Treatment system and treatment method for organic phosphorus-containing waste liquid

Abstract

The invention provides an organic phosphorus-containing waste liquid treatment system and an organic phosphorus-containing waste liquid treatment method. The system comprises an oxidation reactor, a salt conversion and separation device connected with the oxidation reactor, and a potassium sulfate recovery chamber and a phosphorus recovery chamber which are respectively connected with the salt conversion and separation device, the salt conversion and separation device comprises an electrified positive electrode and an electrified negative electrode which are oppositely arranged, and further comprises a plurality of cation exchange membranes and a plurality of anion exchange membranes which are alternately arranged between the electrified positive electrode and the electrified negative electrode. According to the method, efficient decomposition of organic pollutants is achieved in a supercritical water oxygenolysis mode, meanwhile, ferrous sulfate and potassium phosphate obtained through decomposition are subjected to ion exchange in the salt conversion and separation device, blue iron ore with high economic value is generated, efficient recovery of phosphorus can be achieved, and wastewater discharge reaches the standard.

Description

Technical Field

[0001] The present application relates to the field of environmental protection technology, and in particular to a treatment system for waste liquid containing organic phosphorus and a treatment method for waste liquid containing organic phosphorus. Background Art

[0002] In the prior art, wastewater discharged from industries such as pesticides, petrochemicals, coking, medicine, fermentation, food, papermaking, rubber, dyes and textile printing and dyeing often contains organic phosphorus compounds, which can easily cause environmental pollution, eutrophication of surface water bodies, water quality deterioration and other problems. Organic phosphorus compound pollution has attracted increasing attention. At the same time, phosphorus is one of the indispensable elements for human survival and life. It mainly comes from natural phosphate rock and is a non-renewable resource with limited reserves. If waste liquid containing organic phosphorus is directly discharged without treatment, it is also a waste of resources.

[0003] Generally speaking, conventional organic phosphorus wastewater treatment technologies include biological methods, physicochemical methods, wet oxidation, incineration, etc. These treatment methods often have limited applicability, incomplete treatment, secondary pollution, difficult and complicated phosphorus recovery or no recovery, high energy consumption and other problems. Among them, biological methods and physicochemical methods are only suitable for low-concentration organic phosphorus wastewater. Phosphorus is converted into biochemical or physicochemical sludge, which is solid waste, and phosphorus is not actually recovered. Wet oxidation is suitable for higher concentration organic phosphorus wastewater, but the degradation of organic matter is not complete, secondary treatment is required, and phosphorus recovery is difficult and complicated. Incineration treatment of organic phosphorus wastewater requires the addition of a large amount of auxiliary fuel, which has high energy consumption. Phosphorus will generate acidic substances and corrode equipment. The phosphorus is eventually converted into solid waste. In addition, the exhaust gas emissions are large, and there is secondary pollution of phosphorus-containing particles. Although the exhaust gas can achieve standard emissions after exhaust gas treatment, it still contains a variety of atmospheric pollutants and a large amount of carbon dioxide greenhouse gas. Summary of the invention

[0004] The present application aims to propose a system and method for treating organic phosphorus waste liquid, which can achieve efficient and clean treatment of organic phosphorus waste liquid, while achieving efficient recovery of phosphorus to obtain products with high economic value.

[0005] In order to achieve the above-mentioned purpose, the present application discloses a treatment system for waste liquid containing organic phosphorus, the system comprising an oxidation reactor, a salt conversion separation device connected to the oxidation reactor; the salt conversion separation device comprises an electrically powered positive electrode and an electrically powered negative electrode arranged opposite to each other, and also comprises a plurality of cation exchange membranes and a plurality of anion exchange membranes alternately arranged between the electrically powered positive electrode and the electrically powered negative electrode, and also comprises at least one recovery chamber arranged between the cation exchange membrane and the anion exchange membrane; the recovery chamber comprises a phosphorus recovery chamber and a potassium sulfate recovery chamber;

[0006] The oxidation reactor is used to pass the organic phosphorus waste liquid, potassium hydroxide solution and oxidant into the oxidation reactor, react under supercritical conditions to obtain potassium phosphate solution, and pass the potassium phosphate solution into the salt conversion separation device;

[0007] The salt conversion separation device is used to energize through the energized positive electrode and the energized negative electrode, and pass a ferrous sulfate solution; potassium ions in the potassium phosphate solution move under the action of the energized negative electrode and pass through the cation exchange membrane to enter the potassium sulfate recovery chamber; phosphate ions in the potassium phosphate solution move under the action of the energized positive electrode and pass through the anion exchange membrane to enter the phosphorus recovery chamber; ferrous ions in the ferrous sulfate solution move under the action of the energized negative electrode and pass through the cation exchange membrane to enter the phosphorus recovery chamber; sulfate ions in the ferrous sulfate solution move under the action of the energized positive electrode and pass through the anion exchange membrane to enter the potassium sulfate recovery chamber;

[0008] The phosphorus recovery chamber is used to combine the ferrous ions with the phosphate ions to obtain blue iron ore;

[0009] The potassium sulfate recovery chamber is used to combine the potassium ions with the sulfate ions to obtain a potassium sulfate solution;

[0010] Optionally, the system further comprises a concentrating device, wherein the concentrating device is respectively connected to the oxidation reactor and the salt conversion separation device;

[0011] The oxidation reactor is specifically used for passing the potassium phosphate solution into the concentrating device;

[0012] The concentrator is used to concentrate the potassium phosphate solution and then pass the concentrated potassium phosphate solution into the salt conversion separation device.

[0013] Optionally, the system further comprises a compatibility tank, a high-pressure waste liquid delivery pump connected to the compatibility tank, and a preheater connected to the high-pressure waste liquid delivery pump; the preheater is also connected to the oxidation reactor;

[0014] The mixing tank is used to determine the ratio between the potassium hydroxide solution and the organic phosphorus-containing waste liquid according to the phosphorus content in the organic phosphorus-containing waste liquid, and after mixing the organic phosphorus-containing waste liquid and the potassium hydroxide solution according to the ratio, pass them into the high-pressure waste liquid delivery pump;

[0015] The high-pressure waste liquid delivery pump is used to deliver the mixed organic phosphorus-containing waste liquid and the potassium hydroxide solution to the preheater;

[0016] The preheater is used to heat the mixed organic phosphorus waste liquid and the potassium hydroxide solution to a preset temperature and then transport them to the oxidation reactor.

[0017] Optionally, the system further comprises a high-pressure oxidant delivery pump connected to the oxidation reactor;

[0018] The high-pressure oxidant delivery pump is used to pass the oxidant into the oxidation reactor.

[0019] Optionally, the system also includes a nitrogen delivery pump connected to the phosphorus recovery chamber, and the nitrogen delivery pump is used to pass nitrogen to purge the phosphorus recovery chamber to reduce the dissolved oxygen of the solution in the phosphorus recovery chamber; the ferrous ions and the phosphate ions generate blue iron ore in an oxygen-free environment.

[0020] Optionally, a plurality of detachable reaction beds with hollow mesh structures are arranged horizontally or vertically in the phosphorus recovery chamber, and silica sand is arranged on the detachable reaction beds;

[0021] The phosphorus recovery chamber is specifically used for causing the ferrous ions and the phosphate ions to generate blue iron ore uniformly attached to the silica sand in an environment where the nitrogen disturbs the silica sand.

[0022] Optionally, the system further comprises a gas-liquid separation device respectively connected to the oxidation reactor and the salt conversion separation device; the potassium phosphate solution outputted from the oxidation reactor further comprises carbon dioxide and an oxidant;

[0023] The oxidation reactor is specifically used to transport the potassium phosphate solution to the gas-liquid separation device;

[0024] The gas-liquid separation device is used to separate the carbon dioxide and the oxidant in the potassium phosphate solution, and then transport the potassium phosphate solution to the salt conversion separation device.

[0025] Optionally, the gas-liquid separation device includes a primary gas-liquid separation device and a secondary gas-liquid separation device connected to the primary gas-liquid separation device;

[0026] The primary gas-liquid separation device separates the carbon dioxide and the oxidant in the potassium phosphate solution by flash evaporation and pressure reduction, and passes the potassium phosphate solution after the primary gas-liquid separation treatment into the secondary gas-liquid separation device;

[0027] The secondary gas-liquid separation device is used to separate water vapor in the potassium phosphate solution by flash evaporation and pressure reduction, and pass the potassium phosphate solution after the secondary gas-liquid separation treatment into the salt conversion separation device.

