A device and method for recovering high-purity phosphorus in water

Abstract

The present invention discloses a high-purity phosphorus recovery device and method in water, which belongs to the field of water treatment, and specifically relates to the recovery of high-purity phosphorus products in microplastic-contaminated water source water or sewage. The device comprises a protein adsorption unit, a phosphorus adsorption unit and a PLC device, wherein the protein adsorption unit is composed of a pH adjustment solution dosing system, a protein adsorption column, a protein adsorption resin regeneration system, and a resin trap, and the phosphorus adsorption unit is composed of a phosphorus adsorption column, a switchable magnetic field, and a phosphorus adsorption filler regeneration system. The isoelectric point of the phosphorus-containing water source water or sewage is adjusted by pH to allow protein and plastic to combine, and the dual advantages of efficient protein adsorption by ninhydrin-modified resin and strong complexation and separation of phosphate by methyltriethoxysilane-modified filler are utilized to improve the purity of phosphorus recovery products, phosphorus recovery efficiency and phosphorus product purity. The present invention can be used for the removal of microplastic pollutants in water and the recovery of high-purity phosphate.

Description

Technical Field

[0001] The present invention specifically provides a device and method for recovering high-purity phosphate from phosphorus-containing water source water or sewage. Background Art

[0002] Phosphorus is an inaccessible element that maintains the normal activities of living organisms and is a valuable non-renewable resource. However, the shortage of phosphorus resources and phosphorus pollution in water are the two major bottleneck problems currently faced. Using phosphorus recovery technology to obtain phosphorus recovery products from phosphorus-containing or phosphorus-rich water bodies can not only alleviate the phosphorus resource crisis, but also solve the phosphorus pollution problem. Phosphorus recovery methods include crystallization, precipitation, ion exchange, adsorption, and so on. Among them, the superparamagnetic nanomaterial adsorption method still shows a high selective capture ability and strong regeneration ability for phosphate even under the coexistence of nitrate, chloride, sulfate and other ions, so it has received great attention. However, organic pollutants (such as proteins, carbohydrates, fats, urea, etc.) interfere with the phosphorus adsorption and phosphorus desorption processes of superparamagnetic nanomaterials. In particular, protein molecules show a strong affinity for nano-microplastics and can form nano-protein coronas with a size of 13~600nm. In this way, the nano-protein corona is easy to compete with phosphate ions for adsorption. If the nano plastic protein corona is desorbed from the surface of superparamagnetic nanoparticles along with the desorbed phosphate, nano micro plastics are easily mixed into phosphate fertilizer products and enter farmland. If they are internalized by plants and produce toxic effects, they have a significant impact on their growth metabolism, photosynthesis and oxidative stress processes. The present invention focuses on separating the nano plastic protein corona by utilizing the isoelectric point characteristics, and separately setting a protein separation unit and a phosphorus recovery unit to shield the interference effect of the protein on the phosphorus recovery process, thereby improving the phosphorus recovery efficiency and the purity of the phosphorus product, while preventing micro plastics from polluting farmland through the phosphorus fertilizer application route. Summary of the invention

[0003] The present invention aims to address the deficiencies of the prior art and provides a technology that can efficiently recover high-purity phosphate in water, which can solve the problem that the phosphorus recovery process is easily interfered by organic pollutants and microplastic pollutants, thereby achieving the purpose of improving the recovery efficiency of phosphate and alleviating the existing phosphorus shortage and phosphorus pollution. After being processed by the technology of the present invention, high-purity separation and recovery of phosphate can be achieved.

[0004] A further technical task of the present invention is to provide a high-purity phosphorus recovery device and treatment method for phosphorus-containing water.

[0005] The technical solution adopted by the present invention to solve its technical problem is: a phosphorus recovery device and method for phosphorus-containing water source water or sewage that can separate microplastics, including a protein adsorption unit, a phosphorus adsorption unit, and a PLC device;

[0006] The protein adsorption unit is arranged at the front end of the phosphorus adsorption unit, and the protein adsorption unit comprises a protein adsorption column pH adjustment solution dosing system, a protein adsorption column, a protein adsorption resin regeneration system, and a resin trap;

[0007] The protein adsorption column is a column structure filled with ninhydrin modified resin, which is arranged at the bottom of the pH adjustment solution addition system;

[0008] The protein adsorption resin regeneration system stores 6-8% sodium chloride solution and is arranged at the bottom of the protein adsorption column;

[0009] The resin trap is arranged at the bottom of the first outflow pipe;

[0010] The phosphorus adsorption unit is arranged at the end of the liquid outlet pipe of the resin trap, and the phosphorus adsorption unit comprises a phosphorus adsorption column, a magnetic field device that can be turned on and off, and a phosphorus adsorption filler regeneration system;

[0011] The phosphorus adsorption column is a column structure filled with a resin filler modified by methyltriethoxysilane, and is arranged behind the first outflow pipe;

[0012] The detachable arc-shaped magnet in the openable and closable magnetic field device is clamped on the outside of the phosphorus adsorption column tank, fixed by an electric clamp and opened and closed on the outside of the phosphorus adsorption column tank, and controlled by a PLC device; the detachable arc-shaped magnet is made of neodymium iron boron magnet; the filler regeneration system stores 5% sodium hydroxide solution and is arranged at the bottom of the phosphorus adsorption column;

[0013] The filler regeneration system is arranged on the upper part of the phosphorus adsorption column, and is composed of a second stainless steel container, an alkali solution replenishing port, a drain valve, a filler regeneration liquid pipeline electromagnetic valve, a filler regeneration liquid pipeline, and a high-pressure fine water mist open nozzle.

