a constant temperature water bath with a 3% NaOH solution at a solid-to-liquid ratio of 1:10, and stirred at 60°C for 2 h. The fibers were then washed with deionized water until neutral and dried in a dryer at 60°C to obtain the treated hemp fibers.

[0083] S23. 800 g of water glass and 8 mol / L NaOH solution were mixed in a volume ratio of 3:1 to prepare an alkaline excitation solution, which was stirred in a magnetic stirrer for 30 min at a speed of 500 rpm. The SiO2 / Na2O molar ratio was determined to a modulus of 1.3, and the resulting alkaline excitation solution was transferred to a sealed polyethylene bottle;

[0084] S24. The potassium-zinc complex metallurgical sludge treated in step S21 is dry-mixed with 4000 g of fly ash, 2500 g of blast furnace slag, 800 g of metakaolin, and the hemp fiber treated in step S22 in a blender. The blender speed is adjusted to 60 rpm for 3 min. The alkali-activated solution obtained in step S23 is then added to the mixed dry materials in stages. In the first stage, the alkali-activated solution is preheated to 40° C., 70% of the total amount of the alkali activator is slowly poured into the blender, and the blender is stirred at 30 rpm for 5 min to form a uniform paste. In the second stage, the blender speed is increased to 60 rpm, 20% of the total amount of the alkali activator is added, and the blender is stirred for 10 min. In the third stage, 10% of the total amount of the alkali activator is added, and the blender is stirred at 120 rpm for 2 min. No bubbles are observed on the surface of the slurry to obtain a base slurry.

[0085] Among them, the particle size of fly ash is 325 mesh; the particle size of blast furnace slag is 60 mesh; and the particle size of metakaolin is 4000 mesh.

[0086] Sodium alginate-bentonite composite gel is prepared by the following steps:

[0087] S111. 300g of sodium alginate was placed in a magnetic stirrer, and then 10,000g of deionized water was added and stirred in a 60°C water bath for 2h to obtain a transparent adhesive solution. Bentonite was then added to the magnetic stirrer, and the magnetic stirrer speed was adjusted to 800rpm. 600g of bentonite was added while stirring at high speed for 30min. After stirring, the mixture was moved to an ultrasonic instrument and sonicated for 10min to break up bentonite agglomerates to form a homogeneous suspension.

[0088] S112 500g of calcium chloride powder was dissolved in 10000g of deionized water to prepare a crosslinking solution. The homogeneous suspension in step S111 was added dropwise to the crosslinking solution with a syringe. The droplets formed gel balls with a diameter of 2mm at the moment of contact and were allowed to solidify for 30min.

[0089] S113. Rinse the gel three times with deionized water, and dry the washed gel in a drying oven at 60°C for 12 h to obtain a sodium alginate-bentonite composite gel;

[0090] Among them, sodium alginate is in powder form with a particle size of 80 mesh; calcium chloride is in white granular form; and bentonite is in powder form with a particle size of 400 mesh.

[0091] Modified attapulgite is prepared by the following steps:

[0092] S121. 500g of epoxypropyltrimethylammonium chloride was added to a magnetic stirrer, 20,000g of deionized water was added, and magnetic stirring was performed until completely dissolved. The pH was adjusted to 9.0 with 1mol / LNaOH solution. 10,000g of attapulgite was added to the prepared solution and transferred to an ultrasonic instrument. Ultrasonic dispersion was performed at a frequency of 40kHz for 10min, and then transferred to a microwave reactor, the power was set to 500W and the temperature was 60°C. After microwave irradiation for 3min, the mixture was transferred to a centrifuge, the speed was adjusted to 5000rpm, and the mixture was centrifuged for 5min. The mixture was washed with deionized water 3 times until neutral, and then dried in a drying oven at 60°C for 12h to obtain epoxypropyltrimethylammonium chloride-grafted attapulgite.

[0093] S122. 1000 g of acrylic acid and 300 g of chitosan were added to a magnetic stirrer, followed by 10,000 g of deionized water. The mixture was stirred magnetically for 2 h until completely dissolved. The mixture was then transferred to an ultrasonicator, and 200 g of Fe3O4 nanoparticles were added. Ultrasonic dispersion was performed at 40 kHz for 30 min. Nitrogen was introduced into the solution for 30 min and then placed under a microscope at 360 nm and 10 mW / cm 2Irradiate under UV light for 2 h to form pH-sensitive hydrogel microspheres;

[0094] S123. The pH-sensitive hydrogel microspheres obtained in step S122 were placed in a magnetic separation rack for magnetic separation, washed three times with deionized water, freeze-dried for 24 h, and stored sealed and protected from light;

[0095] S124. The attapulgite grafted with epoxypropyltrimethylammonium chloride obtained in step S121 and the pH-sensitive hydrogel microspheres obtained in step S123 are put into a three-dimensional mixer at a ratio of 9:1, the speed is adjusted to 30 rpm and low-speed mixing is carried out for 15 minutes, a 5% sodium alginate solution is prepared, and magnetic stirring is carried out for 20 minutes until it becomes transparent. The solution is evenly sprayed onto the surface of the mixture with a sprayer at a spraying amount of 10 ml / 100 g. The treated mixture is spread flat on a tray and placed in a forced air drying oven at 60°C for 2 hours to obtain modified attapulgite.

[0096] The preparation method of TiO2@wheat husk comprises the following steps:

[0097] S311. The wheat husks were soaked in deionized water and ultrasonically cleaned for 20 minutes to remove surface dust and impurities. The husks were then placed in a drying oven and dried at 60°C for 12 hours. After drying, the husks were crushed into 0.5 mm particles, passed through a 20-mesh sieve, placed in a crucible, and placed in a muffle furnace. The temperature was raised to 400°C at 5°C / min under a nitrogen atmosphere, maintained for 1 hour, and then naturally cooled to room temperature to obtain carbonized wheat husks.

[0098] S312. 10000g of anhydrous ethanol was placed in a magnetic stirrer, 1000g of tetrabutyl titanate was added, the magnetic stirrer speed was adjusted to 800rpm, magnetic stirring was performed for 30min, 300g of 10% citric acid was mixed with 1000g of deionized water and added dropwise to the magnetic stirrer, stirring was continued for 2h, and the pH value of the sol was adjusted to 2.5 to obtain a titanium dioxide sol;

[0099] S313. The carbonized wheat husks prepared in step S311 are immersed in the titanium dioxide sol obtained in step S312 at a solid-to-liquid ratio of 1:10. The husks are then treated in an ultrasonic cleaner for 30 minutes to promote penetration of the sol into the pores of the rice husks. The ultrasonically treated material is then transferred to a vacuum drying oven and dried at 60°C for 12 hours to remove any residual solvent. This step is repeated twice to obtain the loaded wheat husks.

