Whole-flow HPPO wastewater treatment system

Abstract

The utility model relates to the field of organic chemical wastewater treatment, in particular to a full-process HPPO wastewater treatment system which comprises an oil separation device, a front ultraviolet oxidation pond, a homogenizing pond, a hydrolysis acidification pond, an EIC anaerobic reactor, an A / O biochemical pond, a filtration and adsorption device, an electrolyzed water ozone generator and a rear ultraviolet oxidation pond which are sequentially communicated with one another, wherein the oil separation device is provided with an HP wastewater inlet, and the homogenizing tank is provided with a PO wastewater inlet. According to the whole-process HPPO wastewater treatment system provided by the utility model, the wastewater treatment effect can be ensured, and meanwhile, the whole-process HPPO wastewater treatment system is more economical, energy-saving, green and environment-friendly and has higher application and popularization values to solve the HPPO wastewater treatment problem.

Description

Technical Field

[0001] This utility model relates to the field of organic chemical wastewater treatment, specifically to a complete HPPO wastewater treatment system. Background Technology

[0002] The HPPO process, which directly oxidizes propylene with hydrogen peroxide (H2O2) to produce propylene oxide (PO), is an economical, energy-saving, green, and environmentally friendly propylene oxide production process. In addition to propylene oxide wastewater (PO wastewater), the process also produces a type of wastewater containing residual hydrogen peroxide (HP wastewater). PO wastewater contains a large amount of alcohol byproducts and small amounts of ethers, aldehydes, ketones, and methoxyalkanes, with extremely high organic matter concentration, generally poor biodegradability, and a large volume of wastewater. HP wastewater contains a certain concentration of residual hydrogen peroxide, anthrone, hydroxyanthrone, and anthraquinone byproducts generated during the hydrogenation stage of the anthraquinone process for H2O2 production, as well as epoxanthraquinone byproducts generated during the oxidation stage, heavy aromatics used as solvents, trioctyl phosphate, 2-methylcyclohexyl acetate, and 2-ethylanthraquinone used as a carrier for alkylanthraquinones, among other large molecular organic compounds. It has poor biodegradability and a relatively smaller volume of wastewater.

[0003] Existing propylene oxide wastewater treatment systems primarily rely on Fenton catalytic advanced oxidation (ACO) pretreatment, directly mixing HP and PO wastewater without distinguishing between them. However, due to the large volume of wastewater to be treated, these systems suffer from high treatment costs, high chemical consumption, high chemical sludge discharge, and high residual sulfate levels in the catalyst, which are detrimental to subsequent biochemical reactions. For example, Chinese patent document CN217809018U discloses a combined HPPO and hydrogen peroxide wastewater treatment system, which uses HPPO and hydrogen peroxide wastewater together, mixing and adjusting the acidity before utilizing the residual hydrogen peroxide for Fenton oxidation. However, this system also suffers from unstable residual hydrogen peroxide levels, a large total volume of wastewater treated by Fenton oxidation, high chemical reagent dosage, and excessive chemical sludge production.

[0004] In response, Chinese patent document CN116835835A discloses a segmented HPPO wastewater treatment process. While this process addresses the issue of large wastewater volumes to some extent, it still requires the addition of ferrous ions and generates chemical sludge. Furthermore, its reaction conditions are quite stringent (acidification followed by alkali neutralization), and the reaction process is lengthy (oxidation, neutralization, flocculation, clarification, and effluent), hindering its widespread application. Therefore, a more economical, energy-efficient, green, and environmentally friendly solution to the HPPO wastewater treatment problem, while ensuring treatment effectiveness and possessing greater application and promotion value, is urgently needed. Utility Model Content

[0005] Therefore, the technical problem to be solved by this utility model is to overcome the shortcomings of existing HPPO wastewater treatment systems, which mostly adopt Fenton oxidation pretreatment, resulting in high treatment costs, large amounts of reagents, large amounts of chemical sludge production, and strict reaction conditions. These systems are difficult to solve HPPO wastewater treatment problems in a more economical, energy-saving, green, and environmentally friendly way while ensuring treatment effect, and thus provide a full-process HPPO wastewater treatment system to solve the above problems.

