Preparation process and application method of water treatment filler capable of synchronously removing nitrogen and phosphorus

Abstract

The invention provides a preparation process and application method of a water treatment filling material capable of synchronously removing nitrogen and phosphorus, and the preparation process comprises the following steps: step S100, preparing magnesium slag; s200, magnesium slag and quick lime are fully mixed, and a magnesium slag mixture is obtained; s300, the magnesium slag mixture obtained in the step S200 is mixed with struvite seed crystals, and a seed crystal mixture is obtained; and step S400, adding the seed crystal mixture obtained in the step S300 into industrial wastewater or domestic sewage to remove pollutants, or adding the seed crystal mixture into an agricultural non-point source ditch to reduce pollutants in the wastewater. The magnesium slag and the wastewater are fully mixed and then filtered, the magnesium slag is added for reaction, and the struvite seed crystal filter material is used for reaction, so that the content of nitrogen and phosphorus in pollutants can be reduced, and the subsequent treatment operation cost is further reduced. The problem that in the prior art, total nitrogen and total phosphorus in effluent exceed the standard is solved.

Description

Technical Field

[0001] The invention relates to the technical field of a preparation process for a water treatment filler for removing nitrogen and phosphorus, and in particular to a preparation process and an application method for a water treatment filler for simultaneously removing nitrogen and phosphorus. Background Art

[0002] Domestic sewage, industrial wastewater, agricultural non-point source drainage and other water bodies contain a certain concentration of ammonia nitrogen and inorganic phosphorus. The methods for removing nitrogen and phosphorus from domestic sewage and industrial wastewater include: A2O process, oxidation ditch process, breakpoint chlorination, coagulation and sedimentation, etc. Ammonia nitrogen and inorganic phosphorus in agricultural non-point source drainage are removed through ecological ditches, wetlands and other processes. Biological treatment processes such as A2O, oxidation ditches, ecological ditches, and artificial wetlands have harsh operating conditions and are difficult to remove nitrogen and phosphorus simultaneously. Breakpoint chlorination, coagulation and sedimentation and other processes have problems such as the inability to remove pollutants simultaneously and high operating costs.

[0003] In view of the above process characteristics, in order to save the operating cost of the treatment equipment, a preparation and application of water treatment filler for simultaneous removal of nitrogen and phosphorus was invented. Summary of the invention

[0004] The purpose of the present invention is to provide a method for preparing a water treatment filler and an application method thereof, which can solve the problem that the existing water treatment process is difficult to simultaneously and efficiently remove nitrogen and phosphorus, solve the problem that pollutants such as nitrogen and phosphorus in agricultural non-point sources are difficult to remove and the removal effect is unstable, solve the problem of secondary utilization of magnesium slag waste, and realize waste treatment by using magnesium slag modification to remove ammonia nitrogen and total phosphorus pollutants in wastewater and simultaneously remove nitrogen and phosphorus.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A preparation process of a water treatment filler for simultaneously removing nitrogen and phosphorus comprises the following steps:

[0007] Step S100, preparing magnesium slag;

[0008] Step S200, fully mixing magnesium slag and quicklime to obtain a magnesium slag mixture;

[0009] Step S300, mixing the magnesium slag mixture obtained in step S200 with struvite seed crystals to obtain a seed crystal mixture;

[0010] Step S400, adding the seed mixture obtained in step S300 into industrial wastewater or domestic sewage to remove pollutants, or adding it into agricultural non-point source ditches to reduce pollutants in the wastewater.

[0011] Preferably, the magnesium slag preparation in step S100 specifically includes the following steps:

[0012] Step S110, screening magnesium slag, wherein the magnesium slag is solid waste discharged during the process of magnesium smelting by the Pidgeon process, and the main components include CaO, SiO2 and unreduced MgO;

[0013] Step S120, pre-treating the magnesium slag, grinding the screened magnesium slag with a planetary grinder, and filtering with a 50-mesh sieve, wherein the average size of the filtered magnesium slag is less than 0.3 mm;

[0014] Step S130, cleaning the magnesium slag, taking out the magnesium slag powder in step S120, washing it repeatedly with pure water for 3 to 5 times, and drying it naturally for standby use.

