An ozone catalytic oxidation-coagulation integrated device with adjustable catalyst dosage and composition

Abstract

The application discloses an ozone catalytic oxidation-coagulation integrated device capable of adjusting catalyst adding amount and composition, adopts an integrated structure of reaction pool and sedimentation pool nested inside and outside, the height of the reaction pool is lower than that of the sedimentation pool, a plurality of independent detachable screens are arranged in the reaction pool, the screens are filled with catalysts, handles are arranged at the top of the screens so as to facilitate flexible taking and placing, and thus the catalyst adding amount can be adjusted. Different kinds of catalysts can be filled in different screens, and multi-metal collaborative catalysis can be realized through adjustment and deployment. The screens effectively isolate the flocs formed in the coagulation process, and prevent the catalyst from being inactivated. Ozone, catalysts and coagulants are synergistically reacted under the stirring action, and organic matters are efficiently degraded. After reaction, the water flow carrying the flocs is naturally overflowed into the sedimentation pool by gravity, and solid-liquid separation is realized through the inclined plate; an overflow weir is arranged at the water outlet of the sedimentation pool, the height of the overflow weir is lower than the liquid level of the reaction pool, and the separated clean water can be smoothly discharged. The application has the advantages of compact structure, efficient reaction and flexible regulation and control, and is suitable for treating high-salinity organic wastewater.

Description

Technical Field

[0001] This invention belongs to the field of industrial wastewater deep treatment technology, and specifically relates to an ozone catalytic oxidation-coagulation integrated device with adjustable catalyst dosage and composition. Background Technology

[0002] High-salinity organic wastewater is a major challenge in industrial wastewater treatment, characterized by extremely high salinity and a complex coexistence of recalcitrant organic matter. This type of wastewater typically originates from various industries, including energy and chemical engineering, pharmaceuticals, printing and dyeing, and seawater desalination concentrates. Its salinity (based on total dissolved solids (TDS)) often exceeds 10,000 mg / L, and can even reach tens or hundreds of thousands of milligrams per liter. The main ions include Cl-. - SO4 2- Na + Ca 2+ Mg 2+ Meanwhile, the wastewater contains a large amount of recalcitrant organic matter, such as phenols, aromatics, halogenated hydrocarbons, dye intermediates, drug residues, and polycyclic aromatic hydrocarbons. Its chemical oxygen demand (COD) is typically in the hundreds to thousands of milligrams per liter, or even higher, and its biodegradability is poor (BOD5 / COD is often below 0.3). High-salt environments cause osmotic pressure stress, ion toxicity, and enzyme activity inhibition in microbial cells, leading to a severe decline in microbial metabolic activity, sludge floc disintegration, and a significant reduction or even failure of system treatment efficiency in traditional biological treatment systems (such as activated sludge and biofilm processes). Even if salinity is reduced through dilution, it significantly increases treatment costs and water consumption, and cannot fundamentally solve the problem of removing recalcitrant organic matter. Therefore, developing efficient and stable physicochemical or physicochemical-biochemical coupled processes has become an inevitable choice for treating high-salt organic wastewater.

[0003] Among numerous physicochemical treatment technologies, advanced oxidation processes (AOPs) have attracted considerable attention due to their ability to generate highly oxidizing free radicals (such as hydroxyl radicals ·OH), which can non-selectively degrade and even mineralize recalcitrant organic matter. Ozone catalytic oxidation technology combines ozone (O3) with a solid catalyst, catalyzing the decomposition of ozone to produce reactive oxygen species (ROS) such as ·OH, thereby significantly improving oxidation efficiency and the degree of organic matter mineralization. Compared with ozone oxidation alone, catalytic oxidation can more effectively destroy aromatic ring structures, break long-chain molecules, and improve ozone utilization. Commonly used catalysts include transition metal oxides (such as MnO2, Fe2O3, CuO, Co3O4), supported catalysts (such as activated carbon, Al2O3, and molecular sieve-supported metals), and heterogeneous composite catalysts developed in recent years. However, this technology still faces several prominent bottlenecks in practical engineering applications: one is the susceptibility of catalysts to fouling and deactivation. Suspended solids, colloids, and Ca²⁺ present in wastewater... + Mg² +First, ions of equal hardness and some organic intermediates easily deposit, adsorb, or form inorganic scale layers on the catalyst surface, covering active sites and causing a rapid decline in catalytic efficiency. Second, the catalyst composition is fixed, making it difficult to optimize and adjust according to changes in water quality. Third, mass transfer is limited. Ozone has low solubility in water, and gas-liquid mass transfer efficiency often restricts the overall reaction rate, requiring good mixing and contact conditions. Fourth, operating costs are high. Ozone generation consumes a lot of energy, and the regeneration or replacement of deactivated catalysts increases maintenance costs and operational complexity.

