A safe treatment device for phosphorus and arsenic-containing waste liquid

Abstract

The application relates to a safe treatment device for phosphorus-containing and arsenic-containing waste liquid, which comprises a crushing mechanism for containing the phosphorus-containing and arsenic-containing waste liquid and crushing solid matters in the waste liquid; a first closed reaction container for receiving the waste liquid from the crushing mechanism; an oxidation mechanism comprising a sodium hypochlorite storage tank one and a sodium hydroxide storage tank two; a second closed reaction container for receiving the waste liquid from the first closed reaction container; and a precipitation mechanism comprising a calcium chloride storage tank three, a lime milk storage tank four, a ferric chloride storage tank five and a polyaluminum chloride storage tank six. The application can effectively treat elemental phosphorus and simultaneously dispose of the arsenic-containing waste liquid, solves the problem that the prior art lacks a device for simultaneously and safely treating the phosphorus-containing and arsenic-containing waste liquid, reduces equipment investment and operation cost, and improves the treatment efficiency.

Description

Technical Field

[0001] This application relates to the field of waste liquid treatment and recycling technology, and in particular to a safe treatment device for phosphorus- and arsenic-containing waste liquid. Background Technology

[0002] The phosphorus- and arsenic-containing hazardous waste originates from the etching of diodes and semiconductors in the display screen industry, which adheres to stainless steel pipes. This wastewater is generated from cleaning pipes using a mixture of ammonia and hydrogen peroxide in a 1:4 ratio. The main components of this wastewater are trivalent arsenic, pentavalent arsenic, elemental phosphorus, and phosphides, and it often contains a significant amount of caking material.

[0003] Arsenic is a globally distributed element. Due to its toxicity, it poses numerous health risks to both the environment and humans. Excessive arsenic intake can cause skin diseases, heart disease, and high blood pressure, and can also harm crop growth. Arsenic can be divided into organic and inorganic arsenic, with inorganic arsenic being the most toxic. Inorganic arsenic is further divided into trivalent and pentavalent arsenic. Trivalent arsenic precipitates have high solubility and are generally oxidized to pentavalent arsenic, which is then reacted with calcium and iron salts to form calcium arsenate and ferric arsenate precipitates, which are then solidified and landfilled. Elemental phosphorus is flammable and highly toxic. Direct discharge without treatment will cause serious environmental damage. Because elemental phosphorus is insoluble in water, it is difficult to degrade once it enters water bodies, posing a serious threat to human health. Elemental phosphorus is generally treated by oxidation with potassium permanganate and calcium hypochlorite, followed by chemical coagulation and precipitation.

[0004] In current technological processes, calcium salt precipitation is commonly used for phosphorus-containing wastewater, while iron salt precipitation is typically used for arsenic-containing wastewater. However, separating phosphorus and arsenic in phosphorus- and arsenic-containing wastewater for separate treatment is time-consuming and costly. Furthermore, since elemental phosphorus is insoluble in water, conventional methods for treating phosphorus-containing wastewater are unsuitable for treating elemental phosphorus. Failure to treat them separately may lead to complex chemical reactions and the generation of unpredictable intermediate products due to the lack of relevant processes. These intermediate products may possess higher toxicity or reactivity, increasing the safety risks of the treatment process. Therefore, there is an urgent need to provide a safe treatment device for phosphorus- and arsenic-containing wastewater to address these issues. Utility Model Content

[0005] This invention provides a safe treatment device for phosphorus- and arsenic-containing waste liquid, which solves the problem that the prior art lacks a device for simultaneously and safely treating phosphorus- and arsenic-containing waste liquid.

[0006] This utility model provides a safe treatment device for phosphorus and arsenic-containing waste liquid, including a crushing mechanism for holding the phosphorus and arsenic-containing waste liquid and crushing the solids in the waste liquid; a first closed reaction vessel for receiving waste liquid from the crushing mechanism; an oxidation mechanism including a storage tank 1 containing sodium hypochlorite and a storage tank 2 containing sodium hydroxide, the storage tanks 1 and 2 being used to respectively input sodium hypochlorite and sodium hydroxide into the first closed reaction vessel; a second closed reaction vessel for receiving waste liquid from the first reaction vessel; and a precipitation mechanism including a storage tank 3 containing calcium chloride, a storage tank 4 containing lime milk, a storage tank 5 containing ferric chloride, and a storage tank 6 containing polyaluminum chloride, the storage tanks 3, 4, 5, 6, and 2 being used to respectively input calcium chloride, lime milk, ferric chloride, polyaluminum chloride, and sodium hydroxide into the second closed reaction vessel.

