Process device for co-processing industrial wastewater by using ferric trichloride etching waste liquid

Abstract

The utility model relates to the technical field of hazardous waste treatment, in particular to a process device for co-processing industrial wastewater by using ferric trichloride etching waste liquid. Comprising a ferric trichloride etching waste liquid storage tank, an industrial wastewater storage tank, an oxidation reaction tank, a neutralization and flocculation tank, an inclined plate precipitation tank, a plate-and-frame filter press, a waste gas treatment device and a sewage treatment device which are sequentially arranged from left to right, a 30% hydrogen peroxide dosing storage tank is arranged on the oxidation reaction tank, and a 28% sodium hydroxide solution dosing storage tank is arranged on the neutralization and flocculation tank; and a polymeric ferric sulfate solution dosing storage tank is arranged at the front end of the inclined plate precipitation tank. According to the combined type process device, three wastes of a system are effectively collected and treated in the whole reaction process, so that industrial wastewater is cooperatively treated by the ferric trichloride etching waste liquid, and meanwhile, compared with a Fenton oxidation system process, the COD degradation rate of the waste liquid is improved by about 20% compared with the COD degradation rate before and after the ferric trichloride etching waste liquid is used.

Description

Technical Field

[0001] The utility model relates to the technical field of hazardous waste treatment, in particular to a process device for collaboratively treating industrial wastewater with ferric chloride etching waste liquid. Background Art

[0002] During industrial production, when using ferric chloride (iron content greater than 200g / L, density 1.4-1.5g / mL) etching processes, etching efficiency decreases as heavy metals accumulate in the etching solution. Therefore, it is necessary to regularly replace the ferric chloride etching solution that does not meet production needs. Ferric chloride etching wastewater is considered hazardous waste, and the heavy metals it contains are classified as Class I pollutants under national wastewater discharge standards. If not properly treated, it not only pollutes the environment, but also significantly wastes resources by leaving a large amount of iron as waste. Because ferric chloride etching wastewater contains large amounts of hydrochloric acid and iron ions, direct neutralization and precipitation treatment methods result in waste gas emissions and fail to achieve resource utilization.

[0003] Machining cutting fluid wastewater is generated during metal cutting, drilling, milling, turning, and other processes. It contains cutting fluid, coolant, and metal shavings. This type of industrial wastewater has a complex composition, typically including water, cutting fluid, coolant, and metal shavings. Oxidation is often used to treat this wastewater, but the residue contains a large amount of secondary hazardous waste, such as metal shavings, resulting in environmental pollution and resource waste. Therefore, the use of comprehensive utilization processes for industrial treatment of this wastewater reduces environmental pollution while maximizing resource utilization, resulting in significant environmental and economic benefits.

[0004] To solve the above problems, this patent research uses the characteristics of ferric chloride to enhance the Fenton oxidation effect, and collects the treated iron sludge and hands it over to a qualified enterprise for the preparation of polyferric sulfate. The wastewater treated by this process device adopts evaporation and desalination combined with biochemical treatment, and after treatment, it can be discharged or reused in compliance with the standards. Utility Model Content

[0005] The purpose of the utility model is to solve the problem of utilizing iron in ferric chloride etching waste liquid in order to address the problem mentioned in the background technology, and to propose a process device for co-treating industrial wastewater with ferric chloride etching waste liquid.

[0006] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0007] A process device for co-treating industrial wastewater with ferric chloride etching waste liquid comprises a ferric chloride etching waste liquid storage tank, an industrial wastewater storage tank, an oxidation reaction tank, a neutralization and flocculation tank, an inclined plate sedimentation tank, a plate and frame filter press, an exhaust gas treatment device, and a sewage treatment device, which are arranged in sequence from left to right. A 30% hydrogen peroxide dosing tank is provided on the oxidation reaction tank, a 28% sodium hydroxide solution dosing tank is provided on the neutralization and flocculation tank, a polyferric sulfate solution dosing tank is provided at the front end of the inclined plate sedimentation tank, and sludge discharge ports of the neutralization and flocculation tank and the inclined plate sedimentation tank are connected to the plate and frame filter press.