[0100] S314. Place the loaded wheat husk obtained in step S313 into a muffle furnace, heat it to 350°C at a rate of 2°C / min, keep it at that temperature for 2 hours, and cool it naturally to room temperature to obtain a TiO2@wheat husk composite material.

[0101] The preparation method of the biological filter layer comprises the following steps:

[0102] S11. 2500g of modified attapulgite, 1000g of carbonized rice husk powder, and 300g of discarded eggshell powder were placed in a blender, the blender speed was adjusted to 200rpm, and dry mixed for 2min. 5000g of the base slurry was then added to the mixture, the blender speed was adjusted to 60rpm, and stirred at low speed for 5min. 500g of sodium alginate - bentonite composite gel was slowly added to the blender, the blender speed was adjusted to 120rpm, and stirred at medium speed for 3min.

[0103] S12. The mold was cleaned and sprayed with pure silicone oil solution. 20 mm diameter ceramic tubes were embedded above and below the mold. The tubes were drilled and covered with a layer of gauze. The interior of the tubes was filled with hemp silk and further purified. The mixture obtained in step S11 was filled into the mold and vibrated and compacted. Except for the top surface, the remaining surfaces were sprayed with acrylic waterproof coating to form an 80 mm thick biofiltration layer.

[0104] Among them, the waste eggshell powder is in powder form with a particle size of 500 mesh; the carbonized rice husk powder has a particle size of 25 mesh; and the attapulgite is in powder form with a particle size of 200 mesh.

[0105] The photocatalytic purification layer is prepared by the following steps:

[0106] S31. 1500gTiO2@ wheat husk, 2000g rice husk ash, 1000g expanded perlite powder was placed in a blender, the blender speed was adjusted to 200rpm, dry mixed for 5min, then 6000g of base slurry was added, the blender speed was adjusted to 500rpm, wet mixed for 10min until the slurry was uniform without agglomeration;

[0107] S32. Clean the mold and spray it with pure silicone oil solution. Pre-buried Φ20mm ceramic tubes under the mold, drilled the surface of the ceramic tubes, and wrapped the surface of the ceramic tubes with a layer of gauze to prevent mortar from clogging the pores. The inside of the ceramic tubes was filled with hemp silk for further purification. The mixture obtained in step S31 was filled into the mold and vibrated and compacted. Six 20mm deep water retention ditches were pressed out of the mold on the upper surface to form a 50mm thick primary photocatalytic purification layer.

[0108] S33. Except for the upper surface, the rest of the surface is sprayed with acrylic waterproof coating, dried at 50℃ for 2h, and then sprayed with 365nm and 30mW / cm 2 Irradiate with UV light for 48 hours to obtain a photocatalytic purification layer;

[0109] Among them, rice husk ash is in black powder form with a particle size of 30 mesh; expanded perlite powder is in powder form with a particle size of 100 mesh.

[0110] The method for preparing the adsorption stabilization layer comprises the following steps:

[0111] S41. 1500 g of biochar was placed in a magnetic stirrer and an FeCl3 solution was added to the mixture at a solid-to-liquid ratio of 1:5. The stirrer was adjusted to 60°C and magnetic stirring was performed for 6 h. The biochar was then dried in a drying oven at 105°C for 12 h to obtain the iron-loaded biomass. The biochar was then placed in a ceramic crucible with a lid, sealed with aluminum foil, and heated directly to 500°C in a muffle furnace for 1 h. The biochar was then rinsed three times with deionized water to obtain the magnetic biochar.

[0112] S42. 2000 g of zeolite powder, the magnetic biochar obtained in step S41, and 1500 g of modified attapulgite were placed in a blender and dry-mixed for 5 min until uniform. A total of 4000 g of the base slurry was added thereto in three portions. The stirring speed was increased in stages from 60 rpm to 120 rpm and then to 180 rpm for a total of 8 min.

[0113] S43. Clean the mold and spray it with pure silicone oil solution. Pre-buried Φ20mm ceramic tubes above and below the mold are drilled, wrapped with a layer of gauze, and filled with hemp inside the ceramic tube for further purification. Fill the mold with the mixture obtained in step S42, vibrate and compact it, and spray the remaining surfaces with acrylic waterproof coating except the upper surface to form a 120mm thick adsorption stabilization layer.

[0114] The preparation of the drainage gradient dynamic adsorption organic matter and heavy metal blocking water filtration bird habitat brick includes the following steps:

[0115] S1. After the photocatalytic purification layer, biological filtration layer, and adsorption stabilization layer are formed, they are demoulded. Except for the upper surface of each brick layer, the remaining surfaces are treated for anti-seepage;

[0116] S2. Attach the bricks in the order of photocatalytic purification layer, biological filtration layer, and adsorption stabilization layer from top to bottom. Precisely connect the ceramic tube clips of each layer to form a complete ecological composite brick. This is the drainage gradient dynamic adsorption of organic matter and heavy metal retardation and filtration bird habitat brick. The brick density is 1500 kg / m³. The side length and volume of the three layers are:

[0117] Photocatalytic purification layer: 0.4×0.4×0.05=0.008m³;

[0118] Biological filter layer: 0.4×0.4×0.08=0.0128m³;

[0119] Adsorption stabilization layer: 0.4×0.4×0.12=0.0192m³.

[0120] Example 2

[0121] A drainage gradient dynamic adsorption of organic matter and heavy metal blocking and filtration bird habitat brick:

[0122] First, the base slurry, sodium alginate-bentonite composite gel, modified attapulgite, TiO2@wheat husk, biological filtration layer, photocatalytic purification layer, and adsorption stabilization layer were prepared:

[0123] The base slurry is prepared by the following steps:

[0124] S21. 1500 g of potassium-zinc complex metallurgical dust was mixed with 5% citric acid solution at a solid-liquid ratio of 1:5, stirred at 400 r / min at room temperature for 60 min to remove soluble contaminants attached to the surface, rinsed twice with deionized water, heated to 80°C, and stirred for 70 min. After rinsing with deionized water five times, the mixture was placed in a microwave reactor, the microwave power was adjusted to 500 w, stirred at 60°C for 30 min, and then vacuum filtered. The filtered residue was washed with deionized water until neutral and dried at 60°C to obtain the treated potassium-zinc complex metallurgical dust;

[0125] S22. 500 g of hemp fiber was cut into 5 mm short fibers, soaked in a constant temperature water bath with a 3% NaOH solution at a solid-to-liquid ratio of 1:10, and stirred at 60°C for 2 h. The fibers were then washed with deionized water until neutral and dried in a dryer at 60°C to obtain the treated hemp fibers.

[0126] S23. 1000g of water glass and 8mol / L NaOH solution were mixed in a volume ratio of 3:1 to prepare an alkaline excitation solution. The solution was stirred on a magnetic stirrer for 30min at a speed of 500rpm. The SiO2 / Na2O molar ratio was determined to a modulus of 1.3. The resulting alkaline excitation solution was transferred to a sealed polyethylene bottle.

