Chromium-containing wastewater treatment system

Abstract

The chromium-containing wastewater treatment system is characterized in that the output end of a water storage tank is connected with the input end of a chromium reduction reactor, the output end of the chromium reduction reactor is connected with the input end of a coagulation tank, the output end of the coagulation tank is connected with the input end of a gelling tank, and the output end of the gelling tank is connected with the input end of an inclined plate sedimentation tank; the output end of the inclined plate sedimentation tank is connected with the input end of the terminal tank, the output end of the terminal tank is connected with the input end of the Pasteur discharge tank, the output end of the Pasteur discharge tank is connected with an external discharge pipeline, the chromium reduction reactor, the coagulation tank and the gelling tank are connected with the dosing device, and the dosing device is used for providing reaction drugs for the chromium reduction reactor, the coagulation tank and the gelling tank. The existing chromium wastewater treatment process with high energy consumption is replaced, and the treatment cost is reduced; a buffer water tank is arranged and is used for achieving a buffer effect; a sand filter is further arranged between the buffer water tank and the terminal groove and used for removing suspended solids, colloids, silt and rust in the treated water, the auxiliary treatment effect is achieved, and the treatment cleanliness is guaranteed.

Description

Technical Field

[0001] The utility model relates to the technical field of wastewater treatment, and more specifically, to a chromium-containing wastewater treatment system. Background Art

[0002] Electroplating industry is an important processing industry in my country, and chromium-containing wastewater is a large amount of wastewater produced in the electroplating industry. The main component of chromium-containing wastewater is Cr6+, which is the first type of pollutant and has the strongest toxicity. In addition, chromium-containing wastewater also includes a small amount of other metal ions such as Cu2+, Co2+, Ni2+, Fe2+, Ca2+, Cr3+ and other impurities. If it is discharged directly without treatment, it will cause great harm to the environment and ecology.

[0003] The technology closest to the existing technology is the publication number: CN111484155A, a process for improving the treatment of chromium-containing wastewater, which discloses the following steps: (1) physical and chemical pretreatment of chromium-containing wastewater: the chromium-containing wastewater is sequentially passed through a reduction tank → a decomposition tank → a first pH adjustment tank → a first coagulation reaction tank → a first sedimentation tank → a second pH adjustment tank → a second coagulation reaction tank → a second sedimentation tank → a third pH adjustment tank → a sand filtration; (2) the wastewater that meets the pollutant standards after the pretreatment in step (1) is divided into high-salt water and low-salt water according to the salt concentration in the wastewater; wherein the low-salt water is subjected to biochemical treatment, sand filtration, ultrafiltration and reverse osmosis, and the produced water is reused as recycled water, and the concentrated water is mixed with the high-salt water and enters the high-salt wastewater regulating tank; (3) the wastewater in the high-salt wastewater regulating tank is sequentially subjected to electrolytic oxidation → primary sedimentation → secondary sedimentation → sand filtration, and then discharged into the quasi-discharge tank after meeting the standards.

[0004] The existing chromium-containing wastewater is pre-treated by adsorption with polymer compounds, which has high treatment costs. In addition, it is treated by electro-Fenton electrolysis and oxidation equipment, which has high energy consumption, further increasing the treatment costs.

[0005] In view of this, the utility model proposes a chromium-containing wastewater treatment system with low energy consumption and low cost. Utility Model Content

[0006] The utility model aims to provide a chromium-containing wastewater treatment system with low energy consumption and low cost.

