A device for removing refractory organic matter from wastewater

Abstract

This invention belongs to the technical field of wastewater treatment devices, and specifically relates to a device for removing recalcitrant organic matter from wastewater. The technical solution is as follows: a device for removing recalcitrant organic matter from wastewater includes, from bottom to top, an inlet regulating unit, an inlet pressurizing and distributing unit, a rectifier unit, and an electrocatalytic core treatment unit; the inlet regulating unit is equipped with an S-ZVI inlet, a wastewater inlet, and an oxidant inlet, and the electrocatalytic core treatment unit is equipped with a drain outlet. This invention provides a device for efficiently removing recalcitrant organic matter from wastewater through electrocatalytic enhancement of zero-valent iron sulfide.

Description

Technical Field

[0001] This invention belongs to the technical field of wastewater treatment devices, and specifically relates to a device for removing recalcitrant organic matter from wastewater. Background Technology

[0002] This invention relates to a process and apparatus for removing recalcitrant organic matter from high-fluoride and high-salinity wastewater using electrocatalytically enhanced zero-valent iron sulfide. It primarily aims to address key technological bottlenecks in the field of advanced industrial wastewater treatment. Wastewater generated in industries such as semiconductors, petrochemicals, and pesticides typically exhibits characteristics including fluoride ion concentrations of 500–2000 mg / L, conductivity as high as 20–50 mS / cm, COD concentrations of 1000–5000 mg / L, BOD concentrations of 500–1000 mg / L, and SS concentrations of 800–1000 mg / L. These complex water quality conditions severely limit the application of traditional treatment processes.

[0003] Currently, mainstream technologies face numerous challenges in treating this type of wastewater. While chemical precipitation is simple to operate, its removal efficiency for recalcitrant organic matter is unsatisfactory, and it generates large amounts of chemical sludge requiring secondary treatment. Traditional Fenton oxidation processes require continuous addition of large amounts of hydrogen peroxide, resulting in high operating costs and significantly reduced oxidation efficiency in high-salt environments. Biological treatment processes suffer from the dual inhibition of high salt and high fluoride ion levels, making it difficult to maintain microbial activity. Membrane separation technology, due to membrane fouling and scaling issues, requires frequent cleaning and replacement, leading to excessively high operating and maintenance costs.

[0004] The closest approach, the sulfidation-based zero-valent iron / hydrogen peroxide treatment system, while improving the stability of zero-valent iron through sulfidation modification, still fails to completely solve the problem of material deactivation under high-salt conditions. Furthermore, the continuous increase in hydrogen peroxide dosage significantly increases operating costs. This technology also has limited effectiveness in removing fluoride ions, failing to meet stringent emission standards. Simultaneously, the reaction process lacks precise control, making it difficult to adapt to fluctuations in influent water quality.

[0005] In summary, the existing technology has the following disadvantages:

[0006] First, there are issues with poor material stability and short lifespan: In existing technologies, zero-valent iron is prone to passivation and agglomeration under high-salt conditions, leading to a reduction in active sites and a rapid decline in reaction efficiency. Although traditional surface modification methods can improve material stability to some extent, the effect is not ideal, and the catalyst lifespan is generally short.

[0007] Secondly, there are problems with low treatment efficiency and high energy consumption: Traditional processes such as Fenton oxidation and electrochemical oxidation often require the addition of large amounts of oxidant or the application of high voltage to achieve the desired treatment effect when treating high-salt and high-fluoride wastewater. This not only results in high energy consumption but also low treatment efficiency.

[0008] Third, the technology suffers from poor adaptability to water quality and weak resistance to interference: Existing technologies are highly sensitive to fluctuations in influent water quality, especially under complex water conditions such as high salinity and high fluoride, where the treatment effect is often not stable enough.

[0009] Fourth, the problem of poor fluoride ion removal efficiency: Conventional processes are generally not ideal for removing fluoride ions, especially in high-salt environments, where the removal rate of fluoride ions often fails to meet emission standards.

[0010] Fifth, the problem of complex processes and low automation: Traditional processes often require frequent adjustment of operating parameters, which makes the operation complex and has a low degree of automation. Summary of the Invention

[0011] In order to solve the above-mentioned problems in the prior art, the purpose of this invention is to provide a device for efficiently removing recalcitrant organic matter from wastewater by electrocatalytically enhancing zero-valent iron sulfide.