[0015] Preferably, the composition range of the magnesium slag in step S110 includes the following: CaO is 40% to 50%, SiO2 is 20% to 30%, Al2O3 is 4% to 7%, MgO<5%, and Fe2O3 is 2.5% to 6.5%.

[0016] Preferably, the step S200 includes the following steps:

[0017] Step S210: the magnesium slag is pretreated and mixed with quicklime in a ratio of 10:10 to 0.5.

[0018] Preferably, in step S300, the magnesium slag mixture S200 is mixed with struvite seed crystals to obtain a seed crystal mixture.

[0019] Preferably, in step S400, the ratio of the amount of the seed mixture added to the ammonia nitrogen in the wastewater is 5:1.

[0020] Preferably, in step S400, the seed mixture obtained in step S300 is fully mixed with the wastewater in a pipeline mixer, and the mixing time is 1 to 2 minutes.

[0021] According to the process for preparing a water treatment filler for simultaneously removing nitrogen and phosphorus according to claim 1, the preparation of struvite crystal seeds in step S300 comprises the following steps:

[0022] Step S310, seed core screening: select activated carbon with a mesh size of 100 to 200 and an iodine adsorption value of 600 to 850 mg / g;

[0023] Step S320, seed core cleaning: all the filter materials screened out in step S310 are placed in hydrochloric acid with a mass concentration of 1% and stirred for 30 minutes, and then taken out and washed with pure water until neutral, and then set aside;

[0024] Step S330, seed crystal preparation: put the filter material in step S320 into pure water, add urea, phosphoric acid and magnesium oxide into the pure water in sequence, slowly stir and react for 3 to 6 hours, and control the end point pH to 7 to 8;

[0025] Step S340, seed crystal stabilization and solidification: the modified biological filter material in step S330 is naturally dried to obtain the struvite seed crystal filter material.

[0026] The present invention also provides an application method of a water treatment filler for synchronously removing nitrogen and phosphorus, characterized in that when applied to industrial wastewater or domestic sewage treatment, the reaction tank is two sets of reaction tanks connected in series, and flocculants are added to the effluent from the reaction tank and enter the sedimentation tank.

[0027] Preferably, when applied to agricultural non-point source ditch treatment, a suspended fixed bed is used as the dosing method in the agricultural non-point source ditch, and the contact area with the water body during water withdrawal accounts for less than 1 / 2 of the ditch cross section.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] The present invention mixes magnesium slag and wastewater thoroughly and then filters them. By adding magnesium slag for reaction and reacting through struvite seed filter material, the nitrogen and phosphorus content in the pollutants can be reduced, and the subsequent treatment and operation costs can be further reduced. The problem of excessive total nitrogen and total phosphorus in effluent in the prior art is solved. The present invention is simple to operate, low in energy consumption, and uses a small-footprint device to replace conventional processes. It can solve the problem that existing water treatment processes are difficult to remove nitrogen and phosphorus efficiently at the same time; the removal of pollutants such as nitrogen and phosphorus from agricultural non-point sources is difficult and the removal effect is unstable; magnesium slag modification is used to achieve waste treatment by waste to remove ammonia nitrogen and total phosphorus pollutants in wastewater. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A schematic flow chart of a process for preparing a water treatment filler for simultaneously removing nitrogen and phosphorus provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0032] like Figure 1 As shown, a preparation process of a water treatment filler for simultaneously removing nitrogen and phosphorus provided in this embodiment includes the following steps:

[0033] Step S100, magnesium slag preparation, specifically includes the following steps:

[0034] Step S110, magnesium slag screening, the magnesium slag is solid waste discharged during the Pijiang process of magnesium smelting, and the main components include CaO, SiO2 and unreduced MgO; the magnesium slag composition range includes the following: CaO is 40% to 50%, SiO2 is 20% to 30%, Al2O3 is 4% to 7%, MgO <5%, and Fe2O3 is 2.5% to 6.5%.