[0127] S24. The potassium-zinc complex metallurgical dust treated in step S21 is placed in a blender with 4500 g of fly ash, 3000 g of blast furnace slag, 1500 g of metakaolin, and the hemp fiber treated in step S22 for dry mixing. The blender speed is adjusted to 60 rpm for 3 min. The alkali-activated solution obtained in step S23 is then added to the mixed dry materials in stages. In the first stage, the alkali-activated solution is preheated to 40° C., 70% of the total amount of the alkali activator is slowly poured into the blender, and the blender is stirred at 30 rpm for 5 min to form a uniform paste. In the second stage, the blender speed is increased to 60 rpm, 20% of the total amount of the alkali activator is added, and the blender is stirred for 10 min. In the third stage, 10% of the total amount of the alkali activator is added, and the blender is stirred at 120 rpm for 2 min. No bubbles are observed on the surface of the slurry to obtain the base slurry.

[0128] Among them, the particle size of fly ash is 325 mesh; the particle size of blast furnace slag is 100 mesh; and the particle size of metakaolin is 4000 mesh.

[0129] Sodium alginate-bentonite composite gel is prepared by the following steps:

[0130] S111. 400g of sodium alginate was placed in a magnetic stirrer, and then 10,000g of deionized water was added and stirred in a water bath at 60°C for 2h to obtain a transparent adhesive solution. Bentonite was then added to the magnetic stirrer, and the magnetic stirrer speed was adjusted to 800rpm. 800g of bentonite was added while stirring at high speed for 30min. After stirring, the mixture was moved to an ultrasonic instrument and sonicated for 10min to break up bentonite agglomerates to form a homogeneous suspension.

[0131] S112 800g of calcium chloride powder was dissolved in 10000g of deionized water to prepare a crosslinking solution. The homogeneous suspension in step S111 was added dropwise to the crosslinking solution with a syringe. The droplets formed gel balls with a diameter of 4mm at the moment of contact and were allowed to solidify for 30min.

[0132] S113. Rinse the gel three times with deionized water, and dry the washed gel in a drying oven at 60°C for 12 h to obtain a sodium alginate-bentonite composite gel;

[0133] Among them, sodium alginate is in powder form with a particle size of 100 mesh; calcium chloride is in white granular form; and bentonite is in powder form with a particle size of 500 mesh.

[0134] Modified attapulgite is prepared by the following steps:

[0135] S121. 800g of epoxypropyltrimethylammonium chloride was added to a magnetic stirrer, 20,000g of deionized water was added, and magnetic stirring was performed until completely dissolved. The pH was adjusted to 9.0 with 1mol / LNaOH solution. 11,000g of attapulgite was added to the prepared solution and transferred to an ultrasonic instrument. Ultrasonic dispersion was performed at a frequency of 40kHz for 10min, and then transferred to a microwave reactor, the power was set to 500W and the temperature was 60°C. After microwave irradiation for 3min, the mixture was transferred to a centrifuge, the speed was adjusted to 5000rpm, and the mixture was centrifuged for 5min. The mixture was washed with deionized water 3 times until neutral, and then dried in a drying oven at 60°C for 12h to obtain epoxypropyltrimethylammonium chloride-grafted attapulgite.

[0136] S122. 1500 g of acrylic acid and 500 g of chitosan were added to a magnetic stirrer, followed by 10,000 g of deionized water. The mixture was stirred magnetically for 2 h until completely dissolved. The mixture was then transferred to an ultrasonicator, and 400 g of Fe3O4 nanoparticles were added. Ultrasonic dispersion was performed at 40 kHz for 30 min. Nitrogen was introduced into the solution for 30 min and then placed at 360 nm, 10 mW / cm 2 Irradiate under UV light for 2 h to form pH-sensitive hydrogel microspheres;

[0137] S123. The pH-sensitive hydrogel microspheres obtained in step S122 were placed in a magnetic separation rack for magnetic separation, washed three times with deionized water, freeze-dried for 24 h, and stored sealed and protected from light;

[0138] S124. The attapulgite grafted with epoxypropyltrimethylammonium chloride obtained in step S121 and the pH-sensitive hydrogel microspheres obtained in step S123 are put into a three-dimensional mixer at a ratio of 9:1, the speed is adjusted to 30 rpm and low-speed mixing is carried out for 15 minutes, a 5% sodium alginate solution is prepared, and magnetic stirring is carried out for 20 minutes until it becomes transparent. The solution is evenly sprayed onto the surface of the mixture with a sprayer at a spraying amount of 10 ml / 100 g. The treated mixture is spread flat on a tray and placed in a forced air drying oven at 60°C for 2 hours to obtain modified attapulgite.

[0139] The preparation method of TiO2@wheat husk comprises the following steps:

[0140] S311. The wheat husks were soaked in deionized water and ultrasonically cleaned for 20 minutes to remove surface dust and impurities. The husks were then placed in a drying oven and dried at 60°C for 12 hours. After drying, the husks were crushed into 1 mm particles, passed through a 20-mesh sieve, placed in a crucible, and placed in a muffle furnace. The temperature was increased to 400°C at 5°C / min under a nitrogen atmosphere. The mixture was kept at this temperature for 1 hour and then naturally cooled to room temperature to obtain carbonized wheat husks.

[0141] S312. 10000g of anhydrous ethanol was placed in a magnetic stirrer, 1000g of tetrabutyl titanate was added, the magnetic stirrer speed was adjusted to 800rpm, magnetic stirring was performed for 30min, 300g of 10% citric acid was mixed with 1000g of deionized water and added dropwise to the magnetic stirrer, stirring was continued for 2h, and the pH value of the sol was adjusted to 3.0 to obtain a titanium dioxide sol;

[0142] S313. The carbonized wheat husks prepared in step S311 are immersed in the titanium dioxide sol obtained in step S312 at a solid-to-liquid ratio of 1:10. The husks are then treated in an ultrasonic cleaner for 30 minutes to promote penetration of the sol into the pores of the rice husks. The ultrasonically treated material is then transferred to a vacuum drying oven and dried at 60°C for 12 hours to remove any residual solvent. This step is repeated twice to obtain the loaded wheat husks.

[0143] S314. Place the loaded wheat husk obtained in step S313 into a muffle furnace, heat it to 350°C at a rate of 2°C / min, keep it at that temperature for 2 hours, and cool it naturally to room temperature to obtain a TiO2@wheat husk composite material.

