High-salt printing and dyeing wastewater treatment device and wastewater treatment method based on coagulation-heterogeneous Fenton-reverse osmosis process

Abstract

The invention relates to a high-salinity printing and dyeing wastewater treatment device based on a coagulation-heterogeneous Fenton-reverse osmosis process and a wastewater treatment method. The invention aims to overcome the defect of poor effluent quality caused by the fact that a traditional decoloration wastewater treatment process is difficult to adapt to the characteristics of high salinity and high pollutant concentration of decoloration wastewater. According to the high-salt printing and dyeing wastewater treatment device, an iron-carbon micro-electrolysis tank, a coagulation-aeration tank, a first-stage sedimentation tank, a heterogeneous Fenton reaction tank, a second-stage sedimentation tank, a sand filter and a reverse osmosis tank are sequentially arranged in a box body in the water flow direction, polyferric sulfate is added into the coagulation-aeration tank, the heterogeneous Fenton reaction tank is filled with zeolite filler, and the reverse osmosis tank is filled with the zeolite filler. A Fenton reagent is added into the heterogeneous Fenton reaction tank, supernate of the secondary sedimentation tank flows into a sand filter tank, and effluent of the sand filter tank flows into a reverse osmosis tank. By combining a coagulation method, a heterogeneous Fenton oxidation method and a reverse osmosis process, salt, sulfite, organic matters and toxic and harmful substances in the wastewater are efficiently removed.

Description

Technical Field

[0001] The invention relates to a printing and dyeing wastewater treatment device based on a coagulation-heterogeneous Fenton-reverse osmosis process, and a method for treating printing and dyeing wastewater by using the water treatment device. Background Art

[0002] With the rapid development of the textile printing and dyeing industry, the problem of wastewater discharge has become increasingly severe. Printing and dyeing wastewater usually contains a large amount of organic matter, dyes, salts, sulfites and other toxic and harmful substances. Its composition is complex and the degree of pollution is serious, posing a great threat to the environment and water bodies. In particular, the wastewater generated in the decolorization process generally has high salt concentration, sulfite content and organic pollutant concentration, which has become a major problem in wastewater treatment. Although traditional wastewater treatment methods such as chemical precipitation, physical adsorption and biodegradation have achieved results in some aspects, they still have problems such as low treatment efficiency, high cost, and complex operation and maintenance, making it difficult to meet increasingly stringent emission standards.

[0003] At present, some treatment technologies have made certain progress in the application of pollutants such as high salt, sulfite and organic matter in textile printing and dyeing wastewater. Among them, physical and chemical methods such as coagulation and biological treatment methods have been widely studied and applied to the preliminary treatment of wastewater. However, the traditional decolorization wastewater treatment process often has the following shortcomings when applied: it can remove some macromolecular organic matter and suspended matter, but it has limited effect on soluble organic pollutants, dyes and high-salinity wastewater, and it is difficult to remove some fine pollutants in the wastewater, and the treated wastewater is still difficult to meet the discharge standards; biological treatment methods have low costs and good effects in treating low-concentration organic pollutants, but when facing wastewater containing high concentrations of salt and sulfite, its treatment effect is severely limited. In addition, under the action of various biological toxic substances in decolorization wastewater, it is extremely difficult to control the biological treatment unit, a large amount of residual sludge will be generated and this type of solid waste needs to be further treated, which increases the overall difficulty of treatment; reverse osmosis technology can effectively remove soluble substances in wastewater, but for high-salinity wastewater, reverse osmosis membranes are easily contaminated, and the frequency of membrane cleaning and replacement is high, which limits its application.

[0004] Therefore, how to design an efficient, energy-saving, and cost-controlled wastewater treatment process for complex pollutants such as high salt, sulfite, organic matter, and dyes has become a technical problem that needs to be urgently solved in the field of textile printing and dyeing wastewater treatment. Summary of the invention

[0005] The present invention aims to solve the defect that the traditional bleaching wastewater treatment process is difficult to adapt to the characteristics of high salinity and high pollutant concentration of bleaching wastewater, resulting in poor effluent water quality, and provide a high-salt printing and dyeing wastewater treatment device and wastewater treatment method based on coagulation-heterogeneous Fenton-reverse osmosis process.

