High-concentration dye wastewater treatment method

Abstract

The invention discloses a high-concentration dye wastewater treatment method, and belongs to the technical field of textile wastewater treatment. The method comprises the following steps: firstly, adding a flocculating agent into wastewater to be treated, stirring and mixing, settling, and then carrying out solid-liquid separation to obtain first treatment liquid and sludge; under the action of an electric field, carrying out electrolytic oxidation treatment on the first treatment liquid to obtain a second treatment liquid; adsorbing the second treating fluid through activated carbon and quartz sand in sequence to obtain a third treating fluid; detecting the third treating fluid, and discharging the third treating fluid if the third treating fluid reaches a discharge or reuse standard; and if the emission or reuse standard is not met, the previous steps are repeated for retreatment until the emission or reuse standard is met. Through the synergistic effect of multiple processes, the high-concentration dye wastewater treatment device has efficient treatment capacity on a large amount of high-concentration dye wastewater generated in industrial production, especially the high-concentration disperse dye wastewater, and the treated wastewater reaches the discharge standard or reuse requirement.

Description

Technical Field

[0001] The invention belongs to the technical field of textile wastewater treatment, and particularly relates to a method for treating high-concentration dye wastewater. Background Art

[0002] The main components of high-concentration dye wastewater include dye molecules, organic pollutants, inorganic pollutants, and suspended solids. Its specific concentration range is typically defined based on indicators such as COD, color, TOC, and SS. In the printing and dyeing industry, wastewater with COD > 2000 mg / L, color > 1000 degrees, TOC > 500 mg / L, and SS > 500 mg / L is generally considered high-concentration dye wastewater. Treatment of this type of wastewater is challenging, requiring efficient treatment processes and equipment to ensure compliance with discharge or reuse standards.

[0003] Currently, deep-combing and membrane technologies are commonly used to treat high-concentration dye wastewater. Deep-combing technology is ineffective against recalcitrant organic matter (such as new dyes) and is not practical for treating high-salt wastewater and alkali-reduction wastewater. High concentrations of chemicals inhibit microbial activity, leading to system breakdown when treating such wastewater. Furthermore, membrane technology can be susceptible to clogging of membrane pores by large solid particles during filtration, making it susceptible to clogging by oily substances such as silica. Subsequent cleaning is difficult, shortening the membrane's service life and making it inefficient for treating such wastewater.

[0004] There are other treatment methods for high-concentration dye wastewater. For example, Chinese invention patent application number 200910199042.1 optimizes the combination of electrochemical oxidation and photocatalytic oxidation technologies into a three-stage wastewater treatment process: electrochemical pre-oxidation - photoelectric synergistic oxidation - photocatalytic oxidation. This process can significantly reduce the TOC value of dye wastewater and achieve decolorization. However, the experimental environment is different from industrial production. The high-concentration wastewater content in industrial production is more complex, and the industrial production process continuously generates large amounts of wastewater, which places higher requirements on treatment efficiency and cost. For example, the reaction tank treatment volume in the experimental environment is only 100-300ml, while the required industrial treatment volume is usually cubic meters or even 10,000 tons. Directly scaling up the device size will lead to problems such as uneven stirring and insufficient light penetration. The magnetic stirring used in the experimental environment is only suitable for small-scale beaker experiments and cannot meet the mixing requirements of large-scale reaction tanks. Industrial applications require more complex and efficient mechanical stirring or hydraulic circulation systems. The experiment relied on point sources inserted into quartz tubes to provide uniform UV illumination. In large-scale reactors, a large array of light sources must be deployed to ensure an intensity of 3mW / cm² across all areas. Quartz tube maintenance, energy consumption, and the sharp drop in light penetration in dark or large wastewater volumes pose significant challenges. Maintaining constant current electrolysis (current density 2-30mA / cm²) and strong UV illumination (3mW / cm²) simultaneously consumes significant amounts of electricity. In large-scale applications, electricity costs will become the primary operating cost, making the process far less economical than traditional methods.