[0014] Preferably, the ninhydrin modified resin is a polymer material obtained by using styrene type strong acid cationic resin as a substrate, and using ninhydrin to tightly cover and combine on the surface of the cationic resin under hydrothermal conditions to modify it. The preparation steps of the filler are: prepare a 10% mass fraction ninhydrin aqueous solution, slowly add the ninhydrin aqueous solution to a styrene type strong acid cationic resin solution with a mass concentration of 40~50 mg / ml at 2~3 times the mass at room temperature of 25°C, and continue stirring for 20min~40min during the whole process; finally obtain a mixed solution of ninhydrin and styrene type strong acid cationic resin; centrifuge the mixed solution, wash off the foam, and freeze-dry to constant weight to obtain the ninhydrin modified resin.

[0015] Preferably, the silane-modified phosphorus-absorbing spherical filler is a silane-modified phosphorus-absorbing spherical filler having a semi-interpenetrating network structure, which is obtained by reacting superparamagnetic nanoparticles surface-modified with methyltriethoxysilane and star-shaped poly(glycidyl methacrylate). The preparation steps of the filler are: first, synthesizing Fe by coprecipitation method; 3 O 4 The magnetic core is then covered with a silicate coating to form the Fe 3 O 4 @SiO 2 Magnetic nanocore. Fe 3 O 4 @SiO 2 The steps of preparing magnetic nanocores include synthesizing magnetite and coating with silica. Magnetite was synthesized by the commonly used coprecipitation method. 8 g of FeCl 3 6H 2 O and 3 g FeCl 2 ·4H 2 O is put into a flask and dissolved in 100 ml of deionized water. At the same time, 1. 5 mol / L monohydrate ammonia solution is added dropwise to the above mixture under stirring at room temperature. After the final pH value reaches 8-8.5, the stirring can be stopped, the black precipitate is magnetically separated and washed three times with deionized water; the black precipitate is dispersed in 120 ml of deionized water and mixed with 120 ml of 0.66 mol / L nitric acid solution, and 80 ml of diluted ammonia water is added under stirring, and the mixture is heated to 70-72°C; sodium silicate solution is added with a syringe under stirring and continued stirring for 5 minutes, and a silicon dioxide coating is formed on the surface of the magnetite, that is, Fe 3 O 4 @SiO 2 Magnetic nanocore solution. Then, 5 g MgCl 2 6H 2 O and 6gAlCl 3 6H 2 O was dissolved in 100 ml of water and 1 mol / L of Na 2 CO 3 and 1.5 mol / L NaOH alkaline solution 50 ml each, then add 10-12 g CeCl 3 7H 2 O, and crystallized at 80°C for 24 hours to obtain a Ce-loaded hydroxy bimetallic oxide suspension. 3 O 4 @SiO 2The superparamagnetic nanoparticle solution was mixed, stirred and ultrasonically treated (5000~5500hz) for 20~30min to obtain a superparamagnetic nanoparticle suspension. At room temperature of 25℃, 5ml of ethanol solution of methyltriethoxysilane with a concentration of about 40mg / ml was slowly added to 10ml of superparamagnetic nanoparticle suspension, maintained at a stirring speed of 200~300r / min for 20min~40min, and then ultrasonically treated at 4800~5200hz and dried to obtain silanized magnetic nanoparticles. Then 20g of silanized magnetic nanoparticles was added to 50ml of star-shaped poly(glycidyl methacrylate) solution in a constant temperature water bath at 40℃, and stirred continuously for 15min~20min to allow the two to react fully. Finally, the mixed solution was centrifuged, the foam was washed off, freeze-dried to constant weight, and pressed into a sphere with a diameter of 10~12mm, so as to obtain a silane-modified phosphorus adsorption spherical filler with a semi-interpenetrating network structure.

[0016] Preferably, the protein adsorption column includes a first liquid inlet pipe, a first liquid inlet pipe solenoid valve, a first exhaust valve, a protein adsorption column tank body, a first fixed flange, a resin inlet, a ninhydrin-modified resin, a resin outlet, a first porous leakage plate, a first screen, a first outflow pipe and a first outflow pipe solenoid valve. The first fixed flange is tightly clamped on the outside of the protein adsorption column tank body. The ninhydrin-modified resin is used to adsorb nanoplastic protein coronas in phosphorus-containing water sources or sewage.

[0017] Preferably, the pH adjusting solution dosing system is composed of a glass fiber reinforced plastic container, a drain valve, an electromagnetic valve of the regulating liquid outflow pipeline, a regulating solution replenishment port, and an outflow pipeline of the regulating solution dosing system. The electromagnetic valve of the regulating liquid outflow pipeline is controlled by a PLC device, and 2-4 mol / L of dilute hydrochloric acid is stored in the glass fiber reinforced plastic container; the PLC device is electrically connected to the electromagnetic valve of the regulating liquid outflow pipeline, and the PLC device is used to control the opening and closing of the electromagnetic valve of the regulating liquid outflow pipeline. When the TOC concentration of the outlet water in the first outflow pipeline of the protein adsorption column is higher than 40% of the TOC concentration of the inlet water, the PLC device controls the electromagnetic valve of the regulating liquid outflow pipeline to open, and 2-4 mol / L of dilute hydrochloric acid can be added to the phosphorus-containing water source water or sewage. When the TOC concentration of the outlet water in the first outflow pipeline of the protein adsorption column is lower than 40% of the TOC concentration of the inlet water, the PLC device controls the electromagnetic valve of the regulating liquid outflow pipeline to close.