[0006] The high-salt printing and dyeing wastewater treatment device based on the coagulation-heterogeneous Fenton-reverse osmosis process of the present invention comprises a box, an iron-carbon micro-electrolysis cell, a coagulation-aeration tank, a primary sedimentation tank, a heterogeneous Fenton reaction tank, a secondary sedimentation tank, a sand filter tank and a reverse osmosis tank, wherein the iron-carbon micro-electrolysis cell, the coagulation-aeration tank, the primary sedimentation tank, the heterogeneous Fenton reaction tank, the secondary sedimentation tank, the sand filter tank and the reverse osmosis tank are sequentially arranged in the box along the water flow direction, the iron-carbon micro-electrolysis cell is filled with iron-carbon fillers, and an aeration device is arranged at the bottom of the iron-carbon micro-electrolysis cell;

[0007] Polyferric sulfate is added to a coagulation-aeration tank, an aeration device is arranged at the bottom of the coagulation-aeration tank, the effluent of the coagulation-aeration tank enters a primary sedimentation tank, the supernatant of the primary sedimentation tank flows into a heterogeneous Fenton reaction tank, the heterogeneous Fenton reaction tank is filled with a zeolite filler, the zeolite filler is a zeolite loaded with nano-iron particles, and a Fenton reagent is added to the heterogeneous Fenton reaction tank;

[0008] The effluent of the heterogeneous Fenton reaction tank flows into the secondary sedimentation tank, the supernatant of the secondary sedimentation tank flows into the sand filter tank filled with fine sand filler, and the effluent of the sand filter tank flows into the reverse osmosis tank, which is equipped with a reverse osmosis membrane assembly.

[0009] The method for treating high-salt printing and dyeing wastewater by using a high-salt printing and dyeing wastewater treatment device based on a coagulation-heterogeneous Fenton-reverse osmosis process is implemented according to the following steps:

[0010] 1. After adjusting the pH value of high-salt printing and dyeing wastewater, it flows into the iron-carbon micro-electrolysis cell for electrochemical reaction. The effluent of the iron-carbon micro-electrolysis cell flows into the coagulation-aeration tank. Polyferric sulfate is added to the coagulation-aeration tank for coagulation reaction and aeration at the same time. The effluent of the coagulation-aeration tank flows into the primary sedimentation tank.

[0011] 2. The effluent from the primary sedimentation tank flows into a heterogeneous Fenton reaction tank, which is filled with a zeolite filler, wherein the zeolite filler is a zeolite loaded with nano-iron particles, and a Fenton reagent is added to the heterogeneous Fenton reaction tank for reaction, and the effluent from the heterogeneous Fenton reaction tank flows into a secondary sedimentation tank;

[0012] The effluent from the third and second sedimentation tanks flows into the sand filter tank, and is sand filtered through fine sand filler. The wastewater after sand filtration enters the reverse osmosis tank for desalination treatment, thereby completing the treatment of high-salt printing and dyeing wastewater.

[0013] The present invention adopts a three-stage combined process of iron-carbon micro-electrolysis-coagulation, heterogeneous Fenton and reverse osmosis, which can efficiently remove salt, dyes, high-concentration organic matter and toxic and harmful substances in wastewater. The iron-carbon micro-electrolysis and coagulation-aeration process is mainly aimed at a large number of suspended matter such as macromolecular chromogenic organic matter and plant fibers in high-salinity printing and dyeing wastewater. The current is used to pass through the electrolyte solution between the anode and the cathode in the iron-carbon micro-electrolysis system to induce a redox reaction, and the above two substances are synergistically removed, thereby improving the quality of wastewater and reducing the organic load of subsequent high-energy consumption physical and chemical treatment units. The heterogeneous Fenton process targets a large number of difficult-to-degrade organic matter in high-salinity printing and dyeing wastewater, and plays a core role in the degradation of organic pollutants. Most of the organic pollutants are removed under the advanced oxidation of the Fenton reagent, while further reducing the content of suspended matter in the water, improving the inlet water quality of the reverse osmosis process, and finally using the reverse osmosis process to remove a large amount of salt in the printing and dyeing wastewater, so that the effluent meets the discharge standard. The pure physical and chemical process combination of the present invention fundamentally avoids the continuous impact of high-salt and high-contamination organic wastewater on the biological treatment system, solves the problem of suspended matter such as bacterial flocs and microbial particles in the effluent of biological treatment, thereby contaminating the reverse osmosis membrane, and does not need to consider the problem that the effluent effect of the biological treatment unit is unstable and needs frequent regulation when facing high-concentration organic wastewater. Compared with the existing decolorization wastewater treatment method, the present invention has stable effect, clear effluent, and water quality that can reach the reuse level when dealing with decolorization wastewater with small water volume, high concentration, large fluctuation, and high salinity.