[0007] In some of these embodiments, the inlet of the first sealed reaction vessel is connected to the outlet of the crushing mechanism, the outlet of storage tank one, and the outlet of storage tank two, respectively.

[0008] In some of these embodiments, the inlet of the second sealed reaction vessel is connected to the outlets of storage tank three, storage tank four, storage tank five, storage tank six, and storage tank two.

[0009] In some embodiments, the safety treatment device further includes a waste liquid buffer tank, the inlet of which is connected to the outlet of the crushing mechanism, and the outlet of which is connected to the inlet of the first sealed reaction vessel.

[0010] In some of these embodiments, the crushing mechanism, the first sealed reaction vessel, and the second sealed reaction vessel are all equipped with a stirrer for stirring the waste liquid.

[0011] In some of these embodiments, the crushing mechanism, the first sealed reaction vessel, and the second sealed reaction vessel are each equipped with a pH meter for measuring the pH value of the waste liquid.

[0012] In some embodiments, the safety processing apparatus further includes a solid-liquid separation mechanism for separating liquid and solid precipitates from the second closed reaction vessel.

[0013] In some embodiments, the solid-liquid separation mechanism further includes a plate and frame filter press, a wastewater treatment unit, and a filter cake collector. The inlet of the plate and frame filter press is connected to the outlet of the second sealed reaction vessel, and the outlet of the plate and frame filter press is connected to the wastewater treatment unit and the filter cake collector, respectively.

[0014] In some embodiments, the safety handling device further includes a gas handling mechanism for handling harmful gases generated in the crushing mechanism, the first sealed reaction vessel, and the second sealed reaction vessel.

[0015] In some embodiments, the gas processing mechanism includes a measuring cup 1 containing sulfuric acid solution, a measuring cup 2 containing sodium hydroxide solution, and a measuring cup 3 containing activated carbon. Measuring cups 1, 2, and 3 are connected in sequence, and measuring cup 1 is connected to a crushing mechanism, a first sealed reaction vessel, and a second sealed reaction vessel via an exhaust pipe.

[0016] Compared with related technologies, the present invention has the following beneficial effects:

[0017] The lumpy solids (caking material and mixtures of elemental phosphorus and arsenic) in the phosphorus- and arsenic-containing wastewater are crushed by a crushing mechanism, and a separate, sealed reaction vessel is used to ensure full contact with subsequent reactants. An oxidation mechanism then oxidizes elemental phosphorus to phosphate and trivalent arsenic to pentavalent arsenic. A precipitation mechanism in a second sealed reaction vessel allows the phosphate and pentavalent arsenic to react and form a precipitate, which then flocculates. This process effectively treats elemental phosphorus while simultaneously disposing of arsenic-containing wastewater, achieving safe and harmless disposal of such wastewater. Furthermore, the entire reaction process effectively collects and treats the system's three wastes, addressing the lack of existing technologies for the simultaneous safe treatment of phosphorus- and arsenic-containing wastewater. This reduces equipment investment and operating costs while improving treatment efficiency.

[0018] Details of one or more embodiments of this application are set forth in the following drawings and description to make other features, objects and advantages of this application more readily apparent. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the safe treatment device for phosphorus- and arsenic-containing waste liquid proposed in this embodiment.

[0020] In the diagram: 1. Crushing mechanism; 2. Waste liquid buffer tank; 3. Storage tank one; 4. Storage tank two; 5. Storage tank three; 6. Storage tank four; 7. Storage tank five; 8. Storage tank six; 9. First closed reaction vessel; 10. Second closed reaction vessel; 11. Plate and frame filter press; 12. Wastewater treatment plant; 13. Oxidation mechanism; 14. Sedimentation mechanism; 15. Blade; 16. Stirrer; 17. pH meter; 18. Cooling box; 19. Filter residue collector; 20. Measuring cup one; 21. Measuring cup two; 22. Measuring cup three; 23. Vacuum pump. Detailed Implementation

[0021] To better understand the purpose, technical solution, and advantages of this application, the application is described and illustrated below in conjunction with the accompanying drawings and embodiments.