[0028] Optionally, the system further comprises a generator set connected to the secondary gas-liquid separation device;

[0029] The generator set is used to receive the water vapor discharged from the secondary gas-liquid separation device and generate electricity through the water vapor.

[0030] The embodiment of the present application also provides a method for treating organic phosphorus-containing waste liquid, which is applied to a system for treating organic phosphorus-containing waste liquid, the system comprising an oxidation reactor, and a salt conversion separation device connected to the oxidation reactor; the salt conversion separation device comprises an electrically powered positive electrode and an electrically powered negative electrode arranged opposite to each other, and also comprises a plurality of cation exchange membranes and a plurality of anion exchange membranes alternately arranged between the electrically powered positive electrode and the electrically powered negative electrode, and also comprises at least one recovery chamber arranged between the cation exchange membrane and the anion exchange membrane; the recovery chamber comprises a phosphorus recovery chamber and a potassium sulfate recovery chamber;

[0031] The method comprises:

[0032] Passing organic phosphorus waste liquid, potassium hydroxide solution and oxidant into the oxidation reactor, reacting under supercritical state to obtain potassium phosphate solution, and passing the potassium phosphate solution into the salt conversion separation device;

[0033] In the salt conversion separation device, electricity is supplied through the powered positive electrode and the powered negative electrode, and a ferrous sulfate solution is introduced;

[0034] Potassium ions in the potassium phosphate solution move under the action of the energized negative electrode and penetrate the cation exchange membrane to enter the potassium sulfate recovery chamber;

[0035] Phosphate ions in the potassium phosphate solution move under the action of the energized positive electrode and pass through the anion exchange membrane into the phosphorus recovery chamber;

[0036] The ferrous ions in the ferrous sulfate solution move under the action of the energized negative electrode and pass through the cation exchange membrane to enter the phosphorus recovery chamber;

[0037] Sulfate ions in the ferrous sulfate solution move under the action of the energized positive electrode and pass through the anion exchange membrane to enter the potassium sulfate recovery chamber;

[0038] In the phosphorus recovery chamber, the ferrous ions are combined with the phosphate ions to obtain blue iron ore;

[0039] In the potassium sulfate recovery chamber, the potassium ions combine with the sulfate ions to obtain a potassium sulfate solution.

[0040] Optionally, the system further comprises a concentrating device, wherein the concentrating device is respectively connected to the oxidation reactor and the salt conversion separation device;

[0041] The step of passing the potassium phosphate solution into the salt conversion separation device comprises:

[0042] Passing the potassium phosphate solution into the concentrating device;

[0043] After the potassium phosphate solution is concentrated by the concentrating device, the concentrated potassium phosphate solution is passed into the salt conversion separation device.

[0044] Optionally, the system further comprises a compatibility tank, a high-pressure waste liquid delivery pump connected to the compatibility tank, and a preheater connected to the high-pressure waste liquid delivery pump; the preheater is also connected to the oxidation reactor;

[0045] The method further comprises:

[0046] Determining the ratio between the potassium hydroxide solution and the organic phosphorus-containing waste liquid according to the phosphorus content in the organic phosphorus-containing waste liquid;

[0047] After the organic phosphorus waste liquid and the potassium hydroxide solution are mixed in the mixing tank according to the proportion, the mixture is introduced into the high-pressure waste liquid delivery pump;

[0048] The mixed organic phosphorus-containing waste liquid and the potassium hydroxide solution are transported to the preheater by the high-pressure waste liquid transport pump;

[0049] The mixed organic phosphorus waste liquid and the potassium hydroxide solution are heated to a preset temperature by the preheater and then transported to the oxidation reactor.

[0050] Optionally, the system further comprises a high-pressure oxidant delivery pump connected to the oxidation reactor;

[0051] The step of introducing the waste liquid containing organic phosphorus and the potassium hydroxide solution into the oxidation reactor to carry out supercritical water oxidation reaction to obtain the potassium phosphate solution comprises:

[0052] Passing the oxidant into the oxidation reactor via the high-pressure oxidant delivery pump;

[0053] The organic phosphorus-containing waste liquid and the potassium hydroxide solution are introduced into the oxidation reactor; the organic phosphorus-containing waste liquid and the potassium hydroxide solution react with the oxidant under a supercritical state to obtain a potassium phosphate solution.

[0054] Optionally, the step of combining the ferrous ions with the phosphate ions in the phosphorus recovery chamber to obtain blue iron ore comprises:

[0055] introducing nitrogen gas to purge the phosphorus recovery chamber to reduce the dissolved oxygen in the solution in the phosphorus recovery chamber;

[0056] In the phosphorus recovery chamber, the ferrous ions and the phosphate ions generate blue iron ore in an oxygen-free environment.

[0057] Optionally, a plurality of detachable reaction beds with hollow mesh structures are arranged horizontally or vertically in the phosphorus recovery chamber, and silica sand is arranged on the detachable reaction beds;

[0058] The step of combining the ferrous ions with the phosphate ions in the phosphorus recovery chamber to obtain blue iron ore comprises:

[0059] In the environment where the nitrogen disturbs the silica sand in the phosphorus recovery chamber, the ferrous ions and the phosphate ions generate blue iron ions that are uniformly attached to the silica sand.

[0060] Optionally, the system further comprises a gas-liquid separation device respectively connected to the oxidation reactor and the salt conversion separation device; the potassium phosphate solution outputted from the oxidation reactor further comprises carbon dioxide and an oxidant;

[0061] The step of passing the potassium phosphate solution into the salt conversion separation device comprises:

[0062] transporting the potassium phosphate solution in the oxidation reactor to a gas-liquid separation device;

[0063] After the carbon dioxide and the oxidant in the potassium phosphate solution are separated by the gas-liquid separation device, the potassium phosphate solution is transported to the salt conversion separation device.

[0064] Optionally, the gas-liquid separation device includes a primary gas-liquid separation device and a secondary gas-liquid separation device connected to the primary gas-liquid separation device;

[0065] The step of separating the carbon dioxide and the oxidant in the potassium phosphate solution by the gas-liquid separation device comprises:

[0066] The carbon dioxide and the oxidant in the potassium phosphate solution are separated by flash evaporation and pressure reduction by the primary gas-liquid separation device, and the potassium phosphate solution after the primary gas-liquid separation treatment is passed into the secondary gas-liquid separation device;

[0067] The water vapor in the potassium phosphate solution is separated by flash evaporation and pressure reduction vaporization through the secondary gas-liquid separation device.

[0068] Optionally, the system further comprises a carbon dioxide recovery device connected to the primary gas-liquid separation device;

[0069] The method further comprises

[0070] The carbon dioxide recovery device receives the carbon dioxide and the oxidant discharged from the first gas-liquid separation device, and separates the carbon dioxide and the oxidant through pressure swing adsorption or distillation.

[0071] Optionally, the system further comprises a generator set connected to the secondary gas-liquid separation device;

[0072] The method further comprises:

[0073] The water vapor discharged from the secondary gas-liquid separation device is received by the generator set, and electricity is generated by the water vapor.

[0074] Compared with the prior art, this application has the following advantages:

[0075] The treatment system of organic phosphorus waste liquid provided by the embodiment of the present application comprises an oxidation reactor and a salt conversion separation device connected to the oxidation reactor; the salt conversion separation device comprises a powered positive electrode and a powered negative electrode arranged relatively to each other, and also comprises a plurality of cation exchange membranes and a plurality of anion exchange membranes alternately arranged between the powered positive electrode and the powered negative electrode, and also comprises at least one recovery chamber arranged between the cation exchange membrane and the anion exchange membrane; the recovery chamber comprises a phosphorus recovery chamber and a potassium sulfate recovery chamber; the oxidation reactor is used to pass the organic phosphorus waste liquid, potassium hydroxide solution and oxidant into the oxidation reactor, react under supercritical state to obtain potassium phosphate solution, and pass the potassium phosphate solution into the salt conversion separation device; the salt conversion separation device is used to pass the powered positive electrode to The energized negative electrode is energized, and a ferrous sulfate solution is introduced; the potassium ions in the potassium phosphate solution move under the action of the energized negative electrode and pass through the cation exchange membrane to enter the potassium sulfate recovery chamber; the phosphate ions in the potassium phosphate solution move under the action of the energized positive electrode and pass through the anion exchange membrane to enter the phosphorus recovery chamber; the ferrous ions in the ferrous sulfate solution move under the action of the energized negative electrode and pass through the cation exchange membrane to enter the phosphorus recovery chamber; the sulfate ions in the ferrous sulfate solution move under the action of the energized positive electrode and pass through the anion exchange membrane to enter the potassium sulfate recovery chamber; the phosphorus recovery chamber is used for the ferrous ions to combine with the phosphate ions to obtain blue iron ore; the potassium sulfate recovery chamber is used for the potassium ions to combine with the sulfate ions to obtain potassium sulfate. Thus, the present application realizes the efficient decomposition of organic pollutants by supercritical water oxidation and decomposition, and at the same time, by ion exchange of ferrous sulfate and the decomposed potassium phosphate in a salt conversion separation device, blue iron ore with high economic value is generated, and efficient recovery of phosphorus can be achieved, and wastewater discharge meets the standards. BRIEF DESCRIPTION OF THE DRAWINGS

[0076] Figure 1is a schematic diagram of a treatment system for organic phosphorus waste liquid shown in an embodiment of the present application;

[0077] Figure 2 is a schematic diagram of a salt conversion separation device shown in an embodiment of the present application;

[0078] Figure 3 It is a schematic diagram of a phosphorus recovery chamber shown in an embodiment of the present application.