[0006] To achieve the above objectives, this utility model provides the following technical solution:

[0007] A complete HPPO wastewater treatment system includes an oil separator, a pre-treatment ultraviolet oxidation tank, a homogenization tank, a hydrolysis acidification tank, an EIC anaerobic reactor, an A / O biochemical tank, a filtration and adsorption device, an electrolytic water ozone generator, and a post-treatment ultraviolet oxidation tank, which are connected in sequence. The oil separator is equipped with an HP wastewater inlet, and the homogenization tank is equipped with a PO wastewater inlet.

[0008] Preferably, the oil separator is an air flotation tank.

[0009] Preferably, the hydrolysis acidification tank is equipped with a stirring device.

[0010] Preferably, the A / O biological treatment tank consists of an anaerobic zone, an anoxic zone, an aerobic zone, and a sedimentation zone connected in sequence.

[0011] Preferably, the outlet of the aerobic zone is provided with a nitrification liquid return channel that is connected to the inlet of the anaerobic zone, so that part of the effluent is returned to the anaerobic zone to provide nitrates according to the nitrification liquid return ratio, and the remaining effluent enters the sedimentation zone.

[0012] Preferably, the filtration and adsorption device is an activated carbon adsorption fluidized bed.

[0013] Preferably, the pre-ultraviolet oxidation tank consists of a tank body, a guide wall, and an open channel type ultraviolet sterilizer, and the post-ultraviolet oxidation tank has the same structure as the pre-ultraviolet oxidation tank.

[0014] Preferably, the middle part of the pool is divided by a guide wall and the beginning and end of the guide wall are open, and open channel-type ultraviolet sterilizers are provided on both sides of the guide wall.

[0015] Preferably, the pool body is curved at 180° to reduce the floor space required;

[0016] Preferably, the inlet and outlet of the pool are respectively located on both sides of one end of the guide wall.

[0017] The technical solution of this utility model has the following advantages:

[0018] 1. A complete HPPO wastewater treatment system, comprising, in sequence, an oil separator, a pre-treatment ultraviolet (UV) oxidation tank, a homogenizing tank, a hydrolysis acidification tank, an EIC anaerobic reactor, an A / O biological treatment tank, a filtration and adsorption device, an electrolytic water ozone generator, and a post-treatment UV oxidation tank; wherein the oil separator is equipped with an HP wastewater inlet, and the homogenizing tank is equipped with a PO wastewater inlet. HPPO is an advanced, economical, energy-saving, green, and environmentally friendly process that has recently achieved industrialization. Currently, research on complete HPPO wastewater treatment systems is limited, mostly focusing on physicochemical pretreatment or physicochemical pretreatment + biological treatment stages. Based on this, this invention provides a complete HPPO wastewater treatment system, innovatively proposing a combination of a UV / H2O2 pretreatment system constructed with a pre-treatment UV oxidation tank, a UV / O3 post-treatment system constructed with a post-treatment UV oxidation tank, and a traditional biological treatment system to form a complete HPPO wastewater treatment system, with the process sequence being unchangeable. Specifically, this invention first utilizes the residual hydrogen peroxide in HP wastewater to achieve advanced UV / H2O2 oxidation degradation, removing recalcitrant organic matter and residual hydrogen peroxide; then, it mixes with a large amount of PO wastewater with moderate biodegradability for biodegradation, significantly reducing the organic matter content; finally, the biochemical effluent undergoes adsorption filtration, O3 oxidation, and UV / O3 advanced oxidation degradation for deep treatment, fully mineralizing and adsorbing to remove remaining small molecule organic matter, ensuring that wastewater discharge meets standards.

