A construction method for regenerated filter bricks for denitrification deep bed filter

Abstract

The present invention relates to the technical field of sewage treatment, and discloses a method for constructing regenerated filter bricks for a denitrification deep bed filter. A concrete casting base is provided at the bottom of the denitrification deep bed filter, and a groove is reserved for embedding the filter brick footing. A filter brick supporting layer is hoisted on the concrete casting base. The filter brick supporting layer is formed by overlapping regenerated filter bricks in the longitudinal and transverse directions, and joints are reserved at the overlaps. After the filter bricks are installed, the joints in the longitudinal and transverse directions of the filter bricks are caulked with polyvinyl chloride mortar. After the caulking is completed, the joints are immediately pressed with long strips of concrete blocks. The caulking and pressing processes should be carried out continuously to avoid cold joints. In order to increase the structural integrity of the filter brick supporting layer, the filter bricks should be staggered along the length direction and distributed in a shape to avoid forming cross-through seams. The regenerated filter brick construction provided by the present invention has the advantages of better water blocking effect at the joints, and backwash water and gas are not easy to surge from the joints, thus achieving better uniformity in water and gas distribution.

Description

Technical Field

[0001] The invention belongs to the technical field of sewage treatment, and in particular relates to a construction method of regenerated filter bricks for a denitrification deep bed filter. Background Art

[0002] With the rapid development of urbanization in my country, the total amount of municipal wastewater discharged is also increasing dramatically. This means that even if municipal wastewater discharge standards remain unchanged, the total amount of pollutants entering natural water bodies such as rivers and lakes is also rapidly increasing. This puts tremendous pressure on the self-purification capacity of aquatic ecosystems such as rivers and lakes, and is likely to cause excessive accumulation of pollutants and lead to ecological damage. In response, many regions have raised the pollutant discharge standard for newly built or renovated sewage treatment plants from Class B to Class A ("Urban Wastewater Treatment Plant Sewage Sludge Discharge Standard" GB 18918-2002). Regions with higher environmental quality requirements and stricter pollution discharge requirements have even raised the sewage discharge standard from Class A to Class IV water body standards ("Surface Water Environmental Quality Standard" (GB 3838-2002)). This undoubtedly places higher demands on the treatment processes of urban sewage treatment plants.

[0003] As a deep-treatment process, denitrification deep-bed filters are currently widely used in the construction of new municipal wastewater treatment plants and the upgrading of existing ones. In practice, they are generally used as an advanced treatment process alongside secondary biochemical processes such as oxidation ditch processes, AO, and A2O, further reducing the concentrations of COD, SS, TN, and TP in secondary biochemical effluent. Operational data indicates that the effluent quality of deep-treatment denitrification deep-bed filters can typically and consistently meet Class A standards. In particular, during the more favorable spring and autumn temperatures, the effluent quality of stable operation can even meet Class IV surface water standards.

[0004] Filter bricks, a functional component of a denitrification deep-bed filter, have the following primary functions: ① Reducing the collected filtered water with minimal head pressure to achieve separation between the filter media and effluent; ② Providing excellent anti-clogging properties, reducing backwash frequency; ③ Acting as a support layer for the filter media, bearing the gravitational load of the entire filter media and filter water; and ④ Providing uniform water and air distribution during backwash, effectively reducing or avoiding backwash dead zones (i.e., areas where backwash water and air cannot fully reach the filter). Currently, filter bricks commonly used in denitrification deep-bed filters are typically made of HDPE or clay, and they perform well in performing their primary functions. However, the water distribution pores in both HDPE and clay filter bricks are fabricated post-processing, failing to achieve the ideal uniform and dense interconnected pores, resulting in suboptimal water distribution. Filter bricks employing curved, overlapped joints often provide poor water blocking performance, allowing backwash water and air to surge through the joints, leading to uneven water and air distribution. Therefore, we proposed a construction method for regenerated filter bricks for denitrification deep bed filters. Summary of the Invention