[0079] Among them, L1-organic phosphorus waste liquid, L2-potassium hydroxide solution, L3-ferrous sulfate solution, G1-oxidant, G2-carbon dioxide product, G3-nitrogen, S1-blue iron ore, S2-potassium sulfate, E-electricity.

[0080] 1-combination tank, 2-high-pressure waste liquid delivery pump, 3-preheater, 4-oxidation reactor, 5-pressure reduction system, 6-primary gas-liquid separation device, 7-secondary gas-liquid separation device, 8-generator set, 9-cooler, 10-concentrator, 11-salt conversion separation device, 12-washer, 13-vacuum dryer, 14-magnetic separation device, 15-potassium sulfate solution storage tank, 16-potassium sulfate solution delivery pump, 17-potassium sulfate solution evaporator, 18-potassium sulfate separator, 19-potassium sulfate dryer, 20-steam condenser, 21-cooling device, 22-carbon dioxide recovery system, 23-energy storage device, 24-high-pressure oxidant delivery pump, 25-solid-liquid separation device, 26-nitrogen delivery pump;

[0081] 11-1-energized negative electrode, 11-2-energized positive electrode, 11-3-cation exchange membrane, 11-4-anion exchange membrane, 11-5-solution channel, 11-6-potassium sulfate recovery chamber, 11-7-phosphorus recovery chamber. DETAILED DESCRIPTION

[0082] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0083] refer to Figure 1 , Figure 1 Schematic diagram of a treatment system for organic phosphorus waste liquid shown in an embodiment of the present application. The system includes an oxidation reactor 4, a salt conversion separation device 11 connected to the oxidation reactor 4;

[0084] The oxidation reactor 4 is used to pass the organic phosphorus-containing waste liquid L1, the potassium hydroxide solution L2, and the oxidant G1 into the oxidation reactor 4, react under supercritical conditions to obtain a potassium phosphate solution, and pass the potassium phosphate solution into the salt conversion separation device 11;

[0085] The salt conversion separation device 11 is used to energize through the powered positive electrode 11-2 and the powered negative electrode 11-1, and pass the ferrous sulfate solution L3; the potassium ions in the potassium phosphate solution move under the action of the powered negative electrode 11-1 and pass through the cation exchange membrane 11-3 to enter the potassium sulfate recovery chamber 11-7; the phosphate ions in the potassium phosphate solution move under the action of the powered positive electrode 11-2 and pass through the anion exchange membrane 11-4 to enter the phosphorus recovery chamber 11-7; the ferrous ions in the ferrous sulfate solution L3 move under the action of the powered negative electrode 11-1 and pass through the cation exchange membrane 11-3 to enter the phosphorus recovery chamber 11-7; the sulfate ions in the ferrous sulfate solution L3 move under the action of the powered positive electrode 11-2 and pass through the anion exchange membrane 11-4 to enter the potassium sulfate recovery chamber 11-6;

[0086] Phosphorus recovery chamber 11-7 is used to combine ferrous ions with phosphate ions to obtain blue iron ore;

[0087] The potassium sulfate recovery chamber 11-6 is used to combine potassium ions with sulfate ions to obtain potassium sulfate solution S2.

[0088] Specifically, in order to improve the degradation efficiency of organic pollutants, the embodiment of the present application provides a supercritical environment in the oxidation reactor 4. After the organic phosphorus waste liquid L1 is passed into the oxidation reactor 4, it can undergo an oxidation reaction with the oxidant in the supercritical environment. The carbon element in the organic phosphorus is converted into CO2, the hydrogen element is converted into H2O, and the phosphorus element is formed into H3PO4.

[0089] The oxidant G1 may be oxygen, air, hydrogen peroxide, etc., and this application does not impose any limitation on this.

[0090] In order to prevent phosphoric acid from corroding the equipment, potassium hydroxide solution L2 can be introduced at the same time as the organic phosphorus waste liquid L1 is introduced. Potassium hydroxide can neutralize phosphoric acid to form a potassium phosphate solution.

[0091] As an example of the present application, when the oxidant G1 is oxygen, the supercritical water oxidation decomposition reaction can be expressed as:

[0092] C x H y O z P n +O2+KOH→CO2↑+H2O+K3PO4

[0093] Optionally, the organic phosphorus-containing waste liquid L1 may contain a small amount of heavy metal ions. Heavy metal ions can form solid metal oxides under oxidation reaction, so that phosphorus can be enriched in the liquid phase, and heavy metals can be enriched in the solid phase, thereby separating heavy metals from phosphorus, avoiding heavy metals from affecting the purity of subsequent blue iron ore, and can easily recover heavy metals to avoid heavy metal pollution of the environment.

[0094] Specifically, violet iron ore is a phosphorus-related product with high economic value. The unit mass of phosphorus in violet iron ore (Fe3(PO4)2·8H2O) is high, so it can have high economic value. Vitriol ore can be used as a phosphate fertilizer and can also be a synthetic material for lithium batteries.

[0095] At the same time, waste materials in industrial processes, such as pickling wastewater from steel mills, usually contain ferrous sulfate, which can be recovered through proper treatment and purification. The utilization rate of industrial waste can be further improved through the rational use of ferrous sulfate. Ferrous sulfate contains the ferrous element required for the synthesis of blue iron ore, so blue iron ore can be obtained by simultaneously treating ferrous sulfate and potassium phosphate solution.

[0096] Therefore, in order to obtain blue iron ore products with higher economic value, the potassium phosphate solution can be further introduced into the salt conversion separation device 11 for treatment.

[0097] refer to Figure 2 , Figure 2 It is a schematic diagram of a salt conversion separation device 11 shown in an embodiment of the present application. The salt conversion separation device 11 includes a powered positive electrode 11-2 and a powered negative electrode 11-1 arranged relatively, and also includes a plurality of cation exchange membranes 11-3 and a plurality of anion exchange membranes 11-4 alternately arranged between the powered positive electrode 11-2 and the powered negative electrode 11-1, and also includes at least one recovery chamber arranged between the cation exchange membrane 11-3 and the anion exchange membrane 11-; the recovery chamber includes a phosphorus recovery chamber 11-7 and a potassium sulfate recovery chamber 11-6.

[0098] In a specific implementation, there may be a gap between the cation exchange membrane 11-3 and the anion exchange membrane 11-4, and the gap may be used to pass a solution to form a solution channel. Anions and cations may exist in different types of solutions, and electrode liquid e may be added to the powered positive electrode 11-2 and the powered negative electrode 11-1. In an energized environment, cations may begin to move toward the powered negative electrode 11-1 and migrate to other solution channels through the cation exchange membrane 11-3, while anions may begin to move toward the powered positive electrode 11-2 and migrate to other solution channels through the anion exchange membrane 11-4.

[0099] Therefore, by reasonably setting the inlet positions of potassium phosphate solution and ferrous sulfate solution L3, a potassium sulfate recovery chamber 11-6 for recovering potassium sulfate S2 and a phosphorus recovery chamber 11-7 for recovering blue iron ore S1 can be formed in part of the solution channel.

[0100] Specifically, the solution channel 11-5 between the solution channel 11-5 for feeding the ferrous sulfate solution and the solution channel 11-5 for feeding the potassium phosphate solution can be used as the potassium sulfate recovery chamber 11-6, the solution channel 11-5 for feeding the ferrous sulfate solution is located near the side of the powered negative electrode 11-1, and the solution channel 11-5 for feeding the potassium phosphate solution is located near the side of the powered positive electrode 11-2. An anion exchange membrane 11-4 is provided between the potassium sulfate recovery chamber 11-6 and the solution channel 11-5 for feeding the ferrous sulfate solution, and a cation exchange membrane 11-3 is provided between the potassium sulfate recovery chamber 11-6 and the solution channel 11-5 for feeding the potassium phosphate solution.