[0019] Compared to existing Fenton pretreatment technologies involving multiple steps such as acid adjustment, catalyst addition, oxidant addition, flocculant addition, coagulant aid addition, alkali neutralization, and reaction time adjustment, this invention offers more flexible application scenarios, better treatment effects, and superior cost and environmental benefits. The greater flexibility is reflected in the fact that the UV / H2O2 pretreatment stage only requires controlling three parameters—influent light transmittance, hydraulic retention time, and H2O2 concentration—to achieve the desired treatment effect under fixed UV radiation irradiance, making operation more convenient and more tolerant of changes in influent water quality. The superior environmental benefits are reflected in the simple process, mild reaction conditions, and absence of chemical sludge and other chemical byproducts generated by the UV / H2O2 pretreatment and UV / O3 posttreatment technologies employed in this invention. The superior cost-effectiveness is reflected in the fact that the UV / H2O2 pretreatment technology used in this invention treats only a small amount of acidic HP wastewater and requires no additional reagents or auxiliary agents, saving significant amounts of reagents and electricity compared to existing technologies.

[0020] This invention employs a pre-treatment ultraviolet (UV) oxidation tank to treat HP wastewater. This approach utilizes the residual hydrogen peroxide in the wastewater for waste-to-waste treatment and leverages the photochemical sensitivity of aromatic hydrocarbons, the main components of HP wastewater. These aromatic hydrocarbons absorb light energy (especially UV light) and are excited to a high-energy state, leading to photolysis and the generation of more reactive intermediates (such as free radicals). These intermediates can further react, resulting in the degradation of aromatic hydrocarbons; or, through photochemical reactions, aromatic hydrocarbons can be converted into simpler compounds, such as aldehydes and acids, which are then degraded in subsequent biological treatment systems. Therefore, compared to Fenton pretreatment, this invention significantly improves the degradation efficiency of aromatic hydrocarbons in HP wastewater through the pre-treatment UV oxidation tank. Furthermore, the use of a hydrolysis-acidification + anaerobic + aerobic biological treatment system to treat HPPO mixed wastewater achieves a COD removal rate of 97% or higher in the biological stage, effectively reducing the overall operating cost of the process. The system employs filtration and adsorption, O3 oxidation, and UV / O3 advanced oxidation to deeply degrade residual organic matter in the effluent. The adsorption and filtration device effectively adsorbs and degrades small-molecule organic matter, improving the effluent color. O3 oxidation of micro-pollutants improves the effluent transmittance. The UV / O3 advanced oxidation utilizes the residual O3 in the influent at the front end of the post-ultraviolet oxidation tank to perform UV / O3 advanced oxidation. Through direct ultraviolet radiation, ozone oxidation, and ultraviolet-excited O3 oxidation, it generates highly oxidizing hydroxyl radicals to further mineralize and degrade small-molecule organic matter in the biological effluent, enhancing the deep treatment effect and meeting the Class A standard of effluent COD < 50 mg / L.

[0021] 2. In the full-process HPPO wastewater treatment system provided by this utility model, the tank structure of the pre- / post-UV oxidation tank can not only flexibly adjust the hydraulic retention time or effluent recirculation for retreatment according to the water treatment effect, but also reduce the floor space occupied.

[0022] 3. In the complete HPPO wastewater treatment system provided by this utility model, the water electrolysis ozone generator adopts the principle of low-pressure water electrolysis, which can generate a stable concentration of ozone water in a short time, fully oxidizing the micro-pollutants in the influent and significantly improving the water quality permeability. It also solves the problems of numerous accessories, high noise, and high ozone oxidation costs associated with using air or oxygen as a gas source for ozone generation. The technical principle and implementation are more stable and faster, making it more conducive to industrialization. Specifically, the low-pressure water electrolysis principle is as follows: using water as raw material, under the action of a DC electric field, water molecules ionize and decompose into hydrogen and oxygen ions, and oxygen ions (O2... - It will move towards the anode and react with H in water molecules. + Ions combine and generate ozone (O3) through a redox reaction, thus producing ozone water with a stable concentration. Attached Figure Description

[0023] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the entire HPPO wastewater treatment system provided by this utility model;