[0022] The main components of phosphorus- and arsenic-containing waste liquid are trivalent arsenic, pentavalent arsenic, elemental phosphorus, phosphides, and lumpy solids (caking material and mixtures of elemental phosphorus and arsenic).

[0023] This embodiment provides a safe treatment device for phosphorus- and arsenic-containing wastewater. Please refer to [link / reference]. Figure 1 The device includes a crushing mechanism 1, a first sealed reaction vessel 9, an oxidation mechanism 13, a second sealed reaction vessel 10, a precipitation mechanism 14, a waste liquid buffer tank 2, a solid-liquid separation mechanism, and a gas treatment mechanism. The crushing mechanism 1 is used to crush lumpy solids in the waste liquid. The first sealed reaction vessel 9 is used to receive the waste liquid after treatment by the crushing mechanism 1. The oxidation mechanism 13 is used to oxidize elemental phosphorus and trivalent arsenides contained in the waste liquid in the first sealed reaction vessel 9. The second reaction vessel 10 is used to receive the waste liquid from the first reaction vessel 9. The precipitation mechanism 14 is used to react with phosphates and arsenates contained in the waste liquid in the second sealed reaction vessel 10 to form insoluble precipitates. The solid-liquid separation mechanism is used to separate the liquid and solid precipitates from the second reaction vessel 10. The gas treatment mechanism is used to treat the harmful gases generated by the reactions in the crushing mechanism 1, the first reaction vessel 9, and the second reaction vessel 10.

[0024] The crushing mechanism 1 includes a housing, blades 15, a stirrer 16, and a pH meter 17. The housing holds phosphorus- and arsenic-containing waste liquid and crushes lumpy solids (caking materials and mixtures of elemental phosphorus and arsenic) within it. An inlet for the phosphorus- and arsenic-containing waste liquid is located at the top. Blades 15 are rotatably mounted inside the crushing mechanism 1 and can be driven to rotate by an external motor. Because the caking materials and lumpy mixtures of elemental phosphorus and arsenic have relatively large particles, rotating blades 15 can thoroughly crush them into smaller particles to improve the subsequent reaction efficiency, increasing the contact area of ​​the reactants. Furthermore, since the crushing process takes place in a liquid, it effectively prevents elemental phosphorus from spontaneously combusting upon contact with air. The fixed end of the stirrer 16 is fixedly mounted inside the crushing mechanism 1. The output end of the stirrer 16 can rotate to uniformly stir the waste liquid, thoroughly crushing and mixing the lumpy solids. Stirring also increases the reaction rate. The pH meter is fixedly mounted inside the crushing mechanism 1 and is used to measure the pH changes of the waste liquid in real time. The crushing mechanism 1 can also be connected to the gas processing mechanism to prevent the leakage of harmful gases.

[0025] The oxidation unit 13 includes a storage tank 3 containing sodium hypochlorite and a storage tank 4 containing sodium hydroxide. The storage tank 3 and the storage tank 4 are used to respectively introduce sodium hypochlorite and sodium hydroxide into the first closed reaction vessel 9. Adding sodium hypochlorite can oxidize elemental phosphorus in the waste liquid into phosphate ions and oxidize trivalent arsenic in arsenite into pentavalent arsenic (arsenate ions). Adding sodium hydroxide can neutralize the acid in the waste liquid, thereby increasing its pH value (the first adjustment controls the pH value to around 7 to provide a suitable environment for the redox reaction).