[0012] The technical solution adopted in this invention is as follows:

[0013] An apparatus for removing recalcitrant organic matter from wastewater includes, from bottom to top, an inlet regulating unit, an inlet pressurizing and distributing unit, a rectifier unit, and an electrocatalytic core treatment unit; the inlet regulating unit is provided with an S-ZVI inlet, a wastewater inlet, and an oxidant inlet, and the electrocatalytic core treatment unit is provided with a drain outlet.

[0014] This invention aims to develop an integrated treatment process capable of efficiently removing recalcitrant organic matter under high-salt and high-fluoride conditions, exhibiting good material stability, low operating costs, high intelligence, and waste gas resource recovery capabilities. This process aims to meet the increasingly stringent environmental and economic requirements in the industrial wastewater treatment field. During wastewater treatment, nano-S-ZVI material is added through the S-ZVI inlet, wastewater is added through the wastewater inlet, and oxidant is added through the oxidant inlet. The mixed liquid is then sequentially processed through an inlet regulating unit, an inlet pressurizing and distributing unit, a rectification unit, and an electrocatalytic core treatment unit, effectively removing recalcitrant organic matter from high-fluoride and high-salt wastewater.

[0015] This invention successfully solves the material stability problem through an innovative sulfidation-modified zero-valent iron process and a new processing device, thereby increasing the catalyst's service life by more than 50% and significantly reducing operating costs.

[0016] This invention organically combines zero-valent iron sulfide with electrocatalytic technology. By optimizing the electrode structure and process parameters, it can achieve efficient COD removal under low energy consumption conditions, improving the treatment efficiency by more than 30%.

[0017] Through innovative process design, this invention enables the system to have strong resistance to shock loads. Even when the influent water quality fluctuates greatly, it can still maintain a stable treatment effect, and all indicators of the effluent can consistently meet the standards.

[0018] This invention significantly improves the removal efficiency of fluoride ions through sulfidation modification and electrocatalytic enhancement, achieving a removal rate of over 85%, which is far higher than that of traditional processes.

[0019] In a preferred embodiment of the present invention, the water inlet regulating unit includes a water inlet regulating cylinder, which is connected to the lower side of the liquid inlet pressurization and dispensing unit. The S-ZVI inlet, wastewater inlet, and oxidant inlet are all connected to the water inlet regulating cylinder, and an ultrasonic disperser is installed inside the water inlet regulating cylinder. The ultrasonic disperser can fully disperse and mix the S-ZVI, wastewater, and oxidant added to the water inlet regulating cylinder.

[0020] In a preferred embodiment of the present invention, the liquid inlet pressurizing and distributing unit includes a pressurizing and distributing cylinder, which is connected between the water inlet regulating unit and the rectifying unit. A nozzle fixing plate is installed inside the pressurizing and distributing cylinder. A pressurizing impeller is rotatably connected to the lower side of the nozzle fixing plate, and several oblique nozzles are arranged on the upper side of the nozzle fixing plate. The pressurizing impeller rotates in a fixed direction, generating upward pressure on the wastewater; simultaneously, it further mixes the wastewater. The liquid swirls within the cavity through the several oblique nozzles, allowing the materials to mix more thoroughly and flow upwards.

[0021] As a preferred embodiment of the present invention, the flow rate of the plurality of angled nozzles decreases sequentially from the inner ring to the outer ring.

[0022] In a preferred embodiment of the present invention, the rectifying unit includes a rectifying cylinder connected between the liquid inlet pressurization and dispensing unit and the electrocatalytic core treatment unit. A water pipe is provided in the middle of the cylinder, and rectifying spirals are arranged on the outer wall of the water pipe. The number of rectifying spiral layers is determined according to the average wastewater treatment flow rate, and the material is rectified by the determined number of rectifying spiral layers. The flow rate and velocity are larger at the edge, while the flow rate and velocity are smaller in the middle. By providing a water pipe in the middle to directly connect the middle section, the head loss in the middle section is reduced.

[0023] As a preferred embodiment of the present invention, the electrocatalytic core processing unit includes an electrocatalytic cylinder, a cathode is installed in the middle of the electrocatalytic cylinder, a drain outlet is located at the top of the cathode, and an anode assembly is provided on the outer sleeve of the cathode.