[0025] Figure 2 This is a schematic diagram of the pre- / post-ultraviolet oxidation tank of Embodiment 1 of this utility model;

[0026] Explanation of reference numerals in the attached diagram: 1-Oil separator, 2-Pre-treatment UV oxidation tank, 3-Homogenization tank, 4-Hydrolysis acidification tank, 5-EIC anaerobic reactor, 6-A / O biochemical tank, 7-Filtration and adsorption device, 8-Electrolytic water ozone generator, 9-Post-treatment UV oxidation tank, W1-HP wastewater inlet, W2-PO wastewater inlet, 10-Tank body, 11-Guide wall, 12-Open channel UV sterilizer, 13-Inlet, 14-Outlet, 15-Flow direction. Detailed Implementation

[0027] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0028] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0029] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0030] Furthermore, the technical features involved in the different embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.

[0031] This utility model discloses a full-process HPPO wastewater treatment system, which includes an oil separator 1, a pre-ultraviolet oxidation tank 2, a homogenization tank 3, a hydrolysis acidification tank 4, an EIC anaerobic reactor 5, an A / O biochemical tank 6, a filtration and adsorption device 7, an electrolytic water ozone generator 8, and a post-ultraviolet oxidation tank 9, which are connected in sequence. The oil separator 1 is provided with an HP wastewater inlet W1, and the homogenization tank 3 is provided with a PO wastewater inlet W2.

[0032] In one optional embodiment, the oil separator 1 is an air flotation tank.

[0033] In one optional embodiment, the actual treatment load of the hydrolysis acidification tank 4 is 5.3-6.6 kg COD / m³. 3 •d, with an effective residence time of 10-12 hours, and equipped with a stirring device.

[0034] In one optional embodiment, the actual treatment load of the A / O biological treatment tank 6 is 0.3-1.0 kg COD / m³. 3 •d, the effective retention time of the entire pool is 3-4 days. The A / O biological tank 6 consists of an anaerobic zone, an anoxic zone, an aerobic zone and a sedimentation zone connected in sequence. The effluent end of the aerobic zone is equipped with a nitrification liquid return channel connected to the influent end of the anaerobic zone, so that part of the effluent is returned to the anaerobic zone to provide nitrate according to the nitrification liquid return ratio, and the remaining effluent enters the sedimentation zone.

[0035] In one optional embodiment, the filtration and adsorption device 7 is an activated carbon adsorption fluidized bed, and the activated carbon used in the activated carbon adsorption fluidized bed is briquette crushed activated carbon, with an activated carbon pore volume (including macropores) of not less than 1.2 mL / g.

[0036] In one optional embodiment, the pre-UV oxidation tank 2 consists of a tank body 10, a guide wall 11, and an open channel UV sterilizer 12. The post-UV oxidation tank 9 has the same structure as the pre-UV oxidation tank 2. The tank body 10 is divided in the middle by the guide wall 11, with both ends of the guide wall 11 open. Open channel UV sterilizers 12 are installed on both sides of the guide wall 11. The tank body 10 is bent at 180°, and the inlet 13 and outlet 14 are respectively located on both sides of one end of the guide wall 11. The pre-UV oxidation tank 2 utilizes the UV / H2O2 advanced oxidation principle to fully utilize the residual hydrogen peroxide in HP wastewater and degrades organic matter in the HP wastewater through direct UV radiation and the generation of highly oxidizing hydroxyl radicals from H2O2 under acidic conditions. The UV radiation dose is 800-1000 mJ / cm². 2 The post-ultraviolet oxidation tank 9 utilizes the advanced UV / O3 oxidation principle of residual ozone in the influent to generate highly oxidizing hydroxyl radicals through direct ultraviolet radiation, ozone oxidation, and ultraviolet-excited O3 oxidation, which further mineralize and degrade small-molecule organic matter in the biochemical effluent. The ultraviolet radiation dose is 600-800 mJ / cm². 2 .