[0008] As a further description of the above technical solution:

[0009] The upper part of the neutralization and flocculation tank is connected to an external suction hood, and the suction hood is connected to a waste gas treatment device. The waste gas treatment device includes a sulfuric acid solution absorption device, a sodium hydroxide solution absorption device, an activated carbon absorption device and an induced draft fan which are arranged in sequence from the air outlet of the suction hood outward.

[0010] As a further description of the above technical solution:

[0011] The oxidation reaction tank is provided with a pH meter, a thermometer and an ORP meter, and an aeration plate is laid at the bottom.

[0012] As a further description of the above technical solution:

[0013] The outlet output end of the ferric chloride etching waste liquid storage tank is provided with a first pump, and the first pump is connected to the inlet end of the oxidation reaction tank.

[0014] As a further description of the above technical solution:

[0015] The outlet output end of the industrial wastewater storage tank is provided with a second pump, and the second pump is connected to the inlet end of the oxidation reaction tank.

[0016] As a further description of the above technical solution:

[0017] The outlet output end of the oxidation reaction tank is provided with a third pump, and the third pump is connected to the inlet end of the neutralization and flocculation tank.

[0018] As a further description of the above technical solution:

[0019] The outlet output end of the neutralization and flocculation tank is provided with a fourth pump, and the fourth pump is connected to the inlet end of the inclined plate sedimentation tank.

[0020] As a further description of the above technical solution:

[0021] The outlet output end of the neutralization and flocculation tank is provided with a fifth pump, and the fifth pump is connected to the inlet end of the plate and frame filter press.

[0022] As a further description of the above technical solution:

[0023] A sixth pump is provided at the outlet output end of the inclined plate sedimentation tank, and the sixth pump is connected to the inlet end of the plate and frame filter press.

[0024] As a further description of the above technical solution:

[0025] A seventh pump is provided at the outlet output end of the plate-frame filter press, and the seventh pump is connected to the inlet end of the sewage treatment device. A residue collection tank for collecting solid phase is detachably installed at the lower part of the plate-frame filter press.

[0026] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0027] 1. This utility model effectively treats ferric chloride etching wastewater while leveraging the wastewater's properties to synergistically treat industrial wastewater (COD content: 20,000-30,000 mg / L). It safely treats high-concentration ferric chloride etching wastewater (acidity: 3-8 mol / L, iron content: 1,500-4,000 mg / L, nickel content: 5-10 mg / L). Furthermore, ferric chloride etching wastewater can enhance the Fenton oxidation system to treat other industrial wastewaters. Under acidic conditions, the iron and nickel ions in the wastewater catalyze hydrogen peroxide to produce hydroxyl radicals with strong oxidizing activity, which facilitates COD degradation. Subsequently, alkalinization treatment forms a ferric hydroxide precipitate, which, due to its gel properties, further adsorbs and captures organic pollutants in the wastewater.

[0028] 2. In the utility model, the three wastes of the system are effectively collected and treated throughout the reaction process to achieve a combined process device for the coordinated treatment of industrial wastewater with ferric chloride etching waste liquid. At the same time, compared with the Fenton oxidation system process, the COD degradation rate before and after the use of ferric chloride etching waste liquid is compared, and the COD degradation rate of the waste liquid is increased by about 20%. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic structural diagram of a process device for co-treating industrial wastewater with ferric chloride etching waste liquid proposed in the present invention.

[0030] Legend:

[0031] 1. Ferric chloride etching waste liquid storage tank; 2. Industrial wastewater storage tank; 3. Oxidation reaction tank; 4. Neutralization flocculation tank; 5. Inclined plate sedimentation tank; 6. Plate and frame filter press; 7. Waste gas treatment device; 8. Sewage treatment device; 9. 30% hydrogen peroxide dosing tank; 10. 28% sodium hydroxide solution dosing tank; 11. Polyferric sulfate solution dosing tank; 12. First pump; 13. Second pump; 14. Third pump; 15. Fourth pump; 16. Fifth pump; 17. Sixth pump; 18. Seventh pump. DETAILED DESCRIPTION