[0007] A chromium-containing wastewater treatment system comprises a water storage tank 1, a chromium reduction reactor 2, a coagulation tank 3, a gelling tank 4, an inclined plate sedimentation tank 5, a terminal tank 6, a pasteurization tank 7, and a dosing device, wherein the output end of the water storage tank 1 is connected to the input end of the chromium reduction reactor 2, the output end of the chromium reduction reactor 2 is connected to the input end of the coagulation tank 3, the output end of the coagulation tank 3 is connected to the input end of the gelling tank 4, the output end of the gelling tank 4 is connected to the input end of the inclined plate sedimentation tank 5, the output end of the inclined plate sedimentation tank 5 is connected to the input end of the terminal tank 6, the output end of the terminal tank 6 is connected to the input end of the pasteurization tank 7, the output end of the pasteurization tank 7 is connected to an external discharge pipeline, the chromium reduction reactor 2, the coagulation tank 3, and the gelling tank 4 are connected to the dosing device, and the dosing device is used to provide reaction drugs for the chromium reduction reactor 2, the coagulation tank 3, and the gelling tank 4.

[0008] Furthermore, the dosing device includes a sodium bisulfite dosing tank 8, a lime tank 9, an iron material tank 10, a sulfuric acid tank 11, and a polyelectrolyte tank 12. The sodium bisulfite dosing tank 8 is used to provide sodium bisulfite material for reaction, the lime tank 9 is used to provide lime material for reaction, the iron material tank 10 is used to provide trivalent iron material for reaction, the sulfuric acid tank 11 is used to provide sulfuric acid material for reaction, and the polyelectrolyte tank 12 is used to provide polyelectrolyte material for reaction. The chromium reduction reactor 2 is connected to the sodium bisulfite dosing tank 8 and the sulfuric acid tank 11, the coagulation tank 3 is connected to the lime tank 9, the iron material tank 10, and the sulfuric acid tank 11, and the gelling tank 4 is connected to the polyelectrolyte tank 12.

[0009] Furthermore, the reaction chemical formula in the chromium reduction reactor 2 is: 2H2Cr2O7+6NaHSO3+3H2SO4→2Cr2(SO4)3+3Na2SO4+8H2O.

[0010] Furthermore, the reaction chemical formula in the coagulation tank 3 is: ①Fe+H2SO4=FeSO4+H2 (iron filings and sulfuric acid react to form iron sulfate)

[0011] ②6FeSO4 + Cr2O7 + 7H2SO4 = 3Fe2(SO4)3 +SO4 + Cr2(SO4)3 + 7H2O

[0012] ③Cr(3+)+OH-=Cr(OH)3(precipitation)

[0013] Furthermore, the reaction chemical formula in the gelling tank 4 is: the polymer electrolyte polymerizes the Cr(OH)3 in the gelling tank body and some suspended particles that are not easy to react to accelerate their sedimentation.

[0014] Furthermore, the trivalent iron material in the iron material pool 10 is one of iron powder and iron filings.

[0015] In some embodiments, a buffer water tank 13 is further provided between the inclined plate sedimentation tank 5 and the terminal tank 6, and the buffer water tank 13 is used to play a buffering role.

[0016] In some embodiments, a sand filter 14 is further provided between the buffer water tank 13 and the terminal tank 6. The sand filter 14 is used to remove suspended matter, colloid, silt, and rust from the treated water, thereby playing an auxiliary treatment role.

[0017] In some embodiments, the water storage tank 1, the buffer water tank 13, and the inclined plate sedimentation tank 5 are also connected to a sludge treatment device for treating the sludge in the chromium-containing wastewater treatment system.

[0018] Furthermore, the sludge treatment device includes a sludge storage tank 15, a filter press 16, and an effluent storage tank 17. A sludge output end and a sludge input end are provided at the bottom of the inclined plate sedimentation tank 5. The sludge output end is connected to the input end of the sludge storage tank 15, and the output end of the sludge storage tank 15 is connected to the input end of the filter press 16. The output end of the filter press 16 is respectively connected to the input end of the buffer water tank 13 and the input end of the effluent storage tank 17, and the output end of the effluent storage tank 17 is connected to the input end of the water storage tank 1.