[0037] In one optional embodiment, the actual processing load of the EIC anaerobic reactor 5 is 2.2-3.0 kg COD / m³. 3 •d, with an effective residence time of 3-4 days, operates using a high-efficiency vortex internal circulation mode, and maintains a temperature of approximately 36℃ with an insulation device.

[0038] In one optional embodiment, the electrolyzed water ozone generator 8 adopts the principle of low-pressure water electrolysis (total dissolved solids (TDS) > 100) to generate a high concentration (0.3-4 mg / L) of ozone and ozone water in a short time, which fully oxidizes the micro-pollutants in the incoming water and significantly improves the water quality transmittance. By using the ultraviolet treatment system provided by this utility model to prepare ozone and ozone water online, it not only has the characteristics of low cost, controllable ozone generation, and convenient operation, but also has fewer bypass components and no risk of ozone or other gas leakage. While oxidizing, sterilizing, and purifying water with ozone, no disinfection byproducts are generated, which is more environmentally friendly.

[0039] Example 1

[0040] The water quality of wastewater from a certain HPPO process for producing propylene oxide is shown in Table 1 below:

[0041] Table 1 Basic Water Quality of HPPO Wastewater

[0042]

[0043] As is known in the art, the HPPO process for preparing propylene oxide generates two streams of wastewater. One stream is a relatively small amount of acidic wastewater (HP wastewater) containing residual hydrogen peroxide at a concentration of 200-500 mg / L and a low COD concentration of 1000-2000 mg / L, exhibiting poor biodegradability. The other stream is a high-concentration organic wastewater containing alcohol (PO wastewater) with a COD concentration of 16000-20000 mg / L, exhibiting moderate biodegradability and a large volume of water.

[0044] This embodiment provides a complete HPPO wastewater treatment system. See the process diagram below. Figure 1 The process includes the following steps:

[0045] 1) HP wastewater is collected through HP wastewater inlet W1 and pretreated in oil separator 1 (specifically, flotation tank) to remove a small amount of floating oil, resulting in a lower water transmittance (UVT). 254 nm The concentration of hydrogen peroxide is greater than 90%, and the residual hydrogen peroxide concentration is 400 mg / L.

[0046] 2) The effluent from step 1) is pumped into the pre-UV oxidation tank 2. The recalcitrant organic matter in the HP wastewater is degraded using the UV / H2O2 advanced oxidation principle, and residual hydrogen peroxide is consumed. This tank consists of a tank body 10, a guide wall 11, and an open channel UV sterilizer 12. See the schematic diagram of the pre-UV oxidation tank 2. Figure 2 The pool body 10 is divided in the middle by a guide wall 11, and the two ends of the guide wall 11 are open. Open channel type ultraviolet sterilizers 12 are installed on both sides of the guide wall 11. The pool body 10 is curved at 180°. The inlet 13 and outlet 14 of the pool body 10 are respectively located on both sides of one end of the guide wall 11. The ultraviolet radiation dose is 800 mJ / cm². 2 .

[0047] 3) Pump the effluent from step 2) into the homogenizing tank 3, which is equipped with a stirring device and a PO wastewater inlet W2. The HP wastewater and the PO water that enters the homogenizing tank 3 through the PO wastewater inlet W2 are mixed evenly. The mixing ratio of HP wastewater to PO wastewater is 2:10.

[0048] 4) The effluent from step 3) is introduced into hydrolysis acidification tank 4. The hydrolysis acidification reaction requires a wide pH range, and the mixed wastewater does not require additional pH adjustment. The actual treatment load of hydrolysis acidification tank 4 is 5.3 kg COD / m³. 3 •d, with an effective residence time of 12h, and equipped with a stirring device.

[0049] 5) The effluent from step 4) is introduced into EIC anaerobic reactor 5. The actual treatment load of EIC anaerobic reactor 5 is 2.3 kg COD / m³. 3•d, with an effective residence time of 90h, operates using a high-efficiency vortex internal circulation mode, and maintains a temperature of around 36℃.