[0004] Meanwhile, coagulation, as a classic physicochemical treatment unit, can effectively remove colloidal particles, some dissolved organic matter, and color from wastewater by adding inorganic coagulants such as aluminum salts and iron salts or organic polymeric flocculants, forming flocs that are easy to settle and separate. Combining coagulation with advanced oxidation technology can achieve complementary advantages: the oxidation process can decompose large molecules and recalcitrant organic matter into smaller molecules and more polar intermediate products, improving their coagulability; coagulation can effectively capture tiny organic particles, colloids, and some intermediate products generated during oxidation, reducing effluent turbidity and COD, and may also enrich pollutants on the floc surface through adsorption, improving local oxidation efficiency.

[0005] However, in current engineering practices, the integration of ozone catalytic oxidation and coagulation processes often adopts a "series" model, that is, setting up independent catalytic oxidation reactors and coagulation sedimentation tanks, connected by pipelines, pumps, etc. Examples include patents CN207391147U and CN109775896A. This model has the following inherent drawbacks: First, the process flow is lengthy, requiring a large area and high infrastructure investment. Two independent units require their own structures, supporting equipment, and control instruments, increasing land occupation and construction costs. Second, during continuous operation, especially when treating high-concentration, high-suspended-solids wastewater, the flocs generated during the coagulation stage are easily carried into the catalytic oxidation unit by the reflux or water flow, adhering to and encapsulating catalyst particles, causing rapid surface contamination and shielding of active sites on the catalyst, leading to a sharp decline in catalytic efficiency. Frequent catalyst cleaning, regeneration, or replacement not only increases operating and maintenance costs but may also lead to production interruptions, affecting the continuous and stable operation of the system. Secondly, tandem systems often suffer from reaction timing mismatches, meaning that small molecule products after oxidation may not be effectively captured by subsequent coagulation, while coagulation pretreatment may alter the morphology of pollutants, affecting the subsequent catalytic oxidation effect. Furthermore, high salinity also impacts the coagulation process itself; for example, the salt effect may alter colloidal stability and interfere with floc formation, and existing tandem systems often lack synergistic optimization of fluid dynamics and reaction kinetics for high-salt environments.

[0006] Patent CN121405243A discloses a device and method for treating organic matter in high-salt wastewater by ozone catalytic oxidation coupled with coagulation. It adopts an integrated structure in which the reaction zone and sedimentation zone share the same wall, which can solve the problems caused by the series structure to a certain extent. However, it still lacks flexible catalyst adjustment methods, resulting in poor flexibility in the face of water quality fluctuations.

[0007] Therefore, the industry urgently needs a new type of processing device that can break through the limitations of the traditional series mode. Summary of the Invention

[0008] Addressing the technical bottlenecks in high-salt organic wastewater treatment, such as lengthy process flows, easy catalyst deactivation, difficulty in optimizing catalyst composition, and insufficient system stability, this invention aims to provide an integrated ozone catalytic oxidation-coagulation device and treatment method with adjustable catalyst dosage and composition. This solution achieves simultaneous, efficient, and synergistic effects of catalytic oxidation, coagulation reaction, and solid-liquid separation within a single device through reactor structure reconstruction and process integration. The core innovation of this invention lies in the introduction of independently detachable columnar screen units, allowing for rapid and flexible placement or removal of single or multiple screens. This enables precise adjustment of the total catalyst dosage based on the water quality and target. Simultaneously, by loading different types of catalysts (such as aluminum-based, manganese-based, copper-based, and iron-based catalysts) into different screens, flexible catalyst composition and multi-metal synergistic catalysis are achieved, significantly improving organic matter removal efficiency. The present invention aims to achieve the following overall objectives: to solve the key problem of catalyst deactivation due to floc attachment while significantly saving land area and infrastructure investment; to achieve optimized matching of the catalytic system through an adjustable mechanism for catalyst dosage and composition; to effectively improve the removal efficiency and system operation stability of high-salt recalcitrant organic matter by enhancing reaction mass transfer and process synergy; and finally, to reduce system energy consumption and maintenance costs through structural optimization and process integration, thereby achieving synergistic optimization of treatment efficiency and economy.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows: An integrated ozone catalytic oxidation-coagulation device with adjustable catalyst dosage and composition includes a reaction tank and a sedimentation tank nested inside and outside. The height of the reaction tank is lower than that of the sedimentation tank. A vertical baffle is installed in the sedimentation tank to separate the tank wall of the reaction tank from the tank wall of the sedimentation tank. The bottom of the baffle is suspended and the top is higher than the height of the reaction tank, thereby forming a top overflow channel between the reaction tank and the sedimentation tank. An inclined plate is installed in the space between the baffle and the tank wall of the sedimentation tank. An overflow weir is installed above the inclined plate and the overflow weir is lower than the liquid level of the reaction tank. The bottom of the reaction tank is equipped with a microporous aeration head, which is connected to an ozone inlet pipe; the lower part of the reaction tank is connected to an inlet water pipe and a coagulant dosing pipe. The reaction tank is equipped with a stirring device and several independent, detachable columnar screens. Each screen is filled with a different type of catalyst. Different screens may be filled with the same or different types of catalysts. By assembling and disassembling different screens, the amount and composition of catalysts can be quickly adjusted.