[0101] Water can be passed into the potassium sulfate recovery chamber 11-6. Under the energized environment, the sulfate ions in the ferrous sulfate solution move toward the energized positive electrode 11-2 and enter the potassium sulfate recovery chamber 11-6 through the anion exchange membrane 11-4. The potassium ions in the potassium phosphate solution can move toward the energized negative electrode 11-1 and enter the potassium sulfate recovery chamber 11-6 through the cation exchange membrane 11-3. In the potassium sulfate recovery chamber 11-6, one side near the energized negative electrode 11-1 is the anion exchange membrane 11-4, and one side near the energized positive electrode 11-2 is the cation exchange membrane 11-3. Thus, after entering the potassium sulfate recovery chamber 11-6, the sulfate ions can not continue to move toward the energized positive electrode 11-2 due to the blocking of the cation exchange membrane 11-3, and stay in the potassium sulfate recovery chamber 11-6. After potassium ions enter potassium sulfate recovery chamber 11-6, they cannot continue to move toward energized negative electrode 11-1 due to the blocking of anion exchange membrane 11-4, and stay in potassium sulfate recovery chamber 11-6. Thus, potassium ions and sulfate ions can combine in potassium sulfate recovery chamber 11-6 to obtain potassium sulfate S2 solution.

[0102] At the same time, the solution channel 11-5 between the solution channel 11-5 for feeding the ferrous sulfate solution and the solution channel 11-5 for feeding the potassium phosphate solution can be used as the phosphorus recovery chamber 11-7, the solution channel 11-5 for feeding the ferrous sulfate solution is located near the side of the energized positive electrode 11-2, and the solution channel 11-5 for feeding the potassium phosphate solution is located near the side of the energized negative electrode 11-1. A cation exchange membrane 11-3 is provided between the phosphorus recovery chamber 11-7 and the solution channel 11-5 for feeding the ferrous sulfate solution, and an anion exchange membrane 11-4 is provided between the phosphorus recovery chamber 11-7 and the solution channel 11-5 for feeding the potassium phosphate solution.

[0103] Water can be passed into the phosphorus recovery chamber 11-7. Under the power-on environment, the ferrous ions in the ferrous sulfate solution can move toward the powered negative electrode 11-1 and enter the phosphorus recovery chamber 11-7 through the cation exchange membrane 11-3. The phosphate ions in the potassium phosphate solution can move toward the powered positive electrode 11-2 and enter the phosphorus recovery chamber 11-7 through the anion exchange membrane 11-4. In the phosphorus recovery chamber 11-7, the side close to the powered negative electrode 11-1 is the anion exchange membrane 11-4, and the side close to the powered positive electrode 11-2 is the cation exchange membrane 11-3. Therefore, after entering the phosphorus recovery chamber 11-7, the phosphate ions can not continue to move toward the powered positive electrode 11-2 due to the obstruction of the cation exchange membrane 11-3, and stay in the phosphorus recovery chamber 11-7. After the ferrous ions enter the phosphorus recovery chamber 11-7, they cannot continue to move toward the energized negative electrode 11-1 due to the obstruction of the anion exchange membrane 11-4, and stay in the phosphorus recovery chamber 11-7. Thus, the ferrous ions and phosphate ions can be combined in the phosphorus recovery chamber 11-7 to obtain a solution mixed with blue iron ore S1 solid.

[0104] Optionally, since violet iron ore S1 is more easily formed in an acidic environment, an acidic solution may be introduced into the phosphorus recovery chamber 11-7 to maintain the pH value of the phosphorus recovery chamber 11-7 between 5.5 and 6.5, so as to better generate violet iron ore S1.

[0105] As for the solution channel 11-5 into which the ferrous sulfate solution is introduced, under the power-on environment, the ferrous ions therein move toward the powered negative electrode 11-1, migrate to the phosphorus recovery chamber 11-7 through the cation exchange membrane 11-3, and the sulfate ions move toward the powered positive electrode 11-2, migrate to the potassium sulfate recovery chamber 11-6 through the anion exchange membrane 11-4. Thus, the solution channel 11-5 of the ferrous sulfate solution can eventually discharge the desalted water.

[0106] For the solution channel 11-5 into which the potassium phosphate solution is introduced, in an electrically powered environment, the potassium ions therein move toward the powered negative electrode 11-1, and migrate to the potassium sulfate recovery chamber 11-6 through the cation exchange membrane 11-3, and the phosphate ions move toward the powered positive electrode 11-2, and migrate to the phosphorus recovery chamber 11-7 through the anion exchange membrane 11-4. Thus, the solution channel 11-5 of the potassium phosphate solution can eventually discharge desalted water.

[0107] The desalted water discharged from the solution channel 11-5 for introducing the potassium phosphate solution and the solution channel 11-5 for introducing the ferrous sulfate solution can be recycled to improve environmental protection.

[0108] Specifically, the concentration of the ferrous sulfate solution can be determined according to the concentration of the potassium phosphate solution flowing out of the potassium phosphate concentration, wherein the molar ratio of ferrous sulfate / potassium phosphate is 1.2 to 2, preferably 1.5.

[0109] In summary, the embodiment of the present application can realize the recovery and treatment of phosphorus in the organic phosphorus waste liquid L1, and the obtained blue iron ore product has a high economic value. At the same time, other products produced during the treatment process, such as potassium sulfate S2 and carbon dioxide G2, can also be further recycled. The raw materials used in the overall treatment process and the products obtained are environmentally friendly, do not generate more pollution, and improve the environmental friendliness of organic phosphorus treatment.

[0110] In one embodiment of the present application, the system further comprises a concentrating device 10, and the concentrating device 10 is respectively connected to the oxidation reactor 4 and the salt conversion separation device 11;

[0111] The oxidation reactor 4 is specifically used for passing the potassium phosphate solution into the concentration device 10;

[0112] The concentrator 10 is used to concentrate the potassium phosphate solution and then pass the concentrated potassium phosphate solution into the salt conversion separation device 11.

[0113] Specifically, before the potassium phosphate solution is passed into the salt conversion separation device 11, it can be further cooled by the cooler 9 and then passed into the concentration device 10 for concentration treatment to improve the efficiency of the subsequent ion exchange process. The fresh water obtained after the concentration treatment can be used for the oxidation reactor 4 as cooling water for recycling.

[0114] In one embodiment of the present application, the system further comprises a compatibility tank, a high-pressure waste liquid delivery pump 2 connected to the compatibility tank, and a preheater 3 connected to the high-pressure waste liquid delivery pump 2; the preheater 3 is also connected to the oxidation reactor 4;

[0115] The mixing tank is used to determine the ratio between the potassium hydroxide solution L2 and the organic phosphorus waste liquid L1 according to the phosphorus content in the organic phosphorus waste liquid L1, and mix the organic phosphorus waste liquid L1 and the potassium hydroxide solution L2 according to the ratio, and then pass the mixture into the high-pressure waste liquid delivery pump 2;

[0116] The high-pressure waste liquid delivery pump 2 is used to deliver the mixed organic phosphorus-containing waste liquid L1 and potassium hydroxide solution L2 to the preheater 3;

[0117] The preheater 3 is used to heat the mixed organic phosphorus-containing waste liquid L1 and potassium hydroxide solution L2 to a preset temperature and then transport them to the oxidation reactor 4.

[0118] Specifically, in order to allow the potassium hydroxide solution L2 to fully react with the organic phosphorus-containing waste liquid L1, the ratio between the potassium hydroxide solution L2 and the organic phosphorus-containing waste liquid L1 can be determined according to the phosphorus content in the organic phosphorus-containing waste liquid L1.

[0119] Specifically, the ratio between the organic phosphorus waste liquid L1 and the potassium hydroxide solution L2 can be calculated as follows:

[0120] Q P / Q KOH =31×C KOH / (3×56×C P )

[0121] Among them, Q P - Flow rate of waste liquid containing organic phosphorus L1, m 3 / h;Q P - Potassium hydroxide solution L2 flow rate, m 3 / h; C P -Phosphorus concentration of organic phosphorus waste liquid L1, g / L; C KOH -Potassium hydroxide concentration, g / L.

[0122] After the preparation is completed in the mixing tank, the mixed organic phosphorus-containing waste liquid L1 and potassium hydroxide solution L2 can be transported to the preheater 3 through the high-pressure waste liquid delivery pump 2.