[0005] Therefore, this type of process is not suitable for the treatment of large quantities of industrial wastewater, and has problems such as complex equipment, high energy consumption, high treatment cost, and low treatment efficiency. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a method for treating industrial large-scale high-concentration dye wastewater.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is: a method for treating high-concentration dye wastewater, comprising the following steps: S1. Adding a flocculant to the wastewater to be treated, stirring and mixing, and then settling, and then performing solid-liquid separation to obtain a first treated liquid and sludge; S2. Under the action of an electric field, electrolytically oxidizing the first treatment liquid to obtain a second treatment liquid; S3, the second treatment liquid is sequentially adsorbed by activated carbon and quartz sand to obtain a third treatment liquid; S4. The third treated liquid is tested. If it meets the discharge or reuse standard, it is discharged. If it does not meet the discharge or reuse standard, S1 to S3 are repeated for reprocessing until it meets the discharge or reuse standard.

[0008] Furthermore, S1 is carried out in the pretreatment area, S2 is carried out in the electrolytic oxidation area, S3 is carried out in the adsorption filtration area, and S4 is carried out in the clean water collection area.

[0009] Another technical solution adopted by the present invention is: the high-concentration dye wastewater treatment method described above, wherein S1 to S4 are performed in a high-concentration dye wastewater treatment device, and the high-concentration dye wastewater treatment device includes a tank body, and the tank body is sequentially provided with a pretreatment zone, an electrolytic oxidation zone, an adsorption and filtration zone, and a clear water collection zone from bottom to top; The volume of the pretreatment zone accounts for 15-20% of the total volume of the tank body, the volume of the electrolytic oxidation zone accounts for 30-35% of the total volume of the tank body, the volume of the adsorption and filtration zone accounts for 30-35% of the total volume of the tank body, and the volume of the clean water collection zone accounts for 10-15% of the total volume of the tank body.

[0010] The beneficial effects of the present invention are as follows: The method for treating high-concentration dye wastewater provided by the present invention, through the synergistic action of multiple processes including precipitation pretreatment, electrolytic oxidation, and adsorption filtration, has high efficiency in treating large amounts of high-concentration dye wastewater generated by industrial production, particularly high-concentration disperse dye wastewater. It can effectively reduce indicators such as the chromaticity and chemical oxygen demand (COD) of the wastewater, ensuring that the treated wastewater meets discharge standards or reuse requirements. The reagents and equipment applicable to the method for treating high-concentration dye wastewater provided by the present invention are low-cost and suitable for treating large quantities of industrial wastewater. The method has strong adaptability to high-concentration disperse dye wastewater of different types and concentrations, and can meet the treatment requirements of different wastewater types by adjusting parameters such as the reagent dosage, electrolysis voltage and current, and adsorption and filtration materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is a schematic diagram of the operating principle of a device for treating high-concentration dye wastewater according to a specific embodiment of the present invention. DETAILED DESCRIPTION

[0012] To illustrate the technical content, achieved objectives and effects of the present invention in detail, the following description is given in conjunction with the embodiments and accompanying drawings.

[0013] A method for treating high-concentration dye wastewater comprises the following steps: S1. Adding a flocculant to the wastewater to be treated, stirring and mixing, and then settling, and then performing solid-liquid separation to obtain a first treated liquid and sludge; S2. Under the action of an electric field, electrolytically oxidizing the first treatment liquid to obtain a second treatment liquid; S3, the second treatment liquid is sequentially adsorbed by activated carbon and quartz sand to obtain a third treatment liquid; S4. The third treated liquid is tested. If it meets the discharge or reuse standard, it is discharged. If it does not meet the discharge or reuse standard, S1 to S3 are repeated for reprocessing until it meets the discharge or reuse standard.