[0024] The interaction between the cathode liquid and the anode assembly enables thorough electrocatalytic treatment of wastewater. This invention organically combines zero-valent iron sulfide with electrocatalytic technology. By optimizing the electrode structure and process parameters, it achieves highly efficient COD removal under low energy consumption conditions, increasing treatment efficiency by more than 30%. Through sulfide modification and enhanced electrocatalysis, this invention significantly improves the removal efficiency of fluoride ions, achieving a removal rate of over 85%, far exceeding the level of traditional processes.

[0025] As a preferred embodiment of the present invention, the anode assembly includes two layers of anode plate supports, with an inner anode plate mounted on the inner anode plate support and an outer anode plate mounted on the outer anode plate support.

[0026] In a preferred embodiment of the present invention, the upper section of the electrocatalytic cylinder is connected to a plurality of integrated water quality detection probes. These integrated water quality detection probes detect the pH, DO, temperature, and other properties of the treated wastewater.

[0027] As a preferred embodiment of the present invention, the upper section of the electrocatalytic cylinder is connected to several temporary drain ports. These temporary drain ports can discharge liquid in cases of excessive flow.

[0028] In a preferred embodiment of the present invention, a heating pipe is wound around the outer wall of the electrocatalytic cylinder, and a wastewater inlet is connected to a wastewater pipe. One end of the heating pipe is connected to the wastewater pipe. The electrocatalytic unit releases heat, which is used to heat the heating pipe, thereby heating the wastewater fed into the inlet regulating unit and improving the wastewater treatment effect.

[0029] The beneficial effects of this invention are as follows:

[0030] 1. The present invention, with its sequentially arranged inlet water regulating unit, inlet pressurization and dispensing unit, rectification unit, and electrocatalytic core treatment unit, successfully solves the material stability problem through an innovative sulfide-modified zero-valent iron process and a novel treatment device, increasing catalyst lifespan by more than 50% and significantly reducing operating costs. The present invention also innovatively designs a multi-stage composite waste gas treatment system, which not only achieves efficient waste gas treatment but also reduces treatment costs through resource utilization.

[0031] 2. This invention incorporates nano-S-ZVI material into the influent conditioning unit and performs electrocatalytic treatment on the wastewater through an electrocatalytic core treatment unit. It organically combines zero-valent iron sulfide with electrocatalytic technology. By optimizing the electrode structure and process parameters, it achieves highly efficient COD removal under low energy consumption conditions, increasing treatment efficiency by more than 30%. This invention significantly improves the removal efficiency of fluoride ions through sulfide modification and electrocatalytic enhancement, achieving a removal rate of over 85%, far exceeding the level of traditional processes.

[0032] 3. This invention is equipped with an inlet water regulating unit, an inlet liquid pressurization and dispensing unit, and a rectification unit. Through innovative process design, the system has a strong resistance to shock loads. Even when the inlet water quality fluctuates greatly, it can still maintain a stable treatment effect, and all indicators of the effluent can stably meet the standards. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the cross-sectional structure in the first direction of the present invention;

[0034] Figure 2 This is a schematic diagram of the cross-sectional structure in the second direction of the present invention;

[0035] Figure 3 This is a schematic diagram of the water inlet regulating unit;

[0036] Figure 4 This is a schematic diagram of the liquid inlet pressurization and dispensing unit in the first direction;

[0037] Figure 5 This is a schematic diagram of the second direction of the liquid inlet pressurization and dispensing unit;

[0038] Figure 6 This is a cross-sectional view of the rectifier unit;

[0039] Figure 7 This is a schematic diagram of the electrocatalytic core processing unit;

[0040] Figure 8 This is a schematic diagram of the cathode and anode assembly.

[0041] In the diagram: 1-Water inlet regulating unit; 2-Liquid inlet pressurization and dispensing unit; 3-Rectifying unit; 4-Electrocatalytic core treatment unit; 11-Water inlet regulating cylinder; 12-S-ZVI inlet; 13-Wastewater inlet; 14-Oxidant inlet; 15-Wastewater pipeline; 16-Ultrasonic disperser; 21-Pressing and dispensing cylinder; 22-Nozzle fixing plate; 23-Pressing impeller; 24-Angled nozzle; 31-Rectifying cylinder; 32-Water pipeline; 33-Rectifying spiral; 41-Electrocatalytic cylinder; 42-Cathode; 43-Drain outlet; 44-Anode plate support; 45-Inner anode plate; 46-Outer anode plate; 47-Integrated water quality detection probe; 48-Temporary drain outlet; 49-Heating pipeline. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0043] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention. It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of the invention can be combined with each other.