[0050] 6) The effluent from step 5) is introduced into the A / O biological treatment tank 6. The A / O biological treatment tank 6 consists of an anaerobic zone, an anoxic zone, an aerobic zone, and a sedimentation zone. The effluent outlet of the aerobic zone is equipped with a nitrification liquor return channel connected to the inlet of the anaerobic zone. This allows a portion of the effluent to be returned to the anaerobic zone to provide nitrates according to the nitrification liquor return ratio. The remaining effluent enters the sedimentation zone. The actual treatment load of the A / O biological treatment tank 6 is 0.3 kg COD / m³. 3 •d, the effective retention time of the entire pool is 90h, and the nitrification liquor recirculation ratio is 200%.

[0051] 7) After biological treatment, the COD value of the mixed wastewater is significantly reduced. Before entering the post-ultraviolet oxidation tank 9, in order to ensure the clarity of its effluent, it first enters the filtration and adsorption device 7 for filtration and adsorption treatment. The filtration and adsorption device 7 is an activated carbon adsorption fluidized bed. The activated carbon used is briquette crushed activated carbon. The activated carbon pore volume (including macropores) is 1.2 mL / g. Specifically, micropores and mesopores play the role of adsorption and biological regeneration, while nano-sized macropores play the role of biodegradation, forming an adsorption-regeneration equilibrium state.

[0052] 8) After filtration, the effluent enters the water electrolysis ozone generator 8, which uses low-pressure water electrolysis to generate high-concentration ozone water (3mg / L) in a short time, fully oxidizing the micro-pollutants in the influent and significantly improving the water quality permeability.

[0053] 9) The effluent from step 8) is introduced into the post-UV oxidation tank 9 to further oxidize and degrade small molecule organic matter using the UV / O3 advanced oxidation principle. The post-UV oxidation tank 9 has the same structure as the pre-UV oxidation tank 2, and the UV radiation dose is 600 mJ / cm². 2 .

[0054] The COD of the effluent at each stage of the HPPO wastewater treatment system provided in this embodiment, as tested, is shown in Table 2 below:

[0055] Table 2

[0056]

[0057] Example 2

[0058] This embodiment provides a complete HPPO wastewater treatment system. The water quality conditions and process diagram are the same as in Embodiment 1. The specific steps are as follows:

[0059] 1) HP wastewater is collected through HP wastewater inlet W1 and pretreated in oil separator 1 (specifically, flotation tank) to remove a small amount of floating oil, resulting in a lower water transmittance (UVT). 254nm The concentration of hydrogen peroxide is greater than 90%, and the residual hydrogen peroxide concentration is 400 mg / L.

[0060] 2) The effluent from step 1) is pumped into the pre-treatment ultraviolet oxidation tank 2. The recalcitrant organic matter in the HP wastewater is degraded using the UV / H2O2 advanced oxidation principle, and the residual hydrogen peroxide is consumed. The structure of this tank is the same as in Example 1, and the ultraviolet radiation dose is 1000 mJ / cm². 2 .

[0061] 3) Pump the effluent from step 2) into the homogenizing tank 3, which is equipped with a stirring device and a PO wastewater inlet W2. The HP wastewater and the PO water that enters the homogenizing tank 3 through the PO wastewater inlet W2 are mixed evenly. The mixing ratio of HP wastewater to PO wastewater is 2:10.

[0062] 4) The effluent from step 3) is introduced into hydrolysis acidification tank 4. The hydrolysis acidification reaction requires a wide pH range, and the mixed wastewater does not require additional pH adjustment. The actual treatment load of hydrolysis acidification tank 4 is 5.3 kg COD / m³. 3 •d, with an effective residence time of 12h, and equipped with a stirring device.

[0063] 5) The effluent from step 4) is introduced into EIC anaerobic reactor 5. The actual treatment load of EIC anaerobic reactor 5 is 2.2 kg COD / m³. 3 •d, with an effective residence time of 96h, operates using a high-efficiency vortex internal circulation mode, and maintains a temperature of around 36℃.