[0026] The first closed reaction vessel 9 is used to receive the waste liquid after it has been processed by the crushing mechanism 1. Its inlet can be connected to the outlet of the crushing mechanism 1, the outlet of storage tank 3, and the outlet of storage tank 4, respectively. Pumps are installed between these connected pipelines. These pumps not only provide the power for transporting the waste liquid, sodium hypochlorite, and sodium hydroxide, but can also be shut off at any time to control the amount of substances being transported. Similarly, the first closed reaction vessel 9 can also be equipped with a stirrer 16 and a pH meter 17 to ensure the reaction proceeds fully and to monitor the pH changes in the waste liquid in real time.

[0027] To ensure the accuracy of sodium hypochlorite dosage, in this embodiment, the inlet of the waste liquid buffer tank 2 is connected to the outlet of the crushing mechanism 1, and the outlet of the waste liquid buffer tank 2 is connected to the inlet of the first sealed reaction vessel 9. A pump is installed between these two connected pipelines. The waste liquid treated by the crushing mechanism 1 can be transported to the waste liquid buffer tank 2 through the pipeline for cooling and buffering (and left to stand for observation for a period of time). Then, the concentrations of elemental phosphorus and arsenite in the waste liquid are measured, and then the pump is turned on to deliver the corresponding amount of waste liquid to the first sealed reaction vessel 9, so that the amount of sodium hypochlorite added subsequently corresponds to the amount of elemental phosphorus and arsenite in the corresponding proportion.

[0028] The precipitation mechanism 14 includes a storage tank 3 (5) containing calcium chloride, a storage tank 4 (6) containing lime slurry, a storage tank 5 (7) containing ferric chloride, and a storage tank 6 (8) containing polyaluminum chloride. These tanks are used to introduce calcium chloride, lime slurry, ferric chloride, polyaluminum chloride, and sodium hydroxide into the second closed reaction vessel 10 to react with the phosphates and arsenates contained in the waste liquid, forming insoluble precipitates. First, lime slurry and sodium hydroxide are added to adjust the pH of the waste liquid (the second adjustment controls the pH to around 9 to provide a suitable environment for precipitation). Then, calcium chloride and ferric chloride are added to react with the phosphates and arsenates to form precipitates (calcium ions can combine with phosphate and arsenate ions to form calcium phosphate and calcium arsenate precipitates, and iron ions can combine with arsenate ions to form ferric arsenate precipitates). Finally, a polyaluminum chloride (PAC) solution is added. PAC has a strong adsorption capacity and a high degree of polymerization, enabling it to aggregate fine particles through adsorption bridging, forming larger flocs and accelerating the precipitation process.

[0029] The second closed reaction vessel 10 is used to receive waste liquid from the first closed reaction vessel 9. Its outlet can be connected to the inlet of storage tanks 5, 6, 7, and 8. Pumps are installed between these connecting pipelines. By adjusting the switch of each pump, the reactants are sequentially added to the second closed reaction vessel 10. Similarly, the second closed reaction vessel 10 can also be equipped with a stirrer 16 and a pH meter 17 to ensure the reaction proceeds fully and to monitor the pH changes in the waste liquid in real time.

[0030] Since a large amount of heat is released during the reaction, in this embodiment, the first sealed reaction vessel 9 and the second sealed reaction vessel 10 can be placed in a cooling tank 18, and coolant can be continuously circulated into the cooling tank to cool the two vessels and control the temperature of the reaction system below 60°C. In other embodiments, the first sealed reaction vessel 9 and the second sealed reaction vessel 10 can also be placed in a semi-open cooling pool, and circulating coolant can be circulated into the cooling pool to cool them.

[0031] The solid-liquid separation mechanism is used to separate liquid and precipitate from the second closed reaction vessel 10. Specifically, the solid-liquid separation mechanism includes a plate and frame filter press 11, a wastewater treatment unit 12, and a filter cake collector 19. The inlet of the plate and frame filter press 11 is connected to the outlet of the second closed reaction vessel 10, and the outlet of the plate and frame filter press 11 is connected to both the wastewater treatment unit 12 and the filter cake collector 19. The plate and frame filter press 11 forms filter chambers through the alternating arrangement of internal filter plates and filter frames. Pressure is used to trap the precipitate in the wastewater on the filter cloth, which is then collected and recycled in the filter cake collector 19. The harmless liquid (free of phosphorus and arsenic) is discharged through the filter cloth and enters the wastewater treatment unit 12 for further treatment to meet wastewater discharge standards before being discharged.