[0019] In some embodiments, the water storage tank 1, chromium reduction reactor 2, dosing device, inclined plate sedimentation tank 5, buffer water tank 13, and terminal tank 6 are all equipped with a liquid level meter 18 for monitoring the liquid level in the water storage tank 1, chromium reduction reactor 2, dosing device, inclined plate sedimentation tank 5, buffer water tank 13, and terminal tank 6.

[0020] In some embodiments, the chromium reduction reactor 2, the coagulation tank 3, the gelling tank 4, the sodium bisulfite dosing tank 8, the lime tank 9, the iron material tank 10, and the polyelectrolyte tank 12 are all provided with a stirrer 19 for stirring and mixing the reaction.

[0021] In some embodiments, a pH sensor 20 is provided in the chromium reduction reactor 2 , the coagulation tank 3 , and the terminal tank 6 , for monitoring the pH value in the chromium reduction reactor 2 , the coagulation tank 3 , and the terminal tank 6 .

[0022] Beneficial effects of the utility model: The utility model proposes a chromium-containing wastewater treatment system, comprising a water storage tank 1, a chromium reduction reactor 2, a coagulation tank 3, a gelling tank 4, an inclined plate sedimentation tank 5, a terminal tank 6, a pasteurization discharge tank 7, and a dosing device, characterized in that: the output end of the water storage tank 1 is connected to the input end of the chromium reduction reactor 2, the output end of the chromium reduction reactor 2 is connected to the input end of the coagulation tank 3, the output end of the coagulation tank 3 is connected to the input end of the gelling tank 4, the output end of the gelling tank 4 is connected to the input end of the inclined plate sedimentation tank 5, the output end of the inclined plate sedimentation tank 5 is connected to the input end of the terminal tank 6, and the output end of the terminal tank 6 is connected to the pasteurization discharge tank 7 input end is connected, the output end of the pasteurization discharge tank 7 is connected to the external discharge pipeline, the chromium reduction reactor 2, the coagulation tank 3, and the gelling tank 4 are connected to the dosing device, the dosing device is used to provide reaction drugs for the chromium reduction reactor 2, the coagulation tank 3, and the gelling tank 4, replace the existing high-energy consumption chromium wastewater treatment process, and reduce the treatment cost; a buffer water tank 13 is set, and the buffer water tank 13 is used to play a buffering role; a sand filter 14 is also provided between the buffer water tank 13 and the terminal tank 6, and the sand filter 14 is used to remove suspended matter, colloid, silt, and rust in the treated water, play an auxiliary treatment role, and ensure the cleanliness of the treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the structure of a chromium-containing wastewater treatment system of the present application.

[0024] Main component symbols

[0025] Water storage tank 1, chromium reduction reactor 2, coagulation tank 3, gelling tank 4, inclined plate sedimentation tank 5, terminal tank 6, pasteurization discharge tank 7, sodium bisulfite dosing tank 8, lime tank 9, iron material tank 10, sulfuric acid tank 11, sulfuric acid tank 12, buffer water tank 13, sand filter 14, sludge storage tank 15, filter press 16, effluent storage tank 17, liquid level meter 18, agitator 19, PH sensor 20

[0026] The following specific implementation manner will further illustrate the present utility model in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0027] The following examples are described to assist the understanding of the present application, and the examples are not and should not be interpreted in any way as limiting the scope of protection of the present application.

[0028] In the following description, those skilled in the art will recognize that throughout this discussion, components may be described as separate functional units (which may include sub-units), but those skilled in the art will recognize that various components or portions thereof may be divided into separate components or may be integrated together (including within a single system or component).

[0029] At the same time, the connections between components or systems are not intended to be limited to direct connections, rather, the data between these components may be modified, reformatted, or otherwise changed by intermediate components. In addition, additional or fewer connections may be used. It should also be noted that the terms "coupled," "connected," or "input" should be understood to include direct connections, indirect connections through one or more intermediate devices, and wireless connections. Embodiment 1:

[0030] like Figure 1 Shown is a schematic diagram of the structure of a chromium-containing wastewater treatment system of the present application.