[0044] like Figure 1 and Figure 2 As shown, the device for removing recalcitrant organic matter from wastewater in this embodiment includes, from bottom to top, an inlet regulating unit 1, an inlet pressurizing and spreading unit 2, a rectifier unit 3, and an electrocatalytic core treatment unit 4; the inlet regulating unit 1 is provided with an S-ZVI inlet 12, a wastewater inlet 13, and an oxidant inlet 14, and the electrocatalytic core treatment unit 4 is provided with a drain outlet 43.

[0045] This invention aims to develop an integrated treatment process capable of efficiently removing recalcitrant organic matter under high-salt and high-fluoride conditions, exhibiting good material stability, low operating costs, high intelligence, and waste gas resource recovery capabilities, to meet the increasingly stringent environmental and economic requirements in the field of industrial wastewater treatment. During wastewater treatment, nano-S-ZVI material is added through the S-ZVI inlet 12, wastewater is added through the wastewater inlet 13, and oxidant is added through the oxidant inlet 14. The mixed liquid is then sequentially processed through the inlet regulating unit 1, the inlet pressurizing and spreading unit 2, the rectification unit 3, and the electrocatalytic core treatment unit 4, effectively removing recalcitrant organic matter from high-fluoride and high-salt wastewater.

[0046] This invention successfully solves the material stability problem through an innovative sulfidation-modified zero-valent iron process and a new processing device, thereby increasing the catalyst's service life by more than 50% and significantly reducing operating costs.

[0047] This invention organically combines zero-valent iron sulfide with electrocatalytic technology. By optimizing the electrode structure and process parameters, it can achieve efficient COD removal under low energy consumption conditions, improving the treatment efficiency by more than 30%.

[0048] Through innovative process design, this invention enables the system to have strong resistance to shock loads. Even when the influent water quality fluctuates greatly, it can still maintain a stable treatment effect, and all indicators of the effluent can consistently meet the standards.

[0049] This invention significantly improves the removal efficiency of fluoride ions through sulfidation modification and electrocatalytic enhancement, achieving a removal rate of over 85%, which is far higher than that of traditional processes.

[0050] Specifically, such as Figure 3 As shown, the water inlet regulating unit 1 includes a water inlet regulating cylinder 11, which is connected to the lower side of the liquid inlet pressurization and dispensing unit 2. The S-ZVI inlet 12, wastewater inlet 13, and oxidant inlet 14 are all connected to the water inlet regulating cylinder 11. The wastewater inlet 13 is connected to a wastewater pipeline 15. An ultrasonic disperser 16 is installed inside the water inlet regulating cylinder 11. The ultrasonic disperser 16 can fully disperse and mix the S-ZVI, wastewater, and oxidant added to the water inlet regulating cylinder 11.

[0051] The nano-S-ZVI material is pre-mixed in deionized water to facilitate subsequent ultrasonic dispersion. The dosage is 2-5% of the wastewater COD, and a stepped dosing strategy is recommended. Initial stage (0-30 min): COD < 2000 mg / L: 2%; COD 2000-3500 mg / L: 2.5%; COD > 3500 mg / L: 3%. Intermediate stage (30-60 min): Adjust according to COD removal rate; removal rate < 40%: increase by 0.5%; removal rate > 60%: decrease by 0.3%. Late stage (> 60 min): Maintain the minimum effective dosage; monitor COD trends; it is recommended not to exceed 50% of the initial dosage.

[0052] The treated / untreated wastewater first passes through the electrocatalytic reaction zone, and after being appropriately heated, it enters the water distribution zone through the wastewater inlet 13.

[0053] The oxidant can be hydrogen peroxide, persulfate, perdisulfate, periodate, etc. Simultaneously, HCl or NaOH is added according to the pH of the influent wastewater to maintain the pH of the wastewater in the influent adjustment zone between 3 and 4.

[0054] Specifically, such as Figure 4 and Figure 5 As shown, the liquid inlet pressurization and dispensing unit 2 includes a pressurization and dispensing cylinder 21, which is connected between the water inlet regulating unit 1 and the rectifier unit 3. A nozzle fixing plate 22 is installed inside the pressurization and dispensing cylinder 21. A pressurization impeller 23 is rotatably connected to the lower side of the nozzle fixing plate 22, and a plurality of oblique nozzles 24 are provided on the upper side of the nozzle fixing plate 22.

