Sulfate radical wastewater treatment system

Abstract

The utility model relates to a sulfate radical wastewater treatment system which comprises the following components: a reaction tank which is added with Ca (OH) 2 powder and is used for carrying out chemical precipitation reaction on the introduced sulfate radical wastewater, adjusting the pH value of the sulfate radical wastewater to be neutral and forming floc; the coagulation tank is used for carrying out coagulation reaction on the sulfate radical wastewater of which the pH is adjusted to be neutral to form larger flocs; and the precipitation tank is used for carrying out solid-liquid separation on the sulfate radical wastewater subjected to the coagulation reaction, supernate obtained after solid-liquid separation overflows and is discharged, and sludge at the bottom of the precipitation tank is discharged into the sludge treatment unit through pumping. The device is scientific and reasonable in design and easy to realize, sulfate radicals in water are removed by adopting calcium hydroxide with high mesh number through a chemical precipitation method, on one hand, OH <-> ions can be utilized to neutralize H < + > ions in the water to adjust the water to be neutral to meet the discharge requirement, and on the other hand, calcium ions and sulfate ions react to form gypsum which can be recycled, so that the environment is protected; and waste is reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to wastewater treatment technical field especially relates to a sulfate wastewater treatment system. BACKGROUND

[0002] Sulfuric acid as a common inorganic acid, not only is widely used in chemical fertilizer industry, metallurgical industry, petroleum industry, machinery industry, pharmaceutical industry, the production of detergent, military industry, atomic energy industry and aerospace industry etc.

[0003] Sulfate-containing wastewater discharged into water body can acidify the water body, reduce the pH value, harm aquatic organisms, and when discharged into farmland, can destroy soil structure, cause soil compaction, reduce crop yield and lower the quality of agricultural products; sulfate can also be converted to produce toxic and smelly hydrogen sulfide under anaerobic conditions of reducing bacteria, even more toxic thiosulfate and tetrathionate, etc. SUMMARY

[0004] The utility model wants to overcome the technical problems existing in prior art, provide a sulfate wastewater treatment system.

[0005] The utility model is realized through the following technical schemes:

[0006] A sulfate wastewater treatment system, characterized in that, comprising:

[0007] The reaction tank is used for making the incoming sulfate wastewater undergo chemical precipitation reaction, adjusting the pH of the sulfate wastewater to neutral, and forming flocs by adding Ca (OH) 2 powder;

[0008] The pH adjusting tank is arranged between the reaction tank and the coagulation tank, and is used for adjusting the pH of the sulfate wastewater to neutral by introducing Ca (OH) 2 solution;

[0009] The coagulation tank is used for making the sulfate wastewater with neutral pH undergo coagulation reaction to form larger flocs;

[0010] The sedimentation tank is used for solid-liquid separation of the sulfate wastewater after coagulation reaction, and the supernatant of solid-liquid separation is overflowed and discharged.

[0011] According to the above technical solution, preferably, the outlet of the reaction tank is connected to the inlet of the pH adjustment tank, and the sulfate wastewater in the pH adjustment tank overflows into the coagulation tank.

[0012] According to the above technical solution, preferably, the reaction tank is connected to the pH adjustment tank through a pipeline and a booster pump.

[0013] According to the above technical solution, preferably, a PAM solution is introduced into the coagulation tank, and the outlet of the coagulation tank is connected to the sedimentation tank.

[0014] According to the above technical solution, preferably, it further includes:

[0015] A sludge treatment unit is used to receive and treat the sludge at the bottom of the sedimentation tank.

[0016] According to the above technical solution, preferably, the sludge treatment unit includes a vacuum filter press. The sludge at the bottom of the sedimentation tank is pumped to the vacuum filter press, dewatered, and formed into a sludge cake for off-site transport. The sludge at the bottom of the sedimentation tank can also be pumped back to the reaction tank.

[0017] According to the above technical solution, preferably, it further includes:

[0018] The supernatant from the sedimentation tank overflows into the external drainage tank, and the sludge at the bottom of the sedimentation tank is pumped into the sludge treatment unit.