[0031] A chromium-containing wastewater treatment system comprises a water storage tank 1, a chromium reduction reactor 2, a coagulation tank 3, a gelling tank 4, an inclined plate sedimentation tank 5, a terminal tank 6, a pasteurization tank 7, and a dosing device, wherein the output end of the water storage tank 1 is connected to the input end of the chromium reduction reactor 2, the output end of the chromium reduction reactor 2 is connected to the input end of the coagulation tank 3, the output end of the coagulation tank 3 is connected to the input end of the gelling tank 4, the output end of the gelling tank 4 is connected to the input end of the inclined plate sedimentation tank 5, the output end of the inclined plate sedimentation tank 5 is connected to the input end of the terminal tank 6, the output end of the terminal tank 6 is connected to the input end of the pasteurization tank 7, the output end of the pasteurization tank 7 is connected to an external discharge pipeline, the chromium reduction reactor 2, the coagulation tank 3, and the gelling tank 4 are connected to the dosing device, and the dosing device is used to provide reaction drugs for the chromium reduction reactor 2, the coagulation tank 3, and the gelling tank 4.

[0032] The dosing device includes a sodium bisulfite dosing tank 8, a lime tank 9, an iron material tank 10, a sulfuric acid tank 11, and a polyelectrolyte tank 12. The sodium bisulfite dosing tank 8 is used to provide sodium bisulfite material for reaction, the lime tank 9 is used to provide lime material for reaction, the iron material tank 10 is used to provide trivalent iron material for reaction, the sulfuric acid tank 11 is used to provide sulfuric acid material for reaction, and the polyelectrolyte tank 12 is used to provide polyelectrolyte material for reaction. The chromium reduction reactor 2 is connected to the sodium bisulfite dosing tank 8 and the sulfuric acid tank 11, the coagulation tank 3 is connected to the lime tank 9, the iron material tank 10, and the sulfuric acid tank 11, and the gelling tank 4 is connected to the polyelectrolyte tank 12.

[0033] The reaction chemical formula in the chromium reduction reactor 2 is: 2H2Cr2O7+6NaHSO3+3H2SO4→2Cr2(SO4)3+3Na2SO4+8H2O.

[0034] The reaction chemical formula in the coagulation tank 3 is: ①Fe+H2SO4=FeSO4+H2 (iron filings and sulfuric acid react to form ferrous sulfate)

[0035] ②6FeSO4 + Cr2O7 + 7H2SO4 = 3Fe2(SO4)3 +SO4 + Cr2(SO4)3 + 7H2O

[0036] ③Cr(3+)+OH-=Cr(OH)3(precipitation)

[0037] The reaction chemical formula in the gelling tank 4 is: the polymer electrolyte polymerizes the Cr(OH)3 in the gelling tank body and some suspended particles that are not easy to react to accelerate their sedimentation.

[0038] The trivalent iron material in the iron material pool 10 is iron powder or iron filings.

[0039] A buffer water tank 13 is further provided between the inclined plate sedimentation tank 5 and the terminal tank 6 , and the buffer water tank 13 is used to play a buffering role.

[0040] A sand filter 14 is also provided between the buffer water tank 13 and the terminal tank 6. The sand filter 14 is used to remove suspended matter, colloid, silt, and rust from the treated water, thus playing an auxiliary treatment role.

[0041] The water storage tank 1, the buffer water tank 13 and the inclined plate sedimentation tank 5 are also connected to a sludge treatment device for treating the sludge in the chromium-containing wastewater treatment system.

[0042] The sludge treatment device includes a sludge storage tank 15, a filter press 16, and an effluent storage tank 17. A sludge output end and a sludge input end are provided at the bottom of the inclined plate sedimentation tank 5. The sludge output end is connected to the input end of the sludge storage tank 15, and the output end of the sludge storage tank 15 is connected to the input end of the filter press 16. The output end of the filter press 16 is respectively connected to the input end of the buffer water tank 13 and the input end of the effluent storage tank 17, and the output end of the effluent storage tank 17 is connected to the input end of the water storage tank 1.