[0005] The present invention aims to address the shortcomings of the prior art mentioned in the background art by proposing a method for constructing regenerative filter bricks for denitrification deep bed filters. Compared to conventional filter bricks made of HDPE or clay, the regenerative filter bricks provided by the present invention offer improved joint sealing, less backwash water and air from surging through the joints, and more uniform water and air distribution.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A construction method for regenerated filter bricks for a denitrification deep bed filter is designed, including:

[0008] A concrete base is set at the bottom of the denitrification deep bed filter;

[0009] A filter brick supporting layer is hoisted on the concrete pouring base. The filter brick supporting layer is formed by overlapping recycled filter bricks in the longitudinal and transverse directions. Joints are reserved at the overlaps. Joint filling is provided in the joints. The lower part of the joint filling is a polyvinyl chloride mortar filling part, and the upper part is a concrete block press joint part.

[0010] Recycled filter bricks are made of engineering construction waste and solidified by aerated cement mortar;

[0011] The bottom of the regeneration filter brick is provided with a filter brick foot, and a cavity for placing the backwash air distribution pipe and the backwash water distribution pipe is formed between the filter brick feet;

[0012] The construction method of the regenerated filter brick masonry specifically includes the following steps:

[0013] 1) Clean the bottom of the denitrification deep bed filter, lay a concrete base at the bottom of the denitrification deep bed filter, reserve grooves for the filter brick feet to be embedded, and lay backwash air pipes and backwash water pipes;

[0014] 2) The regenerated filter bricks are laid on the concrete base in an overlapping manner, and a 10cm wide installation deviation space is reserved at the edge where the filter brick supporting layer is connected to the pool wall;

[0015] 3) The joints of the regenerated filter brick in the longitudinal and transverse directions are caulked with polyvinyl chloride mortar. When caulking, the polyvinyl chloride mortar is heated to 120-130°C. The caulking height is 2 / 3 of the total height of the joint to form the polyvinyl chloride mortar caulking part;

[0016] 4) After step 3) of caulking is completed, immediately press the joints with long strips of concrete blocks. When pressing the joints, ensure that the temperature of the polyvinyl chloride mortar is above 110°C. After the pressing is completed, the top of the concrete block is level with the top of the regenerated filter brick, forming a concrete block pressing joint area;

[0017] 5) After the continuous construction of grouting and pressing of steps 3) and 4) is completed, concrete pouring is used to fill the installation deviation space reserved in step 2). The grouting and pressing processes should be carried out continuously to avoid cold joints.

[0018] 6) After drying naturally, the construction is completed.

[0019] Furthermore, the regenerated filter bricks have two length specifications of 1.2m and 1.5m, three width specifications of 0.6m, 0.9m and 1.2m, a height of 0.3m, and a filter brick filter layer thickness of 40mm. The selection of the structure and size of a single regenerated filter brick comprehensively considers the influence of multiple factors such as hoisting, joints and thermal deformation. If the filter brick dimensions are too small, the joint width will be small and there will be many joints, which will increase the difficulty of caulking and reduce the reliability of caulking and water blocking. If the filter brick dimensions are too large, the difficulty of manufacturing and hoisting will be increased, and the deformation and stress of large components caused by temperature will increase, which will easily cause component damage, and then lead to a decrease in uniform water and air distribution performance. The selection of the filter layer thickness of the regenerated filter brick comprehensively considers the requirements of its compressive strength and flow resistance. Excessive layer thickness will increase the flow resistance, shorten the filter brick layer clogging cycle, increase the backwashing frequency and energy consumption during backwashing. Too small a layer thickness will result in insufficient load-bearing strength of the filter brick, which will be easily damaged by the gravity of the filter media and water and the impact of backwashing air and water.

[0020] Furthermore, the filter brick foot is an inverted isosceles trapezoid with a height of 40 mm, and the horizontal inclination angle of the trapezoidal hypotenuse is 75°.