[0014] As can be seen from the above description, the beneficial effects of the present invention are as follows: the high-concentration dye wastewater treatment method provided by the present invention first fully mixes the wastewater with a flocculant, so that the suspended particles and some dye molecules in the wastewater are flocculated and precipitated, and the settled sludge is discharged, reducing the subsequent treatment load and reducing the energy consumption of the subsequent electrolytic oxidation treatment; then, under the action of the electric field, the dye molecules and organic matter in the wastewater undergo an oxidation-reduction reaction and are decomposed into small molecules, thereby reducing the chroma and organic matter content of the wastewater; then, after adsorption and filtration by activated carbon and quartz sand, the suspended impurities in the wastewater are further removed, and finally, after testing, the wastewater meets the discharge standards. At the same time, by adjusting the parameters such as the dosage of the reagent, the electrolysis voltage and current, and the adsorption and filtration materials, the treatment requirements of different wastewaters can be met. The high-concentration dye wastewater treatment method provided by the present invention has strong adaptability to high-concentration disperse dye wastewater of different types and concentrations. Furthermore, the high-concentration dye wastewater treatment method provided by the present invention is easy to implement in a simple-structured device, does not require complex, large-scale equipment, and has the characteristics of low energy consumption and low cost.

[0015] In one or more embodiments, a coagulant is added at the same time as the flocculant in S1. The coagulant helps to aggregate and settle particles.

[0016] In one or more embodiments, the coagulant aid is Al2(SO4)3 at a concentration of 20-30 mg / L.

[0017] From the above description, it can be seen that the suspended particles and colloids in wastewater usually carry negative charges, and the aluminum ions in aluminum sulfate carry positive charges, which can neutralize the negative charges on the surface of suspended particles and colloids, thereby weakening the electrostatic repulsion between particles, making it easier for particles to aggregate together to form larger flocs, which is more conducive to subsequent sedimentation and solid-liquid separation.

[0018] In one or more embodiments, the flocculant is polyacrylamide at a concentration of 5-10 mg / L.

[0019] The concentrations of polyacrylamide and Al2(SO4)3 are designed primarily based on the composition of high-concentration dye wastewater commonly found in the textile industry. These concentrations can be adjusted based on the quality of the water being treated. After adding the reagents, the mixture is stirred and mixed, then stopped to allow sedimentation to flocculate and precipitate suspended particles and some dye molecules in the wastewater. For typical high-concentration disperse dye wastewater, a stirring speed of 30 to 60 r / min is recommended, and this rate can be adjusted based on the wastewater flow rate and concentration.

[0020] In one or more embodiments, in S2, an electric field is formed by connecting an anode plate and a cathode plate to a DC power supply via wires. The anode plate is a titanium-based lead dioxide electrode, and the cathode plate is a stainless steel electrode. The electrodes are connected to the DC power supply via wires. Under the action of the electric field, dye molecules and organic matter in the wastewater undergo redox reactions, breaking them down into small molecules, thereby reducing the color and organic matter content of the wastewater.

[0021] A titanium-based lead dioxide electrode is used as the anode. This electrode has a high oxygen evolution potential (approximately 1.75 V relative to a calomel electrode) and produces highly oxidizing hydroxyl radicals (·OH), significantly degrading organic matter. It also exhibits excellent corrosion resistance in acidic or neutral environments, making it suitable for treating complex wastewaters. While the initial investment cost of a titanium-based lead dioxide electrode is relatively high, its service life is 1.5 to 2 times that of traditional lead anodes, and the base material is reusable. Furthermore, the use of titanium-based lead dioxide anodes does not cause lead pollution, thus avoiding secondary environmental contamination by heavy metals. Furthermore, its current efficiency can reach 93 to 95%, a 4 to 5% improvement over traditional lead anodes, enhancing treatment efficiency. Its cell voltage is 5 to 8% lower than that of lead anodes, significantly saving energy.

[0022] Stainless steel electrodes are used as cathode plates. Stainless steel has excellent electrical conductivity, effectively conducting current and ensuring the smooth progress of electrochemical reactions. Stainless steel exhibits excellent corrosion resistance in aqueous solutions, making it adaptable to complex wastewater environments. Its high mechanical strength allows it to withstand certain physical and water impacts. Furthermore, stainless steel is relatively inexpensive and readily available, reducing overall treatment costs.

[0023] Commonly used anode electrodes include graphite electrodes, precious metal electrodes, boron-doped diamond electrodes, and titanium-based metal oxide electrodes, but these electrodes suffer from poor water treatment effects and high costs. Commonly used cathode electrodes include copper electrodes, nickel electrodes, and titanium electrodes, but these electrodes also suffer from poor water treatment effects and high costs.