[0010] In one embodiment, a porous support plate is provided in the space between the partition and the wall of the sedimentation tank. The porous support plate is arranged horizontally to isolate the upper and lower spaces. The inclined plate is arranged on the porous support plate and fixed by the porous support plate. In the sedimentation tank, an overflow weir and an outlet pipe are provided above the inclined plate, and a sludge discharge pipe is provided at the bottom.

[0011] In one embodiment, the inclination angle of the inclined plate is 45°-60°, the plate spacing is 5-10cm, the effective settling height is 50-100cm, and the top height of the partition plate is consistent with the height of the sedimentation tank wall.

[0012] In one embodiment, the overflow weir is located at the outlet of the sedimentation tank, with its height lower than the liquid level of the reaction tank, and is connected to the outlet pipe to collect and discharge the supernatant after separation by the inclined plate.

[0013] In one embodiment, the stirring device is a double-layer paddle stirring device arranged in the center of the reaction tank; the top of the screen is provided with a handle for picking up and putting down; multiple screens are arranged circumferentially or in an array in the reaction tank, each screen is independently filled with catalyst, and the addition or removal of one or more screens can be achieved by using the handle to adjust the total amount of catalyst added.

[0014] In one embodiment, the double-layer impeller stirring device includes a drive motor, a stirring rod, and two layers of impellers. The drive motor is a variable frequency motor with a rotation speed of 100-200 r / min. The two layers of impellers are divided into upper and lower layers. The diameter of the aeration bubbles in the microporous aeration head is 100-300 μm.

[0015] In one embodiment, the sieve is filled with different types of catalysts, including several of aluminum-based catalysts, manganese-based catalysts, copper-based catalysts, iron-based catalysts, or supported metal oxides. By combining and adjusting different catalysts, a multi-metal synergistic catalytic effect can be achieved.

[0016] In one embodiment, the screen has an aperture of 0.2-1.0 mm and is made of stainless steel or a metal mesh with a catalytic coating on its surface. Its height covers the catalyst area. Several horizontal fixing rings are provided in the reaction tank, and the screen is fixed in the reaction tank by the fixing rings.

[0017] This invention also provides an integrated ozone catalytic oxidation-coagulation treatment method with adjustable catalyst dosage and composition, implemented using the aforementioned integrated ozone catalytic oxidation-coagulation device with adjustable catalyst dosage and composition, and the steps are as follows: The coagulant is added through the coagulant dosing pipe and thoroughly mixed with the high-salt organic wastewater before being introduced into the reaction tank through the inlet pipe. Depending on the water quality and target, one or more screens can be selectively added or removed to adjust the total catalyst dosage; by filling different types of catalysts into different screens, multi-metal synergistic catalysis can be achieved through catalyst composition adjustment. Ozone is introduced through the ozone inlet pipe and uniformly aerated using microporous aeration heads. At the same time, the stirring device is activated to ensure that the wastewater, ozone, coagulant and catalyst are fully mixed and in contact, promoting the simultaneous occurrence of ozone catalytic oxidation and coagulation processes. Active oxygen components are generated in the synergistic reaction to degrade organic matter and form flocs. The screen prevents the flocs from adhering to the catalyst surface. The reacted water rises in the reaction tank and overflows from the top, entering the sedimentation tank below the baffle. In the sedimentation tank, water carries flocs upwards, where solid-liquid separation is achieved by the inclined plate, and the flocs are discharged separately.

[0018] In one embodiment, the high-salt organic wastewater has a TDS ≥ 10,000 mg / L and a COD of 200-1000 mg / L; the ozone dosage is 20-150 mg / L, the hydraulic retention time is 20-60 min, and the stirring speed is 100-200 r / min; the coagulant is PAC or PFS, with a dosage of 100-500 mg / L, a COD removal rate ≥ 90%, and an effluent COD ≤ 100 mg / L.

[0019] Compared with the prior art, the beneficial effects of the present invention are: 1. The integrated layout and gravity-fed design significantly reduce the footprint and energy consumption.

[0020] This invention employs a nested structure of reaction tank and sedimentation tank, combined with a three-stage layout where the reaction tank is lower than the sedimentation tank and the overflow weir is lower than the liquid level in the reaction tank. This enables gravity-fed operation throughout the entire process, eliminating the need for additional lifting equipment. This design not only eliminates the transitional structures and complex piping found in traditional processes, significantly reducing the footprint, but also substantially reduces infrastructure investment, construction time, and operating energy consumption, providing an intensive solution for engineering implementation.

[0021] 2. The catalyst dosage and composition are both adjusted to achieve precise control and multi-metal synergy.

[0022] This invention allows for the independent handling and placement of multiple screens, enabling flexible adjustment of the total catalyst dosage based on water quality changes and treatment load, thus avoiding resource waste. Different screens can be filled with various catalysts such as aluminum-based, manganese-based, copper-based, and iron-based catalysts. Optimized combinations achieve multi-metal synergistic catalysis, fully utilizing the differences in properties of each metal to significantly improve reactive oxygen species yield and organic matter degradation efficiency, greatly enhancing the process's adaptability to different wastewater characteristics.