[0021] Furthermore, the regenerated filter brick has an internal right-angle bend with an axil angle. The length of the axil angle of the internal right-angle bend at the joint is 40 mm, and the length of the axil angle of the internal right-angle bend at other locations is 20 mm. The provision of the axil angle is to increase the structural strength of the internal right-angle bend of the regenerated filter brick. The internal right-angle bend at the joint of the filter brick has a special trapezoidal and beveled joint structure, which results in a thinning of the structural layer. Therefore, the design considers increasing the length of the axil angle of the internal right-angle bend at the joint, thereby improving the strength of the internal right-angle bend at the joint of the filter brick.

[0022] Furthermore, the transverse and longitudinal joints of the regenerated filter bricks adopt a stepped and inclined surface structure, and the horizontal inclination angle of the inclined surface is 45°.

[0023] Furthermore, in step 2), in order to increase the structural integrity of the filter brick supporting layer, the regenerated filter bricks should be staggered along the length direction and distributed in a shape of a triangle to avoid forming a cross seam.

[0024] Furthermore, in step 3), the longitudinal and transverse joints formed after the installation of the regenerated filter bricks form a "Y"-shaped structure with a bottom width of about 5 mm, a top width of about 20 mm, and a depth of 40 mm. The polyvinyl chloride mortar caulking portion is located on the lower column of the "Y"-shaped joint, and the concrete block pressing portion is located on the opening of the "Y"-shaped joint. The polyvinyl chloride mortar caulking and the concrete block pressing play the role of caulking and blocking water during backwashing. The correct construction process plays a vital role in the caulking and blocking water performance of the polyvinyl chloride mortar and concrete block. The appropriate construction temperature is to ensure the appropriate fluidity and cohesion of the polyvinyl chloride mortar, so that it can fully fill the reserved grooves of the joints between the filter bricks under the action of gravity, and penetrate into the filter brick assembly gaps under the pressure of the concrete block. At the same time, the concrete block can also prevent the polyvinyl chloride mortar from being washed out by the backwashing water vapor during the backwashing of the filter bed, thereby ensuring the caulking and blocking water performance of the polyvinyl chloride mortar. Excessively high heating temperatures will increase the fluidity of the PVC mortar and weaken its cohesiveness, making it easy for the PVC mortar to flow out of the gaps between the filter bricks, thereby reducing its effectiveness in sealing and blocking water. The PVC mortar caulking height is selected to ensure that the PVC mortar can fully penetrate the filter brick joints under the pressure of the concrete block, but will not be squeezed out in large quantities, resulting in waste of caulking material.

[0025] Compared with the existing technology, the construction method of regenerated filter bricks for denitrification deep bed filter using this technical solution has the following beneficial effects:

[0026] (1) The raw materials of the present invention form interconnected pores densely distributed on the surface of the regenerated filter brick under the bonding and curing action of aerated concrete. Compared with the dispersed pore structure formed by post-processing of traditional filter bricks, the regenerated flow cross-section of the present invention is larger, the flow resistance is smaller, and the water and air distribution uniformity is closer to the ideal level. In addition, through experimental research, it is found that the interconnected porosity of up to 58% inside the regenerated filter brick reserves a large space for the retained SS, and SS is not easy to occupy the flow channel, so the clogging period of the regenerated filter brick is longer. Compared with traditional filter bricks, these characteristics of the regenerated filter brick of the present application mean lower backwash frequency and lower energy consumption during backwashing.

[0027] (2) The present invention adopts polyvinyl chloride mortar to fill the joints and concrete blocks to press the joints to achieve the function of filling the joints and blocking water during backwashing. The appropriate construction temperature is used to ensure the appropriate fluidity and cohesion of the polyvinyl chloride mortar, so that it can fully fill the joints between the regenerated filter bricks under the action of gravity and penetrate into the assembled gaps of the regenerated filter bricks under the pressure of the concrete blocks. At the same time, the concrete blocks can also prevent the polyvinyl chloride mortar from being washed out by the backwashing water vapor during the backwashing of the filter bed, thereby ensuring the filling and blocking water performance of the polyvinyl chloride mortar.