[0035] Step S120, pre-treating the magnesium slag, grinding the screened magnesium slag with a planetary grinder, and filtering with a 50-mesh sieve, wherein the average size of the filtered magnesium slag is less than 0.3 mm.

[0036] Step S130, cleaning the magnesium slag, taking out the magnesium slag powder in step S120, washing it repeatedly with pure water for 3 to 5 times, and drying it naturally for standby use.

[0037] Step S200: fully mix the magnesium slag and quicklime to obtain a magnesium slag mixture.

[0038] Step S210: the magnesium slag is pretreated and mixed with quicklime in a ratio of 10:10 to 0.5.

[0039] Step S300: Mix the magnesium slag mixture obtained in step S200 with struvite seed crystals to obtain a seed crystal mixture.

[0040] The seed mixture obtained in step S300 is added to industrial wastewater or domestic sewage to remove pollutants, or is added to agricultural non-point source ditches to reduce pollutants in the wastewater.

[0041] The preparation of struvite seed crystals in step S300 includes the following steps:

[0042] Step S310, seed core screening: select activated carbon with a mesh size of 100 to 200 and an iodine adsorption value of 600 to 850 mg / g.

[0043] Step S320, seed core cleaning: all the filter materials screened out in step S310 are placed in hydrochloric acid with a mass concentration of 1% and stirred for 30 minutes. After taking out, they are washed with pure water until neutral and set aside.

[0044] Step S330, seed crystal preparation: put the filter material described in step S320 into pure water, add urea, phosphoric acid and magnesium oxide into the pure water in sequence, slowly stir and react for 3 to 6 hours, and control the end point pH to 7 to 8.

[0045] Step S340, seed crystal stabilization and solidification: the modified biological filter material in step S330 is naturally dried to obtain the struvite seed filter material. Implementation effect: the influent ammonia nitrogen is 130 mg / L and the total phosphorus is 1300 mg / L. After 30 minutes of reaction, the ammonia nitrogen is 50 mg / L and the total phosphorus is 6 mg / L.

[0046] Step S400, adding the seed mixture obtained in step S300 into industrial wastewater or domestic sewage to remove pollutants and reduce pollutants in the wastewater.

[0047] Further, in this embodiment, the ratio of the amount of the seed mixture added in step S300 to the ammonia nitrogen in the wastewater is 5:1.

[0048] Further, in this embodiment, in step S400, the seed mixture obtained in step S300 is fully mixed with wastewater in a pipeline mixer, and the mixing time is 1 to 2 minutes.

[0049] When this embodiment is applied to the treatment of industrial wastewater or domestic sewage, the reaction tanks are two sets of reaction tanks connected in series, and the effluent from the reaction tanks is added with flocculants and enters the sedimentation tank.

[0050] Embodiment 2

[0051] This second embodiment is based on the first embodiment. When applied to agricultural non-point source ditch treatment, a suspended fixed bed is used as the dosing method in the agricultural non-point source ditch, and the contact area with the water body during water withdrawal occupies less than 1 / 2 of the ditch cross section.

[0052] On the basis of Example 1, in the preparation of struvite seed crystals, step S340, seed crystal stabilization and solidification: the modified biological filter material in step S330 is naturally dried to obtain the struvite seed crystal filter material. Implementation effect: the influent ammonia nitrogen is 3mg / L and the total phosphorus is 1.2mg / L. After 60min of reaction, the ammonia nitrogen is 2.5mg / L and the total phosphorus is 0.7mg / L.

[0053] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0054] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0055] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A preparation process for a water treatment filler for simultaneous removal of nitrogen and phosphorus, characterized in that: The steps include: Step S100, preparing magnesium slag; Step S200, fully mixing magnesium slag and quicklime to obtain a magnesium slag mixture; Step S300, mixing the magnesium slag mixture obtained in step S200 with struvite seed crystals to obtain a seed crystal mixture; Step S400, adding the seed mixture obtained in step S300 into industrial wastewater or domestic sewage to remove pollutants, or adding it into agricultural non-point source ditches to reduce pollutants in the wastewater.