[0055] The pressure impeller 23 rotates in a fixed direction, generating upward pressure on the wastewater; at the same time, it further mixes the wastewater. The liquid swirls within the cavity through several angled nozzles 24, allowing the materials to mix more thoroughly and flow upwards.

[0056] Several angled nozzles 24 have flow rates that decrease sequentially from the inner to the outer ring. Based on empirical parameters: the flow rate of the first ring nozzle is Q; the flow rate of the second ring nozzle is 1.05 to 1.1Q; the flow rate of the third ring nozzle is 1.2 to 1.4Q; and the flow rate of the fourth ring nozzle is 1.3 to 1.5Q.

[0057] Specifically, such as Figure 6 As shown, the rectifying unit 3 includes a rectifying cylinder 31, which is connected between the liquid inlet pressurization and dispensing unit 2 and the electrocatalytic core treatment unit 4. A water pipe 32 is provided in the middle of the cylinder, and rectifying spirals 33 are arranged on the outer wall of the water pipe 32. Based on the average wastewater treatment flow rate and existing test data, the number of rectifying spirals 33 is determined, and the material is rectified by the rectifying spirals 33 with the determined number of layers. The flow rate and velocity at the edge are larger, while the flow rate and velocity in the middle are smaller. By setting a water pipe 32 in the middle to directly connect the middle, the head loss in the middle is reduced.

[0058] The optimization of the number of 33 layers of the rectifier spiral is determined based on the hydraulic residence time (HRT):

[0059] Less than 5m 3 Daily processing capacity:

[0060] 1st floor: HRT = 4-6 hours, suitable for low pollution;

[0061] 2-layer: HRT = 6-8 hours, suitable for moderate pollution;

[0062] 3-layer: HRT = 8-10 hours, suitable for high pollution levels.

[0063] 5~10m 3 Daily processing capacity:

[0064] 3 layers: HRT = 3-4 hours, to ensure basic treatment effect;

[0065] 4 layers: HRT = 4-5 hours, improving processing efficiency;

[0066] 5 layers: HRT = 5-6 hours, for treating recalcitrant pollutants.

[0067] 10~20m 3 Daily processing capacity:

[0068] 6 floors: HRT = 2.5-3 hours, meeting basic needs;

[0069] 7 layers: HRT = 3-4 hours, improving processing efficiency;

[0070] 8 layers: HRT = 4-5 hours to ensure deep processing.

[0071] Specifically, such as Figure 7 and Figure 8 As shown, the electrocatalytic core processing unit 4 includes an electrocatalytic cylinder 41, a cathode 42 is installed in the middle of the electrocatalytic cylinder 41, a drain outlet 43 is located on the top of the cathode 42, and an anode assembly is installed on the outer sleeve of the cathode 42.

[0072] The cathode 42 is made of graphite with millimeter-sized pores, used to collect treated wastewater.

[0073] The current density of the anode assembly is 5–20 mA / cm². 2 :

[0074] The system is divided into sections based on different water quality conditions:

[0075] Low concentration pollutants (COD < 2000 mg / L): 5–8 mA / cm² 2 It avoids energy waste, reduces electrode wear, and is suitable for the degradation of common pollutants.

[0076] Medium concentration (COD 2000~3500mg / L): 8~15mA / cm 2 It provides sufficient oxidation capacity, maintains good current efficiency, and is suitable for most industrial wastewater.

[0077] High concentration pollutants (COD>3500mg / L): 15~20mA / cm 2 Ensures sufficient oxidative degradation capacity, suitable for treating recalcitrant organic matter, and recommends temperature control (35-40℃).

[0078] Specific selection criteria: Conductivity: For every 5 mS / cm increase, the conductivity can be reduced by 2–3 mA / cm. 2 Fluoride ion concentration: For every 500 mg / L increase, it is recommended to increase by 2–3 mA / cm². 2 Water temperature: For every 5°C increase, the flow rate decreases by 1–2 mA / cm². 2 .