[0018] Preferably, the protein adsorption resin regeneration system is arranged at the bottom of the protein adsorption column, and is composed of a first stainless steel container, a liquid replenishment port, a drain valve, a regeneration liquid pipeline electromagnetic valve, a No. 1 water pump, and a regeneration liquid pipeline. The regeneration liquid pipeline electromagnetic valve is arranged on the regeneration liquid pipeline, and the regeneration liquid pipeline electromagnetic valve is provided with a silicone sealing ring and is controlled by a PLC device. A 6-8% sodium chloride solution is stored in the first stainless steel container; the regeneration liquid pipeline of the protein adsorption resin regeneration system is connected to the water pump through a pipeline, and the No. 1 water pump is connected to the lower end of the protein adsorption column through a pipeline; when the TOC removal rate in the liquid discharged from the first outflow pipeline is lower than 80%, the PLC device controls the regeneration liquid pipeline electromagnetic valve and the No. 1 water pump to open, and the mass fraction of 6-8% sodium chloride solution is conveyed to the protein adsorption column through the pressure of the No. 1 water pump to regenerate the protein adsorption resin; the regeneration liquid pipeline electromagnetic valve is arranged on the regeneration liquid pipeline of the protein adsorption resin regeneration system, and the regeneration liquid pipeline electromagnetic valve is provided with a silicone sealing ring to prevent water leakage.

[0019] Preferably, the resin catcher is composed of a water inlet, an internal screen, a cylinder, a water outlet, and a sewage outlet. After the liquid flowing out of the first outflow pipe passes through the resin catcher, the resin in the liquid is intercepted by the screen in the resin catcher.

[0020] Preferably, the phosphorus adsorption column is arranged behind the first outflow pipe, including a second liquid inlet pipe, a second liquid inlet pipe valve, a second exhaust valve, a phosphorus adsorption column tank body, a second fixed flange, a filler inlet, silane-modified phosphorus adsorption spherical filler, a filler outlet, a second porous leakage plate, a second screen, a phosphorus adsorption column outflow pipe and a phosphorus adsorption column outflow pipe valve, and the second fixed flange is tightly clamped on the outside of the phosphorus adsorption column tank body; the second fixed flange is tightly clamped on the outside of the phosphorus adsorption column tank body, and the internal silane-modified phosphorus adsorption filler is used to adsorb phosphate in phosphorus-containing water source water or sewage.

[0021] Preferably, when the phosphorus adsorption column is less than 70% within 24 hours after regeneration, the PLC device controls the electric gripper so that the arc magnet is not close to the column, the switchable magnetic field device is in a closed state, and new spherical resin is added to the packing layer of the phosphorus adsorption column to replenish the silane-modified phosphorus adsorption spherical packing, and at the same time, the packing outlet of the phosphorus adsorption column is opened to discharge the old packing equal to the replenishment amount. When the filler replenishment amount reaches 30% to 40% of the original filler total amount, the replenishment and discharge of the filler are stopped.

[0022] Preferably, the detachable arc-shaped magnet in the switchable magnetic field device is clamped on the outside of the phosphorus adsorption column tank, and is fixed and opened and closed on the outside of the phosphorus adsorption column tank by an electric gripper, and is controlled by a PLC device. The detachable arc-shaped magnet is made of a neodymium iron boron magnet; the PLC device controls the opening and closing of the electric gripper, and when the phosphorus adsorption column is in the adsorption process, the electric gripper is controlled to drive the detachable arc-shaped magnet to close, and the detachable arc-shaped magnet of the switchable magnetic field device is magnetically attracted, and the switchable magnetic field device is in an open state; when the phosphorus adsorption column is in a desorption state, the PLC device controls the electric gripper so that the detachable arc-shaped magnet is not close to the column, and the switchable magnetic field device is in a closed state. Under the control of the PLC device, the switchable magnetic field device can be automatically opened and closed.

[0023] Preferably, the filler regeneration system is arranged at the upper part of the phosphorus adsorption column, and is composed of a second stainless steel container, an alkali solution replenishing port, a drain valve, a filler regeneration liquid pipeline electromagnetic valve, a filler regeneration liquid pipeline, and a high-pressure fine water mist open nozzle. The filler regeneration liquid pipeline electromagnetic valve is arranged on the filler regeneration liquid pipeline, and the high-pressure fine water mist open nozzle is connected to the filler regeneration liquid pipeline. A group of two high-pressure fine water mist open nozzles are arranged, which are equidistantly installed on the inner side of the top of the phosphorus adsorption column. The filler regeneration liquid pipeline electromagnetic valve is controlled by a PLC device. A 5% sodium hydroxide solution is stored in the second stainless steel container. When the phosphorus recovery efficiency of the phosphorus adsorption column is lower than 80%, the PLC device controls the filler regeneration liquid pipeline electromagnetic valve to open, so that the 5% sodium hydroxide solution is transported to the high-pressure fine water mist open nozzle through the filler regeneration liquid pipeline, and is evenly sprayed into the silane-modified phosphorus adsorption spherical filler in the form of fine water mist. The silane-modified phosphorus adsorption spherical filler in the phosphorus adsorption column can complete the desorption process under the action of the 5% by mass sodium hydroxide solution, that is, the silane-modified phosphorus adsorption spherical filler is regenerated.