[0043] The water storage tank 1, chromium reduction reactor 2, dosing device, inclined plate sedimentation tank 5, buffer water tank 13, and terminal tank 6 are all provided with liquid level meters 18 for monitoring the liquid levels in the water storage tank 1, chromium reduction reactor 2, dosing device, inclined plate sedimentation tank 5, buffer water tank 13, and terminal tank 6.

[0044] The chromium reduction reactor 2, the coagulation tank 3, the gelling tank 4, the sodium bisulfite dosing tank 8, the lime tank 9, the iron material tank 10, and the polyelectrolyte tank 12 are all provided with a stirrer 19 for stirring and mixing the reaction.

[0045] The chromium reduction reactor 2 , the coagulation tank 3 , and the terminal tank 6 are all provided with a pH sensor 20 for monitoring the pH value in the chromium reduction reactor 2 , the coagulation tank 3 , and the terminal tank 6 .

[0046] Beneficial effects of the utility model: The utility model proposes a chromium-containing wastewater treatment system, comprising a water storage tank 1, a chromium reduction reactor 2, a coagulation tank 3, a gelling tank 4, an inclined plate sedimentation tank 5, a terminal tank 6, a pasteurization discharge tank 7, and a dosing device, characterized in that: the output end of the water storage tank 1 is connected to the input end of the chromium reduction reactor 2, the output end of the chromium reduction reactor 2 is connected to the input end of the coagulation tank 3, the output end of the coagulation tank 3 is connected to the input end of the gelling tank 4, the output end of the gelling tank 4 is connected to the input end of the inclined plate sedimentation tank 5, the output end of the inclined plate sedimentation tank 5 is connected to the input end of the terminal tank 6, and the output end of the terminal tank 6 is connected to the pasteurization discharge tank 7 input end is connected, the output end of the pasteurization discharge tank 7 is connected to the external discharge pipeline, the chromium reduction reactor 2, the coagulation tank 3, and the gelling tank 4 are connected to the dosing device, the dosing device is used to provide reaction drugs for the chromium reduction reactor 2, the coagulation tank 3, and the gelling tank 4, replace the existing high-energy consumption chromium wastewater treatment process, and reduce the treatment cost; a buffer water tank 13 is set, and the buffer water tank 13 is used to play a buffering role; a sand filter 14 is also provided between the buffer water tank 13 and the terminal tank 6, and the sand filter 14 is used to remove suspended matter, colloid, silt, and rust in the treated water, play an auxiliary treatment role, and ensure the cleanliness of the treatment.

[0047] Although the present application has disclosed multiple aspects and embodiments, other aspects and embodiments will be obvious to those skilled in the art, and several modifications and improvements may be made without departing from the concept of the present application, all of which belong to the protection scope of the present application. The multiple aspects and embodiments disclosed in the present application are only for illustration and are not intended to limit the present application. The actual protection scope of the present application shall be subject to the claims.

Claims

1. A chromium-containing wastewater treatment system, comprising a water storage tank (1), a chromium reduction reactor (2), a coagulation tank (3), a gelling tank (4), an inclined plate sedimentation tank (5), a terminal tank (6), a pasteurization tank (7), and a dosing device, characterized in that: The output end of the water storage tank (1) is connected to the input end of the chromium reduction reactor (2), the output end of the chromium reduction reactor (2) is connected to the input end of the coagulation tank (3), the output end of the coagulation tank (3) is connected to the input end of the gelling tank (4), the output end of the gelling tank (4) is connected to the input end of the inclined plate sedimentation tank (5), the output end of the inclined plate sedimentation tank (5) is connected to the input end of the terminal tank (6), the output end of the terminal tank (6) is connected to the input end of the pasteurization discharge tank (7), the output end of the pasteurization discharge tank (7) is connected to an external discharge pipeline, the chromium reduction reactor (2), the coagulation tank (3) and the gelling tank (4) are connected to a dosing device, and the dosing device is used to provide reaction drugs for the chromium reduction reactor (2), the coagulation tank (3) and the gelling tank (4).