[0024] In one or more embodiments, within a range of about 3 to 5 m 3 The electrolytic oxidation treatment area consists of a titanium-based lead dioxide anode plate measuring 300 mm × 400 mm × 5 mm and a stainless steel cathode plate measuring 300 mm × 400 mm × 3 mm, arranged in parallel with a spacing of 30 to 50 mm between them. This parallel arrangement increases the contact area between the wastewater and the electrodes. The electrolysis voltage is 10 to 15 V, the current density is 10 to 20 mA / cm², and the reaction time is 60 to 90 minutes.

[0025] In one or more embodiments, the activated carbon particle size is 0.2-3 mm, with 0.5-3 mm being common. The activated carbon is typically replaced every 3-6 months. Based on a comprehensive consideration of adsorption capacity, mechanical strength, and resistance to water flow, activated carbon with the above particle sizes achieves optimal treatment results.

[0026] In one or more embodiments, the quartz sand has a particle size of 0.2 to 1.2 mm, with 0.5 to 1.2 mm being common. The quartz sand is typically replaced every 1 to 2 years. Based on a comprehensive consideration of filtration efficiency, mechanical strength, and resistance to water flow, quartz sand with the above particle size achieves optimal treatment results.

[0027] In one or more embodiments, the filling ratio of activated carbon to quartz sand is 1-4:1-2. Furthermore, a filling ratio of 1:1 is more suitable for high-concentration dye wastewater with high suspended solids and organic content. A filling ratio of 2:1 is more suitable for high-concentration dye wastewater with high organic content but moderate suspended solids content. A filling ratio of 3:1 or 4:1 is more suitable for high-concentration dye wastewater with high organic content and low suspended solids content. More specifically, when the organic concentration is high (COD > 5000 mg / L), the chroma is high (> 2000 degrees), and the suspended solids content is moderate (500-1000 mg / L), a filling ratio of 2:1-3:1 can be selected to effectively remove organic matter and dye molecules while ensuring a certain filtration effect. When the organic concentration is low (COD < 2000 mg / L) and the suspended solids content is high (> 1000 mg / L), a filling ratio of 1:1-1:2 can be selected to better remove suspended solids while also ensuring the adsorption of organic matter. When the organic matter concentration and suspended solids content are at medium levels (COD 2000 ~ 5000 mg / L, suspended solids 500 ~ 1000 mg / L), the filling ratio can be selected as 1:1 ~ 2:1 to balance the needs of adsorption and filtration.

[0028] In one or more embodiments, S1 is performed in the pretreatment zone, S2 is performed in the electrolytic oxidation zone, S3 is performed in the adsorption filtration zone, and S4 is performed in the clean water collection zone.

[0029] From the above description, it can be seen that partitioning each step is conducive to achieving functional partitioning, improving processing efficiency and quality, and avoiding mutual interference between different processing links; at the same time, it is easy to manage and maintain.

[0030] Please refer to Figure 1 , S1~S4 are carried out in a high-concentration dye wastewater treatment device, which includes a tank body, and the tank body is sequentially provided with a pretreatment area, an electrolytic oxidation area, an adsorption filtration area and a clean water collection area from bottom to top; The volume of the pretreatment zone accounts for 15~20% of the total volume of the tank, the volume of the electrolytic oxidation zone accounts for 30~35% of the total volume of the tank, the volume of the adsorption and filtration zone accounts for 30~35% of the total volume of the tank, and the volume of the clean water collection zone accounts for 10~15% of the total volume of the tank.

[0031] As can be seen from the above description, the tank body is cylindrical, with a cylindrical structure being preferred, as it reduces dead angles and ensures smooth water flow. The tank body is a one-piece structure, with various areas connected by pipes within the tank. The preferred material for the tank body is fiberglass reinforced plastic, which has a corrosion resistance coefficient exceeding 0.95 and offers excellent chemical resistance, effectively preventing wastewater erosion and extending the equipment's service life.