[0024] The present invention also discloses a wastewater treatment method, which is based on the microplastic separation and phosphorus recovery device for phosphorus-containing water source water or sewage as described in claim 1, and includes the following steps: S01), microplastic protein separation and removal stage: when the phosphorus-containing water source water or sewage passes through the first liquid inlet pipe, under the action of pH adjustment, the microplastics and protein macromolecules in the water are combined into nano-protein coronas, and the nano-protein coronas are very easy to combine with the ninhydrin modified resin, so they are removed and separated after entering the protein adsorption column. When the TOC removal rate in the liquid discharged from the first outflow pipe is lower than 80%, the first liquid inlet pipe solenoid valve is controlled to be closed by the PLC device, and the protein adsorption resin regeneration system is turned on, and a 6-8% sodium chloride solution is transported to the protein adsorption column through the No. 1 water pump, and the No. 1 water pump uses a solvent metering dosing pump to regenerate the resin. The resin capture device is used to intercept residual resin in the liquid coming from the first outflow pipe; S02), phosphorus recovery stage: phosphorus-containing water source water or sewage after removing microplastics and proteins enters the phosphorus adsorption column, and phosphorus is adsorbed by silane-modified phosphorus adsorption spherical filler. At this time, the PLC device controls the electric gripper to make the arc magnet close to the column, and the on-off magnetic field device is in the open state, and the treated phosphorus-free sludge supernatant is discharged; when the phosphorus recovery rate is lower than 80%, the PLC device controls the second liquid inlet pipeline valve to close, the PLC device controls the first liquid inlet pipeline solenoid valve to close and controls the filler regeneration liquid pipeline solenoid valve to open, so that 5% sodium hydroxide solution in the regeneration system is sent to the high-pressure fine water mist open nozzle through the filler regeneration liquid pipeline, and the nozzle sprays 5% sodium hydroxide solution to the silane-modified phosphorus adsorption spherical filler in the phosphorus adsorption column. At this time, the discharged liquid is alkaline phosphorus recovery liquid. S03) Filler replenishment stage: When the phosphorus recovery rate is lower than 70% within 24 hours after the phosphorus adsorption filler regeneration stage is completed, the PLC device controls the electric gripper so that the arc magnet is not close to the column, and the magnetic field device is in a closed state. New spherical resin is added to the filler layer of the phosphorus adsorption column through the filler inlet of the phosphorus adsorption column to replenish the silane-modified phosphorus adsorption spherical filler. At the same time, the filler outlet of the phosphorus adsorption column is opened to discharge the old filler equal to the replenishment amount. When the filler replenishment amount reaches 30%~40% of the original filler total amount, stop replenishing and discharging the filler.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. Higher protein separation efficiency: By setting ninhydrin-modified resin in the protein adsorption column and adjusting the pH of phosphorus-containing source water or sewage, the ninhydrin-modified resin in the protein adsorption column can achieve efficient separation of protein within a suitable pH range, thereby ensuring highly selective phosphorus adsorption in the rear-end phosphorus adsorption column.

[0027] 2. The purity of phosphorus recovery products is better: by setting silane-modified phosphorus adsorption spherical fillers in the phosphorus adsorption column, the phosphorus adsorption efficiency is increased by more than 30%, and the product purity is increased by more than 30%.

[0028] 3. Timely update of phosphorus adsorption filler: By adding new spherical resin to the filler inlet of the phosphorus adsorption column, the amount of resin in the phosphorus adsorption column and its overall adsorption capacity can be kept stable, and the problem of filler loss is solved in time, thereby improving the phosphorus recovery efficiency.

[0029] 4. Adopt new modification method:

[0030] (1) Using a new modification method - Ninhydrin modified resin is to modify styrene-based strong acidic cationic resin using the affinity protein ninhydrin. Under hydrothermal conditions, ninhydrin tightly covers and binds to the surface of the cationic resin, forming a tightly bound state. This binding state greatly improves the diffusion and adsorption efficiency of the resin for macromolecules such as proteins, making it an excellent modified protein adsorbent.

[0031] (2) Using a new modification method - silane-modified phosphorus adsorption spherical filler is a resin material synthesized from cerium-modified magnetic nanoparticles modified by methyltriethoxysilane and star-shaped poly(glycidyl methacrylate) and has a semi-interpenetrating network structure. During the preparation process, the two are fully reacted through heat treatment and stirring to form an interpenetrating structure. The material has excellent magnetic responsiveness, outstanding chemical stability, good biocompatibility and excellent mechanical strength properties.

[0032] 5. The several component units in the present invention have simple structures, complement each other, and have complementary advantages. They can achieve the separation of protein and plastic in sludge supernatant and the recovery of phosphorus, especially can effectively improve the purity of phosphorus recovery products and reduce the environmental risks of organic matter and microplastic pollution.

[0033] In summary, the processing device of the present invention has advantages in the separation of proteins and plastics and the phosphate recovery method, and provides a more efficient and intelligent solution to the problem of recovering high-purity phosphorus products from sludge supernatant. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Attached Figure 1 A schematic diagram of a phosphorus recovery device and method for phosphorus-containing water source water or sewage that can separate microplastics

[0035] Attached Figure 1 The symbols in represent:

[0036] 1. Protein adsorption unit, 11. pH adjustment solution dosing system, 111. FRP container, 112. Drain valve, 113. Solenoid valve of adjusting solution outflow pipeline, 114. Adjusting solution replenishing port, 115. Outflow pipeline of adjusting solution dosing system, 12. Protein adsorption column, 121. First liquid inlet pipe, 122. First liquid inlet pipeline solenoid valve, 123. First exhaust valve, 124. Protein adsorption column tank, 125. First fixing flange, 126. Resin inlet, 127 , ninhydrin modified resin, 128, resin outlet, 129, first porous cloth leakage plate, 12-10, first screen, 12-11, first outflow pipe, 12-12, first outflow pipe solenoid valve, 13, protein adsorption resin regeneration system, 131, first stainless steel container, 132, liquid replenishment port, 133, drain valve, 134, regeneration liquid pipeline solenoid valve, 135, No. 1 water pump, 136, regeneration liquid pipeline, 14, resin capture device, 141, water inlet, 1 42. Internal screen, 143. Cylinder, 144. Water outlet, 145. Drainage outlet, 146. Resin trap outlet pipe, 2. Phosphorus adsorption unit, 21. Phosphorus adsorption column, 211. Second liquid inlet pipe, 212. Second liquid inlet pipe valve, 213. Second exhaust valve, 214. Phosphorus adsorption column tank, 215. Second fixing flange, 216. Filler inlet, 217. Silane-modified phosphorus adsorption spherical filler, 218. Filler outlet, 219. Second porous cloth leakage plate, 21 -10. Second screen, 21-11. Outflow pipe of phosphorus adsorption column, 21-12. Valve of outflow pipe of phosphorus adsorption column, 22. Openable and closable magnetic field device, 221. Removable arc magnet, 222. Electric gripper, 23. Phosphorus adsorption filler regeneration system, 231. Second stainless steel container, 232. Alkali solution replenishment port, 233. Drain valve, 234. Solenoid valve of filler regeneration liquid pipeline, 235. Filler regeneration liquid pipeline, 236. High-pressure fine water mist open nozzle, 3. PLC device. DETAILED DESCRIPTION

[0037] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments, but is not intended to limit the present invention.