[0144] The preparation method of the biological filter layer comprises the following steps:

[0145] S11. 3000g modified attapulgite, 1500g carbonized rice husk powder, 500g discarded eggshell powder were placed in a blender, the blender speed was adjusted to 200rpm, dry mixed for 2min, 5500g of base slurry was added to the mixture, the blender speed was adjusted to 60rpm, stirred at low speed for 5min, 800g of sodium alginate - bentonite composite gel was slowly added to the blender, the blender speed was adjusted to 120rpm, and stirred at medium speed for 3min;

[0146] S12. The mold was cleaned and sprayed with pure silicone oil solution. 20 mm diameter ceramic tubes were embedded above and below the mold. The tubes were drilled and covered with a layer of gauze. The interior of the tubes was filled with hemp silk and further purified. The mixture obtained in step S11 was filled into the mold and vibrated and compacted. Except for the top surface, the remaining surfaces were sprayed with acrylic waterproof coating to form an 80 mm thick biofiltration layer.

[0147] Among them, the waste eggshell powder is in powder form with a particle size of 550 mesh; the carbonized rice husk powder has a particle size of 40 mesh; and the attapulgite is in powder form with a particle size of 300 mesh.

[0148] The photocatalytic purification layer is prepared by the following steps:

[0149] S31. 2000gTiO2@ wheat husk, 3000g rice husk ash, 1500g expanded perlite powder was placed in a blender, the blender speed was adjusted to 200rpm, dry mixed for 5min, then 6500g of base slurry was added, the blender speed was adjusted to 500rpm, wet mixed for 10min until the slurry was uniform without agglomeration;

[0150] S32. Clean the mold and spray it with pure silicone oil solution. Pre-buried Φ20mm ceramic tubes under the mold, drilled the surface of the ceramic tubes, and wrapped the surface of the ceramic tubes with a layer of gauze to prevent mortar from clogging the pores. The inside of the ceramic tubes was filled with hemp silk for further purification. The mixture obtained in step S31 was filled into the mold and vibrated and compacted. Six 20mm deep water retention ditches were pressed out of the mold on the upper surface to form a 50mm thick primary photocatalytic purification layer.

[0151] S33. Except for the upper surface, the rest of the surface is sprayed with acrylic waterproof coating, dried at 50℃ for 2h, and then sprayed with 365nm and 30mW / cm 2 Irradiate with UV light for 48 hours to obtain a photocatalytic purification layer;

[0152] Among them, rice husk ash is in black powder form with a particle size of 40 mesh; expanded perlite powder is in powder form with a particle size of 200 mesh.

[0153] The method for preparing the adsorption stabilization layer comprises the following steps:

[0154] S41. 2000 g of biochar was placed in a magnetic stirrer and an FeCl3 solution was added to the mixture at a solid-to-liquid ratio of 1:5. The stirrer was adjusted to 60°C and magnetic stirring was performed for 6 h. The biochar was then dried in a drying oven at 105°C for 12 h to obtain the iron-loaded biomass. The biochar was then placed in a ceramic crucible with a lid, sealed with aluminum foil, and heated directly to 500°C in a muffle furnace for 1 h. The biochar was then rinsed three times with deionized water to obtain the magnetic biochar.

[0155] S42. 2500 g of zeolite powder, the magnetic biochar obtained in step S41, and 2000 g of modified attapulgite were placed in a blender and dry-mixed for 5 min until uniform. A total of 5000 g of the base slurry was added thereto in three portions. The stirring speed was increased in stages from 60 rpm to 120 rpm and then to 180 rpm for a total of 8 min.

[0156] S43. Clean the mold and spray it with pure silicone oil solution. Pre-buried Φ20mm ceramic tubes above and below the mold are drilled, wrapped with a layer of gauze, and filled with hemp inside the ceramic tube for further purification. Fill the mold with the mixture obtained in step S42, vibrate and compact it, and spray the remaining surfaces with acrylic waterproof coating except the upper surface to form a 120mm thick adsorption stabilization layer.

[0157] The preparation of the drainage gradient dynamic adsorption organic matter and heavy metal blocking water filtration bird habitat brick includes the following steps:

[0158] S1. After the photocatalytic purification layer, biological filtration layer, and adsorption stabilization layer are formed, they are demoulded. Except for the upper surface of each brick layer, the remaining surfaces are treated for anti-seepage;

[0159] S2. Attach the bricks in the order of photocatalytic purification layer, biological filtration layer, and adsorption stabilization layer from top to bottom. Precisely connect the ceramic tube clips of each layer to form a complete ecological composite brick. This is the drainage gradient dynamic adsorption of organic matter and heavy metal retardation and filtration bird habitat brick. The brick density is 1500 kg / m³. The side length and volume of the three layers are:

[0160] Photocatalytic purification layer: 0.4×0.4×0.05=0.008m³;

[0161] Biological filter layer: 0.4×0.4×0.08=0.0128m³;

[0162] Adsorption stabilization layer: 0.4×0.4×0.12=0.0192m³.

[0163] Example 3

[0164] A drainage gradient dynamic adsorption of organic matter and heavy metal blocking and filtration bird habitat brick:

[0165] First, the base slurry, sodium alginate-bentonite composite gel, modified attapulgite, TiO2@wheat husk, biological filtration layer, photocatalytic purification layer, and adsorption stabilization layer were prepared:

[0166] The base slurry is prepared by the following steps:

[0167] S21. 1200 g of potassium-zinc complex metallurgical dust was mixed with 5% citric acid solution at a solid-liquid ratio of 1:5, stirred at 350 r / min at room temperature for 45 min to remove soluble contaminants attached to the surface, rinsed twice with deionized water, heated to 70°C, and stirred for 65 min. After rinsing five times with deionized water, the mixture was placed in a microwave reactor, the microwave power was adjusted to 500 w, stirred at 60°C for 30 min, and then vacuum filtered. The filtered residue was washed with deionized water until neutral and dried at 60°C to obtain the treated potassium-zinc complex metallurgical dust;

[0168] S22. 400 g of hemp fiber was cut into 4 mm short fibers, soaked in a constant temperature water bath with a 3% NaOH solution at a solid-to-liquid ratio of 1:10, and stirred at 60°C for 2 h. The fibers were then washed with deionized water until neutral and dried in a dryer at 60°C to obtain the treated hemp fibers.

[0169] S23. 900 g of water glass and 8 mol / L NaOH solution were mixed in a volume ratio of 3:1 to prepare an alkaline excitation solution, which was stirred on a magnetic stirrer for 30 min at a speed of 500 rpm. The SiO2 / Na2O molar ratio was determined to a modulus of 1.3, and the resulting alkaline excitation solution was transferred to a sealed polyethylene bottle;

[0170] S24. The potassium-zinc complex metallurgical sludge treated in step S21, 4200 g of fly ash, 2800 g of blast furnace slag, 1100 g of metakaolin, and the hemp fiber treated in step S22 were placed in a blender for dry mixing. The blender speed was adjusted to 60 rpm for 3 min. The alkali-activated solution obtained in step S23 was then added to the mixed dry materials in stages. In the first stage, the alkali-activated solution was preheated to 40° C., 70% of the total amount of the alkali activator was slowly poured into the blender, and the blender was stirred at 30 rpm for 5 min to form a uniform paste. In the second stage, the blender speed was increased to 60 rpm, 20% of the total amount of the alkali activator was added, and the blender was stirred for 10 min. In the third stage, 10% of the total amount of the alkali activator was added, and the blender was stirred at 120 rpm for 2 min. No bubbles were observed on the surface of the slurry to obtain the base slurry.