[0032] The primary function of the pretreatment zone is to remove suspended particles and some dye molecules from the wastewater through flocculation and sedimentation, reducing the load on subsequent treatment. On the one hand, the flocculation and sedimentation processes in the pretreatment stage typically take a short time, approximately 30 to 40 minutes, and do not require a large volume. On the other hand, flocculation and sedimentation primarily target large suspended particles and some precipitable dye molecules in the wastewater, resulting in relatively high treatment efficiency and requiring no excessive reaction space. A design of 15-20% ensures that the wastewater can complete initial treatment quickly before entering the subsequent treatment zone, while leaving ample space for subsequent treatment.

[0033] The primary function of the electrolytic oxidation zone is to decompose dye molecules and organic matter in the wastewater into small molecules through electrochemical reactions, thereby reducing the wastewater's color and chemical oxygen demand (COD). The electrolytic oxidation reaction takes a long time, approximately 60-90 minutes, necessitating a large volume to ensure sufficient wastewater retention time in the zone. Furthermore, electrolytic oxidation is a relatively complex chemical process, requiring ample space to ensure adequate contact between the wastewater and the electrodes, thereby improving treatment efficiency. A design of 30-35% ensures that the electrolytic oxidation reaction can proceed adequately after the initial treatment of the wastewater through flocculation and sedimentation. The primary function of the adsorption and filtration zone is to remove residual dye molecules and small organic matter from the wastewater using activated carbon and quartz sand, further reducing the wastewater's color and COD. The adsorption and filtration process requires a certain residence time, approximately 30-60 minutes, to ensure sufficient adsorption and filtration of pollutants in the wastewater. However, the adsorption and filtration capacity of activated carbon and quartz sand is limited, requiring sufficient filling height and volume to ensure effective treatment. The adsorption and filtration zone is located above the electrolytic oxidation zone. Its larger volume ensures further treatment of wastewater after electrolytic oxidation while leaving ample space for the clean water collection area. The 30-35% design balances the adsorption material's lifespan with replacement costs. This rational volume design effectively extends the adsorption material's lifespan and reduces operating costs.

[0034] The clean water collection area is primarily used to temporarily store treated clean water. Its short residence time reduces the need for excessive volume. This smaller volume ensures that the water quality testing device can quickly detect the water quality and promptly initiate a return flow operation if the water quality does not meet standards. Furthermore, the clean water collection area, located at the top of the tank, maintains a compact overall layout while leaving ample space for other treatment areas.

[0035] The high-concentration dye wastewater treatment device is fully compatible with the treatment process (high-concentration dye wastewater treatment method) of this invention. Each zone is rationally arranged within a single tank, resulting in a simple overall structure and ease of operation and maintenance. The vertical layout effectively reduces the equipment footprint while ensuring that the water flows upward from bottom to top, ensuring sufficient contact and reaction between each layer. This device offers significant advantages in terms of floor space, sedimentation efficiency, operating costs, treatment effectiveness, adaptability, and operational reliability.

[0036] In one or more embodiments, a stirring device is provided in the pretreatment zone; an anode plate and a cathode plate are provided in the electrolytic oxidation zone; the adsorption filtration zone is filled with adsorption filtration material; the clean water collection zone is provided with an outlet pipe and a return pipe, and the return pipe is connected to the pretreatment zone.

[0037] In one or more embodiments, an inclined tube sedimentation device is further provided in the pretreatment area. The inclined tube sedimentation device is provided at the bottom of the pretreatment area, below the stirring device. The pretreatment area is provided with a mud discharge port, which is connected to the inclined tube sedimentation device. After stirring by the stirring device, the stirring device is first turned off to carry out sedimentation. The precipitated wastewater is separated into solid and liquid through the inclined tube sedimentation device, and the precipitated sludge enters the mud discharge pipe through the mud discharge port for discharge. The mud discharge pipe is provided with a valve for regular mud discharge operations. A vibration device can also be further provided on the outside of the bottom of the tank body. The vibration device is turned on so that the flocculent sediment on the inclined plate that has not fallen into the mud discharge pipe is shaken off into the mud discharge pipe, so as to better collect and discharge the sediment.