[0032] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0033] See also Figure 1 The utility model provides a technical solution: a process device for co-treating industrial wastewater with ferric chloride etching waste liquid, comprising a ferric chloride etching waste liquid storage tank 1, an industrial wastewater storage tank 2, an oxidation reaction tank 3, a neutralization and flocculation tank 4, an inclined plate sedimentation tank 5, a plate and frame filter press 6, an exhaust gas treatment device 7 and a sewage treatment device 8, which are arranged in sequence from left to right; a 30% hydrogen peroxide dosing tank 9 is provided on the oxidation reaction tank 3, a 28% sodium hydroxide solution dosing tank 10 is provided on the neutralization and flocculation tank 4, a polyferric sulfate solution dosing tank 11 is provided at the front end of the inclined plate sedimentation tank 5, and sludge discharge ports of the neutralization and flocculation tank 4 and the inclined plate sedimentation tank 5 are connected to the plate and frame filter press 6.

[0034] Specifically, such as Figure 1 As shown, the upper part of the neutralization and flocculation tank 4 is connected to an external suction hood, and the suction hood is connected to a waste gas treatment device 7. The waste gas treatment device 7 includes a sulfuric acid solution absorption device, a sodium hydroxide solution absorption device, an activated carbon absorption device and an induced draft fan which are sequentially arranged from the air outlet of the suction hood to the outside.

[0035] Specifically, such as Figure 1 As shown, the oxidation reaction tank 3 is provided with a pH meter, a thermometer and an ORP meter, which facilitates the operator to understand the pH value, temperature and oxidation potential data of the oxidation reaction tank 3. An aeration plate is laid at the bottom to allow the sewage in the tank to contact with the air for oxygenation, and to stir the liquid to accelerate the transfer of oxygen in the air to the liquid.

[0036] Specifically, such as Figure 1As shown, the outlet output end of the ferric chloride etching waste liquid storage tank 1 is provided with a first pump 12, and the first pump 12 is connected to the inlet end of the oxidation reaction tank 3, and can pump the ferric chloride etching waste liquid into the oxidation reaction tank 3 for subsequent oxidation reaction operation.

[0037] The outlet output end of the industrial wastewater storage tank 2 is provided with a second pump 13, which is connected to the inlet end of the oxidation reaction tank 3 and can pump the industrial wastewater into the oxidation reaction tank 3 for subsequent oxidation reaction operations.

[0038] A third pump 14 is provided at the outlet output end of the oxidation reaction tank 3, and the third pump 14 is connected to the inlet end of the neutralization and flocculation tank 4. The sewage and solid mixture after the oxidation reaction can be pumped into the neutralization and flocculation tank 4 through the third pump 14 for subsequent neutralization and flocculation treatment.

[0039] The outlet of the neutralization and flocculation tank 4 is provided with a fourth pump 15 , which is connected to the inlet of the inclined plate sedimentation tank 5 . The flocculated sewage can be pumped into the inclined plate sedimentation tank 5 through the fourth pump 15 for subsequent sedimentation and separation treatment.

[0040] A fifth pump 16 is provided at the outlet output end of the neutralization flocculation tank 4, and the fifth pump 16 is connected to the inlet end of the plate and frame filter press 6. The flocculated sewage can be transported to the plate and frame filter press 6 through the fifth pump 16, so that the suspended matter and solid impurities generated by flocculation can be filtered.

[0041] A sixth pump 17 is provided at the outlet output end of the inclined plate sedimentation tank 5, and the sixth pump 17 is connected to the inlet end of the plate and frame filter press 6. The impure sewage generated when the inclined plate sedimentation tank 5 is working can be transported to the plate and frame filter press 6 through the sixth pump 17 for subsequent filtration treatment of the impure sewage.

[0042] A seventh pump 18 is provided at the outlet output end of the plate and frame filter press 6, and the seventh pump 18 is connected to the inlet end of the sewage treatment device 8. The sewage generated by the plate and frame filter press 6 can be pumped into the sewage treatment device 8 through the seventh pump 18. For subsequent treatment of the sewage, a residue collection tank for collecting the solid phase is detachably installed at the lower part of the plate and frame filter press 6, which facilitates the centralized collection and discharge operations of the filter press residue.