2. The chromium-containing wastewater treatment system according to claim 1, characterized in that: The dosing device comprises a sodium bisulfite dosing tank (8), a lime tank (9), an iron material tank (10), a sulfuric acid tank (11), and a polyelectrolyte tank (12). The sodium bisulfite dosing tank (8) is used to provide sodium bisulfite material for reaction, the lime tank (9) is used to provide lime material for reaction, the iron material tank (10) is used to provide trivalent iron material for reaction, the sulfuric acid tank (11) is used to provide sulfuric acid material for reaction, and the polyelectrolyte tank (12) is used to provide polyelectrolyte material for reaction. The chromium reduction reactor (2) is connected to the sodium bisulfite dosing tank (8) and the sulfuric acid tank (11), the coagulation tank (3) is connected to the lime tank (9), the iron material tank (10), and the sulfuric acid tank (11), and the gelling tank (4) is connected to the polyelectrolyte tank (12).

3. The chromium-containing wastewater treatment system according to claim 1, characterized in that: A buffer water tank (13) is also provided between the inclined plate sedimentation tank (5) and the terminal tank (6), and the buffer water tank (13) is used to play a buffering role.

4. The chromium-containing wastewater treatment system according to claim 3, characterized in that: A sand filter (14) is also provided between the buffer water tank (13) and the terminal tank (6). The sand filter (14) is used to remove suspended matter, colloid, silt and rust from the treated water, thus playing an auxiliary treatment role.

5. The chromium-containing wastewater treatment system according to claim 3, characterized in that: The water storage tank (1), the buffer water tank (13) and the inclined plate sedimentation tank (5) are also connected to a sludge treatment device for treating the sludge in the chromium-containing wastewater treatment system.

6. The chromium-containing wastewater treatment system according to claim 5, characterized in that: The sludge treatment device comprises a sludge storage tank (15), a filter press (16), and an outlet water storage tank (17). A sludge output end and a sludge input end are provided at the bottom of the inclined plate sedimentation tank (5). The sludge output end is connected to the input end of the sludge storage tank (15), the output end of the sludge storage tank (15) is connected to the input end of the filter press (16), the output end of the filter press (16) is respectively connected to the input end of the buffer water tank (13) and the input end of the outlet water storage tank (17), and the output end of the outlet water storage tank (17) is connected to the input end of the water storage tank (1).

7. The chromium-containing wastewater treatment system according to claim 1, characterized in that: The water storage tank (1), the chromium reduction reactor (2), the dosing device, the inclined plate sedimentation tank (5), the buffer water tank (13), and the terminal tank (6) are all provided with a liquid level meter (18) for monitoring the liquid level in the water storage tank (1), the chromium reduction reactor (2), the dosing device, the inclined plate sedimentation tank (5), the buffer water tank (13), and the terminal tank (6).

8. The chromium-containing wastewater treatment system according to claim 1, characterized in that: The chromium reduction reactor (2), the coagulation tank (3), the gelling tank (4), the sodium bisulfite dosing tank (8), the lime tank (9), the iron material tank (10), and the polyelectrolyte tank (12) are all provided with a stirrer (19) for stirring and mixing the reaction.

9. The chromium-containing wastewater treatment system according to claim 1, characterized in that: The chromium reduction reactor (2), the coagulation tank (3) and the terminal tank (6) are all provided with a pH sensor (20) for monitoring the pH value in the chromium reduction reactor (2), the coagulation tank (3) and the terminal tank (6).

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