[0038] In one or more embodiments, an aeration device is further provided in the electrolytic oxidation zone. The aeration device is provided at the bottom of the electrolytic oxidation zone, below the anode plate and the cathode plate. Aeration can increase the dissolved oxygen in the wastewater, improve the efficiency of electrolytic oxidation, and at the same time play a stirring role so that the wastewater is fully in contact with the electrodes. Furthermore, the aeration device is composed of an aeration pipe and an air pump. The aeration pipe is distributed at the bottom of the electrolytic oxidation zone and is connected to the air pump outside the tank body, such as at a height of about 3 to 5 m. 3 The electrolytic oxidation treatment zone can be equipped with aeration tubes with a pore diameter of 2-3 mm, a pore spacing of 50-100 mm, an air pump power of 0.5-1.0 kW, and an aeration flow rate of 0.5-1.0 m³ / h. Furthermore, the electrolytic oxidation zone is equipped with a cooling or heating device to assist in regulating the wastewater temperature, keeping it within a range of 20-40°C.

[0039] In one or more embodiments, a water distribution device is provided in the adsorption and filtration zone and is installed at the bottom of the adsorption and filtration zone so that the wastewater from the electrolytic oxidation zone passes through the adsorption and filtration material evenly.

[0040] In one or more embodiments, the water distribution device is a porous plate structure, such as a porous plate with a pore size of 5 to 10 mm, a pore spacing of 100 to 150 mm, and an adsorption filtration time of 30 to 60 min.

[0041] In one or more embodiments, a water quality detection device is provided in the clean water collection area to monitor the effluent quality in real time. The test indicators include chromaticity, chemical oxygen demand (COD), pH value, turbidity, etc.

[0042] In one or more embodiments, the pipes used for communication at various locations are preferably made of corrosion-resistant PVC or HDPE, with a diameter of DN100 to DN150 mm, and are connected by hot melt connection or flange connection.

[0043] The first embodiment of the present invention is: A method for treating high-concentration dye wastewater comprises the following steps: S1. In the pretreatment area, flocculants and coagulants are added to the wastewater to be treated (COD of 15,000 mg / L, chroma of 3,000 degrees, suspended solids content (SS) of 800 mg / L, total organic carbon (TOC) of 2,000 mg / L, and pH of 8.5). The wastewater is stirred for 15 minutes and then settled for 30 minutes. The solid-liquid separation is then performed to obtain the first treated liquid and sludge. Among them, the flocculant is polyacrylamide with a concentration of 10 mg / L; the coagulant aid is Al2(SO4)3 with a concentration of 25 mg / L; S2. In the electrolytic oxidation zone, a titanium-based lead dioxide electrode and a stainless steel electrode are connected to a DC power supply via a wire to form an electric field. An aeration device is provided below the titanium-based lead dioxide electrode and the stainless steel electrode. Under the action of aeration and the electric field, the first treatment liquid is electrolytically oxidized to obtain a second treatment liquid. The electrolysis voltage was 15 V, the current density was 20 mA / cm², the reaction time was 60 min, and the aeration flow rate was 1 m³ / h. S3. In the adsorption filtration zone, the second treated liquid is sequentially subjected to adsorption filtration by activated carbon and quartz sand for 45 minutes to obtain a third treated liquid; The filling ratio of activated carbon and quartz sand in the adsorption and filtration area is 4:1, the particle size of the activated carbon is 0.42~1.42mm, and the particle size of the quartz sand is 0.42~0.85mm; S4. In the clean water collection area, the third treated liquid is tested. If it meets the discharge or reuse standards, it is discharged. If it does not meet the discharge or reuse standards, S1 to S3 are repeated for reprocessing until it meets the discharge or reuse standards. After testing, the effluent treated once by S1~S4 has a COD of 160 mg / L, a chromaticity of 30 degrees, a suspended solid content (SS) of 15 mg / L, a total organic carbon (TOC) of 30 mg / L, and a pH value of 7.0.