[0038] like Figure 1 As shown, the phosphorus adsorption device of this embodiment mainly includes: a protein adsorption unit 1, a phosphorus adsorption unit 2, and a PLC device 3.

[0039] The protein adsorption unit 1 is arranged at the front end of the phosphorus adsorption unit 2, and includes a pH adjustment solution dosing system 11, a protein adsorption column 12, a protein adsorption resin regeneration system 13, and a resin trap 14;

[0040] The protein adsorption column 12 is a column structure filled with ninhydrin modified resin, and is arranged at the bottom of the pH adjustment solution addition system 11;

[0041] The protein adsorption resin regeneration system 13 stores 6-8% sodium chloride solution and is arranged at the bottom of the protein adsorption column 12;

[0042] The resin catcher 14 is arranged at the bottom of the first outflow pipe 12-11;

[0043] The phosphorus adsorption unit 2 is arranged at the rear end of the protein adsorption unit 1, and includes a phosphorus adsorption column 21, a magnetic field device 22 that can be turned on and off, and a filler regeneration system 23;

[0044] The phosphorus adsorption column 21 is a column structure filled with a silane-modified phosphorus adsorption spherical filler, and is arranged behind the first outflow pipe 12-11;

[0045] The detachable arc-shaped magnet 221 is installed on the outside of the phosphorus adsorption column 21 through the electric gripper 222. The outer side of the detachable arc-shaped magnet 221 is fixed to the electric gripper 222. The detachable arc-shaped magnet 221 can be detached and assembled on the outside of the phosphorus adsorption column 21 by opening and closing the electric gripper 222.

[0046] The filler regeneration system 23 stores 5% sodium hydroxide solution and is arranged at the bottom of the phosphorus adsorption column 21;

[0047] The principle and method for preparing ninhydrin-modified protein adsorption resin are as follows:

[0048] 1. The filler is a polymer material obtained by using styrene-type strongly acidic cationic resin as a base and modifying the cationic resin surface by tightly covering and combining it with ninhydrin under hydrothermal conditions.

[0049] 2. The preparation steps of the resin are: prepare a 10% by mass ninhydrin aqueous solution, slowly add the ninhydrin aqueous solution to a styrene-type strongly acidic cationic resin solution with a mass concentration of 40-50 mg / ml, which is 2-3 times the mass of the ninhydrin aqueous solution, at room temperature of 25°C, and continue stirring for 20-40 minutes during the whole process; finally obtain a mixed solution of ninhydrin and styrene-type strongly acidic cationic resin; centrifuge the mixed solution, wash off the foam, and freeze-dry to constant weight to obtain the ninhydrin-modified resin.

[0050] The principle and method for preparing phosphorus adsorption filler modified by methyltriethoxysilane are as follows:

[0051] 1. The filler is a silane-modified phosphorus-adsorbing spherical filler with a semi-interpenetrating network structure, which is formed by the co-reaction of superparamagnetic nanoparticles with methyltriethoxysilane surface modified and star-shaped poly(glycidyl methacrylate).

[0052] 2. The preparation steps of the filler are: first, Fe 3 O4 The magnetic core is then covered with a silicate coating to form the Fe 3 O 4 @SiO 2 Magnetic nanocore. Fe 3 O 4 @SiO 2 The steps of preparing magnetic nanocores include synthesizing magnetite and coating with silica. Magnetite was synthesized by the commonly used coprecipitation method. 8 g of FeCl 3 6H 2 O and 3 g FeCl 2 ·4H 2 O is put into a flask and dissolved in 100 ml deionized water. At the same time, 1.5 mol / L monohydrate ammonia solution is added dropwise to the above mixture under stirring at room temperature. After the final pH value reaches 8-8.5, the stirring can be stopped, the black precipitate is magnetically separated and washed three times with deionized water; the black precipitate is dispersed in 120 ml deionized water and mixed with 120 ml 0.66 mol / L nitric acid solution, and 80 ml of diluted ammonia water is added under stirring, and the mixture is heated to 70-72°C; sodium silicate solution is added with a syringe under stirring and continued stirring for 5 minutes, and a silicon dioxide coating is formed on the surface of the magnetite, that is, Fe 3 O 4 @SiO 2 Magnetic nanocore solution. Then, 5 g MgCl 2 6H 2 O and 6gAlCl 3 6H 2 O was dissolved in 100 ml of water and 1 mol / L of Na 2 CO 3 and 1.5 mol / L NaOH alkaline solution, 50 mL each, and then add 10-12 g CeCl 3 7H 2 O, and crystallized at 80°C for 24 hours to obtain a Ce-loaded hydroxy bimetallic oxide suspension. 3 O 4 @SiO 2The superparamagnetic nanoparticle solution was mixed, stirred and ultrasonically treated (5000~5500hz) for 20~30min to obtain a superparamagnetic nanoparticle suspension. At room temperature of 25℃, 5ml of ethanol solution of methyltriethoxysilane with a concentration of about 40mg / ml was slowly added to 10ml of superparamagnetic nanoparticle suspension, maintained at a stirring speed of 200~300r / min for 20min~40min, and then ultrasonically treated at 4800~5200hz and dried to obtain silanized magnetic nanoparticles. Then 20g of silanized magnetic nanoparticles was added to 50ml of star-shaped poly(glycidyl methacrylate) solution in a constant temperature water bath at 40℃, and stirred continuously for 15min~20min to allow the two to react fully. Finally, the mixed solution was centrifuged, the foam was washed off, freeze-dried to constant weight, and pressed into a sphere with a diameter of 10~12mm, so as to obtain a silane-modified phosphorus adsorption spherical filler with a semi-interpenetrating network structure. Embodiment 1