[0028] (3) The present invention adopts a special joint structure design and post-installation joint treatment of the regenerated filter brick. Compared with the traditional filter brick that directly adopts the curved surface structure overlapping joint form, the joint water blocking effect is better, and the backwash water and gas are not easy to surge from the joint, so the water and gas distribution uniformity is better. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0030] Figure 1 This is a top surface structural diagram of the Type I regenerative filter brick of the present invention;

[0031] Figure 2 This is a horizontal structural diagram of the Type I regenerative filter brick of the present invention;

[0032] Figure 3 This is a top surface structural diagram of the Type II regenerative filter brick of the present invention;

[0033] Figure 4 This is a horizontal structural diagram of the type II regenerative filter brick of the present invention;

[0034] Figure 5 This is a top structural diagram of the Type III regenerative filter brick of the present invention;

[0035] Figure 6 This is a horizontal structural diagram of the Type III regenerative filter brick of the present invention;

[0036] Figure 7This is a longitudinal structural diagram of type I regenerative filter bricks in the present invention;

[0037] Figure 8 yes Figure 7 Schematic diagram of the enlarged structure at E;

[0038] Figure 9 yes Figure 7 Schematic diagram of the enlarged structure of F;

[0039] Figure 10 The structural diagram of the longitudinal installation and connection of the regenerative filter bricks in the present invention;

[0040] Figure 11 The structural diagram of the horizontal installation and connection of the regenerated filter bricks in the present invention;

[0041] Figure 12 yes Figure 11 Schematic diagram of the enlarged structure at A;

[0042] Figure 13 yes Figure 11 Schematic diagram of the enlarged structure of point B;

[0043] Figure 14 yes Figure 11 Schematic diagram of the enlarged structure at C;

[0044] Figure 15 yes Figure 10 Schematic diagram of the enlarged structure at D;

[0045] The markings in the figure are: 1. Concrete pouring base; 2. Filter brick supporting layer; 3. Regenerated filter brick, 31. Filter brick foot, 32. Cavity, 33. Armpit corner, 34; 4. Joint; 5. Joint filling, 51. PVC mortar filling area, 52. Concrete block pressing area; 6. Backwash air distribution pipe; 7. Backwash water distribution pipe. DETAILED DESCRIPTION

[0046] The present invention will be further described below with reference to specific examples. These examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention.

[0047] The present invention will now be further described with reference to the accompanying drawings. The described embodiments apply only to Type I regenerative filter bricks, which are 0.6m wide. The Type II and Type III regenerative filter bricks, which are 0.9m wide and 1.2m wide, are the result of widening the transverse structure of the Type I filter brick to reduce joints during installation. Their construction methods are the same as those for the Type I filter bricks, and therefore will not be described in detail here. Obviously, the described embodiments represent only a portion of the present invention and are not intended to be exhaustive.