[0064] 6) The effluent from step 5) is introduced into the A / O biological treatment tank 6, which has the same structure as in Example 1. The actual treatment load of the A / O biological treatment tank 6 is 1.0 kg COD / m³. 3 •d, the effective retention time of the entire pool is 72h, and the nitrification liquor recirculation ratio is 200%.

[0065] 7) After biological treatment, the COD value of the mixed wastewater is significantly reduced. Before entering the post-ultraviolet oxidation tank 9, in order to ensure the clarity of its effluent, it first enters the filtration and adsorption device 7 for filtration and adsorption treatment. The filtration and adsorption device 7 is an activated carbon adsorption fluidized bed. The activated carbon used is briquette crushed activated carbon. The activated carbon pore volume (including macropores) is 1.2 mL / g. Specifically, micropores and mesopores play the role of adsorption and biological regeneration, while nano-sized macropores play the role of biodegradation, forming an adsorption-regeneration equilibrium state.

[0066] 8) After filtration, the effluent enters the water electrolysis ozone generator 8, which uses low-pressure water electrolysis to generate high-concentration ozone water (0.3mg / L) in a short time, fully oxidizing the micro-pollutants in the influent and significantly improving the water quality permeability.

[0067] 9) The effluent from step 8) is introduced into the post-UV oxidation tank 9 to further oxidize and degrade small molecule organic matter using the UV / O3 advanced oxidation principle. The post-UV oxidation tank 9 has the same structure as the pre-UV oxidation tank 2, and the UV radiation dose is 800 mJ / cm². 2 .

[0068] The COD of the effluent at each stage of the HPPO wastewater treatment system provided in this embodiment, as tested, is shown in Table 3 below:

[0069] Table 3

[0070]

[0071] Example 3

[0072] This embodiment provides a complete HPPO wastewater treatment system. The water quality conditions and process diagram are the same as in Embodiment 1. The specific steps are as follows:

[0073] 1) HP wastewater is collected through HP wastewater inlet W1 and pretreated in oil separator 1 (specifically, flotation tank) to remove a small amount of floating oil, resulting in a lower water transmittance (UVT). 254 nm The concentration of hydrogen peroxide is greater than 90%, and the residual hydrogen peroxide concentration is 400 mg / L.

[0074] 2) The effluent from step 1) is pumped into the pre-treatment ultraviolet oxidation tank 2. The recalcitrant organic matter in the HP wastewater is degraded using the UV / H2O2 advanced oxidation principle, and the residual hydrogen peroxide is consumed. The structure of this tank is the same as in Example 1, and the ultraviolet radiation dose is 800 mJ / cm². 2 .

[0075] 3) Pump the effluent from step 2) into the homogenizing tank 3, which is equipped with a stirring device and a PO wastewater inlet W2. The HP wastewater and the PO water that enters the homogenizing tank 3 through the PO wastewater inlet W2 are mixed evenly. The mixing ratio of HP wastewater to PO wastewater is 2:10.

[0076] 4) The effluent from step 3) is introduced into hydrolysis acidification tank 4. The hydrolysis acidification reaction requires a wide pH range, and the mixed wastewater does not require additional pH adjustment. The actual treatment load of hydrolysis acidification tank 4 is 6.6 kg COD / m³. 3 •d, with an effective residence time of 10h, and equipped with a stirring device.

[0077] 5) The effluent from step 4) is introduced into EIC anaerobic reactor 5. The actual treatment load of EIC anaerobic reactor 5 is 3.0 kg COD / m³. 3 •d, with an effective residence time of 72h, operates using a high-efficiency vortex internal circulation mode, and maintains a temperature of around 36℃.

[0078] 6) Introduce the effluent from step 5) into the A / O biological treatment tank 6. The structure of the A / O biological treatment tank 6 is the same as in Example 1. The actual treatment load of the A / O biological treatment tank 6 is 0.3 kg COD / m³. 3 •d, the effective retention time of the entire pool is 96h, and the nitrification liquor recirculation ratio is 200%.