[0079] The interaction between the cathode 42 liquid and the anode components enables thorough electrocatalytic treatment of wastewater. This invention organically combines zero-valent iron sulfide with electrocatalytic technology. By optimizing the electrode structure and process parameters, it achieves highly efficient COD removal under low energy consumption conditions, increasing treatment efficiency by more than 30%. Through sulfide modification and enhanced electrocatalysis, this invention significantly improves the removal efficiency of fluoride ions, achieving a removal rate of over 85%, far exceeding the level of traditional processes.

[0080] The anode assembly includes two anode plate supports 44. An inner anode plate 45 is mounted on the inner anode plate support 44, and an outer anode plate 46 is mounted on the outer anode plate support 44. The inner anode plate 45 is made of titanium-based conductive material; the outer anode plate 46 is made of RuO2-IrO2 / Ti, a titanium-based conductive material. Both the outer anode plate 46 and the inner anode plate 45 are arc-shaped, and their angles are adjustable.

[0081] The upper section of the electrocatalytic cylinder 41 is connected to two integrated water quality detection probes 47. These probes detect the pH, DO, and temperature of the treated wastewater. The upper section of the electrocatalytic cylinder 41 is also connected to two temporary drain ports 48. These ports allow for the discharge of liquid in cases of excessive flow.

[0082] Furthermore, a heating pipe 49 is wound around the outer wall of the electrocatalytic cylinder 41. One end of the heating pipe 49 is connected to the wastewater pipe 15, and the heating pipe 49 has high thermal conductivity. The electrocatalytic unit releases heat, which is used to heat the heating pipe 49, thereby heating the wastewater fed into the inlet water regulating unit 1 and improving the wastewater treatment effect.

[0083] Example 1 (Treatment of Low-Concentration Pollutants):

[0084] Influent water quality (sampled 3 times every 2 hours, average value): COD: 1832±127 mg / L; BOD: 587±43 mg / L; Fluoride ion: 778±65 mg / L; Conductivity: 24.7±1.8 mS / cm; SS: 863±72 mg / L; pH: 6.3~6.8

[0085] Operating parameters: S-ZVI dosage: 35.8±2.1 mg / L; Current density: 6.2±0.4 mA / cm² 2 ; Rectifier unit 3: 2 layers; HRT: 5.8 ± 0.3 hours; Temperature: 22~26℃.

[0086] Treatment results (continuous operation for 72 hours, sampling every 8 hours): COD: 162±28 mg / L (removal rate 91.2±1.8%); BOD: 35±5.2 mg / L (removal rate 94.1±1.2%); fluoride ions: 101±12 mg / L (removal rate 87.0±2.1%); SS: 42±6.8 mg / L (removal rate 95.1±1.4%).

[0087] Example 2 (Treatment of moderate concentrations of pollutants):

[0088] Influent water quality: COD: 3267±186mg / L; BOD: 812±58mg / L; Fluoride ion: 1478±112mg / L; Conductivity: 34.8±2.3mS / cm; SS: 938±81mg / L; pH: 7.0~7.5.

[0089] Operating parameters: S-ZVI dosage: 82.3±4.7 mg / L; Current density: 11.8±0.6 mA / cm² 2 Rectifier unit: 3-4 layers; HRT: 4.6 ± 0.2 hours; Temperature: 24~28℃.

[0090] Treatment results: COD: 408±45 mg / L (removal rate 87.5±2.2%); BOD: 89±11 mg / L (removal rate 89.1±1.8%); fluoride ions: 238±26 mg / L (removal rate 83.9±2.4%); SS: 62±8.9 mg / L (removal rate 93.4±1.6%).

[0091] Example 3 (Treatment of High Concentration Recalcitrant Pollutants):

[0092] Influent water quality: COD: 4756±243mg / L; BOD: 968±82mg / L; Fluoride ion: 1823±156mg / L; Conductivity: 44.3±3.1mS / cm; SS: 992±93mg / L; pH: 7.8~8.2.

[0093] Operating parameters: S-ZVI dosage: 142±7.8 mg / L; Current density: 17.6±0.9 mA / cm² 2 Rectifier unit 3: 6 layers; HRT: 3.2 ± 0.3 hours; Temperature: 37~39℃.

[0094] Treatment results: COD: 747±68 mg / L (removal rate 84.3±2.8%); BOD: 138±18.5 mg / L (removal rate 85.7±2.3%); fluoride ions: 327±34 mg / L (removal rate 82.1±2.7%); SS: 86±11.2 mg / L (removal rate 91.3±1.9%).