[0048] Example

[0049] See also Figure 1 、 7 As shown in Figure 15, a method for constructing regenerated filter bricks for a denitrification deep bed filter comprises: setting a concrete base layer 1 at the bottom of the denitrification deep bed filter; hoisting a filter brick support layer 2 on the concrete base layer 1; and forming the filter brick support layer 2 by overlapping regenerated filter bricks 3 in the longitudinal and transverse directions. The regenerated filter bricks 3 are made of a raw material composition consisting of 15% waste stone, 25% broken bricks, and 60% concrete fragments by weight, with the raw material particle size controlled to approximately 6 mm by crushing and screening. The cement mortar mix has a bulk ratio of 1:1.5 for dry cement powder to river sand, and the dosage of aerated aluminum powder admixture in the aerated cement mortar is 350 g / m³ of the cement mortar bulk volume. The bulk ratio of the aerated cement mortar to the consolidated construction waste is 2:10. Through experiments, the amount of mixing water required for a cement mortar slump of 90 mm and the amount of accelerator added for an initial setting time of 14 minutes were determined. Regenerated filter bricks 3 were manufactured according to the preparation procedure. The resulting regenerated filter bricks had dimensions of 1.2 m × 0.6 m × 0.3 m and a thickness of 40 mm. Their appearance and compressive strength were then tested. The right-angled side of the internal right-angled bend 33 at the joint of regenerated filter brick 3 was 40 mm long, while the right-angled side of the other internal right-angled bends 33 at regenerated filter brick 3 was 20 mm long. The horizontal and vertical joints of regenerated filter brick 3 were stepped and sloped, with the slopes having a horizontal inclination angle of 45°. After installation, the regenerated filter brick 3's stepped and inclined transverse and longitudinal joints form a Y-shaped joint 4. The joint 4 has a base width of approximately 5 mm, a top width of approximately 20 mm, and a depth of 40 mm. Joint filler 5 is installed within the joint 4. The lower portion of the joint filler 5 comprises a PVC mortar caulking area 51, while the upper portion comprises a concrete block caulking area 52. The PVC mortar caulking area 51 is located on the lower column of the Y-shaped joint 4, while the concrete block caulking area 52 is located at the opening of the Y-shaped joint 4. The foot 31 of the regenerated filter brick 3 is an inverted isosceles trapezoid, 40 mm high, with a horizontal inclination angle of 75° on the hypotenuse. The regenerated filter brick 3 that passed inspection was then placed in a deep-bed filter pilot test. The test filter had an effective water depth of 1.5 m, a filter media layer thickness of 0.8 m, and internal dimensions of 7.3 m x 3.7 m.

[0050] The construction method of the regenerated filter brick masonry specifically includes the following steps:

[0051] 1) Clean the bottom of the denitrification deep bed filter, lay a concrete base 1 on the bottom of the denitrification deep bed filter, reserve a groove 11 for the filter brick footing 31 to be embedded, and lay the backwash air distribution pipe 6 and the backwash water distribution pipe 7.

[0052] 2) The regenerated filter bricks 3 are laid on the concrete base 1 in an overlapping manner. The number of regenerated filter bricks 3 installed is 81, and the total installation size is 7.2×3.6m, forming a filter brick supporting layer 2. A 10cm wide installation deviation space is reserved at the edge connecting with the pool wall. In order to increase the structural integrity of the filter brick supporting layer 2, the regenerated filter bricks 3 should be staggered along the length direction and distributed in a shape to avoid the formation of cross seams.

[0053] 3) The longitudinal and transverse joints 4 of the regeneration filter brick 3 are caulked with polyvinyl chloride mortar. When caulking, the polyvinyl chloride mortar is heated to 125° C. The caulking height is 2 / 3 of the total height of the joint 4, forming a polyvinyl chloride mortar caulking portion 51.

[0054] 4) After step 3) of caulking is completed, the joints are immediately pressed with long strips of concrete blocks. The temperature of the polyvinyl chloride mortar should be kept at 113° C. When pressing the joints, the top of the concrete block is flush with the top of the regenerated filter brick 3 to form a concrete block pressing joint portion 52 .

[0055] 5) After the joint filling and pressing in steps 3) and 4) are completed continuously, concrete pouring is used to fill the installation deviation space reserved in step 2).

[0056] 6) After drying naturally, the construction is completed.

[0057] Test results of the filter brick support layer 2 after construction showed that the interconnected porosity of the regenerated filter bricks ranged from 43% to 51%. Studies on the uniformity of water and air distribution showed that, using clean water as the flow medium, at filtration rates of 5 L / (m2·s) and 10 L / (m2·s), the standard deviations of the water velocity at 25 test points on a 1m2 horizontal surface were 4.8×10-4 m / s and 9.2×10-4 m / s, respectively. Using compressed air as the flow medium, after deducting the aeration pressure requirement caused by the water pressure at the aeration point, the aeration pressures required to achieve aeration rates of 30 L / (m2·s) and 60 L / (m2·s) were 0.25 bar and 0.59 bar, respectively.