[0123] Specifically, if a supercritical water environment is required to be formed in the oxidation reactor 4, a high requirement is placed on the temperature of the oxidation reactor 4. Generally speaking, when the water temperature reaches above 374°C, the solution system in the oxidation reactor 4 can be transformed into a supercritical state.

[0124] In order to facilitate the formation of a supercritical water environment, the mixed organic phosphorus waste liquid L1 and the potassium hydroxide solution L2 can be heated by the preheater 3. The preheater 3 can heat the mixed organic phosphorus waste liquid L1 and the potassium hydroxide solution L2 to 200-300°C, and then pass the mixed organic phosphorus waste liquid L1 and the potassium hydroxide solution L2 into the oxidation reactor 4.

[0125] In one embodiment of the present application, the system further comprises a high-pressure oxidant delivery pump 24 connected to the oxidation reactor 4;

[0126] The high-pressure oxidant delivery pump 24 is used to pass the oxidant G1 into the oxidation reactor 4;

[0127] The oxidation reactor 4 is specifically used to pass the organic phosphorus waste liquid L1 and the potassium hydroxide solution L2 into the oxidation reactor 4; after the organic phosphorus waste liquid L1 and the potassium hydroxide solution L2 react with the oxidant G1 to produce an exothermic oxidation reaction, the temperature in the oxidation reactor 4 rises and reaches a supercritical state, and the organic phosphorus waste liquid L1, the potassium hydroxide solution L2, and the oxidant G1 undergo an oxidative decomposition reaction under the supercritical state to obtain a potassium phosphate solution.

[0128] Specifically, in order to carry out the oxidation decomposition reaction under the supercritical state, the oxidant G1 may be introduced into the oxidation reactor 4 through a high-pressure oxidant delivery pump 24. As a specific example of the present application, the oxidant G1 may be liquid oxygen.

[0129] After the organic phosphorus waste liquid L1 and potassium hydroxide solution L2 in the oxidation reactor 4 react with the oxidant G1 to produce an exothermic oxidation reaction, the temperature in the oxidation reactor 4 rises, and after reaching above 374° C., a supercritical environment is formed. In this environment, the organic phosphorus waste liquid L1, potassium hydroxide solution L2, and oxidant G1 undergo an oxidative decomposition reaction at a reaction temperature of 550-650° C. and a pressure of 22.1-24 MPa to obtain a potassium phosphate solution.

[0130] In one embodiment of the present application, the system also includes a nitrogen delivery pump 26 connected to the phosphorus recovery chamber 11-7. The nitrogen delivery pump 26 can pass nitrogen G3 to purge the phosphorus recovery chamber 11-7 to reduce the dissolved oxygen in the solution in the phosphorus recovery chamber 11-7; ferrous ions and phosphate ions generate blue iron ore in an oxygen-free environment.

[0131] In a specific implementation, in order to facilitate the generation of blue iron ore in an anaerobic environment, nitrogen G3 can be used to purge the phosphorus recovery chamber 11-7 to reduce the dissolved oxygen in the solution in the phosphorus recovery chamber 11-7 and form an anaerobic environment. Among them, the purge speed is 30-70m / h. The phosphorus recovery chamber 11-7 can generate blue iron ore in powder form. After the reaction is completed, the solid-liquid mixture is discharged from the phosphorus recovery chamber 11-7. After filtering, the solid produced can be vacuum cleaned in the water scrubber 12. After cleaning, it is vacuum dried by the vacuum dryer 13 to obtain pure blue iron ore powder. The remaining solution in the phosphorus recovery chamber 11-7 can be reused in the system as an acidic solution.

[0132] The prepared blue iron ore can be in powder form and is suitable for preparing phosphate fertilizer.

[0133] In one embodiment of the present application, Figure 3 Schematic diagram of a phosphorus recovery chamber 11-7 shown in an embodiment of the present application. Figure 3 As shown in (a), a plurality of detachable reaction beds with hollow mesh structures can be horizontally arranged in the phosphorus recovery chamber. Figure 3 As shown in (b), a plurality of detachable reaction beds with hollow mesh structures can be vertically arranged in the phosphorus recovery chamber, wherein silica sand with a particle size of 0.2-0.6 mm is arranged on the detachable reaction beds.

[0134] The phosphorus recovery chamber 11-7 is specifically used for generating blue iron ions and phosphate ions uniformly attached to silica sand in an environment where the silica sand is disturbed by nitrogen.

[0135] Silica sand can help blue iron ore crystals to adhere and grow, and the particle size of the reaction product is 0.7-2.1 mm. During the reaction process, nitrogen can be used to purge the phosphorus recovery chamber 11-7 at a purge speed of 30-70 m / h. The nitrogen purge reduces the dissolved oxygen in the solution and increases the disturbance of the silica sand. The blue iron ore fully adheres to the surface of the silica sand to form large-particle blue iron ore crystals.

[0136] After the reaction is completed, a solution mixed with blue iron ore discharged from the phosphorus recovery chamber 11-7 can be obtained. In the case where a reaction bed is not provided, the blue iron ore in the solution mixed with blue iron ore can be in powder form. In the case where a reaction bed is provided, the reaction bed can be removed and the blue iron ore particles can be recovered. Thus, oxidation caused by excessive specific surface area of ​​powdered blue iron ore during subsequent processing, transportation and storage can be avoided. At the same time, the reaction bed can be disassembled to facilitate product removal and avoid damage to the device by powdered blue iron ore.

[0137] Afterwards, the blue iron ore can be passed through the solid-liquid separator 25 to remove excess water from the blue iron ore. The blue iron ore is then transported to the water washer 12 for vacuum cleaning, and after cleaning, it is vacuum dried in the vacuum dryer 13 to obtain pure blue iron ore. In order to prevent part of the silica sand from adhering to the blue iron ore, the pure silica sand is screened by the magnetic separation device 14 and reused in the phosphorus recovery chamber 11-7.

[0138] The potassium sulfate solution discharged from the potassium sulfate recovery chamber 11-6 can be stored in a potassium sulfate storage tank 15. Thereafter, it can be transported to a potassium sulfate solution evaporator 17 by a potassium sulfate solution delivery pump 16. The potassium sulfate solution evaporator 17 can be in the form of multiple-effect evaporation or MVR (Mechanical Vapor Recompression).

[0139] After the evaporation and crystallization are completed, the liquid phase is passed into a potassium sulfate separator 18 to obtain potassium sulfate salt. The potassium sulfate salt is then transported to a potassium sulfate dryer 19 and dried to obtain a potassium sulfate salt product S2. The vapor phase output from the potassium sulfate solution evaporator 17 is cooled by a steam condenser 20 to obtain distilled water L4, which can be reused.

[0140] In one embodiment of the present application, the system further comprises a gas-liquid separation device connected to the oxidation reactor 4 and the salt conversion separation device 11 respectively; the potassium phosphate solution outputted from the oxidation reactor 4 also contains carbon dioxide and an oxidant G1;

[0141] The oxidation reactor 4 is specifically used to transport the potassium phosphate solution to the gas-liquid separation device;

[0142] The gas-liquid separation device is used to separate the carbon dioxide and the oxidant G1 in the potassium phosphate solution, and then transport the potassium phosphate solution to the salt conversion separation device 11.

[0143] Specifically, since the potassium phosphate solution output from the oxidation reactor 4 also contains carbon dioxide and the oxidant G1, the carbon dioxide and the oxidant G1 in the potassium phosphate solution can be separated by a gas-liquid separation device before the salt conversion separation.

[0144] In one embodiment of the present application, the gas-liquid separation device includes a primary gas-liquid separation device 6 and a secondary gas-liquid separation device 7 connected to the primary gas-liquid separation device 6;

[0145] The primary gas-liquid separation device 6 separates the carbon dioxide and the oxidant G1 in the potassium phosphate solution by flash evaporation and pressure reduction, and passes the potassium phosphate solution after the primary gas-liquid separation treatment into the secondary gas-liquid separation device 7;

[0146] The secondary gas-liquid separation device 7 is used to separate water vapor in the potassium phosphate solution by flash evaporation and pressure reduction, and pass the potassium phosphate solution after the secondary gas-liquid separation treatment into the salt conversion separation device 11.

[0147] Specifically, the potassium phosphate solution output from the oxidation reactor 4 can be reduced in pressure to 4-6 MPa by the pressure reduction system 5, and then enter the primary gas-liquid separation device 6 for flash evaporation and pressure reduction to separate the gas phase from the liquid phase. The gas phase generated by the primary gas-liquid separation mainly contains water vapor, CO2, and O2, and has a pressure of 2-4 MPa.