2. The preparation process of a water treatment filler for simultaneous removal of nitrogen and phosphorus according to claim 1, characterized in that: The magnesium slag preparation in step S100 specifically includes the following steps: Step S110, screening magnesium slag, wherein the magnesium slag is solid waste discharged during the process of magnesium smelting by the Pidgeon process, and the main components include CaO, SiO2 and unreduced MgO; Step S120, pre-treating the magnesium slag, grinding the screened magnesium slag with a planetary grinder, and filtering with a 50-mesh sieve, wherein the average size of the filtered magnesium slag is less than 0.3 mm; Step S130, cleaning the magnesium slag, taking out the magnesium slag powder in step S120, washing it repeatedly with pure water for 3 to 5 times, and drying it naturally for standby use.

3. The preparation process of a water treatment filler for simultaneous removal of nitrogen and phosphorus according to claim 2, characterized in that: The composition range of the magnesium slag in step S110 includes the following: CaO is 40% to 50%, SiO2 is 20% to 30%, Al2O3 is 4% to 7%, MgO <5%, and Fe2O3 is 2.5% to 6.5%.

4. The preparation process of a water treatment filler for simultaneous removal of nitrogen and phosphorus according to claim 1, characterized in that: The step S200 includes the following steps: Step S210: the magnesium slag is pretreated and mixed with quicklime in a ratio of 10:10 to 0.

5.

5. The preparation process of the water treatment filler for simultaneous removal of nitrogen and phosphorus according to claim 2, characterized in that: In the step S300, the magnesium slag mixture S200 is mixed with struvite seed crystals to obtain a seed crystal mixture.

6. The preparation process of the water treatment filler for simultaneous removal of nitrogen and phosphorus according to claim 3, characterized in that: The ratio of the amount of the seed mixture added in step S400 to the ammonia nitrogen in the wastewater is 5:

1.

7. The preparation process of the water treatment filler for simultaneous removal of nitrogen and phosphorus according to claim 1, characterized in that: In the step S400, the seed mixture obtained in the step S300 is fully mixed with the wastewater in a pipeline mixer, and the mixing time is 1 to 2 minutes.

8. The process for preparing a water treatment filler for simultaneous removal of nitrogen and phosphorus according to claim 1, wherein the preparation of struvite seed crystals in step S300 comprises the following steps: Step S310, seed core screening: select activated carbon with a mesh size of 100 to 200 and an iodine adsorption value of 600 to 850 mg / g; Step S320, seed core cleaning: all the filter materials screened out in step S310 are placed in hydrochloric acid with a mass concentration of 1% and stirred for 30 minutes, and then taken out and washed with pure water until neutral, and then set aside; Step S330, seed crystal preparation: put the filter material in step S320 into pure water, add urea, phosphoric acid and magnesium oxide into the pure water in sequence, slowly stir and react for 3 to 6 hours, and control the end point pH to 7 to 8; Step S340, seed crystal stabilization and solidification: the modified biological filter material in step S330 is naturally dried to obtain the struvite seed crystal filter material.

9. An application method of a water treatment filler for simultaneous removal of nitrogen and phosphorus according to any one of claims 1 to 8, characterized in that: When applied to the treatment of industrial wastewater or domestic sewage, the reaction tank is two sets of reaction tanks connected in series, and the effluent from the reaction tank is added with flocculants and enters the sedimentation tank.

10. The application method of the water treatment filler for simultaneous removal of nitrogen and phosphorus according to claim 9, characterized in that: When applied to agricultural non-point source ditch treatment, a suspended fixed bed is used as the dosing method in the agricultural non-point source ditch, and the contact area with the water body occupies less than 1 / 2 of the ditch cross section when the water recedes.

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