[0023] 3. The screen isolation design ensures long-term stable operation of the catalyst.

[0024] This invention innovatively uses a columnar sieve to construct the catalytic reaction zone, which ensures efficient transfer of free radicals and substances while physically isolating the flocs from the catalyst, thus preventing the catalyst's active sites from being covered and contaminated, and significantly extending the catalyst's service life.

[0025] 4. Deep synergy between oxidation and coagulation comprehensively improves treatment efficiency.

[0026] In the dual-layer stirring system of this invention, ozone catalytic oxidation and coagulation processes are synchronized in time and coupled in space. The highly active components generated by catalytic oxidation immediately improve the coagulability of organic matter, while the flocs formed by coagulation effectively adsorb and enrich organic matter and oxidation intermediates, providing a concentrated micro-reaction interface for catalytic oxidation and forming a positive feedback loop. The stirring system takes into account both mixing and mass transfer and floc protection, and combined with the inclined plate high-efficiency sedimentation unit, it achieves synergistic optimization of the reaction and separation processes, resulting in clear effluent and good sludge concentration.

[0027] 5. Flexible operation and control, and strong technical applicability.

[0028] The system constructed in this invention supports flexible adjustment of multiple parameters, such as stirring intensity, reagent dosage, and catalyst quantity and composition, to cope with different water quality fluctuations. The synergistic effect of the process improves oxidation efficiency while reducing ozone dosage and sludge production, achieving a balance between treatment effectiveness and economy. This invention is particularly suitable for treating high-salt, recalcitrant organic wastewater and has broad application prospects in multiple industrial fields such as chemical, pharmaceutical, and dyeing industries, providing the industry with a highly efficient, stable, flexible, and economical technical solution.

[0029] In summary, this invention innovatively combines an integrated structure, adjustable and controllable catalyst, screen isolation protection, and deep synergy between oxidation and coagulation to construct a highly efficient, flexible, stable, and economical treatment system for high-salt, recalcitrant organic wastewater. The integrated layout significantly reduces land area and infrastructure costs; the adjustable mechanism enables precise optimization of the catalytic system and multi-metal synergy; the static screen isolation mechanism fundamentally solves the problem of catalyst deactivation; the gravity-driven hydraulic design reduces operating energy consumption; and the deep synergy between oxidation and coagulation significantly improves the degradation efficiency and mineralization degree of pollutants. This system combines operational flexibility and economic efficiency, adapting to different water quality conditions while reducing ozone consumption and sludge production, ensuring stable effluent quality that meets standards. This invention provides a solution with significant technological competitiveness and engineering application value for the treatment of high-salt organic wastewater in industries such as energy, chemical engineering, pharmaceuticals, and dyeing. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure of the present invention.

[0031] Figure 2 This is a top view of the reaction tank of the present invention.

[0032] In the diagram: 1-Drive motor, 2-Agitator rod, 3-Handle, 4-Double-layer blades, 5-Screen, 6-Catalyst, 7-Reaction tank, 8-Coagulant dosing pipe, 9-Inlet pipe, 10-Ozone inlet pipe, 11-Sedimentation tank, 12-Baffle plate, 13-Overflow weir, 14-Outlet pipe, 15-Inclined plate, 16-Porous support plate, 17-Fixing ring, 18-Microporous aeration head, 19-Sludge discharge pipe. Detailed Implementation

[0033] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings and examples.

[0034] Based on the numerous problems inherent in traditional series structures, an ideal integrated ozone catalytic oxidation and coagulation technology solution should possess the following characteristics: First, high integration, organically combining catalytic oxidation and coagulation functions within a single reactor, shortening the process and reducing footprint; second, effective isolation between the catalyst and coagulated flocs, fundamentally preventing catalyst contamination and deactivation, and ensuring long-term stable system operation; third, enhanced mixing and mass transfer within the reactor, optimized flow field design, and simultaneous improvement of ozone utilization efficiency, catalytic oxidation rate, and coagulation / flocculation effect; fourth, efficient solid-liquid separation, avoiding interference from sludge recirculation to the reaction zone; and fifth, good operational flexibility and adaptability, capable of coping with water quality fluctuations caused by high salinity and high organic loads. Developing such integrated devices is not only key to improving the treatment efficiency of high-salinity organic wastewater but also a significant innovation driving the development of advanced oxidation-coagulation coupling technology towards engineering, intensification, and intelligence.

[0035] Based on the above objectives, this invention provides an integrated ozone catalytic oxidation-coagulation device with adjustable catalyst dosage and composition. By simultaneously realizing ozone catalytic oxidation, coagulation reaction, and solid-liquid separation in a single device, and innovatively introducing an adjustable catalyst dosage and composition mechanism, this invention addresses key technical challenges such as catalyst deactivation due to flocculent encapsulation during synergistic processes, low mass transfer efficiency, lengthy process flow, and difficulty in optimizing catalyst composition. It provides a compact, efficient, flexible, and stable solution for treating high-salt, recalcitrant organic matter.