[0044] Please refer to Figure 1 , the second embodiment of the present invention is: A high-concentration dye wastewater treatment device includes a cylindrical tank body, which is sequentially provided with a pretreatment area, an electrolytic oxidation area, an adsorption and filtration area, and a clean water collection area from bottom to top; The volume of the pretreatment area accounts for 20% of the total volume of the tank, the volume of the electrolytic oxidation area accounts for 35% of the total volume of the tank, the volume of the adsorption and filtration area accounts for 35% of the total volume of the tank, and the volume of the clean water collection area accounts for 10% of the total volume of the tank; The pretreatment area is equipped with a stirring device and an inclined tube settling device. The stirring device includes a motor, a stirring shaft connected to the motor, and a stirring paddle mounted on the stirring shaft. The motor is located outside the tank, while the majority of the stirring shaft and stirring paddle are located inside the tank. The inclined tube settling device is located at the bottom of the pretreatment area, below the stirring device. The pretreatment area is equipped with a mud discharge port, which is connected to the inclined tube settling device and has a mud discharge pipe with a valve installed on it. The electrolytic oxidation zone is equipped with an aeration device, anode plates, and cathode plates. The aeration device is located at the bottom of the electrolytic oxidation zone, below the anode plates and cathode plates. The aeration device consists of an aeration pipe and an air pump. The aeration pipe is distributed at the bottom of the electrolytic oxidation zone and is connected to the air pump outside the tank. A water distribution device is provided in the adsorption and filtration area, and the water distribution device is a porous plate structure; above the water distribution device are arranged in sequence an activated carbon filling area and a quartz stone filling area; The clean water collection area is provided with an outlet pipe and a return pipe. The return pipe is connected to the pretreatment area. Valves are provided on both the outlet pipe and the return pipe. A water quality detection device is provided in the clean water collection area.

[0045] The third embodiment of the present invention is: A method for treating high-concentration dye wastewater, using the high-concentration dye wastewater treatment device of Example 2 to treat high-concentration dye wastewater, specifically comprising the following steps: S1. In the pretreatment area, flocculants and coagulants are added to the wastewater to be treated (COD: 8000 mg / L, chroma: 2000 degrees, SS: 500 mg / L, TOC: 1200 mg / L, pH: 7.5). The wastewater is stirred for 20 minutes and then settled for 40 minutes. The solid-liquid separation is then performed to obtain the first treated liquid and sludge. Among them, the flocculant is polyacrylamide with a concentration of 5 mg / L; the coagulant aid is Al2(SO4)3 with a concentration of 20 mg / L; S2. In the electrolytic oxidation zone, a titanium-based lead dioxide electrode and a stainless steel electrode are connected to a DC power supply via a wire to form an electric field. Under the action of aeration and the electric field, the first treatment liquid is electrolytically oxidized to obtain a second treatment liquid. The electrolysis voltage is 10 V, the current density is 10 mA / cm², the reaction time is 90 min, and the aeration flow rate is 0.5 m³ / h. S3. In the adsorption filtration zone, the second treated liquid is sequentially subjected to adsorption filtration by activated carbon and quartz sand for 45 minutes to obtain a third treated liquid; The filling ratio of activated carbon and quartz sand in the adsorption and filtration area is 3.5:1, the particle size of the activated carbon is 0.25~0.85mm, and the particle size of the quartz sand is 0.25~0.5mm; S4. In the clean water collection area, the third treated liquid is tested. If it meets the discharge or reuse standards, it is discharged. If it does not meet the discharge or reuse standards, S1 to S3 are repeated for reprocessing until it meets the discharge or reuse standards. After testing, the effluent treated once by S1~S4 has a COD of 150 mg / L, a chromaticity of 30 degrees, a SS of 20 mg / L, a TOC of 35 mg / L, and a pH of 7.2.