[0053] The following test is used to verify the effect of the present invention:

[0054] The present invention is used to solve the problem that the existing phosphorus recovery technology is susceptible to interference and the water treatment method of phosphorus recovery product has low purity, and the following steps are performed:

[0055] 1) Protein and plastic removal stage

[0056] The PLC device 3 controls the first liquid inlet pipe electromagnetic valve 122 to open. When the influent (phosphorus-containing water source water or sewage) enters the protein adsorption column 12 through the first inlet pipe 121, the PLC device 3 controls the opening of the regulating liquid outflow pipe electromagnetic valve 113 of the pH regulating solution dosing system 11, and 4 mol / L hydrochloric acid enters the first inlet pipe 121 of the protein adsorption column 12 and mixes with the influent, so that the pH range is adjusted to 5.5-6.5. At this time, the microplastics and proteins are combined into the nanoplastic protein crown with the highest degree of combination. The influent enters the protein adsorption column 12 and contacts with the ninhydrin modified resin 127, and the nanoplastic protein crown is adsorbed by the ninhydrin modified resin 127. After removing the microplastics and proteins, the phosphorus-containing water source water or sewage flows out through the protein adsorption column outflow pipe 12-11 and enters the phosphorus adsorption column 21 through the resin capture device outlet pipe 146, thereby starting the next stage, namely the phosphorus adsorption stage.

[0057] 2) Phosphorus adsorption stage

[0058] After the phosphorus-containing source water or sewage enters the phosphorus adsorption column 21, the phosphorus is adsorbed and removed by the silane-modified phosphorus adsorption spherical filler 217, and the purified water is discharged through the phosphorus adsorption column outflow pipe.

[0059] 3) Protein adsorption resin regeneration stage

[0060] When the COD (TOC) in the liquid discharged from the first outflow pipeline 12-11 is higher than 85% of the inlet COD (TOC), the PLC device controls the closing of the first inlet pipeline solenoid valve 122, the first outflow pipeline solenoid valve 12-12 and the second inlet pipeline valve 222, and at the same time controls the regeneration liquid pipeline electric water pump 135 of the protein adsorption resin regeneration system 13 to open, and delivers 6-8% sodium chloride solution to the protein adsorption column 12 through the No. 1 water pump 135. The No. 1 water pump 135 uses a solvent metering dosing pump to regenerate the resin. In this process, the PLC device controls the first exhaust valve to exhaust air to ensure pressure balance.

[0061] 4) Phosphorus adsorption filler regeneration stage

[0062] When the phosphorus recovery efficiency of the phosphorus adsorption column 21 is lower than 70%, the PLC device 3 controls the closing of the first liquid inlet pipeline solenoid valve 122, the first outflow pipeline solenoid valve 12-12 and the second liquid inlet pipeline valve 212, and controls the packing regeneration liquid pipeline solenoid valve 234 to open, so that the sodium hydroxide solution with a mass fraction of 5% is transported to the high-pressure fine water mist open nozzle 236 through the packing regeneration liquid pipeline 235, and is evenly sprayed on the silane-modified phosphorus adsorption spherical filler 217 in the form of fine water mist. Under the action of the sodium hydroxide solution with a mass fraction of 5%, the silane-modified phosphorus adsorption spherical filler 217 in the phosphorus adsorption column 21 can complete the desorption process, that is, regenerate the silane-modified phosphorus adsorption spherical filler 217. The phosphorus-rich alkali liquid is discharged through the phosphorus adsorption column outflow pipeline 21-11 and phosphorus is subsequently collected.

[0063] 5) Silane modified phosphorus adsorption spherical filler supplementation stage

[0064] When the phosphorus recovery rate is lower than 70% within 24 hours after the phosphorus adsorption filler regeneration stage in stage 4 is completed, the PLC device 3 controls the electric gripper 222 to prevent the arc magnet 221 from being close to the column, so that the switchable magnetic field device 22 is in a closed state, and the new spherical resin is added to the silane-modified phosphorus adsorption spherical filler 217 of the phosphorus adsorption column 21 through the filler inlet 216 of the phosphorus adsorption column 21 to replenish the silane-modified phosphorus adsorption spherical filler 217, and at the same time, the filler outlet 218 of the phosphorus adsorption column 21 is opened to discharge the old filler equal to the replenished amount. When the filler replenishment amount reaches 30% to 40% of the original filler total amount, the filler replenishment and discharge are stopped. Embodiment 2

[0065] The difference from the first embodiment is that the ninhydrin-modified resin 127 in the protein adsorption column 12 is replaced by a styrene-type strongly acidic cationic resin that has not been modified by ninhydrin. Embodiment 3

[0066] Different from the first embodiment, the filler in the phosphorus adsorption column 21 is a phosphorus adsorption spherical filler that is not modified by the silane coupling agent methyltriethoxysilane. Embodiment 4

[0067] The difference from the first embodiment is that hydrochloric acid is not added to adjust the pH of the phosphorus-containing source water or sewage before the phosphorus-containing source water or sewage enters the protein adsorption column 12 . Embodiment 5

[0068] The difference from the first embodiment is that no resin trap 14 is installed behind the protein adsorption column 12 , and only a protein adsorption resin regeneration system 13 is provided. Embodiment 6

[0069] The difference from the first embodiment is that: no switchable magnetic field device 22 is arranged around the phosphorus adsorption column 21, and an annular magnet is fixedly arranged on the outer wall of the phosphorus adsorption column 21 and is not removed. Embodiment 7

[0070] Different from the first embodiment, the phosphorus adsorption spherical filler in the phosphorus adsorption column 21 is not modified by the silane coupling agent methyltriethoxysilane during the preparation process.

[0071] The device of Example 1 is used to treat phosphorus-containing water source water or sewage rich in microplastics.