[0019] The beneficial effects of this utility model are:

[0020] This invention is scientifically sound and easy to implement. It removes sulfate ions from water using a chemical precipitation method with high-mesh calcium hydroxide. On the one hand, it utilizes OH... - ions neutralize H in water + The ions help to neutralize the water to meet discharge requirements. On the other hand, calcium ions and sulfate ions react to form gypsum, which can be reused, protecting the environment and reducing waste generation.

[0021] In summary, this utility model, through the organic combination of material optimization, process innovation, and resource utilization pathways, constructs a circular economy model of "waste treatment with waste - product reuse," providing an efficient and reliable technical solution for the treatment of sulfur-containing wastewater, and has high application and promotion value. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the system connection of this utility model.

[0023] In the diagram: 1. Reaction tank; 2. pH adjustment tank; 3. Coagulation tank; 4. Sedimentation tank; 5. External drainage tank; 6. Sludge treatment unit. Detailed Implementation

[0024] To enable those skilled in the art to better understand the technical solution of this utility model, the present utility model will be further described in detail below with reference to the accompanying drawings and preferred embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0025] In the description of the utility model, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the utility model.

[0026] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "setting," and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection, an indirect connection through an intermediate medium, or a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0027] As shown in the figure, this utility model includes:

[0028] In reaction tank 1, Ca(OH)2 powder is added to induce a chemical precipitation reaction in the sulfate wastewater, adjust the pH of the sulfate wastewater to neutral, and form flocs.

[0029] pH adjustment tank 2 is set between reaction tank 1 and coagulation tank 3. Ca(OH)2 solution is introduced to adjust the pH of the sulfate wastewater to neutral (pH preferably between 8 and 9).

[0030] Coagulation tank 3 is used to coagulate the sulfate wastewater whose pH has been adjusted to neutral to form larger flocs.

[0031] Sedimentation tank 4 is used for solid-liquid separation of the sulfate wastewater that has undergone coagulation reaction, and the supernatant from the solid-liquid separation overflows and is discharged.

[0032] Sludge treatment unit 6 is used to receive and treat sludge from the bottom of the sedimentation tank 4;

[0033] External drainage tank 5, the supernatant of the sedimentation tank 4 overflows into the external drainage tank 5, and the sludge at the bottom of the sedimentation tank 4 is pumped into the sludge treatment unit 6.

[0034] In this example, the outlet of the reaction tank 1 is connected to the inlet of the pH adjustment tank 2. Preferably, but not limited to, the reaction tank 1 is connected to the pH adjustment tank 2 through a pipe and a booster pump. The sulfate wastewater in the pH adjustment tank 2 overflows into the coagulation tank 3. PAM solution is introduced into the coagulation tank 3. The outlet of the coagulation tank 3 is connected to the sedimentation tank 4.

[0035] In addition, the sludge treatment unit 6 includes a vacuum filter press. The sludge at the bottom of the sedimentation tank 4 is pumped to the vacuum filter press, dewatered, and formed into a sludge cake for off-site transport. The sludge at the bottom of the sedimentation tank 4 can also be pumped back to the reaction tank 1, so that a small portion of the sludge is returned to the reaction tank 1, reusing the incompletely reacted Ca(OH)2, saving the amount of Ca(OH)2 used, and helping the reaction process to form flocs better.

[0036] Reaction tank 1 contains Ca(OH)2 powder, which causes a chemical precipitation reaction in the wastewater, forming flocs. After pH adjustment in pH tank 2, the wastewater overflows into coagulation tank 3, which contains PAM solution, where a coagulation reaction occurs to form larger flocs. The outlet of coagulation tank 3 is connected to sedimentation tank 4, where solid-liquid separation takes place. The supernatant from sedimentation tank 4 overflows into external drainage tank 5, and the bottom sludge is pumped into sludge treatment unit 6.