[0171] Among them, the particle size of fly ash is 325 mesh; the particle size of blast furnace slag is 80 mesh; and the particle size of metakaolin is 4000 mesh.

[0172] Sodium alginate-bentonite composite gel is prepared by the following steps:

[0173] S111. 350 g of sodium alginate was placed in a magnetic stirrer, and then 10,000 g of deionized water was added and stirred in a 60 ° C water bath for 2 h to obtain a transparent glue solution. Bentonite was then added to the magnetic stirrer, and the magnetic stirrer speed was adjusted to 800 rpm. 700 g of bentonite was added while stirring at high speed for 30 min. After stirring, the mixture was moved to an ultrasonic instrument and sonicated for 10 min to break up bentonite agglomerates to form a homogeneous suspension.

[0174] S112. 700 g of calcium chloride powder was dissolved in 10,000 g of deionized water to prepare a crosslinking solution. The homogeneous suspension in step S111 was added dropwise to the crosslinking solution using a syringe. The droplets formed gel balls with a diameter of 3 mm at the moment of contact and were allowed to solidify for 30 min.

[0175] S113. Rinse the gel three times with deionized water, and dry the washed gel in a drying oven at 60°C for 12 h to obtain a sodium alginate-bentonite composite gel;

[0176] Among them, sodium alginate is in powder form with a particle size of 90 mesh; calcium chloride is in white granular form; and bentonite is in powder form with a particle size of 450 mesh.

[0177] Modified attapulgite is prepared by the following steps:

[0178] S121. 600g of epoxypropyltrimethylammonium chloride was added to a magnetic stirrer, 20,000g of deionized water was added, and magnetic stirring was performed until completely dissolved. The pH was adjusted to 9.0 with 1mol / LNaOH solution. 10,500g of attapulgite was added to the prepared solution and transferred to an ultrasonic instrument. Ultrasonic dispersion was performed at a frequency of 40kHz for 10min, and then transferred to a microwave reactor, the power was set to 500W and the temperature was 60°C. After microwave irradiation for 3min, the mixture was transferred to a centrifuge, the speed was adjusted to 5000rpm, and the mixture was centrifuged for 5min. The mixture was washed with deionized water 3 times until neutral, and then dried in a drying oven at 60°C for 12h to obtain epoxypropyltrimethylammonium chloride-grafted attapulgite.

[0179] S122. 1200 g of acrylic acid and 400 g of chitosan were added to a magnetic stirrer, followed by 10,000 g of deionized water. The mixture was stirred magnetically for 2 h until completely dissolved. The mixture was then transferred to an ultrasonicator, and 300 g of Fe3O4 nanoparticles were added. Ultrasonic dispersion was performed at 40 kHz for 30 min. Nitrogen was introduced into the solution for 30 min and then placed under a microscope at 360 nm and 10 mW / cm 2 Irradiate under UV light for 2 h to form pH-sensitive hydrogel microspheres;

[0180] S123. The pH-sensitive hydrogel microspheres obtained in step S122 were placed in a magnetic separation rack for magnetic separation, washed three times with deionized water, freeze-dried for 24 h, and stored sealed and protected from light;

[0181] S124. The attapulgite grafted with epoxypropyltrimethylammonium chloride obtained in step S121 and the pH-sensitive hydrogel microspheres obtained in step S123 are put into a three-dimensional mixer at a ratio of 9:1, the speed is adjusted to 30 rpm and low-speed mixing is carried out for 15 minutes, a 5% sodium alginate solution is prepared, and magnetic stirring is carried out for 20 minutes until it becomes transparent. The solution is evenly sprayed onto the surface of the mixture with a sprayer at a spraying amount of 10 ml / 100 g. The treated mixture is spread flat on a tray and placed in a forced air drying oven at 60°C for 2 hours to obtain modified attapulgite.

[0182] The preparation method of TiO2@wheat husk comprises the following steps:

[0183] S311. The wheat husks were soaked in deionized water and ultrasonically cleaned for 20 minutes to remove surface dust and impurities. The husks were then placed in a drying oven and dried at 60°C for 12 hours. After drying, the husks were crushed into 0.7 mm particles, passed through a 20-mesh sieve, placed in a crucible, and placed in a muffle furnace. The temperature was raised to 400°C at 5°C / min under a nitrogen atmosphere, maintained for 1 hour, and then naturally cooled to room temperature to obtain carbonized wheat husks.

[0184] S312. 10000g of anhydrous ethanol was placed in a magnetic stirrer, 1000g of tetrabutyl titanate was added, the magnetic stirrer speed was adjusted to 800rpm, magnetic stirring was performed for 30min, 300g of 10% citric acid was mixed with 1000g of deionized water and added dropwise to the magnetic stirrer, stirring was continued for 2h, and the pH value of the sol was adjusted to 2.7 to obtain a titanium dioxide sol;

[0185] S313. The carbonized wheat husks prepared in step S311 are immersed in the titanium dioxide sol obtained in step S312 at a solid-to-liquid ratio of 1:10. The husks are then treated in an ultrasonic cleaner for 30 minutes to promote penetration of the sol into the pores of the rice husks. The ultrasonically treated material is then transferred to a vacuum drying oven and dried at 60°C for 12 hours to remove any residual solvent. This step is repeated twice to obtain the loaded wheat husks.

[0186] S314. Place the loaded wheat husk obtained in step S313 into a muffle furnace, heat it to 350°C at a rate of 2°C / min, keep it at that temperature for 2 hours, and cool it naturally to room temperature to obtain a TiO2@wheat husk composite material.

[0187] The preparation method of the biological filter layer comprises the following steps:

[0188] S11. 2800g of modified attapulgite, 1200g of carbonized rice husk powder, and 400g of discarded eggshell powder were placed in a blender, the blender speed was adjusted to 200rpm, and dry mixed for 2min. 5200g of the base slurry was then added to the mixture, the blender speed was adjusted to 60rpm, and stirred at low speed for 5min. 700g of sodium alginate - bentonite composite gel was slowly added to the blender, the blender speed was adjusted to 120rpm, and stirred at medium speed for 3min.