[0014] The present invention integrates the pretreatment measures of the reverse osmosis process into the processes of iron-carbon micro-electrolysis, coagulation-aeration, heterogeneous Fenton, etc. The iron-carbon micro-electrolysis process can reduce the concentration of organic matter in the wastewater and disconnect the macromolecular chain. At the same time, the back-end is connected to the coagulation process, so there is no need to consider the problem of iron ions entrained in the effluent of the iron-carbon micro-electrolysis process. The iron-carbon micro-electrolysis is coupled with the coagulation process, and the iron-carbon reaction product (Fe 2+ ) is directly used as a coagulant to reduce the amount of reagents added; the coagulation-aeration process and the heterogeneous Fenton process can further reduce the concentration of pollutants and suspended solids in the water, which significantly reduces the pollution load of the reverse osmosis membrane. There is no need to set up multi-stage pretreatment filtration facilities, thereby reducing the energy consumption of the reverse osmosis system and the frequency of membrane cleaning, ensuring that the reverse osmosis membrane can maintain high efficiency for a long time. The combination of multiple processes has achieved a significant improvement in the treatment effect. By optimizing the arrangement and distribution of each tank body, the negative effects of different processes on the effluent are avoided, which greatly improves the overall energy efficiency of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic structural diagram of a high-salt printing and dyeing wastewater treatment device based on a coagulation-heterogeneous Fenton-reverse osmosis process according to the present invention. DETAILED DESCRIPTION

[0016] Specific implementation method one: In this implementation method, a high-salt printing and dyeing wastewater treatment device based on a coagulation-heterogeneous Fenton-reverse osmosis process includes a housing 1, an iron-carbon micro-electrolysis cell 2, a coagulation-aeration tank 3, a primary sedimentation tank 4, a heterogeneous Fenton reaction tank 5, a secondary sedimentation tank 6, a sand filter 7, and a reverse osmosis tank 8. The iron-carbon micro-electrolysis cell 2, the coagulation-aeration tank 3, the primary sedimentation tank 4, the heterogeneous Fenton reaction tank 5, the secondary sedimentation tank 6, the sand filter 7, and the reverse osmosis tank 8 are sequentially arranged in the housing 1 along the direction of water flow. The iron-carbon micro-electrolysis cell 2 is filled with an iron-carbon filler 2-1, and an aeration device is arranged at the bottom of the iron-carbon micro-electrolysis cell 2;

[0017] Polyferric sulfate is added to the coagulation-aeration tank 3, an aeration device is arranged at the bottom of the coagulation-aeration tank 3, the effluent of the coagulation-aeration tank 3 enters the primary sedimentation tank 4, the supernatant of the primary sedimentation tank 4 flows into the heterogeneous Fenton reaction tank 5, the heterogeneous Fenton reaction tank 5 is filled with a zeolite filler 5-1, the zeolite filler 5-1 is a zeolite loaded with nano-iron particles, and a Fenton reagent is added to the heterogeneous Fenton reaction tank 5;

[0018] The effluent of the heterogeneous Fenton reaction tank 5 flows into the secondary sedimentation tank 6, and the supernatant of the secondary sedimentation tank 6 flows into the sand filter 7, which is filled with fine sand filler 7-1. The effluent of the sand filter 7 flows into the reverse osmosis tank 8, which is provided with a reverse osmosis membrane assembly 8-1.