[0072] 1. Processing flow:

[0073] The water quality of the phosphorus-containing source water or sewage is: chemical oxygen demand COD is 350-400 mg / L, biochemical oxygen demand BOD is 250-300 mg / L, total suspended solids TSS is 180-200 mg / L, pH value is 7-8, and total phosphorus TP is 4-5 mg / L. After the pH (isoelectric point) is changed by mixing with pH hydrochloric acid, it enters the ninhydrin modified resin 127 through the first liquid inlet pipe 121 of the protein adsorption column 12. After being treated by the ninhydrin modified resin 127, microplastics and proteins in the phosphorus-containing source water or sewage are removed.

[0074] The phosphorus-containing source water or sewage is treated with two-stage resin. The phosphorus-containing source water or sewage treated with the ninhydrin-modified resin 127 in the protein adsorption column 12 will enter the silane-modified phosphorus adsorption spherical filler 217 in the phosphorus adsorption column 21. Through the adsorption process of phosphate by the silane-modified phosphorus adsorption spherical filler 217, the phosphate in the phosphorus-containing source water or sewage is removed.

[0075] Through the above two stages, microplastics, proteins and phosphates in phosphorus-containing water sources or sewage can be removed and recovered respectively.

[0076] 2. Effect analysis:

[0077] The main water quality indicators of the influent and effluent of each embodiment and the purity of the phosphorus product are shown in Table 1 and Table 2:

[0078] Table 1 Main water quality indicators of influent and effluent of each embodiment

[0079] Water quality indicators Water Intake Example 1 Water outlet Example 2 Water outlet Example 3 Water outlet Example 4 Water outlet Example 5 Water outlet Example 6 Water outlet Example 7 Water outlet COD (mg / L) 250~300 (sewage) 261~267 274~277 282~290 278~312 262~294 261~296 291~296 TOC (mg / L) 40~120 (Phosphorus-containing source water) 20~80 35~110 32~110 47~128 25~112 22~120 40~120 pH 7.7 7.2 7.4 7.6 5.6 7.5 7.6 7.6 TP (mg / L) 4.2 0.01 0.8 1.2 1.1 0.9 0.01~1.2 0.4~1.0 Number of microplastic particles (pieces / L) 970 100 792 520 514 754 545 545

[0080] Table 2 Phosphorus recovery product purity (phosphate mass fraction)

[0081] Embodiment 1 Embodiment 2 Embodiment 3 Embodiment 4 Embodiment 5 Embodiment 6 Embodiment 7 Phosphate mass fraction 96~97% 60~75% 89~95% 68~80% 60~85% 80~90% 90~96%

[0082] It can be seen that the treated water quality has a higher total phosphorus removal rate and better phosphorus recovery effect than the influent water quality.

[0083] Compared with a phosphorus recovery device that uses a styrene-type strongly acidic cationic resin that has not been modified with the affinity protein ninhydrin as a protein adsorption resin, the phosphorus recovery rate of the device can be increased by more than 50%.

[0084] Compared with a phosphorus recovery device which uses phosphorus adsorption spherical fillers which are not modified by silane coupling agent methyltriethoxysilane as phosphorus adsorption fillers, the phosphorus recovery rate of the device can be increased by more than 50%.

[0085] Compared with the continuous operation of the phosphorus adsorption column, the present device replenishes the silane-modified phosphorus adsorption spherical filler in the phosphorus adsorption column at irregular intervals and quantitatively, which can maintain the phosphorus recovery efficiency above 50% for a long time.

[0086] The embodiments described above are only preferred specific implementations of the present invention. Common changes and substitutions made by those skilled in the art within the scope of the technical solution of the invention should be included in the protection scope of the present invention.