[0036] refer to Figure 1 and Figure 2 As shown, the core of the device of this invention lies in a nested, staggered, shared-wall shell. Within this shell, a vertical partition 12 divides the space into a lower reaction tank 7 and a higher sedimentation tank 11. This integrated layout fully utilizes the liquid level difference to achieve hydraulic gravity flow, significantly reducing the footprint and equipment piping. The bottom of the partition 12 is suspended, while the top is higher than the wall of the reaction tank 7, and preferably at the same height as the wall of the sedimentation tank 11, thus forming a top overflow channel between the reaction tank 7 and the sedimentation tank 11, allowing the sludge-water mixture that has completed the synergistic reaction to naturally overflow into the sedimentation tank 11.

[0037] The sedimentation tank 11 is equipped with inclined plates 15 to significantly increase the settling area and improve separation efficiency. The inclined plates 15 can be fixed to a porous support plate 16, which can be horizontally positioned between the partition plate 12 and the tank wall of the sedimentation tank 11, creating upper and lower spaces. The sedimentation tank 11 has an overflow weir 13 at its outlet, connected to an outlet pipe 14, for discharging compliant clean water; a sludge discharge pipe 19 is located at the bottom for discharging concentrated settled sludge. The overflow weir 13 is lower than the liquid level in the reaction tank 7, allowing for the collection and discharge of the supernatant after separation by the inclined plates 15.

[0038] The hydraulic design features of this invention are as follows: the height of the reaction tank 7 is lower than that of the sedimentation tank 11, and the liquid level in the tank is maintained stable by overflow; the top of the baffle 12 is higher than the liquid level in the reaction tank, allowing water to naturally overflow into the sedimentation tank 11; the overflow weir 13 at the outlet of the sedimentation tank 11 is lower than the liquid level in the reaction tank 7, ensuring that the separated clear water can be smoothly collected and discharged through the overflow weir. This design fully utilizes gravity flow, achieving unpowered self-flowing operation.

[0039] To achieve the necessary reaction conditions, a stirring device is installed in the reaction tank 7, especially at its center. A microporous aeration head 18 is installed at the bottom of the reaction tank 7, connected to the ozone inlet pipe 10. The diameter of the aeration bubbles is preferably 100-300 μm, ensuring that ozone is released evenly at the bottom of the reaction tank in the form of fine bubbles, guaranteeing sufficient contact between the ozone and the catalyst during its ascent. The reaction tank 7 is connected to a coagulant dosing pipe 8 and an inlet pipe 9 for introducing wastewater and chemicals. The coagulant dosing pipe 8 can be connected to the inlet pipe 9.

[0040] Another key aspect of this invention is that multiple independent, detachable screens 5 are provided in the central region of the reaction tank. Each screen 5 has a handle 3 or similar structure on its top for easy handling. The screens 5 are fixed by fixing rings 17. Preferably, the screens 5 are columnar, and more preferably cylindrical. The screens 5 are filled with a solid catalyst 6, and the types of catalyst 6 in different screens 5 may vary.

[0041] More preferably, the stirring device is a double-layer impeller stirring device, mainly composed of a top-mounted variable frequency drive motor 1, a stirring rod 2 connected to it, and upper and lower impellers 4 fixed on the rod. The drive motor 1 is a variable frequency motor, whose speed can be adjusted within the range of 60-300 r / min, preferably 100-200 r / min; the two impellers 4 are divided into upper and lower layers. Ozone, catalyst, and coagulant react synergistically under stirring, efficiently degrading organic matter.

[0042] More preferably, the inclined plates 15 in the sedimentation tank 11 have an inclination angle of 45°-60°, a plate spacing of 5-10 cm, an effective settling height of 50-100 cm, and are fixed by a porous support plate 16.

[0043] More preferably, the pore size of the screen 5 of the present invention is precisely designed (preferably 0.2-1.0 mm), allowing water molecules, dissolved ozone, small molecules, and reactive oxygen free radicals to freely pass through for efficient mass transfer and reaction, while effectively blocking the main flocs formed during the coagulation process outside the screen. This effectively isolates the flocs formed during coagulation, thereby fundamentally preventing the flocs from encapsulating and covering the active sites on the catalyst surface, and preventing catalyst deactivation. The screen 5 can be made of stainless steel or a metal mesh with a catalytic coating on its surface, and the screen height covers the catalyst area.

[0044] More preferably, the screens 5 of the present invention can be arranged in a circumferential array along the center of the reaction tank 7, or arranged in a longitudinal and transverse array within the tank. Individual screens 5 can be independently picked up and put down using the handle 3, allowing for the addition or removal of one or more screens, thus enabling flexible adjustment of the total catalyst dosage—when the catalyst dosage needs to be increased, one or more screens 5 filled with catalyst 6 can be added; when the catalyst dosage needs to be reduced, some screens 5 can be removed. Simultaneously, different types of catalysts can be filled into different screens 5, such as aluminum-based catalysts in screen A, manganese-based catalysts in screen B, copper-based catalysts in screen C, iron-based catalysts in screen D, and supported metal oxides in screen E. Through this combination and formulation of different catalysts, a multi-metal synergistic catalytic effect can be achieved, fully utilizing the differences in the catalytic characteristics of different metals for ozone decomposition, thereby improving the yield of active oxygen components and the degradation efficiency of organic matter.