[0189] S12. The mold was cleaned and sprayed with pure silicone oil solution. 20 mm diameter ceramic tubes were embedded above and below the mold. The tubes were drilled and covered with a layer of gauze. The interior of the tubes was filled with hemp silk and further purified. The mixture obtained in step S11 was filled into the mold and vibrated and compacted. Except for the top surface, the remaining surfaces were sprayed with acrylic waterproof coating to form an 80 mm thick biofiltration layer.

[0190] Among them, the waste eggshell powder is in powder form with a particle size of 520 mesh; the carbonized rice husk powder has a particle size of 35 mesh; and the attapulgite is in powder form with a particle size of 250 mesh.

[0191] The photocatalytic purification layer is prepared by the following steps:

[0192] S31. 1800gTiO2@ wheat husk, 2500g rice husk ash, 1200g expanded perlite powder was placed in a blender, the blender speed was adjusted to 200rpm, dry mixed for 5min, then 6200g of base slurry was added, the blender speed was adjusted to 500rpm, wet mixed for 10min until the slurry was uniform without agglomeration;

[0193] S32. Clean the mold and spray it with pure silicone oil solution. Pre-buried Φ20mm ceramic tubes under the mold, drilled the surface of the ceramic tubes, and wrapped the surface of the ceramic tubes with a layer of gauze to prevent mortar from clogging the pores. The inside of the ceramic tubes was filled with hemp silk for further purification. The mixture obtained in step S31 was filled into the mold and vibrated and compacted. Six 20mm deep water retention ditches were pressed out of the mold on the upper surface to form a 50mm thick primary photocatalytic purification layer.

[0194] S33. Except for the upper surface, the rest of the surface is sprayed with acrylic waterproof coating, dried at 50℃ for 2h, and then sprayed with 365nm and 30mW / cm 2 Irradiate with UV light for 48 hours to obtain a photocatalytic purification layer;

[0195] Among them, rice husk ash is in black powder form with a particle size of 35 mesh; expanded perlite powder is in powder form with a particle size of 150 mesh.

[0196] The method for preparing the adsorption stabilization layer comprises the following steps:

[0197] S41. 1700 g of biochar was placed in a magnetic stirrer and an FeCl3 solution was added to the mixture at a solid-to-liquid ratio of 1:5. The stirrer was adjusted to 60°C and magnetic stirring was performed for 6 h. The biochar was then dried in a drying oven at 105°C for 12 h to obtain the iron-loaded biomass. The biochar was then placed in a ceramic crucible with a lid, sealed with aluminum foil, and heated directly to 500°C in a muffle furnace for 1 h. The biochar was then rinsed three times with deionized water to obtain the magnetic biochar.

[0198] S42. 2200 g of zeolite powder, the magnetic biochar obtained in step S41, and 1700 g of modified attapulgite were placed in a blender and dry-mixed for 5 min until uniform. A total of 4500 g of the base slurry was added thereto in three portions. The stirring speed was increased in stages from 60 rpm to 120 rpm and then to 180 rpm for a total of 8 min.

[0199] S43. Clean the mold and spray it with pure silicone oil solution. Pre-buried Φ20mm ceramic tubes above and below the mold are drilled, wrapped with a layer of gauze, and filled with hemp inside the ceramic tube for further purification. Fill the mold with the mixture obtained in step S42, vibrate and compact it, and spray the remaining surfaces with acrylic waterproof coating except the upper surface to form a 120mm thick adsorption stabilization layer.

[0200] The preparation of the drainage gradient dynamic adsorption organic matter and heavy metal blocking water filtration bird habitat brick includes the following steps:

[0201] S1. After the photocatalytic purification layer, biological filtration layer, and adsorption stabilization layer are formed, they are demoulded. Except for the upper surface of each brick layer, the remaining surfaces are treated for anti-seepage;

[0202] S2. Attach the bricks in the order of photocatalytic purification layer, biological filtration layer, and adsorption stabilization layer from top to bottom. Precisely connect the ceramic tube clips of each layer to form a complete ecological composite brick. This is the drainage gradient dynamic adsorption of organic matter and heavy metal retardation and filtration bird habitat brick. The brick density is 1500 kg / m³. The side length and volume of the three layers are:

[0203] Photocatalytic purification layer: 0.4×0.4×0.05=0.008m³;

[0204] Biological filter layer: 0.4×0.4×0.08=0.0128m³;

[0205] Adsorption stabilization layer: 0.4×0.4×0.12=0.0192m³.

[0206] Comparative Example

[0207] Comparative Example 1

[0208] Comparative Example 1 differs from Example 1 in that the sodium alginate-bentonite composite gel in the biological filtration layer is eliminated in Comparative Example 1, and the remaining steps are identical in Comparative Example 1 and Example 1.

[0209] Comparative Example 2

[0210] Comparative Example 2 differs from Example 2 in that the modified attapulgite in the biological filtration layer is eliminated in Comparative Example 2, and the remaining steps are exactly the same in Comparative Example 2 and Example 2.

[0211] Performance testing:

[0212] With reference to GB / T 25993-2010 "Permeable Pavement Bricks and Permeable Road Panels", the water permeability coefficient of the drainage gradient dynamic adsorption organic matter and heavy metal retardation water filtration bird perching bricks prepared in Examples 1-3 and Comparative Examples 1-2 was tested by using the constant water head method; 3- 、Cd 2+ , Pb 2+ The solution was used to test the gradient dynamic adsorption of organic matter and heavy metal retardation of the bird habitat bricks prepared in Examples 1-3 and Comparative Examples 1-2 for heavy metals and PO4 3- The retention rate was set, and the COD of the solution was controlled at 480±20mg / L and TN at 75±5mg / L. The removal rates of COD (chemical oxygen demand) and TN (total nitrogen) were tested. The test results are shown in Table 1:

[0213] Table 1

[0214]

[0215] Through the heavy metals and PO4 3- The tests on the interception rate, COD (chemical oxygen demand) and TN (total nitrogen) removal rate have strongly proved that the present invention can better collect polluted water bodies, adopt appropriate filtration mechanisms and effectively adsorb organic matter in stages and layers, improve the interception efficiency of pollutants, and solve the problems of low adsorption capacity and easy desorption after saturation. In addition, the material recovery after the service life is reached is easier and simpler than ordinary brick materials.