[0058] Example 2

[0059] See also Figure 1 、 7 Figure 15 shows a method for constructing regenerated filter bricks for a denitrification deep bed filter. The raw materials for the regenerated filter bricks 3 are composed of 30% waste stone, 30% broken bricks, and 40% concrete fragments in a mass ratio. The remaining material types and proportions, as well as the preparation method and installation parameters for the regenerated filter bricks 3, are the same as those in Example 1.

[0060] The test results of the filter brick support layer 2 after construction show that the interconnected porosity of the regenerated filter brick 3 is 45% to 49%. The research results on the uniformity of water and air distribution show that with clean water as the flow medium, at 5L / (m 2 ·s) and 10L / (m 2 ·s) filtration rate, 1m 2 The standard deviations of the water flow velocities at the 25 test points selected on the horizontal plane were 4.4×10 -4 m / s and 8.9×10 -4 m / s. Using compressed air as the flow medium, minus the aeration pressure demand caused by the water pressure at the aeration point, the aeration pressure reaches 30L / (m 2 ·s) and 60L / (m 2 The aeration pressures required for the aeration rates of ·s) are 0.22 bar and 0.56 bar respectively.

[0061] Example 3

[0062] See also Figure 1 、 7 Figure 15 shows a method for constructing regenerative filter bricks for a denitrification deep bed filter. The particle size of the raw materials used to manufacture the regenerative filter bricks 3 is controlled to be approximately 8 mm. The material types, proportions, preparation method, and installation parameters for the regenerative filter bricks 3 are the same as those in Example 1.

[0063] The test results of the filter brick support layer 2 after construction show that the interconnected porosity of the regenerated filter brick is 52% to 58%. The research results on the uniformity of water and air distribution show that with clean water as the flow medium, at 5L / (m 2 ·s) and 10L / (m 2 ·s) filtration rate, 1m 2 The standard deviations of the water flow velocities at the 25 test points selected on the horizontal surface were 7.9×10 -4 m / s and 1.2×10 -3 m / s. Using compressed air as the flow medium, minus the aeration pressure demand caused by the water pressure at the aeration point, the aeration pressure reaches 30L / (m 2 ·s) and 60L / (m 2 The aeration pressures required for the aeration rates of ·s) are 0.15 bar and 0.32 bar respectively.

[0064] Through the detection of the connected porosity of the regenerated filter brick 3 and the pilot test in Examples 1, 2, and 3, it can be seen that the regenerated filter brick 3 manufactured by the present invention has a very high connected porosity, which also explains the reason why the filter brick has a smaller flow resistance. From the comparison between Example 1 and Example 2, it can be seen that the ratio of different types of raw materials has little effect on the connected porosity, flow resistance, and water distribution uniformity of the filter brick, so the material selection conditions for the filter brick are relatively loose. From the comparison between Example 1 and Example 3, it can be seen that increasing the particle size of the raw material of the filter brick will increase its connected porosity to a certain extent, and reduce the flow resistance to a large extent, but its water distribution uniformity also shows a downward trend. Therefore, the particle size of the raw material of the regenerated filter brick should be controlled within a reasonable range, and the requirements of flow resistance and water distribution uniformity should be taken into account.