[0045] The working principle and synergistic effects of this invention are as follows: The coagulant is added through the coagulant dosing pipe 8 and then enters the reaction tank 7 along with the high-salt organic wastewater through the inlet pipe 9. Based on the wastewater quality characteristics and treatment objectives, an appropriate number of cylindrical screens 5 are pre-filled using the handle 3, and each screen is filled with a selected type and proportion of catalyst 6, achieving optimized catalyst dosage and composition. Ozone is introduced through the air inlet pipe 10 and evenly released through the microporous aeration heads 18 at the bottom of the reaction tank 7, forming rising microbubbles. After the stirring device is started, three key processes occur simultaneously within the system: Catalytic oxidation: Under stirring, the rising ozone bubbles come into full contact with the different types of catalysts 6 within each screen 5, resulting in the efficient catalytic decomposition of ozone on the catalyst surface. Simultaneously, iron, aluminum, and other metal ions generated from the hydrolysis of the coagulant also play a heterogeneous catalytic role in the reaction system, jointly promoting ozone decomposition and generating a large amount of highly oxidizing hydroxyl radicals (·OH) and other active oxygen components. The synergistic effect of multiple catalysts further enhances the yield of active oxygen. These active substances diffuse throughout the reaction tank under stirring, rapidly and non-selectively oxidizing and decomposing recalcitrant organic matter in the wastewater.

[0046] Coagulation and flocculation: In the main area of ​​the reaction tank, inorganic salts or polymeric coagulants react with colloids, suspended solids, and some oxidation intermediates in the wastewater through adsorption, charge neutralization, bridging, and trapping, forming easily settling flocs. The presence of ozone and active oxygen components can simultaneously improve the coagulability of organic matter.

[0047] Synergistic and protective effects: The three-dimensional circulating flow field formed by the double-layer impeller agitation greatly enhances the contact efficiency between ozone bubbles and the catalyst inside the screen, as well as the diffusion of active components to all parts of the reaction tank. Simultaneously, the dynamic hydraulic environment makes it difficult for flocs to stably adhere to the outer wall of the screen. The cylindrical screen 5 constitutes a crucial physical barrier, fundamentally preventing flocs from entering and contaminating the catalyst, ensuring the long-term stability of catalyst activity.

[0048] The mixed liquor, after synergistic reaction, rises in reaction tank 7 and overflows from both sides through baffles 12 into sedimentation tank 11. Under the action of inclined plate 15, the flocs settle and separate rapidly. The clear water rises and is collected by overflow weir 13 and discharged through effluent pipe 14 in compliance with standards or reused. The sludge settles and accumulates and is periodically discharged through sludge discharge pipe 19.

[0049] This invention is applicable to various industrial wastewaters, especially those containing high salinity and recalcitrant organic matter, such as high-salt organic wastewater from the energy, chemical, pharmaceutical, and dyeing industries. Taking high-salt organic wastewater with a TDS ≥ 10,000 mg / L and COD 200-1000 mg / L as an example, the ozone dosage is 20-150 mg / L, the hydraulic retention time is 20-60 min, the stirring speed is 100-200 r / min, and the coagulant is PAC or PFS at a dosage of 100-500 mg / L. The system ultimately achieves a COD removal rate ≥ 90%, with effluent COD ≤ 100 mg / L.

[0050] In a more specific embodiment, refer again Figure 1 The device adopts a rectangular shell made of corrosion-resistant fiberglass, with a total effective volume of 1.8 m³. Inside the shell, a vertical partition 12 divides the space into an integrated treatment unit with nested inner and outer sections at different heights. The inner section is the lower-positioned reaction tank 7, and the outer section is the higher-positioned sedimentation tank 11.

[0051] A drive motor 1 with a power of 1.1 kW and frequency conversion control is installed at the center of the top of the reaction tank 7. The drive motor 1 is connected to and drives the stirring rod 2, which extends vertically into the reaction tank. A double-layer blade 4 is fixedly installed on the stirring rod 2. The upper blade is located about 1 / 3 of the way below the liquid surface, and the lower blade is close to the bottom of the tank. Both the stirring rod and the blades are made of 316L stainless steel, which has good corrosion resistance.

[0052] Multiple cylindrical screens 5 are arranged in the central area of ​​the reaction tank 7 and fixed inside the reaction tank 7 by fixing rings 17. In this embodiment, four screens are set and evenly arranged circumferentially. Each screen has a handle 3 at the top for independent removal and placement. The screens are made of 304 stainless steel mesh with a pore size of 0.5 mm and filled with catalyst 6. In this embodiment, the screens are filled with different types of catalysts: screens 1, 2, and 3 are filled with aluminum-based catalysts (Al2O3 supported type), screens 4 and 5 are filled with manganese-based catalysts (MnO2 particles), screens 6, 7, and 8 are filled with copper-based catalysts (CuO particles), and screens 9 and 10 are filled with iron-based catalysts (Fe2O3 particles). They can be combined and placed in the reaction tank 7 as needed (up to four types can be placed) to achieve a multi-metal synergistic catalytic effect.