[0019] In this embodiment, the iron chips (Fe 0 , anode) and activated carbon (C, cathode) are in direct contact in the wastewater, forming countless tiny primary cells. Under acidic conditions (pH 3-4), iron as an active metal loses electrons and is oxidized, and carbon as an inert electrode accepts electrons, triggering continuous redox reactions to produce active hydrogen ([H]). Active hydrogen ([H]) reacts with difficult-to-degrade organic matter in the wastewater (such as azo dyes and benzene ring substances) to undergo a reduction reaction, destroying chromophores (such as –N=N–) and toxic groups, achieving decolorization and improving biodegradability. The iron-carbon micro-electrolysis process not only pretreats difficult-to-degrade organic matter, but also provides an iron source for the subsequent coagulation process, reduces the amount of reagents added, and reduces operating costs. The Fe(OH) generated by the micro-electrolysis reaction 3 The colloid and coagulant work together to improve the flocculation effect. Waste iron filings and waste activated carbon are used as micro-electrolysis materials to realize waste resource utilization. The Fe generated by the micro-electrolysis reaction 2+ and Fe 3+ It can be directly used in the coagulation process to reduce the consumption of iron salts. The iron-carbon micro-electrolysis reactor has a simple structure, does not require complex equipment, and is easy to apply industrially.

[0020] This embodiment achieves complementarity with the coagulation process by adjusting the micro-electrolysis reaction conditions. The wastewater pH is adjusted to 3.5 and enters the iron-carbon micro-electrolysis reactor. The residence time is 45 minutes, the COD removal rate is about 30%, and the chroma removal rate is about 50%.

[0021] The coagulant of this embodiment selects polyferric sulfate (PSF), which can not only effectively remove suspended solids, but also oxidize sulfite to sulfate, further reducing harmful components in wastewater. The heterogeneous Fenton reaction can give full play to the ability of Fenton reaction to degrade pollutants, and has better removal effect on high-concentration dyes, additives, etc. unique to decolorized wastewater than the traditional homogeneous Fenton process, further purifying wastewater. The ferrous iron consumption is low and the iron mud is low. The heterogeneous Fenton reaction is to accelerate the reduction of the trivalent iron in the Fenton system to ferrous iron, and form a sustainable iron cycle in a short time to carry out the Fenton reaction. Compared with the ferrous iron dosage of the traditional Fenton, the catalytic Fenton only needs to add a small amount of ferrous iron to the system to form an iron cycle, which greatly reduces the ferrous iron consumption and coagulation iron mud. Moreover, the effluent water quality of the catalytic Fenton reaction is stable, and the drug consumption and mud amount are stable, without obvious trend or fluctuation.

[0022] In this embodiment, the water treated by Fenton reaction is adjusted to a neutral pH and then flows into the sedimentation tank. The flocs mainly composed of iron oxides produced by the Fenton reaction are used to separate solids and liquids in the sedimentation tank to further remove solid matter and unreacted chemical reagents in the wastewater. The sand filter device is used to further remove suspended matter and larger particles in the wastewater to improve the effect of subsequent reverse osmosis treatment. The design and operation of the sand filtration system is crucial to ensure further purification of wastewater, especially in the treatment of high-salinity and high-concentration printing and dyeing wastewater. It helps to reduce the pollution of the reverse osmosis membrane and extend the service life of the membrane. At the same time, a primary pressure pump is used to control the water inlet pressure and flow rate of the sand filter device.

[0023] This embodiment proposes a wastewater treatment device based on iron-carbon micro-electrolysis-coagulation-heterogeneous Fenton-reverse osmosis process, which forms a multi-stage treatment system by rationally combining iron-carbon micro-electrolysis, coagulation, heterogeneous Fenton oxidation and reverse osmosis technology. This process can fully remove salt, sulfite, organic matter and toxic and harmful substances in wastewater, improve treatment effect and reduce energy consumption, and at the same time, while removing dyes and other organic pollutants, reduce the addition of iron salts and avoid pollution of reverse osmosis membranes, thereby improving the overall stability and economy of the treatment system.

[0024] Specific implementation method 2: The difference between this implementation method and specific implementation method 1 is that the effluent from the coagulation-aeration tank 3 enters the primary sedimentation tank 4 through the guide tube.

[0025] Specific implementation method three: This implementation method is different from specific implementation methods one or two in that the effluent from the heterogeneous Fenton reaction tank 5 enters the secondary sedimentation tank 6 through a guide tube.