[0095] This invention is not limited to the above-described optional embodiments. Anyone can derive other various forms of products under the guidance of this invention. However, regardless of any changes made in their shape or structure, any technical solution that falls within the scope of the claims of this invention shall be protected by this invention.

Claims

1. A device for removing recalcitrant organic matter from wastewater, characterized in that: It includes, from bottom to top, an inlet water regulating unit (1), an inlet liquid pressurization and spreading unit (2), a rectifier unit (3), and an electrocatalytic core treatment unit (4); the inlet water regulating unit (1) is provided with an S-ZVI inlet (12), a wastewater inlet (13), and an oxidant inlet (14), and the electrocatalytic core treatment unit (4) is provided with a drain outlet (43); The liquid inlet pressurization and dispensing unit (2) includes a pressurization and dispensing cylinder (21), which is connected between the water inlet regulating unit (1) and the rectifier unit (3). A nozzle fixing plate (22) is installed inside the pressurization and dispensing cylinder (21). A pressurization impeller (23) is rotatably connected to the lower side of the nozzle fixing plate (22), and several oblique nozzles (24) are provided on the upper side of the nozzle fixing plate (22). The rectifier unit (3) includes a rectifier cylinder (31), which is connected between the liquid inlet pressurization and spreading unit (2) and the electrocatalytic core treatment unit (4). A water pipe (32) is provided in the middle of the cylinder, and a rectifier spiral (33) is arranged on the outer wall of the water pipe (32). The electrocatalytic core processing unit (4) includes an electrocatalytic cylinder (41), a cathode (42) is installed in the middle of the electrocatalytic cylinder (41), a drain outlet (43) is located on the top of the cathode (42), and an anode assembly is provided on the outer sleeve of the cathode (42). The anode assembly includes two anode plate supports (44), with an inner anode plate (45) mounted on the inner anode plate support (44) and an outer anode plate (46) mounted on the outer anode plate support (44); the inner anode plate (45) is made of titanium-based conductive material; the outer anode plate (46) is made of RuO2-IrO2 / Ti or titanium-based conductive material; the outer anode plate (46) and the inner anode plate (45) are arc-shaped. A heating pipe (49) is wound around the outer wall of the electrocatalytic cylinder (41), and a wastewater pipe (15) is connected to the wastewater inlet (13). One end of the heating pipe (49) is connected to the wastewater pipe (15). Nano-S-ZVI materials are pre-mixed in deionized water, with a dosage of 2-5% of the wastewater COD; a step-by-step dosing strategy is adopted. In the initial stage (0–30 min): when COD < 2000 mg / L, the dosage of nano-S-ZVI material is 2% of the wastewater COD; when COD is 2000–3500 mg / L, the dosage of nano-S-ZVI material is 2.5% of the wastewater COD; when COD > 3500 mg / L, the dosage of nano-S-ZVI material is 3% of the wastewater COD. During the intermediate stage of 30–60 min: when the COD removal rate is <40%, the dosage of nano-S-ZVI material increases by 0.5% of the wastewater COD; when the removal rate is >60%, the dosage of nano-S-ZVI material decreases by 0.3% of the wastewater COD. The later stage (>60 minutes): Do not exceed 50% of the initial dosage.

2. The apparatus for removing recalcitrant organic matter from wastewater according to claim 1, characterized in that: The water inlet regulating unit (1) includes a water inlet regulating cylinder (11), which is connected to the lower side of the liquid inlet pressurization and spreading unit (2). The S-ZVI inlet (12), wastewater inlet (13) and oxidant inlet (14) are all connected to the water inlet regulating cylinder (11), and an ultrasonic disperser (16) is installed inside the water inlet regulating cylinder (11).

3. The apparatus for removing recalcitrant organic matter from wastewater according to claim 1, characterized in that: The flow rate of several angled nozzles (24) decreases sequentially from the inner ring to the outer ring.

4. The apparatus for removing recalcitrant organic matter from wastewater according to claim 1, characterized in that: The upper section of the electrocatalytic cylinder (41) is connected to several integrated water quality detection probes (47).

5. The apparatus for removing recalcitrant organic matter from wastewater according to claim 1, characterized in that: The upper section of the electrocatalytic cylinder (41) is connected to several temporary drain ports (48).

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