[0043] Working Principle: This utility model effectively treats ferric chloride etching wastewater while leveraging the wastewater's properties to synergistically treat industrial wastewater (COD content: 20,000-30,000 mg / L). It safely treats high-concentration ferric chloride etching wastewater (acidity: 3-8 mol / L, iron content: 1,500-4,000 mg / L, nickel content: 5-10 mg / L). Furthermore, the ferric chloride etching wastewater enhances the Fenton oxidation system for treating other industrial wastewaters. Under acidic conditions, the iron and nickel ions in the wastewater catalyze hydrogen peroxide to produce highly active hydroxyl radicals, which facilitate COD degradation. Subsequently, alkalinization forms a ferric hydroxide precipitate, which, due to its gel properties, further adsorbs and captures organic pollutants in the wastewater. This combined process effectively collects and treats the three wastes throughout the reaction process, achieving synergistic treatment of ferric chloride etching wastewater and industrial wastewater.

[0044] Compared with the Fenton oxidation system process, the COD degradation rate of the ferric chloride etching waste liquid before and after use was compared, and the COD degradation rate of the waste liquid was increased by about 20%.

[0045] The specific principle is as follows:

[0046] Fe 3+ + H2O2→Fe 2+ +H + +HO2

[0047] Fe 3+ + HO2·→ Fe 2+ + H + +O2

[0048] Fe 2+ + H2O2 → Fe 3+ + HO·+ OH -

[0049] Fe 2+ + H2O2→ Fe 3+ +OH -

[0050] The process for co-treatment of industrial wastewater with ferric chloride etching waste liquid includes the following steps:

[0051] 1) Oxidation reaction: After the ferric chloride etching waste liquid is pumped into the oxidation reaction tank 3 by the first pump 12 on the ferric chloride etching waste liquid storage tank 1, the second pump 13 is turned on. The industrial waste water (COD content: 2000-3000 mg / L) in the industrial waste water storage tank 2 and the 30% H2O2 solution in the 30% hydrogen peroxide dosing tank 9 are oxidized by Fe 3+ and Ni 2+Catalyze hydrogen peroxide to produce hydroxyl radicals, which can oxidize and degrade organic pollutants in industrial wastewater;

[0052] Fe 3+ + H2O2→Fe 2+ +H + +HO2

[0053] Fe 3+ + HO2·→ Fe 2+ + H + +O2

[0054] Fe 2+ + H2O2 → Fe 3+ + HO·+ OH -

[0055] Fe 2+ + H2O2→ Fe 3+ +OH -

[0056] 2) Neutralization and flocculation: Sodium hydroxide solution is added through the 28% sodium hydroxide solution dosing tank 10 to neutralize the reaction system to a pH of 8.0-9.0, forming nickel hydroxide precipitate and ferric hydroxide gel, removing nickel ions and iron ions in the system, and further adsorbing residual organic matter in the system through its sweeping and coagulation effects;

[0057] H + +OH - →H2O

[0058] Ni 2+ +OH - → Ni(OH)2↓

[0059] Fe 3+ +OH - →Fe(OH)3↓

[0060] 3) Treatment of waste gas: When the oxidation reaction and neutralization flocculation begin, the induced draft fan is turned on to treat the gas generated during the reaction through the waste gas treatment device 7. The waste gas can be absorbed and purified by the sulfuric acid solution absorption device, the sodium hydroxide solution absorption device and the activated carbon absorption device on the waste gas treatment device 7 respectively;

[0061] 4) Inclined plate sedimentation: By adding a flocculant to the front end of the inclined plate sedimentation tank 5, the mixed liquid treated in step 2) can be quickly flocculated and precipitated to remove sediment particles;

[0062] 5) Solid-liquid separation: The sludge precipitated in the neutralization flocculation tank 4 and the inclined plate sedimentation tank 5 is separated into solid and liquid by a plate and frame filter press 6. The residue filtered out is collected and handed over to a qualified enterprise for the preparation of polyferric sulfate. The filtrate is pumped into the sewage treatment device 8 through the seventh pump 18 and is discharged or reused after treatment to meet the standards.