[0148] Afterwards, the liquid phase after the primary gas-liquid separation treatment can be passed into the secondary gas-liquid separation device 7. At this time, the gas phase almost contains no CO2 and O2, so that the secondary gas-liquid separation can mainly separate water vapor. After the secondary gas-liquid separation treatment, the potassium phosphate solution with higher purity can be passed into the salt conversion separation device 11 for further treatment.

[0149] In one embodiment of the present application, the system further comprises a carbon dioxide recovery device 22 connected to the primary gas-liquid separation device 6;

[0150] The carbon dioxide recovery device 22 is used to receive the carbon dioxide and the oxidant G1 discharged from the primary gas-liquid separation device, and separate the carbon dioxide and the oxidant G1 through pressure swing adsorption or distillation.

[0151] Specifically, the carbon dioxide and oxidant G1 discharged from the primary gas-liquid separation device can be cooled by a cooling device 21 to remove water vapor in the gas phase. Thereafter, the carbon dioxide and oxidant G1 can be passed into a carbon dioxide recovery device 22 to extract a carbon dioxide product G2.

[0152] The carbon dioxide G2 can be extracted by pressure swing adsorption or distillation to separate the carbon dioxide and the oxidant G1.

[0153] In the case of pressure swing adsorption, the adsorbent material is used to selectively adsorb carbon dioxide under gas phase pressure. The oxidant G1 and other impurities are not adsorbed and are directly discharged. The gas phase pressure is then reduced, and the carbon dioxide adsorbed by the adsorbent material is desorbed to obtain carbon dioxide G2 with higher purity for recycling.

[0154] When distillation is used, the gas phase can be dried and dehydrated first, then cooled to -5 to -10°C to liquefy the gas phase and then enter the distillation unit, where the unliquefied impurity gas is separated from the liquid carbon dioxide to obtain higher purity carbon dioxide for recycling.

[0155] In one embodiment of the present application, the system further comprises a generator set 8 connected to the secondary gas-liquid separation device 7;

[0156] The generator set 8 is used to receive the water vapor discharged from the secondary gas-liquid separation device 7 and generate electricity through the water vapor.

[0157] In a specific implementation, the generator set 8 can receive the water vapor discharged from the secondary gas-liquid separation device 7, and generate electricity through the water vapor to generate electric energy E and store it in the energy storage device 23. After power generation, the exhaust steam output by the generator set 8 can enter the steam condenser 20 for further use after cooling.

[0158] The embodiment of the present application also provides a method for treating organic phosphorus-containing waste liquid, which is applied to a system for treating organic phosphorus-containing waste liquid, the system comprising an oxidation reactor, a salt conversion separation device connected to the oxidation reactor, wherein the salt conversion separation device comprises an energized positive electrode and an energized negative electrode arranged opposite to each other, a plurality of cation exchange membranes and anion exchange membranes alternately arranged between the energized positive electrode and the energized negative electrode, and at least one recovery chamber arranged between the cation exchange membrane and the anion exchange membrane; the recovery chamber comprises a phosphorus recovery chamber and a potassium sulfate recovery chamber;

[0159] Methods include:

[0160] Step 101, introducing waste liquid containing organic phosphorus and potassium hydroxide solution into an oxidation reactor, reacting under a supercritical state to obtain a potassium phosphate solution, and introducing the potassium phosphate solution into a salt conversion separation device;

[0161] Step 102, in the salt conversion separation device, power is supplied to the positive electrode and the negative electrode, and a ferrous sulfate solution is introduced;

[0162] Step 103, potassium ions in the potassium phosphate solution move under the action of the energized negative electrode and pass through the cation exchange membrane to enter the potassium sulfate recovery chamber;

[0163] Step 104, phosphate ions in the potassium phosphate solution move under the action of the energized positive electrode and pass through the anion exchange membrane to enter the phosphorus recovery chamber;

[0164] Step 105, ferrous ions in the ferrous sulfate solution move under the action of the energized negative electrode and pass through the cation exchange membrane to enter the phosphorus recovery chamber;

[0165] Step 106, sulfate ions in the ferrous sulfate solution move under the action of the energized positive electrode and pass through the anion exchange membrane to enter the potassium sulfate recovery chamber;

[0166] Step 107, combining ferrous ions with phosphate ions in a phosphorus recovery chamber to obtain blue iron ore;

[0167] Step 108, potassium ions are combined with sulfate ions in a potassium sulfate recovery chamber to obtain potassium sulfate.

[0168] Specifically, in order to improve the degradation efficiency of organic pollutants, the embodiment of the present application provides a supercritical environment in the oxidation reactor. After the organic phosphorus waste liquid is passed into the oxidation reactor, oxidative degradation can be carried out in the supercritical environment. The carbon element in the organic phosphorus is converted into CO2, the hydrogen element is converted into H2O, and the phosphorus element is formed into H3PO4.

[0169] The oxidant may be oxygen, air, hydrogen peroxide, etc., and this application does not impose any limitation on this.

[0170] In order to prevent phosphoric acid from corroding the equipment, potassium hydroxide solution can be introduced at the same time as the organic phosphorus waste liquid is introduced. Potassium hydroxide can neutralize phosphoric acid to form potassium phosphate solution.

[0171] As an example of the present application, when the oxidant is oxygen, the supercritical water oxidation decomposition reaction can be expressed as:

[0172] C x H y O z P n +O2+KOH→CO2↑+H2O+K3PO4

[0173] Optionally, the organic phosphorus-containing waste liquid may contain a small amount of heavy metal ions. The heavy metal ions may form solid metal oxides under oxidation reaction, thereby enriching phosphorus in the liquid phase and enriching heavy metals in the solid phase, thereby separating the heavy metals from the phosphorus element, avoiding the heavy metals from affecting the purity of the subsequent blue iron ore, and conveniently recovering the heavy metals to avoid heavy metal pollution of the environment.

[0174] Specifically, violet iron ore is a phosphorus-related product with high economic value. The unit mass of phosphorus in violet iron ore (Fe3(PO4)2·8H2O) is high, so it can have high economic value. Vitriol ore can be used as a phosphate fertilizer and can also be a synthetic material for lithium batteries.

[0175] At the same time, waste materials in industrial processes, such as pickling wastewater from steel mills, usually contain ferrous sulfate, which can be recovered through proper treatment and purification. The utilization rate of industrial waste can be further improved through the rational use of ferrous sulfate. Ferrous sulfate contains the ferrous element required for the synthesis of blue iron ore, so blue iron ore can be obtained by simultaneously treating ferrous sulfate and potassium phosphate solution.

[0176] Therefore, in order to obtain blue iron ore products with higher economic value, the potassium phosphate solution can be further passed into a salt conversion separation device for treatment.

[0177] The salt conversion separation device includes a powered positive electrode and a powered negative electrode that are arranged relatively to each other, and also includes a plurality of cation exchange membranes and a plurality of anion exchange membranes that are alternately arranged between the powered positive electrode and the powered negative electrode, and also includes at least one recovery chamber that is arranged between the cation exchange membrane and the anion exchange membrane; the recovery chamber includes a phosphorus recovery chamber and a potassium sulfate recovery chamber.

[0178] In a specific implementation, there may be a gap between the cation exchange membrane and the anion exchange membrane, and the gap may be used to pass a solution to form a solution channel. Anions and cations may exist in different types of solutions, and electrode liquid may be added at the energized positive electrode and the energized negative electrode. In an energized environment, cations may begin to move toward the energized negative electrode and migrate to other solution channels through the cation exchange membrane, while anions may begin to move toward the energized positive electrode and migrate to other solution channels through the anion exchange membrane.

[0179] Therefore, by reasonably setting the introduction positions of potassium phosphate solution and ferrous sulfate solution, a potassium sulfate recovery chamber for recovering potassium sulfate and a phosphorus recovery chamber for recovering blue iron ore can be formed in some solution channels.

[0180] Specifically, the solution channel between the solution channel for feeding the ferrous sulfate solution and the solution channel for feeding the potassium phosphate solution can be used as the potassium sulfate recovery chamber, the solution channel for feeding the ferrous sulfate solution is located close to the energized negative electrode side, and the solution channel for feeding the potassium phosphate solution is located close to the energized positive electrode side. An anion exchange membrane is provided between the potassium sulfate recovery chamber and the solution channel for feeding the ferrous sulfate solution, and a cation exchange membrane is provided between the potassium sulfate recovery chamber and the solution channel for feeding the potassium phosphate solution.