[0053] Microporous aeration heads 18 are installed at the bottom of the reaction tank 7. The microporous aeration heads 18 are made of sintered titanium material, are evenly distributed along the bottom of the tank, and are connected to the ozone inlet pipe 10 of the external ozone generator, which can release uniform ozone bubbles with a diameter of 100-300 μm.

[0054] A DN50 inlet pipe 9 is installed on the lower side wall of reaction tank 7 near the ozone inlet pipe for introducing high-salt organic wastewater. A coagulant dosing pipe 8 is connected near the inlet pipe 9 for adding PAC. The liquid level in reaction tank 7 is designed to be lower than the top of baffle 12, allowing the treated mixture to overflow evenly from both sides of the reaction tank through baffle 12 into sedimentation tank 11.

[0055] The inclined plates 15 inside the sedimentation tank 11 have an inclination angle of 55° and a plate spacing of 8 cm. The effective settling area is 5-6 times the original tank bottom area. The inclined plates are fixedly installed by a porous support plate 16. An overflow weir 13 is provided at the effluent end of the sedimentation tank 11, its height being lower than the liquid level of the reaction tank 7, and is connected to a DN65 effluent pipe 14. A conical hopper is provided at the bottom of the sedimentation tank 11, connected to a sludge discharge pipe 19 for periodic discharge of concentrated sludge.

[0056] This invention features a compact structure, high reaction efficiency, stable operation, and flexible control, making it particularly suitable for the treatment of high-salt, recalcitrant organic wastewater.

[0057] The apparatus described in this embodiment was used to treat high-salinity organic wastewater discharged from a chemical industrial park. The wastewater's characteristics were: TDS approximately 340,000 mg / L, Cl... -The initial COD was approximately 1,021.3 mg / L, with a concentration of approximately 26,600 mg / L. In this embodiment, eight cylindrical screens were arranged in the reaction tank, and a total of 2 kg of catalyst was loaded, consisting of a manganese-based catalyst (MnO2), an aluminum-based catalyst (Al2O3), a copper-based catalyst (CuO), and an iron-based catalyst (Fe2O3), mixed in a mass ratio of 1:2:1:1. This multi-metal synergistic catalysis improved the oxidation efficiency. Under optimized operating conditions: PAC dosage 300 mg / L, ozone dosage 400 mL / min, stirring speed 100 r / min, and hydraulic retention time in the reaction tank 45 min. After the system stabilized, the effluent COD was below 65 mg / L, with an average removal rate exceeding 92.3%, and the effluent turbidity remained stable below 5 NTU, indicating that the device has good treatment performance under high-salt conditions.

[0058] To further verify the adaptability of the device in this embodiment, high-salinity wastewater from another source was treated, with the following characteristics: TDS approximately 330,000 mg / L, Cl... - The initial COD was approximately 1,108.4 mg / L, with a total concentration of approximately 26,167 mg / L. In this example, to investigate the effect of catalyst dosage, only four cylindrical screens were installed (two for manganese-based catalyst (MnO2) and two for aluminum-based catalyst (Al2O3), reducing the total catalyst amount by approximately 50% compared to Example 1. The operating parameters were adjusted as follows: PAC dosage 300 mg / L, ozone dosage 300 mL / min, stirring speed 60 r / min, and hydraulic retention time in the reaction tank 50 min. Under these conditions, the effluent COD remained stable below 95 mg / L, with a removal rate exceeding 91%, indicating that the system maintains high treatment efficiency even with reduced catalyst dosage. This also demonstrates the excellent treatment stability and adaptability of the system under high salinity and high organic load conditions.

Claims

1. An integrated ozone catalytic oxidation-coagulation device with adjustable catalyst dosage and composition, characterized in that, The reaction tank (7) and sedimentation tank (11) are nested inside and outside. The height of the reaction tank (7) is lower than that of the sedimentation tank (11). A vertical partition (12) is installed inside the sedimentation tank (11) to separate the tank wall of the reaction tank (7) from the tank wall of the sedimentation tank (11). The bottom of the partition (12) is suspended and the top is higher than the height of the reaction tank (7), thereby forming a top overflow channel between the reaction tank (7) and the sedimentation tank (11). An inclined plate (15) is installed in the space between the partition (12) and the tank wall of the sedimentation tank (11). An overflow weir (13) is installed above the inclined plate (15). The overflow weir (13) is lower than the liquid level of the reaction tank. The bottom of the reaction tank (7) is provided with a microporous aeration head (18), which is connected to the ozone inlet pipe (10); the lower part of the reaction tank (7) is connected to the water inlet pipe (9) and the coagulant dosing pipe (8). The reaction tank (7) is equipped with a stirring device and several independent detachable columnar screens (5). Each screen (5) is filled with a catalyst (6). The catalysts (6) filled in different screens (5) may be the same or different. By disassembling and assembling different screens (5), the amount and composition of catalysts can be quickly adjusted.