[0046] The fourth embodiment of the present invention is: A method for treating high-concentration dye wastewater, using the high-concentration dye wastewater treatment device of Example 2 to treat the high-concentration dye wastewater, specifically comprising the following steps: S1, in a pretreatment zone, adding a flocculant and a coagulant aid to the wastewater to be treated, stirring for 18 minutes and then settling for 35 minutes, and then performing solid-liquid separation to obtain a first treated liquid and sludge; Among them, the flocculant is polyacrylamide with a concentration of 8 mg / L; the coagulant aid is Al2(SO4)3 with a concentration of 30 mg / L; S2. In the electrolytic oxidation zone, a titanium-based lead dioxide electrode and a stainless steel electrode are connected to a DC power supply via a wire to form an electric field. Under the action of aeration and the electric field, the first treatment liquid is electrolytically oxidized to obtain a second treatment liquid. The electrolysis voltage was 12 V, the current density was 15 mA / cm², the reaction time was 80 min, and the aeration flow rate was 0.8 m³ / h. S3. In the adsorption filtration zone, the second treated liquid is sequentially subjected to adsorption filtration by activated carbon and quartz sand for 45 minutes to obtain a third treated liquid; The filling ratio of activated carbon and quartz sand in the adsorption and filtration area is 2:1, the particle size of the activated carbon is 0.71~2.38mm, and the particle size of the quartz sand is 0.85~1.2mm; S4. In the clean water collection area, the third treated liquid is tested. If it meets the discharge or reuse standards, it is discharged. If it does not meet the discharge or reuse standards, S1 to S3 are repeated for reprocessing until it meets the discharge or reuse standards.

[0047] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent transformations made using the contents of the present invention's description and drawings, or directly or indirectly applied in related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for treating high-concentration dye wastewater, characterized in that: The following steps are involved: S1. Adding a flocculant to the wastewater to be treated, stirring and mixing, and then settling, and then performing solid-liquid separation to obtain a first treated liquid and sludge; S2. Under the action of an electric field, electrolytically oxidizing the first treatment liquid to obtain a second treatment liquid; S3, the second treatment liquid is sequentially adsorbed by activated carbon and quartz sand to obtain a third treatment liquid; S4. The third treated liquid is tested. If it meets the discharge or reuse standards, it is discharged. If it does not meet the discharge or reuse standards, S1 to S3 are repeated for reprocessing until it meets the discharge or reuse standards.

2. The method for treating high-concentration dye wastewater according to claim 1, wherein: In S1, a coagulant aid is added at the same time as the flocculant.

3. The method for treating high-concentration dye wastewater according to claim 2, wherein: The coagulant aid is Al2(SO4)3 with a concentration of 20-30 mg / L.

4. The method for treating high-concentration dye wastewater according to claim 1, wherein The flocculant is polyacrylamide with a concentration of 5-10 mg / L.

5. The method for treating high-concentration dye wastewater according to claim 1, wherein: In S2, an electric field is formed by connecting the anode plate and the cathode plate to a DC power supply through wires.

6. The method for treating high-concentration dye wastewater according to claim 1, wherein The particle size of the activated carbon is 0.2 to 3 mm.

7. The method for treating high-concentration dye wastewater according to claim 1, wherein The particle size of the quartz sand is 0.2-1.2 mm.

8. The method for treating high-concentration dye wastewater according to claim 1, wherein: S1 is carried out in the pretreatment area, S2 is carried out in the electrolytic oxidation area, S3 is carried out in the adsorption filtration area, and S4 is carried out in the clean water collection area.

9. The method for treating high-concentration dye wastewater according to any one of claim 8, wherein: S1 to S4 are carried out in a high-concentration dye wastewater treatment device, which includes a tank body, which is sequentially provided with a pretreatment area, an electrolytic oxidation area, an adsorption and filtration area, and a clean water collection area from bottom to top; The volume of the pretreatment zone accounts for 15-20% of the total volume of the tank body, the volume of the electrolytic oxidation zone accounts for 30-35% of the total volume of the tank body, the volume of the adsorption and filtration zone accounts for 30-35% of the total volume of the tank body, and the volume of the clean water collection zone accounts for 10-15% of the total volume of the tank body.

10. The method for treating high-concentration dye wastewater according to claim 9, characterized in that: The pretreatment area is provided with a stirring device; the electrolytic oxidation area is provided with an anode plate and a cathode plate; the adsorption filtration area is filled with activated carbon and quartz sand; the clean water collection area is provided with a water outlet pipe and a return pipe, and the return pipe is connected to the pretreatment area.

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