[0032] The gas handling mechanism includes a measuring cup 20 containing sulfuric acid solution, a measuring cup 21 containing sodium hydroxide solution, a measuring cup 22 containing activated carbon, and a vacuum pump 23. Measuring cups 20, 21, and 32 are connected sequentially, and measuring cup 20 is connected to the crushing mechanism 1, the first sealed reaction vessel 9, and the second sealed reaction vessel 10 via an exhaust pipe. Measuring cup 22 can be actively vented by the vacuum pump 23. The sulfuric acid solution is mainly used to absorb phosphine, arsine, and other volatile gases that may overflow during the reaction; the sodium hydroxide solution is mainly used to absorb acidic gases generated during the reaction, such as hydrogen sulfide (H2S), sulfur dioxide (SO2), and hydrogen chloride (HCl). These gases will neutralize with sodium hydroxide in an alkaline environment, producing the corresponding salts and water. It is worth mentioning that, in this embodiment, sodium hydroxide solution can also be used to absorb certain volatile compounds containing phosphorus or arsenic, such as arsine (AsH3), and convert them into harmless substances through oxidation-reduction reactions; activated carbon has a highly porous structure and a large specific surface area, and is mainly used to adsorb volatile organic compounds and some gases that are difficult to remove by chemical absorption, that is, it can adsorb harmful substances in gases to reduce the toxicity or odor of the gases.

[0033] Specifically, in this embodiment, the following steps S1 to S5 are provided for using a safe treatment device for phosphorus- and arsenic-containing wastewater:

[0034] S1, the phosphorus- and arsenic-containing waste liquid is fed into the crushing mechanism 1 (pouring in through the inlet on the housing), and the crushing mechanism 1 is started (the blades 15 and the agitator 16 rotate). The rotation of the blades 15 and the stirring of the agitator 16 are used to fully crush the lumpy solids (caking material and mixtures of elemental phosphorus and arsenic) in the phosphorus- and arsenic-containing waste liquid, so that they can come into full contact with the subsequent reactants.

[0035] S101, the waste liquid processed by the crushing mechanism 1 is pumped into the waste liquid buffer tank 2 for buffering, and the concentration of elemental phosphorus and arsenite in the waste liquid is measured. Then, the pump is turned on to deliver the corresponding amount of waste liquid to the first closed reaction vessel 9 (so that the amount of sodium hypochlorite added later corresponds to the amount of elemental phosphorus and arsenite in the corresponding proportion).

[0036] S2, sodium hypochlorite is added to the first closed reaction vessel 9 through the storage tank. The amount of sodium hypochlorite added is according to the set ratio (elemental phosphorus: sodium hypochlorite = 1:10). After complete mixing and stirring, the sufficient amount of sodium hypochlorite will oxidize the water-insoluble elemental phosphorus into water-soluble phosphate ions. The chemical reaction equation for the oxidation reaction is as follows:

[0037] P4+10NaClO+6H2O=4H3PO4+10NaCl

[0038] P₂ + 5NaClO + 3H₂O = 2H₃PO₄ + 5NaCl

[0039] 2P + 5NaClO + 3H2O = 2H3PO4 + 5NaCl

[0040] S2, sodium hydroxide is added to the first closed reaction vessel 9 through the storage tank. Sodium hydroxide reacts with the acid in the waste liquid to neutralize it. The pH value is observed through pH meter 17 to control the pH value of the waste liquid at around 7.

[0041] S3. Sodium hypochlorite is then added to the first closed reaction vessel 9 via the storage tank for a secondary oxidation reaction. The amount of sodium hypochlorite added is according to a set ratio (sodium hypochlorite: arsenite = 1:1). After complete mixing, the sodium hypochlorite oxidizes trivalent arsenic to pentavalent arsenic (arsenite ions are converted to arsenate ions). Because pentavalent arsenic has lower solubility and less toxicity, the chemical reaction equation for the secondary oxidation is as follows:

[0042] 2OH - +AsO2 - +ClO - =AsO4 3- +Cl - +H2O

[0043] S4, the mixture in the first closed reaction vessel 9 is pumped into the second closed reaction vessel 10. Lime slurry (calcium hydroxide) and sodium hydroxide are added to the second closed reaction vessel 10 through storage tank 6 to adjust the pH of the mixture to approximately 9. Phosphate and arsenate ions exist in different forms at different pH values. For phosphate ions, at lower pH values, they mainly exist as H2PO4. - and HPO4 2- It exists in the form of PO4; when the pH value is high, it mainly exists as PO4. 3- The same applies to arsenate ions, so it is necessary to appropriately increase the pH value of the reaction environment. At this pH value, the reaction between calcium ions and phosphate or arsenate ions is more likely to occur.

[0044] S5, firstly, calcium chloride and ferric chloride are added to the second closed reaction vessel 10 through storage tanks 3 (5) and 5 (7), and then polyaluminum chloride is added to the second closed reaction vessel 10 through storage tank 6 (8). Calcium ions combine with phosphate and arsenate ions to form calcium phosphate and calcium arsenate precipitates, respectively, while iron ions combine with arsenate ions to form ferric arsenate precipitate. The chemical equation for the reaction is:

[0045] 3Ca 2+ +2AsO4 3- =Ca3(AsO4)2

[0046] 3Fe 3+ +2AsO4 3- =FeAsO4

[0047] 3Ca 2+ +2PO4 3- =Ca3(PO4)2

[0048] The subsequently added polyaluminum chloride can aggregate fine particles through adsorption bridging, forming larger flocs and accelerating the sedimentation process. Furthermore, aluminum ions can react chemically with phosphate ions in the waste liquid to form insoluble aluminum phosphate precipitates, thus more effectively removing phosphorus from the mixture. It is worth noting that when agitator 16 stirs the second closed reaction vessel, the stirring speed needs to be properly controlled. Appropriate stirring ensures sufficient contact between the calcium salt and phosphate or arsenate ions in the waste liquid, improving reaction efficiency. If the stirring rate is too low, sufficient contact and reaction may not be guaranteed; if the stirring rate is too high, it may affect the formation and settling of precipitates.

[0049] S501, the mixed liquid after being treated in the second sealed container 10 is pumped into the plate and frame filter press 11 for solid-liquid separation. The precipitate containing phosphorus and arsenic will then enter the filter cake collector 19, while the liquid without phosphorus and arsenic will then enter the wastewater treatment plant 12 for further filtration treatment, and can be discharged after meeting the wastewater discharge standards.

[0050] In summary, the crushing mechanism 1 breaks down the lumpy solids (caking material and a mixture of elemental phosphorus and arsenic), and the independent reaction vessel, the first closed reaction vessel 9, ensures sufficient contact with the subsequent reactants. The oxidation mechanism 13 uses sodium hypochlorite to oxidize elemental phosphorus into phosphate and trivalent arsenic into pentavalent arsenic. The pH of the solution is then adjusted to neutral using sodium hydroxide and calcium hydroxide. Calcium chloride and ferric chloride from the precipitation mechanism 14 are added to the second closed reaction vessel 10 to react the phosphate and pentavalent arsenic to form a precipitate. Finally, polyaluminum chloride is added for flocculation. This process effectively treats elemental phosphorus while simultaneously disposing of arsenic-containing wastewater. It achieves safe and harmless disposal of phosphorus- and arsenic-containing wastewater, and effectively collects and treats the system's three wastes throughout the reaction process. This solves the problem of existing technologies lacking devices for the simultaneous safe treatment of phosphorus- and arsenic-containing wastewater, reducing equipment investment and operating costs while improving treatment efficiency.

[0051] It should be understood that the specific embodiments described herein are merely illustrative of the application and not intended to limit it. All other embodiments derived by those skilled in the art based on the embodiments provided in this application without inventive effort are within the scope of protection of this application.

[0052] Obviously, the accompanying drawings are merely some examples or embodiments of this application. Those skilled in the art can apply this application to other similar situations based on these drawings without any creative effort. Furthermore, it is understood that although the work done in this development process may be complex and lengthy, for those skilled in the art, certain design, manufacturing, or production modifications made based on the technical content disclosed in this application are merely conventional technical means and should not be considered as insufficient disclosure of this application.