[0216] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A drainage gradient dynamic adsorption organic matter and heavy metal blocking water filtration bird habitat brick, characterized in that: It includes a photocatalytic purification layer, a biological filtration layer, and an adsorption stabilization layer; The biological filter layer comprises the following components by mass: 50-55 parts of base slurry, 25-30 parts of modified attapulgite, 10-15 parts of carbonized rice husk powder, 3-5 parts of waste eggshell powder, and 5-8 parts of sodium alginate-bentonite composite gel; The modified attapulgite comprises the following components in parts by mass: 100-110 parts of attapulgite, 5-8 parts of epoxypropyltrimethylammonium chloride, 10-15 parts of sodium hydroxide solution, 300 parts of deionized water, 10-15 parts of acrylic acid, 3-5 parts of chitosan, and 2-4 parts of Fe3O4 nanoparticles. The raw materials of the sodium alginate-bentonite composite gel include the following components in parts by mass: 3-4 parts of sodium alginate, 5-8 parts of calcium chloride powder, 6-8 parts of bentonite, and 200 parts of deionized water; The sodium alginate-bentonite composite gel is prepared by the following steps: S111. Sodium alginate was placed in a magnetic stirrer, and 100 parts of deionized water was added. The mixture was stirred in a water bath at 60°C for 2 hours to obtain a transparent adhesive solution. Bentonite was then added to the magnetic stirrer. The magnetic stirrer speed was adjusted to 800 rpm. The mixture was stirred at high speed while adding bentonite for 30 minutes. After stirring, the mixture was moved to an ultrasonic instrument and sonicated for 10 minutes to break up bentonite agglomerates and form a homogeneous suspension. S112. Calcium chloride powder was dissolved in 100 parts of deionized water to prepare a crosslinking solution. The homogeneous suspension in step S111 was added dropwise to the crosslinking solution using a syringe. The droplets formed gel balls with a diameter of 2-4 mm at the moment of contact and were allowed to solidify for 30 min. S113. Rinse the gel three times with deionized water, and dry the washed gel in a drying oven at 60°C for 12 h to obtain a sodium alginate-bentonite composite gel.

2. The drainage gradient dynamic adsorption organic matter and heavy metal blocking water filtration bird habitat brick according to claim 1 is characterized in that: The modified attapulgite is prepared by the following steps: S121. Add epoxypropyltrimethylammonium chloride to a magnetic stirrer, add 200 parts of deionized water, and stir magnetically until completely dissolved. Adjust the pH to 9.0 with 1 mol / L NaOH solution, add attapulgite to the prepared solution, transfer to an ultrasonic instrument, and ultrasonically disperse for 10 minutes. Then transfer to a microwave reactor, set the power to 500 W and the temperature to 60°C, microwave irradiate for 3 minutes, then transfer to a centrifuge, adjust the speed to 5000 rpm, centrifuge for 5 minutes, wash with deionized water three times until neutral, and then place in a drying oven at 60°C for 12 hours to obtain epoxypropyltrimethylammonium chloride-grafted attapulgite; S122. Acrylic acid and chitosan were added to a magnetic stirrer, followed by 100 parts of deionized water. The mixture was stirred for 2 h until completely dissolved. The mixture was then transferred to an ultrasonicator, and Fe3O4 nanoparticles were added. Ultrasonic dispersion was performed at 40 kHz for 30 min. Nitrogen was introduced into the solution for 30 min and then placed under a microscope at 360 nm and 10 mW / cm 2 Irradiate under UV light for 2 h to form pH-sensitive hydrogel microspheres; S123. The pH-sensitive hydrogel microspheres obtained in step S122 were placed in a magnetic separation rack for magnetic separation, washed three times with deionized water, freeze-dried for 24 h, and stored sealed and protected from light; S124. The attapulgite grafted with epoxypropyltrimethylammonium chloride obtained in step S121 and the pH-sensitive hydrogel microspheres obtained in step S123 are put into a three-dimensional mixer at a ratio of 9:1, the speed is adjusted to 30 rpm and low-speed mixing is carried out for 15 minutes, a 5% sodium alginate solution is prepared, and magnetic stirring is carried out for 20 minutes until it becomes transparent. The solution is evenly sprayed onto the surface of the mixture with a sprayer at a spraying amount of 10 ml / 100 g. The treated mixture is spread flat on a tray and placed in a forced air drying oven at 60°C for 2 hours to obtain modified attapulgite.

3. The drainage gradient dynamic adsorption organic matter and heavy metal blocking water filtration bird habitat brick according to claim 1 is characterized in that: The preparation method of the biological filtration layer comprises the following steps: S11. The modified attapulgite, carbonized rice husk powder, and discarded eggshell powder were placed in a blender, the blender speed was adjusted to 200 rpm, and dry mixed for 2 min. The base slurry was then added to the mixture, the blender speed was adjusted to 60 rpm, and stirred at low speed for 5 min. The sodium alginate-bentonite composite gel was slowly added to the blender, the blender speed was adjusted to 120 rpm, and stirred at medium speed for 3 min. S12. The mold is cleaned and sprayed with a silicone solvent-based release agent. 20 mm diameter ceramic tubes are embedded above and below the mold. The surfaces of the ceramic tubes are drilled, wrapped with a layer of gauze, and filled with hemp fibers. The mixture obtained in step S11 is then filled into the mold and vibrated and compacted. An acrylic anti-seepage liquid is sprayed on all surfaces except the top surface to form an 80 mm thick biofiltration layer.

4. The drainage gradient dynamic adsorption organic matter and heavy metal blocking water filtration bird habitat brick according to claim 1 is characterized in that: The raw materials of the photocatalytic purification layer include the following components in parts by mass: 60-65 parts of base slurry, 15-20 parts of TiO2@wheat husks, 20-30 parts of rice husk ash, and 10-15 parts of expanded perlite powder.

5. The drainage gradient dynamic adsorption and heavy metal retardation bird habitat brick according to claim 4 is characterized in that: The photocatalytic purification layer is prepared by the following steps: S31. The TiO2@ wheat husk, rice husk ash, expanded perlite powder was placed in a blender, the blender speed was adjusted to 200 rpm, dry mixed for 5 min, then the base slurry was added, the blender speed was adjusted to 500 rpm, and wet mixed for 10 min until the slurry was uniform without agglomeration; S32. Clean the mold and spray a silicone solvent-based release agent. Pre-buried Φ20mm ceramic tubes under the mold, drilled the surface of the ceramic tubes, and wrapped the surface of the ceramic tubes with a layer of gauze to prevent mortar from clogging the pores. The interior of the ceramic tubes was filled with hemp silk for further purification. The mixture obtained in step S31 was filled into the mold and vibrated to compact it. Six 20mm deep retention ditches were pressed out on the upper surface using a mold to form a 50mm thick primary photocatalytic purification layer. S33. Except for the upper surface, the remaining surfaces were sprayed with acrylic acid anti-seepage liquid, dried at 50 ° C for 2 hours, and then sprayed with 365nm, intensity 30mW / cm 2 The UV lamp was irradiated for 48 hours to obtain a photocatalytic purification layer.