2. The ozone catalytic oxidation-coagulation integrated device with adjustable catalyst dosage and composition according to claim 1, characterized in that, A porous support plate (16) is provided in the space between the partition (12) and the wall of the sedimentation tank (11). The porous support plate (16) is arranged horizontally to isolate the upper and lower spaces. The inclined plate (15) is arranged on the porous support plate (16) and fixed by the porous support plate (16). In the sedimentation tank (11), an overflow weir (13) and an outlet pipe (14) are provided above the inclined plate (15) and the porous support plate (16), and a sludge discharge pipe (19) is provided at the bottom.

3. The ozone catalytic oxidation-coagulation integrated device with adjustable catalyst dosage and composition according to claim 2, characterized in that, The inclined plate (15) has an inclination angle of 45°-60°, a plate spacing of 5-10 cm, and an effective settlement height of 50-100 cm.

4. The ozone catalytic oxidation-coagulation integrated device with adjustable catalyst dosage and composition according to claim 2, characterized in that, The top height of the baffle (12) is the same as the height of the wall of the sedimentation tank (11). The overflow weir (13) is set at the outlet end of the sedimentation tank (11) and connected to the outlet pipe (14) to collect and discharge the supernatant after separation by the inclined plate (15).

5. The ozone catalytic oxidation-coagulation integrated device with adjustable catalyst dosage and composition according to claim 1, characterized in that, The stirring device is a double-layer paddle stirring device, which is arranged in the center of the reaction tank (7); the top of the screen (5) is provided with a handle (3) for picking up and putting down; multiple screens (5) are arranged circumferentially or in an array in the reaction tank (7), each screen (5) is independently filled with catalyst (6), and the addition or removal of one or more screens (5) can be achieved by using the handle (3) to adjust the total amount of catalyst added.

6. The ozone catalytic oxidation-coagulation integrated device with adjustable catalyst dosage and composition according to claim 5, characterized in that, The double-layer paddle stirring device includes a drive motor (1), a stirring rod (2) and two layers of paddles (4). The drive motor (1) is a variable frequency motor with a speed of 100-200 r / min. The two layers of paddles (4) are divided into upper and lower layers. The diameter of the aeration bubbles of the microporous aeration head (17) is 100-300 μm.

7. The ozone catalytic oxidation-coagulation integrated device with adjustable catalyst dosage and composition according to claim 1, characterized in that, The sieve (5) is filled with different types of catalysts (6), including several of aluminum-based catalysts, manganese-based catalysts, copper-based catalysts, iron-based catalysts or supported metal oxides. By combining and adjusting different catalysts, a multi-metal synergistic catalytic effect can be achieved.

8. The ozone catalytic oxidation-coagulation integrated device with adjustable catalyst dosage and composition according to claim 7, characterized in that, The sieve (5) has a pore size of 0.2-1.0 mm and is made of stainless steel or a metal mesh with a catalytic coating on its surface. Its height covers the catalyst area. Several horizontal fixing rings (17) are set in the reaction tank (7). The sieve (5) is fixed in the reaction tank (7) by the fixing rings (17).

9. A method for integrated ozone catalytic oxidation and coagulation treatment with adjustable catalyst dosage and composition, implemented using the integrated ozone catalytic oxidation and coagulation device with adjustable catalyst dosage and composition as described in any one of claims 1 to 8, characterized in that... The steps are as follows: Coagulant is added through the coagulant dosing pipe (8), and after being fully mixed with the high-salt organic wastewater, it is introduced into the reaction tank (7) through the inlet pipe (9); Depending on the water quality and target, one or more screens (5) are selectively added or removed to adjust the total amount of catalyst added; by filling different types of catalysts (6) into different screens (5), multi-metal synergistic catalysis is achieved through catalyst composition adjustment; Ozone is introduced through the ozone inlet pipe (10) and uniformly aerated using the microporous aeration head (18); at the same time, the stirring device is activated to fully mix and contact the wastewater, ozone, coagulant and catalyst (6), promoting the simultaneous ozone catalytic oxidation and coagulation process, generating active oxygen components in the synergistic reaction to degrade organic matter and form flocs, and the screen (5) blocks the flocs to prevent them from adhering to the surface of the catalyst (6); The reacted water flows up in the reaction tank (7) and overflows from the top, entering the sedimentation tank (11) through the bottom of the baffle (12). In the sedimentation tank (11), the water flow carries the flocs upward, and solid-liquid separation is achieved under the action of the inclined plate (15), and they are discharged separately.

10. The ozone catalytic oxidation-coagulation integrated device with adjustable catalyst dosage and composition according to claim 9, characterized in that, The high-salt organic wastewater has a TDS ≥ 10,000 mg / L and a COD of 200-1000 mg / L; the ozone dosage is 20-150 mg / L, the hydraulic retention time is 20-60 min, and the stirring speed is 100-200 r / min; the coagulant is PAC or PFS, with a dosage of 100-500 mg / L, a COD removal rate ≥ 90%, and an effluent COD ≤ 100 mg / L.

Images