[0026] Specific embodiment 4: This embodiment is different from any one of specific embodiments 1 to 3 in that the Fenton reagent includes ferrous sulfate, sulfuric acid and hydrogen peroxide.

[0027] Specific embodiment 5: This embodiment is different from specific embodiments 1 to 4 in that the preparation method of the zeolite loaded with nano iron particles is as follows:

[0028] The natural zeolite was placed in a 1 mol / L nitric acid solution to remove surface impurities, washed with ultrapure water and dried to obtain the cleaned zeolite. The cleaned zeolite was mixed with FeCl 3 The solution was fully mixed and stirred for 3-5 hours, then transferred to a sealed container and KBH was added dropwise under anaerobic conditions. 4 The solution is stirred continuously to react, and black flocculent particles are produced. After the reaction is completed, the particles are washed with oxygen-free ultrapure water, and freeze-dried to obtain zeolite loaded with nano-iron particles.

[0029] Specific implementation method 6: This implementation method uses a high-salt printing and dyeing wastewater treatment device based on coagulation-heterogeneous Fenton-reverse osmosis process to treat high-salt printing and dyeing wastewater according to the following steps:

[0030] 1. After adjusting the pH value of the high-salt printing and dyeing wastewater, it flows into the iron-carbon micro-electrolysis cell 2 for electrochemical reaction. The effluent of the iron-carbon micro-electrolysis cell 2 flows into the coagulation-aeration tank 3. Polyferric sulfate is added to the coagulation-aeration tank 3 for coagulation reaction and aeration at the same time. The effluent of the coagulation-aeration tank 3 flows into the primary sedimentation tank 4.

[0031] 2. The effluent of the primary sedimentation tank 4 flows into the heterogeneous Fenton reaction tank 5. The heterogeneous Fenton reaction tank 5 is filled with a zeolite filler 5-1. The zeolite filler 5-1 is a zeolite loaded with nano-iron particles. A Fenton reagent is added to the heterogeneous Fenton reaction tank 5 for reaction. The effluent of the heterogeneous Fenton reaction tank 5 flows into the secondary sedimentation tank 6.

[0032] The effluent from the third and second sedimentation tanks 6 flows into the sand filter 7, and is sand filtered through the fine sand filler 7-1. The wastewater after sand filtration enters the reverse osmosis tank 8 for desalination treatment, thereby completing the treatment of high-salt printing and dyeing wastewater.

[0033] In step 1 of this embodiment, the pH of the high-salt printing and dyeing wastewater is adjusted to 3-4, and aeration is performed in the iron-carbon micro-electrolysis cell.

[0034] Specific implementation method seven: This implementation method is different from specific implementation method six in that the coagulation reaction time in step one is controlled to be 8 to 15 minutes.

[0035] Specific embodiment eight: This embodiment is different from specific embodiment six or seven in that the hydraulic retention time in the heterogeneous Fenton reaction tank 5 is controlled to be 0.8 to 1.2 h in step two.

[0036] Specific embodiment 9: The difference between this embodiment and any one of specific embodiments 5 to 8 is that in step 2, the pH value of the wastewater in the secondary sedimentation tank 6 is adjusted to 6.5-7.5.

[0037] Specific embodiment ten: This embodiment is different from any one of specific embodiments five to nine in that the pore size of the reverse osmosis membrane assembly 8 - 1 in the reverse osmosis tank 8 in step three is 0.2 to 0.8 nm.

[0038] Embodiment: In this embodiment, the method for treating high-salt printing and dyeing wastewater using a high-salt printing and dyeing wastewater treatment device based on a coagulation-heterogeneous Fenton-reverse osmosis process is implemented according to the following steps:

[0039] 1. Adjust the pH value of the high-salt printing and dyeing wastewater to 3.5 and then flow it into the iron-carbon micro-electrolysis cell 2 for electrochemical reaction for 1 hour. Aeration is performed in the iron-carbon micro-electrolysis cell 2. The effluent of the iron-carbon micro-electrolysis cell 2 flows into the coagulation-aeration tank 3. Polyferric sulfate is added to the coagulation-aeration tank 3 for coagulation reaction for 10 minutes. Aeration is performed at the same time. Aeration oxidizes sulfite into sulfate and provides stirring. The coagulation reaction promotes the aggregation and precipitation of suspended matter, some organic pollutants and other harmful substances in the wastewater, thereby improving the subsequent treatment effect. The effluent of the coagulation-aeration tank 3 flows into the primary sedimentation tank 4.