[0037] This application, based on the fundamental principles of chemical precipitation, preferentially, but not limited to, using calcium hydroxide with a high specific surface area of ​​600 mesh or higher as the core treatment agent, to achieve wastewater purification through a dual reaction pathway. The first pathway is a neutralization reaction: Ca(OH)₂ → Ca 2+ +2OH - , of which OH - With H in wastewater + The ions undergo a rapid neutralization reaction, precisely adjusting the pH value from the initial acidity to the neutral range of 8-9, meeting the pH limit requirements of the "Integrated Wastewater Discharge Standard" (GB 8978-1996). The second pathway is a precipitation reaction: Ca... 2+ +SO4 2- →CaSO4·2H2O↓, calcium sulfate dihydrate crystals are formed through the coordination of calcium ions and sulfate ions, with a solubility product constant Ksp = 2.4 × 10⁻⁶. -5 (25℃) ensures effective removal of sulfate ions under normal temperature conditions.

[0038] In this embodiment, wastewater first enters reaction tank 1, then is pumped into pH adjustment tank 2, the adjusted wastewater enters coagulation tank 3, the reacted wastewater enters sedimentation tank 4, the supernatant from sedimentation tank 4 overflows into external drainage tank 5, and sludge is discharged into sludge treatment unit 6. Based on the above preferred process, high-mesh calcium hydroxide is used to remove sulfate ions from the water through chemical precipitation, which can utilize OH... -ions neutralize H in water + The ions help to neutralize the water to meet discharge requirements. On the other hand, calcium ions and sulfate ions react to form gypsum, which can be reused, protecting the environment and reducing waste generation.

[0039] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A sulfate wastewater treatment system, characterized in that, include: In reaction tank (1), Ca(OH)2 powder is added to cause the sulfate wastewater to undergo a chemical precipitation reaction, adjust the pH of the sulfate wastewater to neutral, and form flocs. Coagulation tank (3) is used to coagulate the sulfate wastewater with pH adjusted to neutral to form larger flocs; The sedimentation tank (4) is used to separate the sulfate wastewater that has undergone coagulation reaction into solid and liquid components, and the supernatant from the solid-liquid separation overflows and is discharged.

2. The sulfate wastewater treatment system according to claim 1, characterized in that, Also includes: A pH adjustment tank (2) is set between the reaction tank (1) and the coagulation tank (3), and a Ca(OH)2 solution is introduced to adjust the pH of the sulfate wastewater to neutral.

3. The sulfate wastewater treatment system according to claim 2, characterized in that, The outlet of the reaction tank (1) is connected to the inlet of the pH adjustment tank (2). The sulfate wastewater in the pH adjustment tank (2) overflows into the coagulation tank (3).

4. The sulfate wastewater treatment system according to claim 3, characterized in that, The reaction tank (1) is connected to the pH adjustment tank (2) via a pipeline and a booster pump.

5. The sulfate wastewater treatment system according to claim 1, characterized in that, PAM solution is introduced into the coagulation tank (3). The outlet of the coagulation tank (3) is connected to the sedimentation tank (4).

6. The sulfate wastewater treatment system according to any one of claims 1-5, characterized in that, Also includes: The sludge treatment unit (6) is used to receive and treat the sludge at the bottom of the sedimentation tank (4).

7. The sulfate wastewater treatment system according to claim 6, characterized in that, The sludge treatment unit (6) includes a vacuum filter press. The sludge at the bottom of the sedimentation tank (4) is pumped to the vacuum filter press, dewatered, and then formed into sludge cakes for off-site transport.

8. The sulfate wastewater treatment system according to claim 6, characterized in that, The sludge at the bottom of the sedimentation tank (4) can also be pumped back to the reaction tank (1).

9. The sulfate wastewater treatment system according to claim 7, characterized in that, Also includes: External drainage tank (5), the supernatant of the sedimentation tank (4) overflows into the external drainage tank (5), and the sludge at the bottom of the sedimentation tank (4) is pumped into the sludge treatment unit (6).

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