[0063] The above is only a preferred specific implementation method of the present invention, but the protection scope of the present invention is not limited to this. Any technician familiar with the technical field within the technical scope disclosed by the present invention can make equivalent replacements or changes based on the technical solution and utility model concept of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A process device for co-processing industrial wastewater with ferric chloride etching waste liquid, characterized in that: The invention comprises a ferric chloride etching waste liquid storage tank (1), an industrial wastewater storage tank (2), an oxidation reaction tank (3), a neutralization and flocculation tank (4), an inclined plate sedimentation tank (5), a plate and frame filter press (6), an exhaust gas treatment device (7) and a sewage treatment device (8) which are arranged in sequence from left to right. A 30% hydrogen peroxide dosing tank (9) is provided on the oxidation reaction tank (3), a 28% sodium hydroxide solution dosing tank (10) is provided on the neutralization and flocculation tank (4), a polyferric sulfate solution dosing tank (11) is provided at the front end of the inclined plate sedimentation tank (5), and sludge discharge ports of the neutralization and flocculation tank (4) and the inclined plate sedimentation tank (5) are connected to the plate and frame filter press (6).

2. a process device for collaboratively treating industrial waste water using ferric chloride etching waste liquid according to claim 1, characterized in that, The upper portion of the neutralization and flocculation tank (4) is externally connected to an air suction hood, and the air suction hood is connected to a waste gas treatment device (7). The waste gas treatment device (7) comprises a sulfuric acid solution absorption device, a sodium hydroxide solution absorption device, an activated carbon absorption device, and an induced draft fan, which are sequentially arranged outward from the air outlet of the air suction hood.

3. a process device for collaboratively treating industrial waste water using ferric chloride etching waste liquid according to claim 1, characterized in that, The oxidation reaction tank (3) is provided with a pH meter, a thermometer and an ORP meter, and an aeration plate is laid at the bottom.

4. a process device for collaboratively treating industrial waste water using ferric chloride etching waste liquid according to claim 1, characterized in that, The outlet output end of the ferric chloride etching waste liquid storage tank (1) is provided with a first pump (12), and the first pump (12) is connected to the inlet end of the oxidation reaction tank (3).

5. A process device for collaboratively treating industrial wastewater using ferric chloride etching waste liquid according to claim 1, characterized in that, A second pump (13) is provided at the outlet output end of the industrial wastewater storage tank (2), and the second pump (13) is connected to the inlet end of the oxidation reaction tank (3).

6. A process device for collaboratively treating industrial waste water using ferric chloride etching waste liquid according to claim 1, characterized in that, A third pump (14) is provided at the outlet output end of the oxidation reaction tank (3), and the third pump (14) is connected to the inlet end of the neutralization and flocculation tank (4).

7. A process device for collaboratively treating industrial wastewater using ferric chloride etching waste liquid according to claim 1, characterized in that, A fourth pump (15) is provided at the outlet output end of the neutralization and flocculation tank (4), and the fourth pump (15) is connected to the inlet end of the inclined plate sedimentation tank (5).

8. A process device for collaboratively treating industrial wastewater using ferric chloride etching waste liquid according to claim 1, characterized in that, The outlet output end of the neutralization and flocculation tank (4) is provided with a fifth pump (16), and the fifth pump (16) is connected to the inlet end of the plate and frame filter press (6).

9. A process device for collaboratively treating industrial wastewater using ferric chloride etching waste liquid according to claim 1, characterized in that, A sixth pump (17) is provided at the outlet output end of the inclined plate sedimentation tank (5), and the sixth pump (17) is connected to the inlet end of the plate and frame filter press (6).

10. A process device for collaboratively treating industrial wastewater using ferric chloride etching waste liquid according to claim 1, characterized in that, A seventh pump (18) is provided at the outlet output end of the plate-frame filter press (6), and the seventh pump (18) is connected to the inlet end of the sewage treatment device (8). A residue collection tank for collecting solid phase is detachably installed at the lower part of the plate-frame filter press (6).

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