[0040] 2. The effluent from the primary sedimentation tank 4 flows into the heterogeneous Fenton reaction tank 5. The heterogeneous Fenton reaction tank 5 is filled with a zeolite filler 5-1. The zeolite filler 5-1 is a zeolite loaded with nano-iron particles. A Fenton reagent is added to the heterogeneous Fenton reaction tank 5 to react for 1 hour. The effluent from the heterogeneous Fenton reaction tank 5 flows into the secondary sedimentation tank 6.

[0041] 3. Adjust the pH value of the effluent from the secondary sedimentation tank 6 to 7.0 and then flow into the sand filter 7. After the fine sand filler 7-1, the sand filter is used to further remove suspended particles and tiny impurities. The wastewater after sand filtration enters the reverse osmosis tank 8 for desalination treatment. The water inlet flow rate is controlled at 10m 3 / d, the reverse osmosis membrane operating pressure is 0.3MPa, thus completing the treatment of high-salt printing and dyeing wastewater.

[0042] This embodiment applies the high-salt printing and dyeing wastewater treatment device based on the coagulation-heterogeneous Fenton-reverse osmosis process described in the specific implementation method 1. The high-salt printing and dyeing wastewater treatment device is provided with a control room 9, which is used to control the dosing and aeration equipment. The adjacent tank bodies of the iron-carbon micro-electrolysis cell 2, the coagulation-aeration tank 3, the primary sedimentation tank 4, the heterogeneous Fenton reaction tank 5, the secondary sedimentation tank 6, the sand filter 7 and the reverse osmosis tank 8 are separated by partitions.

[0043] The preparation method of the zeolite loaded with nano iron particles in this embodiment is as follows:

[0044] The natural zeolite was placed in a 1 mol / L nitric acid solution to remove surface impurities, washed with ultrapure water and dried to obtain the cleaned zeolite. The cleaned zeolite was mixed with 0.3 mol / L FeCl 3 The solution was thoroughly mixed and stirred for 3 h, then transferred to a sealed container and KBH was added dropwise under anaerobic conditions. 4 The solution was stirred continuously to control the FeCl 3 and KBH 4 The molar ratio of is 1:1, and black flocculent particles are gradually produced. After the reaction is completed, they are rinsed with oxygen-free ultrapure water, frozen, filled with nitrogen, and freeze-dried to obtain zeolite loaded with nano-iron particles.

[0045] The zeolite loaded with nano iron particles is used in this embodiment. Zeolite is a natural mineral material with a high specific surface area, which can provide a wide range of reaction surfaces and enhance the catalytic effect of the Fenton reaction; zeolite has a very rich pore structure, which can increase the contact area between the reactant and the catalyst and promote the oxidation reaction; it has strong chemical corrosion resistance: zeolite has a strong tolerance to chemical substances such as acids, alkalis, and salts, and is suitable for the high-salt environment of decolorizing wastewater. At the same time, the loaded nano iron particles have a high catalytic activity, which can promote the decomposition of hydrogen peroxide to generate free radicals in the Fenton reaction, thereby degrading organic pollutants. This type of iron-based catalyst can play a stable catalytic role in high-salt, high-concentration wastewater, and is particularly suitable for decolorizing wastewater treatment.