Claims

1. A phosphorus recovery device for phosphorus-containing water source water or wastewater capable of separating microplastics, comprising a protein adsorption unit (1), a phosphorus adsorption unit (2), and a PLC device (3), characterized in that: The protein adsorption unit (1) is arranged at the front end of the phosphorus adsorption unit (2), and the protein adsorption unit (1) comprises a pH adjustment solution addition system (11), a protein adsorption column (12), a protein adsorption resin regeneration system (13) and a resin trap (14); The protein adsorption column (12) comprises a first liquid inlet pipe (121), a first liquid inlet pipeline solenoid valve (122), a first exhaust valve (123), a protein adsorption column tank body (124), a first fixed flange (125), a resin input port (126), a ninhydrin-modified resin (127), a resin discharge port (128), a first porous drain plate (129), a first screen (12-10), a first outflow pipeline (12-11) and a first outflow pipeline solenoid valve (12-12); the first fixed flange (125) is tightly clamped on the outside of the protein adsorption column tank body (124); the resin trap (14) is arranged on the first outflow pipeline (12-11); the first liquid inlet pipeline solenoid valve (122) and the first outflow pipeline solenoid valve (12-12) are controlled by a PLC device (3); The pH adjusting solution dosing system (11) is composed of a glass fiber reinforced plastic container (111), a drain valve (112), an outflow pipe electromagnetic valve (113), an adjusting solution replenishing port (114), and an outflow pipe (115) of the adjusting solution dosing system. The adjusting solution outflow pipe electromagnetic valve (113) is controlled by a PLC device (3). 2-4 mol / L of dilute hydrochloric acid is stored in the glass fiber reinforced plastic container (111); The protein adsorption resin regeneration system (13) is arranged at the bottom of the protein adsorption column (12), and is composed of a first stainless steel container (131), a liquid replenishing port (132), a drain valve (133), a regeneration liquid pipeline electromagnetic valve (134), a No. 1 water pump (135), and a regeneration liquid pipeline (136). The regeneration liquid pipeline electromagnetic valve (134) is arranged on the regeneration liquid pipeline (136), and the regeneration liquid pipeline electromagnetic valve (134) is controlled by a PLC device (3). The first stainless steel container (131) is a sodium chloride solution with a content of 6-8%. The ninhydrin-modified resin (127) in the protein adsorption column (12) is a polymer material obtained by using a styrene-type strongly acidic cationic resin as a substrate and tightly covering and bonding the surface of the cationic resin with ninhydrin under hydrothermal conditions to modify the resin. The preparation steps are as follows: preparing a 10% by mass ninhydrin aqueous solution, slowly dropping the ninhydrin aqueous solution into a styrene-type strongly acidic cationic resin solution with a mass concentration of 40-50 mg / mL and a mass fraction of 2-3 times the mass thereof at room temperature of 25°C, and continuously stirring for 20-40 minutes during the whole process; finally obtaining a mixture of ninhydrin and styrene-type strongly acidic cationic resin; centrifuging the mixture, washing off the foam, and freeze-drying to constant weight to obtain the ninhydrin-modified resin; The phosphorus adsorption unit (2) is arranged at the end of the liquid outlet pipe (146) of the resin capture device, and the phosphorus adsorption unit (2) comprises a phosphorus adsorption column (21), a switchable magnetic field device (22), and a phosphorus adsorption filler regeneration system (23); The phosphorus adsorption column (21) comprises a second liquid inlet pipe (211), a second liquid inlet pipeline valve (212), a second exhaust valve (213), a phosphorus adsorption column tank body (214), a second fixed flange (215), a filler inlet (216), a silane-modified phosphorus adsorption spherical filler (217), a filler outlet (218), a second porous drain plate (219), a second screen (21-10), a phosphorus adsorption column outflow pipeline (21-11) and a phosphorus adsorption column outflow pipeline valve (21-12), the second fixed flange (215) being tightly clamped to the outside of the phosphorus adsorption column tank body (214), and the silane-modified phosphorus adsorption spherical filler (217) being prepared in the following steps: First, Fe3O4 magnetic cores were synthesized by coprecipitation method and then covered with silicate coating to form Fe3O4@SiO2 magnetic nanocores. The preparation steps of Fe3O4@SiO2 magnetic nanocores include synthesizing magnetite and coating with silica: Magnetite was synthesized by the commonly used co-precipitation method. 8 g of FeCl3·6H2O and 3 g of FeCl2·4H2O were placed in a flask and dissolved in 100 mL of deionized water. At the same time, 1.5 mol / L monohydrated ammonia solution was added dropwise to the mixture under stirring at room temperature. When the final pH value reached 8-8.5, stirring was stopped, the black precipitate was magnetically separated and washed three times with deionized water. The black precipitate was dispersed in 120 mL of deionized water and mixed with 120 mL of 0.66 mol / L nitric acid solution, and 80 mL of diluted ammonia water was added under stirring, and the mixture was heated to 70-72°C; sodium silicate solution was added with a syringe under stirring and continued to stir for 5 minutes, and a silicon dioxide coating was formed on the surface of the magnetite, that is, a Fe3O4@SiO2 magnetic nanocore solution was prepared; After that, 5 g of MgCl2·6H2O and 6 g of AlCl3·6H2O were dissolved in 100 mL of water, 50 mL of 1 mol / L Na2CO3 and 1.5 mol / L NaOH alkaline solution were added, and then 10-12 g of CeCl3·7H2O was added, and after crystallization at 80 °C for 24 hours, a Ce-loaded hydroxy bimetallic oxide suspension was obtained; The suspension was mixed with 100 mL of Fe3O4@SiO2 magnetic nanocore solution, and superparamagnetic nanoparticle suspension was prepared after stirring and ultrasonic treatment at 5000-5500 Hz for 20-30 min. At room temperature of 25°C, 5 mL of 40 mg / mL methyltriethoxysilane ethanol solution was slowly added dropwise to 10 mL of superparamagnetic nanoparticle suspension, and the mixture was stirred at a speed of 200-300 r / min for 20-40 min, and then ultrasonically treated at 4800-5200 Hz and dried to obtain silanized magnetic nanoparticles; 20 g of silanized magnetic nanoparticles were then added to 50 mL of star-shaped poly(glycidyl methacrylate) solution in a constant temperature water bath at 40°C, and stirred continuously for 15-20 min to allow the two to react fully; Finally, the mixed solution is centrifuged, the foam is washed off, the mixed solution is freeze-dried to a constant weight, and the mixed solution is pressed into a sphere with a diameter of 10 to 12 mm, thereby obtaining a silane-modified phosphorus-adsorbing spherical filler with a semi-interpenetrating network structure. The detachable arc-shaped magnet (221) in the on-off magnetic field device (22) is clamped on the outside of the phosphorus adsorption column tank (214), and is fixed and opened and closed on the outside of the phosphorus adsorption column tank (214) by an electric gripper (222), and is controlled by a PLC device (3); the detachable arc-shaped magnet (221) is made of a neodymium iron boron magnet; the filler regeneration system (23) is arranged on the upper part of the phosphorus adsorption column (21), and is composed of a second stainless steel container (231), an alkali solution replenishing port (232), a drain valve (233), a filler regeneration liquid pipeline electromagnetic valve (234), a filler regeneration liquid pipeline (235), and a high-pressure fine water mist open nozzle (236). The two ends of the filler regeneration liquid pipeline (235) respectively connect the second stainless steel container (231) and the top of the phosphorus adsorption column tank body (214); a filler regeneration liquid pipeline electromagnetic valve (234) is provided on the filler regeneration liquid pipeline (235); a high-pressure fine water mist open nozzle (236) is provided after the filler regeneration liquid pipeline (235) enters the top of the phosphorus adsorption column tank body (214); two high-pressure fine water mist open nozzles (236) are provided and are equidistantly installed on the inner side of the top of the phosphorus adsorption column; the filler regeneration liquid pipeline electromagnetic valve (234) is controlled by the PLC device (3); and a 5% sodium hydroxide solution is stored in the second stainless steel container (231).

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