[0181] Water can be passed into the potassium sulfate recovery chamber, and under an energized environment, the sulfate ions in the ferrous sulfate solution move toward the energized positive electrode and enter the potassium sulfate recovery chamber through the anion exchange membrane, and the potassium ions in the potassium phosphate solution can move toward the energized negative electrode and enter the potassium sulfate recovery chamber through the cation exchange membrane. In the potassium sulfate recovery chamber, one side near the energized negative electrode is an anion exchange membrane, and one side near the energized positive electrode is a cation exchange membrane. Thus, after entering the potassium sulfate recovery chamber, the sulfate ions can not continue to move toward the energized positive electrode due to the blocking of the cation exchange membrane, and stay in the potassium sulfate recovery chamber. After the potassium ions enter the potassium sulfate recovery chamber, they can not continue to move toward the energized negative electrode due to the blocking of the anion exchange membrane, and stay in the potassium sulfate recovery chamber. Thus, potassium ions and sulfate ions can be combined in the potassium sulfate recovery chamber to obtain a potassium sulfate solution.

[0182] At the same time, the solution channel between the solution channel for the ferrous sulfate solution and the solution channel for the potassium phosphate solution can be used as a phosphorus recovery chamber, the solution channel for the ferrous sulfate solution is located near the energized positive electrode, and the solution channel for the potassium phosphate solution is located near the energized negative electrode. A cation exchange membrane is provided between the phosphorus recovery chamber and the solution channel for the ferrous sulfate solution, and an anion exchange membrane is provided between the phosphorus recovery chamber and the solution channel for the potassium phosphate solution.

[0183] The phosphorus recovery chamber can be fed with water. Under the energized environment, the ferrous ions in the ferrous sulfate solution can move toward the energized negative electrode and enter the phosphorus recovery chamber through the cation exchange membrane. The phosphate ions in the potassium phosphate solution can move toward the energized positive electrode and enter the phosphorus recovery chamber through the anion exchange membrane. In the phosphorus recovery chamber, the anion exchange membrane is near the side of the energized negative electrode, and the cation exchange membrane is near the side of the energized positive electrode. Thus, after entering the phosphorus recovery chamber, the phosphate ions can not continue to move toward the energized positive electrode due to the blocking of the cation exchange membrane, and stay in the phosphorus recovery chamber. After the ferrous ions enter the phosphorus recovery chamber, they can not continue to move toward the energized negative electrode due to the blocking of the anion exchange membrane, and stay in the phosphorus recovery chamber. Thus, the ferrous ions and the phosphate ions can be combined in the phosphorus recovery chamber to obtain a solution mixed with blue iron ore solids.

[0184] Optionally, since violet iron ore is more easily formed in an acidic environment, an acidic solution may be introduced into the phosphorus recovery chamber to maintain the pH value of the phosphorus recovery chamber between 5.5 and 6.5, so as to better generate violet iron ore.

[0185] As for the solution channel into which the ferrous sulfate solution is introduced, under the power-on environment, the ferrous ions therein move toward the powered negative electrode and migrate to the phosphorus recovery chamber through the cation exchange membrane, and the sulfate ions move toward the powered positive electrode and migrate to the potassium sulfate recovery chamber through the anion exchange membrane. Thus, the solution channel of the ferrous sulfate solution can eventually discharge the desalted water.

[0186] For the solution channel into which the potassium phosphate solution is introduced, in an electrically powered environment, the potassium ions therein move toward the powered negative electrode and migrate to the potassium sulfate recovery chamber through the cation exchange membrane, and the phosphate ions move toward the powered positive electrode and migrate to the phosphorus recovery chamber through the anion exchange membrane. Thus, the solution channel of the potassium phosphate solution can eventually discharge the desalted water.

[0187] The desalted water discharged from the solution channel for the potassium phosphate solution and the solution channel for the ferrous sulfate solution can be recycled to improve environmental protection.

[0188] Specifically, the concentration of the ferrous sulfate solution can be determined according to the concentration of the potassium phosphate solution flowing out of the oxidation reactor, wherein the molar ratio of ferrous sulfate to potassium phosphate is 1.2 to 2, preferably 1.5.

[0189] In summary, the embodiments of the present application can realize the recovery and treatment of phosphorus in organic phosphorus waste liquid, and the obtained blue iron ore product has a high economic value. At the same time, other products such as potassium sulfate and carbon dioxide produced in the treatment process can also be further recycled. The raw materials used in the overall treatment process and the obtained products are environmentally friendly, do not generate more pollution, and improve the environmental friendliness of organic phosphorus treatment.

[0190] Optionally, the system further comprises a concentrating device, which is respectively connected to the oxidation reactor and the salt conversion separation device;

[0191] The potassium phosphate solution is passed into a salt conversion separation device, comprising:

[0192] Passing the potassium phosphate solution into a concentrating device;

[0193] After the potassium phosphate solution is concentrated by the concentrating device, the concentrated potassium phosphate solution is passed into the salt conversion separation device.

[0194] Optionally, the system further comprises a preparation tank, a high-pressure waste liquid delivery pump connected to the preparation tank, and a preheater connected to the high-pressure waste liquid delivery pump; the preheater is also connected to the oxidation reactor;

[0195] The method also includes:

[0196] Determine the ratio between potassium hydroxide solution and organic phosphorus waste liquid according to the phosphorus content in the organic phosphorus waste liquid;

[0197] After the organic phosphorus waste liquid and potassium hydroxide solution are mixed in a proportion in a mixing tank, they are passed into a high-pressure waste liquid delivery pump;

[0198] The mixed organic phosphorus-containing waste liquid and potassium hydroxide solution are transported to the preheater by a high-pressure waste liquid transport pump;

[0199] The mixed organic phosphorus waste liquid and potassium hydroxide solution are heated to a preset temperature by a preheater and then transported to an oxidation reactor.

[0200] Optionally, the system further comprises a high-pressure oxidant delivery pump connected to the oxidation reactor;

[0201] The step of introducing waste liquid containing organic phosphorus and potassium hydroxide solution into an oxidation reactor to undergo oxidation reaction under supercritical conditions to obtain potassium phosphate solution comprises:

[0202] The oxidant is introduced into the oxidation reactor via a high-pressure oxidant delivery pump;

[0203] The organic phosphorus waste liquid and potassium hydroxide solution are introduced into the oxidation reactor through the oxidation reactor; after the organic phosphorus waste liquid and potassium hydroxide solution react with the oxidant to produce an exothermic oxidation reaction, the temperature in the oxidation reactor rises and reaches a supercritical state, and the organic phosphorus waste liquid, potassium hydroxide solution, and oxidant undergo an oxidation decomposition reaction to obtain a potassium phosphate solution.

[0204] Optionally, the step of combining ferrous ions with phosphate ions to obtain blue iron ore in the phosphorus recovery chamber comprises:

[0205] Passing nitrogen gas to purge the phosphorus recovery chamber to reduce the dissolved oxygen in the solution in the phosphorus recovery chamber;

[0206] In the phosphorus recovery chamber, ferrous ions and phosphate ions form blue iron ore in an oxygen-free environment.

[0207] Optionally, a plurality of detachable reaction beds with hollow mesh structures are arranged horizontally or vertically in the phosphorus recovery chamber, and silica sand is arranged on the detachable reaction beds;

[0208] The step of combining ferrous ions with phosphate ions to obtain blue iron ore in a phosphorus recovery chamber comprises:

[0209] In the environment of nitrogen disturbing silica sand in the phosphorus recovery chamber, ferrous ions and phosphate ions generate blue iron ore that is uniformly attached to the silica sand.

[0210] Optionally, the system further comprises a gas-liquid separation device connected to the oxidation reactor and the salt conversion separation device respectively; the potassium phosphate solution outputted from the oxidation reactor also contains carbon dioxide and an oxidant;

[0211] The step of passing the potassium phosphate solution into the salt conversion separation device comprises:

[0212] transporting the potassium phosphate solution in the oxidation reactor to a gas-liquid separation device;

[0213] After the carbon dioxide and the oxidant in the potassium phosphate solution are separated by the gas-liquid separation device, the potassium phosphate solution is transported to the salt conversion separation device.

[0214] Optionally, the gas-liquid separation device includes a primary gas-liquid separation device and a secondary gas-liquid separation device connected to the primary gas-liquid separation device;

[0215] The step of separating carbon dioxide and oxidant in potassium phosphate solution by a gas-liquid separation device comprises:

[0216] The carbon dioxide and the oxidant in the potassium phosphate solution are separated by flash evaporation and pressure reduction by a primary gas-liquid separation device, and the potassium phosphate solution after the primary gas-liquid separation treatment is passed into a secondary gas-liquid separation device;

[0217] The water vapor in the potassium phosphate solution is separated by flash evaporation and pressure reduction through a secondary gas-liquid separation device.