[0065] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein with equivalents. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A method for constructing regenerated filter bricks for a denitrification deep bed filter, comprising: A concrete base layer (1) is provided at the bottom of the denitrification deep bed filter; A filter brick supporting layer (2) is hoisted on a concrete pouring base (1), wherein the filter brick supporting layer (2) is formed by overlapping regenerated filter bricks (3) in the longitudinal and transverse directions, and a joint (4) is reserved at the overlap. A joint filler (5) is provided in the joint (4), and the lower part of the joint filler (5) is a polyvinyl chloride mortar filling part (51), and the upper part is a concrete block press joint part (52); The regenerated filter brick (3) is made of engineering construction waste and solidified by aerated cement mortar; The bottom of the regeneration filter brick (3) is provided with a filter brick foot (31), and a cavity (32) for placing a backwash air distribution pipe (6) and a backwash water distribution pipe (7) is formed between the filter brick foot (31); The construction method of the regenerated filter brick masonry specifically includes the following steps: 1) Clean the bottom of the denitrification deep bed filter, lay a concrete base (1) at the bottom of the denitrification deep bed filter, reserve a groove (11) for the filter brick foot (31) to be embedded, and lay a backwash air distribution pipe (6) and a backwash water distribution pipe (7); 2) The regenerated filter bricks (3) are laid on the concrete base (1) in an overlapping manner, and a 10 cm wide installation deviation space is reserved at the edge where the filter brick supporting layer (2) is connected to the pool wall; 3) The longitudinal and transverse joints (4) of the regenerated filter brick (3) are caulked with polyvinyl chloride mortar, wherein the polyvinyl chloride mortar is heated to 120-130° C. during caulking, and the caulking height is 2 / 3 of the total height of the joint (4), thereby forming a polyvinyl chloride mortar caulking portion (51); 4) After step 3) of caulking is completed, the joints are immediately pressed with a long strip of concrete block. When pressing the joints, the temperature of the polyvinyl chloride mortar should be ensured to be above 110° C. After the pressing is completed, the top of the concrete block is flush with the top of the regenerated filter brick (3), forming a concrete block pressing joint portion (52); 5) After the joint filling and pressing in steps 3) and 4) are completed, concrete pouring is used to fill the installation deviation space reserved in step 2); 6) After drying naturally, the construction is completed.

2. The method for constructing a regenerated filter brick for a denitrification deep bed filter according to claim 1, wherein: The regenerated filter brick (3) has two length specifications of 1.2m and 1.5m, three width specifications of 0.6m, 0.9m and 1.2m, a height of 0.3m, and a filter brick filter layer thickness of 40mm.

3. The method for constructing a regenerated filter brick for a denitrification deep bed filter according to claim 1, wherein: The filter brick foot (31) is an inverted isosceles trapezoid with a height of 40 mm and a horizontal inclination angle of the trapezoidal hypotenuse of 75°.

4. The method for constructing regenerated filter bricks for a denitrification deep bed filter according to claim 1, wherein: The regeneration filter brick (3) is provided with an axilla corner (33) at a right angle bend inside. The length of the right angle side of the axilla corner (33) at the joint (4) is 40 mm, and the length of the right angle side of the axilla corner (33) at other locations is 20 mm.

5. The method for constructing regenerated filter bricks for a denitrification deep bed filter according to claim 1, wherein: The transverse and longitudinal joints of the regenerated filter brick (3) are provided with a stepped (34) and inclined surface (45) structure, and the horizontal inclination angle of the inclined surface is 45 degrees.

6. The method for constructing regenerated filter bricks for a denitrification deep bed filter according to claim 1, wherein: In step 2), in order to increase the structural integrity of the filter brick supporting layer (2), the regenerated filter bricks (3) should be staggered along the length direction and distributed in a shape of a triangle to avoid forming a cross seam.

7. The method for constructing regenerated filter bricks for a denitrification deep bed filter according to claim 1, wherein: In step 3), the longitudinal and transverse joints (4) formed after the regeneration filter bricks (3) are installed form a "Y"-shaped structure with a bottom width of about 5 mm, a top width of about 20 mm, and a depth of 40 mm. The polyvinyl chloride mortar filling portion (51) is located on the lower column of the "Y"-shaped joint (4), and the concrete block press joint portion (52) is located on the opening of the "Y"-shaped joint (4).

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