[0046] This embodiment uses a single-stage fine sand filter to perform deep filtration treatment on the effluent, further reducing the turbidity and pollutant concentration of the effluent, and greatly reducing the operating pressure of the reverse osmosis device. The water after sand filtration enters the reverse osmosis device for desalination treatment. Since the previous multi-stage treatment process has greatly reduced the pollutant concentration, the burden on the reverse osmosis membrane is significantly reduced, membrane pollution is avoided, and the stability and service life of the reverse osmosis system are improved. This embodiment uses a reverse osmosis (RO) membrane, which is a membrane component widely used in high-salt water treatment. It is suitable for treating high-salt decolorization wastewater with multiple complex components including sodium sulfate and sodium chloride, especially for water-soluble salts such as sodium chloride and sodium sulfate. The reverse osmosis membrane has a better performance. In order to ensure the stable operation of the reverse osmosis device, the device is equipped with equipment such as a flow meter, a pressure gauge and a regulating valve to monitor and control parameters such as water flow, pressure and desalination efficiency, and a secondary booster pump is used to regulate the water inlet pressure. The reverse osmosis membrane is easily affected by pollutants (such as organic matter, microorganisms, inorganic salt scaling, etc.), resulting in a decrease in desalination efficiency; the reverse osmosis device usually requires a higher operating pressure when treating high-salt wastewater, and this feature causes the reverse osmosis process to usually have a higher energy consumption; when treating high-salt wastewater with complex components, the service life of the reverse osmosis membrane assembly is also easily shortened; the energy consumption can be effectively reduced and the economy of the system can be improved by means of graded reverse osmosis, energy recovery devices, etc. This embodiment greatly reduces the water quality of the inlet water of the reverse osmosis process by pre-placing a heterogeneous Fenton reaction chamber and utilizing the flocculation effect of iron mud after the Fenton reaction.

[0047] The effect of using the high-salt printing and dyeing wastewater treatment device based on coagulation-heterogeneous Fenton-reverse osmosis process to treat high-salt printing and dyeing wastewater in this embodiment is as follows:

[0048] COD Ammonia nitrogen Total Nitrogen Total Phosphorus Chroma Total salt unit mg / L mg / L mg / L mg / L multiple mg / L Influent water quality 12000 9.3 18.7 4.2 500 36500 Outlet water quality 45 4.6 8.2 0.6 15 1040

[0049] The water after reverse osmosis treatment in this embodiment is finally discharged, and the effluent can be used for production water reuse in printing and dyeing textile factories, water reuse for device reagent preparation, or directly discharged into natural water bodies.

Claims

1. A high-salt printing and dyeing wastewater treatment device based on coagulation-heterogeneous Fenton-reverse osmosis process, characterized in that A high-salt printing and dyeing wastewater treatment device based on a coagulation-heterogeneous Fenton-reverse osmosis process comprises a housing (1), an iron-carbon micro-electrolysis cell (2), a coagulation-aeration tank (3), a primary sedimentation tank (4), a heterogeneous Fenton reaction tank (5), a secondary sedimentation tank (6), a sand filter (7) and a reverse osmosis tank (8); the iron-carbon micro-electrolysis cell (2), the coagulation-aeration tank (3), the primary sedimentation tank (4), the heterogeneous Fenton reaction tank (5), the secondary sedimentation tank (6), the sand filter (7) and the reverse osmosis tank (8) are sequentially arranged in the housing (1) along the direction of water flow; the iron-carbon micro-electrolysis cell (2) is filled with an iron-carbon filler (2-1); and an aeration device is arranged at the bottom of the iron-carbon micro-electrolysis cell (2); Polyferric sulfate is added to a coagulation-aeration tank (3), an aeration device is arranged at the bottom of the coagulation-aeration tank (3), the effluent of the coagulation-aeration tank (3) enters a primary sedimentation tank (4), the supernatant of the primary sedimentation tank (4) flows into a heterogeneous Fenton reaction tank (5), the heterogeneous Fenton reaction tank (5) is filled with a zeolite filler (5-1), the zeolite filler (5-1) is a zeolite loaded with nano-iron particles, and a Fenton reagent is added to the heterogeneous Fenton reaction tank (5); The effluent of the heterogeneous Fenton reaction tank (5) flows into the secondary sedimentation tank (6), the supernatant of the secondary sedimentation tank (6) flows into the sand filter tank (7), the sand filter tank (7) is filled with fine sand filler (7-1), and the effluent of the sand filter tank (7) flows into the reverse osmosis tank (8), and the reverse osmosis tank (7) is provided with a reverse osmosis membrane assembly (8-1).

2. The high-salt printing and dyeing wastewater treatment device based on coagulation-heterogeneous Fenton-reverse osmosis process according to claim 1 is characterized in that The effluent from the coagulation-aeration tank (3) enters the primary sedimentation tank (4) through the guide tube.