[0218] Optionally, the system further comprises a carbon dioxide recovery device connected to the primary gas-liquid separation device;

[0219] The method also includes:

[0220] The carbon dioxide and the oxidant discharged from the first gas-liquid separation device are received by the carbon dioxide recovery device, and the carbon dioxide and the oxidant are separated by pressure swing adsorption or distillation.

[0221] Optionally, the system further comprises a generator set connected to the secondary gas-liquid separation device;

[0222] The method also includes:

[0223] The water vapor discharged from the secondary gas-liquid separation device is received by the generator set, and electricity is generated by the water vapor.

[0224] The above is a detailed introduction to a treatment system for organic phosphorus waste liquid and a treatment method for organic phosphorus waste liquid provided by the present application. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea; at the same time, for general technical personnel in this field, according to the idea of ​​the present application, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A system for treating waste liquid containing organic phosphorus, characterized in that: The system comprises an oxidation reactor and a salt conversion separation device connected to the oxidation reactor; the salt conversion separation device comprises a powered positive electrode and a powered negative electrode arranged opposite to each other, and also comprises a plurality of cation exchange membranes and a plurality of anion exchange membranes alternately arranged between the powered positive electrode and the powered negative electrode, and also comprises at least one recovery chamber arranged between the cation exchange membrane and the anion exchange membrane; the recovery chamber comprises a phosphorus recovery chamber and a potassium sulfate recovery chamber; The oxidation reactor is used to pass the organic phosphorus waste liquid, potassium hydroxide solution and oxidant into the oxidation reactor, react under supercritical conditions to obtain potassium phosphate solution, and pass the potassium phosphate solution into the salt conversion separation device; The salt conversion separation device is used to energize through the energized positive electrode and the energized negative electrode, and pass a ferrous sulfate solution; potassium ions in the potassium phosphate solution move under the action of the energized negative electrode and pass through the cation exchange membrane to enter the potassium sulfate recovery chamber; phosphate ions in the potassium phosphate solution move under the action of the energized positive electrode and pass through the anion exchange membrane to enter the phosphorus recovery chamber; ferrous ions in the ferrous sulfate solution move under the action of the energized negative electrode and pass through the cation exchange membrane to enter the phosphorus recovery chamber; Sulfate ions in the ferrous sulfate solution move under the action of the energized positive electrode and pass through the anion exchange membrane to enter the potassium sulfate recovery chamber; The phosphorus recovery chamber is used to combine the ferrous ions with the phosphate ions to obtain blue iron ore; The potassium sulfate recovery chamber is used for combining the potassium ions with the sulfate ions to obtain a potassium sulfate solution.

2. The system for treating waste liquid containing organic phosphorus according to claim 1, characterized in that: The system further comprises a concentrating device, which is respectively connected to the oxidation reactor and the salt conversion separation device; The oxidation reactor is specifically used for passing the potassium phosphate solution into the concentrating device; The concentrator is used to concentrate the potassium phosphate solution and then pass the concentrated potassium phosphate solution into the salt conversion separation device.

3. The system for treating waste liquid containing organic phosphorus according to claim 1, characterized in that: The system also includes a preparation tank, a high-pressure waste liquid delivery pump connected to the preparation tank, and a preheater connected to the high-pressure waste liquid delivery pump; the preheater is also connected to the oxidation reactor; The mixing tank is used to determine the ratio between the potassium hydroxide solution and the organic phosphorus-containing waste liquid according to the phosphorus content in the organic phosphorus-containing waste liquid, and after mixing the organic phosphorus-containing waste liquid and the potassium hydroxide solution according to the ratio, pass them into the high-pressure waste liquid delivery pump; The high-pressure waste liquid delivery pump is used to deliver the mixed organic phosphorus-containing waste liquid and the potassium hydroxide solution to the preheater; The preheater is used to heat the mixed organic phosphorus waste liquid and the potassium hydroxide solution to a preset temperature and then transport them to the oxidation reactor.

4. The system for treating waste liquid containing organic phosphorus according to claim 1, characterized in that: The system also includes a high-pressure oxidant delivery pump connected to the oxidation reactor; The high-pressure oxidant delivery pump is used to pass the oxidant into the oxidation reactor.

5. The system for treating waste liquid containing organic phosphorus according to claim 1, characterized in that: The system also includes a nitrogen delivery pump connected to the phosphorus recovery chamber, and the nitrogen delivery pump is used to pass nitrogen to purge the phosphorus recovery chamber to reduce the dissolved oxygen in the solution in the phosphorus recovery chamber; the ferrous ions and the phosphate ions generate blue iron ore in an oxygen-free environment.

6. The system for treating waste liquid containing organic phosphorus according to claim 5, characterized in that: A plurality of detachable reaction beds with hollow mesh structures are arranged horizontally or vertically in the phosphorus recovery chamber, and silica sand is arranged on the detachable reaction beds; The phosphorus recovery chamber is specifically used for causing the ferrous ions and the phosphate ions to generate blue iron ore uniformly attached to the silica sand in an environment where the nitrogen disturbs the silica sand.

7. The system for treating waste liquid containing organic phosphorus according to claim 1, characterized in that: The system further comprises a gas-liquid separation device connected to the oxidation reactor and the salt conversion separation device respectively; the potassium phosphate solution outputted from the oxidation reactor also contains carbon dioxide and an oxidant; The oxidation reactor is specifically used to transport the potassium phosphate solution to the gas-liquid separation device; The gas-liquid separation device is used to separate the carbon dioxide and the oxidant in the potassium phosphate solution, and then transport the potassium phosphate solution to the salt conversion separation device.

8. The system for treating waste liquid containing organic phosphorus according to claim 7, characterized in that: The gas-liquid separation device comprises a primary gas-liquid separation device and a secondary gas-liquid separation device connected to the primary gas-liquid separation device; The primary gas-liquid separation device separates the carbon dioxide and the oxidant in the potassium phosphate solution by flash evaporation and pressure reduction, and passes the potassium phosphate solution after the primary gas-liquid separation treatment into the secondary gas-liquid separation device; The secondary gas-liquid separation device is used to separate water vapor in the potassium phosphate solution by flash evaporation and pressure reduction, and pass the potassium phosphate solution after the secondary gas-liquid separation treatment into the salt conversion separation device.

9. The system for treating waste liquid containing organic phosphorus according to claim 8, characterized in that: The system also includes a generator set connected to the secondary gas-liquid separation device; The generator set is used to receive the water vapor discharged from the secondary gas-liquid separation device and generate electricity through the water vapor.

10. A method for treating waste liquid containing organic phosphorus, characterized in that: The invention is applied to a treatment system of waste liquid containing organic phosphorus, the system comprising an oxidation reactor and a salt conversion separation device connected to the oxidation reactor; the salt conversion separation device comprises a powered positive electrode and a powered negative electrode arranged opposite to each other, and also comprises a plurality of cation exchange membranes and a plurality of anion exchange membranes alternately arranged between the powered positive electrode and the powered negative electrode, and also comprises at least one recovery chamber arranged between the cation exchange membrane and the anion exchange membrane; The recovery chamber includes a phosphorus recovery chamber and a potassium sulfate recovery chamber; The method comprises: Passing organic phosphorus waste liquid, potassium hydroxide solution and oxidant into the oxidation reactor, reacting under supercritical state to obtain potassium phosphate solution, and passing the potassium phosphate solution into the salt conversion separation device; In the salt conversion separation device, electricity is supplied through the powered positive electrode and the powered negative electrode, and a ferrous sulfate solution is introduced; Potassium ions in the potassium phosphate solution move under the action of the energized negative electrode and penetrate the cation exchange membrane to enter the potassium sulfate recovery chamber; Phosphate ions in the potassium phosphate solution move under the action of the energized positive electrode and pass through the anion exchange membrane into the phosphorus recovery chamber; The ferrous ions in the ferrous sulfate solution move under the action of the energized negative electrode and pass through the cation exchange membrane to enter the phosphorus recovery chamber; Sulfate ions in the ferrous sulfate solution move under the action of the energized positive electrode and pass through the anion exchange membrane to enter the potassium sulfate recovery chamber; In the phosphorus recovery chamber, the ferrous ions are combined with the phosphate ions to obtain blue iron ore; In the potassium sulfate recovery chamber, the potassium ions combine with the sulfate ions to obtain a potassium sulfate solution.

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