6. A drainage gradient dynamic adsorption organic matter and heavy metal blocking water filtration bird habitat brick according to any one of claims 4 or 5, characterized in that: The preparation method of TiO2@wheat husk comprises the following steps: S311. The wheat husks were soaked in deionized water and ultrasonically cleaned for 20 minutes to remove surface dust and impurities. The husks were then placed in a drying oven and dried at 60°C for 12 hours. After drying, the husks were crushed into 0.5-1 mm particles, passed through a 20-mesh sieve, and placed in a crucible. The crucible was placed in a muffle furnace and heated at 5°C / min to 400°C under a nitrogen atmosphere. The mixture was kept at this temperature for 1 hour and then naturally cooled to room temperature to obtain carbonized wheat husks. S312. 100 parts of anhydrous ethanol were placed in a magnetic stirrer, 10 parts of tetrabutyl titanate were added, the magnetic stirrer speed was adjusted to 800 rpm, magnetic stirring was performed for 30 min, 3 parts of 10% citric acid was mixed with 10 parts of deionized water and added dropwise to the magnetic stirrer, stirring was continued for 2 h, and the pH value of the sol was adjusted to 2.5-3.0 to obtain a titanium dioxide sol; S313. The carbonized wheat husks prepared in step S311 are immersed in the titanium dioxide sol obtained in step S312 at a solid-to-liquid ratio of 1:

10. The husks are then treated in an ultrasonic cleaner for 30 minutes to promote penetration of the sol into the pores of the rice husks. The ultrasonically treated material is then transferred to a vacuum drying oven and dried at 60°C for 12 hours to remove any residual solvent. This step is repeated twice to obtain the loaded wheat husks. S314. Place the loaded wheat husk obtained in step S313 into a muffle furnace, heat it to 350°C at a rate of 2°C / min, keep it at that temperature for 2 hours, and cool it naturally to room temperature to obtain a TiO2@wheat husk composite material.

7. The drainage gradient dynamic adsorption and heavy metal blocking water filtration bird habitat brick according to claim 1 is characterized in that: The raw materials of the adsorption stabilization layer include the following components in parts by weight: 20-25 parts of zeolite powder, 15-20 parts of biochar, 15-20 parts of modified attapulgite, and 40-50 parts of base slurry. The preparation method of the adsorption stabilization layer includes the following steps: S41. The biochar was placed in a magnetic stirrer and an FeCl3 solution was added to the mixture at a solid-to-liquid ratio of 1:

5. The stirrer was adjusted to 60°C and magnetic stirring was performed for 6 hours. The biochar was then dried in a drying oven at 105°C for 12 hours to obtain the iron-loaded biomass. The biochar was then placed in a ceramic crucible with a lid, sealed with aluminum foil, and heated directly to 500°C in a muffle furnace for 1 hour. The biochar was then rinsed three times with deionized water to obtain the magnetic biochar. S42. Zeolite powder, magnetic biochar, and modified attapulgite were placed in a blender and dry-mixed for 5 minutes until uniform. The base slurry was then added to the blend in three portions. The stirring speed was gradually increased from 60 rpm to 120 rpm and then to 180 rpm for a total of 8 minutes. S43. Clean the mold and spray a silicone oil solvent-based release agent. Pre-embed Φ20mm ceramic tubes above and below the mold. Drill holes on the surface of the ceramic tubes, wrap a layer of gauze on the surface of the ceramic tubes, and fill the inside of the ceramic tubes with hemp silk for further purification. Fill the mold with the mixture obtained in step S42, vibrate and compact it, and spray the remaining surfaces except the top surface with an acrylic anti-seepage liquid to form a 120mm thick adsorption stabilization layer.

8. The drainage gradient dynamic adsorption and heavy metal blocking water filtration bird habitat brick according to claim 1 is characterized in that: The raw materials of the base slurry include the following components in parts by mass: 40-45 parts of fly ash, 25-30 parts of blast furnace slag, 10-15 parts of potassium-zinc complex metallurgical dust, 3-5 parts of hemp fiber, 8-15 parts of metakaolin, and 8-10 parts of water glass; the base slurry is prepared by the following steps: S21. The potassium-zinc complex metallurgical sludge was mixed with 5% citric acid solution at a solid-liquid ratio of 1:5, stirred at 300-400 r / min at room temperature for 30-60 min to remove soluble contaminants attached to the surface, rinsed with deionized water 1-2 times, heated to 60-80°C, and stirred for 60-70 min. After rinsing with deionized water 5 times, the mixture was placed in a microwave reactor with a microwave power of 500 W. The mixture was stirred at 60°C for 30 min, and then vacuum filtered. The filtered residue was washed with deionized water until neutral, and dried at 60°C to obtain the treated potassium-zinc complex metallurgical sludge. S22. The hemp fibers were cut into 3-5 mm short fibers, soaked in a constant temperature water bath with a 3% NaOH solution at a solid-to-liquid ratio of 1:10, and stirred at 60°C for 2 h. The fibers were then washed with deionized water until neutral and dried in a dryer at 60°C to obtain the treated hemp fibers. S23. A base-activated solution was prepared by mixing water glass and 8 mol / L NaOH solution in a volume ratio of 3:

1. The mixture was stirred on a magnetic stirrer for 30 min at 500 rpm. The SiO2 / Na2O molar ratio was determined to a modulus of 1.

3. The resulting base-activated solution was transferred to a sealed polyethylene bottle. S24. The potassium-zinc complex metallurgical dust mud treated in step S21 is put into a blender with fly ash, blast furnace slag, metakaolin and the hemp fiber treated in step S22 for dry mixing. The blender speed is adjusted to 60 rpm and the stirring time is 3 min. The alkali-activated solution obtained in step S23 is then added to the mixed dry materials in stages. In the first stage, the liquid temperature of the alkali-activated solution is preheated to 40°C, 70% of the total amount of the alkali activator is slowly poured in, and the blender is stirred at 30 rpm for 5 min to form a uniform paste; in the second stage, the blender speed is increased to 60 rpm, 20% of the total amount of the alkali activator is added, and the mixture is stirred for 10 min; in the third stage, 10% of the total amount of the alkali activator is added, and the blender is stirred at a high speed of 120 rpm for 2 min. It is observed that there is no bubble accumulation on the surface of the slurry, and the basic slurry is obtained.

9. A method for preparing a drainage gradient dynamic adsorption of organic matter and heavy metal blocking water filtration bird habitat brick, used for preparing the drainage gradient dynamic adsorption of organic matter and heavy metal blocking water filtration bird habitat brick according to claim 8, characterized in that: The following steps are involved: S1. After the photocatalytic purification layer, biological filtration layer, and adsorption stabilization layer are formed, they are demoulded. Except for the upper surface of each brick layer, the remaining surfaces are treated for anti-seepage. S2. The bricks are spliced ​​in the order of photocatalytic purification layer, biological filtration layer and adsorption stabilization layer from top to bottom. The ceramic tube buckles of each layer are precisely docked and the three layers are spliced ​​into a whole ecological combination brick, thus obtaining the drainage gradient dynamic adsorption of organic matter and heavy metal blocking water filtration bird habitat brick.

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