3. The high-salt printing and dyeing wastewater treatment device based on coagulation-heterogeneous Fenton-reverse osmosis process according to claim 1 is characterized in that The effluent from the heterogeneous Fenton reaction tank (5) enters the secondary sedimentation tank (6) through the guide tube.

4. The high-salt printing and dyeing wastewater treatment device based on coagulation-heterogeneous Fenton-reverse osmosis process according to claim 1 is characterized in that The Fenton reagent comprises ferrous sulfate, sulfuric acid and hydrogen peroxide.

5. The high-salt printing and dyeing wastewater treatment device based on coagulation-heterogeneous Fenton-reverse osmosis process according to claim 1 is characterized in that The preparation method of the zeolite loaded with nano iron particles is as follows: The natural zeolite was placed in a 1 mol / L nitric acid solution to remove surface impurities, washed with ultrapure water and dried to obtain the cleaned zeolite, and the cleaned zeolite was fully mixed with a FeCl3 solution with a concentration of 0.2-0.5 mol / L, stirred for 3-5 hours, and then transferred to a closed container, and KBH4 solution was added dropwise under an anaerobic environment and stirred continuously to react to produce black flocculent particles. After the reaction was completed, it was rinsed with oxygen-free ultrapure water and freeze-dried to obtain a zeolite loaded with nano-iron particles.

6. A method for treating high-salt printing and dyeing wastewater using the high-salt printing and dyeing wastewater treatment device based on coagulation-heterogeneous Fenton-reverse osmosis process as claimed in claim 1, characterized in that The method for treating high-salt printing and dyeing wastewater is achieved by following the steps below:

1. After adjusting the pH value of the high-salt printing and dyeing wastewater, the wastewater flows into the iron-carbon micro-electrolysis cell (2) for electrochemical reaction. The effluent of the iron-carbon micro-electrolysis cell (2) flows into the coagulation-aeration tank (3). Polyferric sulfate is added to the coagulation-aeration tank (3) for coagulation reaction. Aeration is performed at the same time. The effluent of the coagulation-aeration tank (3) flows into the primary sedimentation tank (4); 2. The effluent from the primary sedimentation tank (4) flows into the heterogeneous Fenton reaction tank (5), the heterogeneous Fenton reaction tank (5) is filled with a zeolite filler (5-1), and the zeolite filler (5-1) is a zeolite loaded with nano-iron particles. A Fenton reagent is added to the heterogeneous Fenton reaction tank (5) for reaction, and the effluent from the heterogeneous Fenton reaction tank (5) flows into the secondary sedimentation tank (6); The effluent from the third and second sedimentation tanks (6) flows into the sand filter tank (7), and is sand filtered through the fine sand filler (7-1). The wastewater after sand filtration enters the reverse osmosis tank (8) for desalination treatment, thereby completing the treatment of high-salt printing and dyeing wastewater.

7. The method for treating high-salt printing and dyeing wastewater using a high-salt printing and dyeing wastewater treatment device based on a coagulation-heterogeneous Fenton-reverse osmosis process according to claim 6, characterized in that In step 1, the coagulation reaction time is controlled to be 8 to 15 minutes.

8. The method for treating high-salt printing and dyeing wastewater using a high-salt printing and dyeing wastewater treatment device based on a coagulation-heterogeneous Fenton-reverse osmosis process according to claim 6, characterized in that In step 2, the hydraulic retention time in the heterogeneous Fenton reaction tank (5) is controlled to be 0.8 to 1.2 hours.

9. The method for treating high-salt printing and dyeing wastewater using a high-salt printing and dyeing wastewater treatment device based on coagulation-heterogeneous Fenton-reverse osmosis process according to claim 6, characterized in that In step 2, the pH of the wastewater in the secondary sedimentation tank (6) is adjusted to 6.5-7.

5.

10. The method for treating high-salt printing and dyeing wastewater using a high-salt printing and dyeing wastewater treatment device based on a coagulation-heterogeneous Fenton-reverse osmosis process according to claim 6, characterized in that In step 3, the pore size of the reverse osmosis membrane assembly (8-1) in the reverse osmosis tank (8) is 0.2-0.8 nm.

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