Claims

1. A safe treatment device for phosphorus- and arsenic-containing waste liquid, characterized in that, include: Crushing mechanism (1), which is used to hold phosphorus and arsenic-containing waste liquid and crush the solids in the waste liquid; The first closed reaction vessel (9) is used to receive waste liquid from the crushing mechanism (1); The oxidation mechanism (13) includes a storage tank (3) storing sodium hypochlorite and a storage tank (4) storing sodium hydroxide, the storage tank (3) and the storage tank (4) being used to respectively input sodium hypochlorite and sodium hydroxide into a first closed reaction vessel (9); The second closed reaction vessel (10) is used to receive waste liquid from the first closed reaction vessel (9); The precipitation mechanism (14) includes a storage tank three (5) storing calcium chloride, a storage tank four (6) storing lime milk, a storage tank five (7) storing ferric chloride, and a storage tank six (8) storing polyaluminum chloride. The storage tanks three (5), four (6), five (7), six (8), and two (4) are used to respectively input calcium chloride, lime milk, ferric chloride, polyaluminum chloride, and sodium hydroxide into the second closed reaction vessel (10).

2. The safe treatment device for phosphorus- and arsenic-containing waste liquid according to claim 1, characterized in that, The inlet of the first closed reaction vessel (9) is connected to the outlet of the crushing mechanism (1), the outlet of the first storage tank (3), and the outlet of the second storage tank (4), respectively.

3. The safe treatment device for phosphorus- and arsenic-containing waste liquid according to claim 1, characterized in that, The inlet of the second closed reaction vessel (10) is connected to the outlets of the third (5), the fourth (6), the fifth (7), the sixth (8), and the second (4) of the storage tank.

4. The safe treatment device for phosphorus- and arsenic-containing waste liquid according to claim 1, characterized in that, The safety treatment device also includes a waste liquid buffer tank (2), the inlet of which is connected to the outlet of the crushing mechanism (1), and the outlet of which is connected to the inlet of the first closed reaction vessel (9).

5. The safe treatment device for phosphorus- and arsenic-containing waste liquid according to claim 1, characterized in that, The crushing mechanism (1), the first closed reaction vessel (9), and the second closed reaction vessel (10) are all equipped with a stirrer (16) for stirring the waste liquid.

6. The safe treatment device for phosphorus- and arsenic-containing waste liquid according to claim 1, characterized in that, The crushing mechanism (1), the first closed reaction vessel (9), and the second closed reaction vessel (10) are all equipped with pH meters (17) for measuring the pH value of the waste liquid.

7. The safe treatment device for phosphorus- and arsenic-containing waste liquid according to claim 1, characterized in that, The safety processing device also includes a solid-liquid separation mechanism for separating liquid and solid precipitates from the second closed reaction vessel (10).

8. The safe treatment device for phosphorus- and arsenic-containing waste liquid according to claim 7, characterized in that, The solid-liquid separation mechanism includes a plate and frame filter press (11), a wastewater treatment unit (12), and a filter cake collector (19). The inlet of the plate and frame filter press (11) is connected to the outlet of the second closed reaction vessel (10), and the outlet of the plate and frame filter press (11) is connected to the wastewater treatment unit (12) and the filter cake collector (19), respectively.

9. The safe treatment device for phosphorus- and arsenic-containing waste liquid according to claim 1, characterized in that, The safety handling device also includes a gas handling mechanism for handling harmful gases generated in the crushing mechanism (1), the first closed reaction vessel (9), and the second closed reaction vessel (10).

10. The safe treatment device for phosphorus- and arsenic-containing waste liquid according to claim 9, characterized in that, The gas processing mechanism includes a measuring cup 1 (20) storing sulfuric acid solution, a measuring cup 2 (21) storing sodium hydroxide solution, and a measuring cup 3 (22) storing activated carbon. The measuring cups 1 (20), 2 (21), and 3 (22) are connected in sequence, and the measuring cup 1 (20) is connected to the crushing mechanism (1), the first sealed reaction container (9), and the second sealed reaction container (10) through an exhaust pipe.

Images