[0079] 7) After biological treatment, the COD value of the mixed wastewater is significantly reduced. Before entering the post-ultraviolet oxidation tank 9, in order to ensure the clarity of its effluent, it first enters the filtration and adsorption device 7 for filtration and adsorption treatment. The filtration and adsorption device 7 is an activated carbon adsorption fluidized bed. The activated carbon used is briquette crushed activated carbon. The activated carbon pore volume (including macropores) is 1.2 mL / g. Specifically, micropores and mesopores play the role of adsorption and biological regeneration, while nano-sized macropores play the role of biodegradation, forming an adsorption-regeneration equilibrium state.

[0080] 8) After filtration, the effluent enters the water electrolysis ozone generator 8, which uses low-pressure water electrolysis to generate high-concentration ozone water (4mg / L) in a short time, fully oxidizing the micro-pollutants in the influent and significantly improving the water quality permeability.

[0081] 9) The effluent from step 8) is introduced into the post-UV oxidation tank 9 to further oxidize and degrade small molecule organic matter using the UV / O3 advanced oxidation principle. The post-UV oxidation tank 9 has the same structure as the pre-UV oxidation tank 2, and the UV radiation dose is 600 mJ / cm². 2 .

[0082] The COD of the effluent at each stage of the HPPO wastewater treatment system provided in this embodiment, as tested, is shown in Table 4 below:

[0083] Table 4

[0084]

[0085] Comparative Example 1

[0086] This comparative example provides a complete HPPO wastewater treatment system with the same water quality as in Example 1. The difference between Example 1 and Example 2 is that the sequential connection order of the devices in the treatment system is different. The specific steps are as follows:

[0087] 1) HP wastewater is collected through HP wastewater inlet W1 and pretreated in oil separator 1 (specifically, flotation tank) to remove a small amount of floating oil, resulting in a lower water transmittance (UVT). 254 nm The concentration of hydrogen peroxide is greater than 90%, and the residual hydrogen peroxide concentration is 400 mg / L.

[0088] 2) The effluent from step 1) enters the water electrolysis ozone generator 8, which uses low-pressure water electrolysis to generate high-concentration ozone water (3mg / L) in a short time, fully oxidizing the micro-pollutants in the influent and significantly improving the water quality permeability.

[0089] 3) The effluent from step 2) is introduced into the post-UV oxidation tank 9. The recalcitrant organic matter in the HP wastewater is oxidized and degraded using the UV / O3 advanced oxidation principle. The post-UV oxidation tank 9 has the same structure as in Example 1, and the UV radiation dose is 600 mJ / cm². 2 .

[0090] 4) Pump the effluent from step 3) into the homogenizing tank 3, which is equipped with a stirring device and a PO wastewater inlet W2. The HP wastewater and the PO water that enters the homogenizing tank 3 through the PO wastewater inlet W2 are mixed evenly. The mixing ratio of HP wastewater to PO wastewater is 2:10.

[0091] 5) The effluent from step 4) is introduced into hydrolysis acidification tank 4. The hydrolysis acidification reaction requires a wide pH range, and the mixed wastewater does not require additional pH adjustment. The actual treatment load of hydrolysis acidification tank 4 is 5.3 kg COD / m³. 3 •d, with an effective residence time of 12h, and equipped with a stirring device.

[0092] 6) The effluent from step 5) is introduced into EIC anaerobic reactor 5. The actual treatment load of EIC anaerobic reactor 5 is 2.3 kg COD / m³. 3 •d, with an effective residence time of 90h, operates using a high-efficiency vortex internal circulation mode, and maintains a temperature of around 36℃.

[0093] 7) Introduce the effluent from step 6) into the A / O biological treatment tank 6. The structure of the A / O biological treatment tank 6 is the same as in Example 1. The actual treatment load of the A / O biological treatment tank 6 is 0.3 kg COD / m³. 3 •d, the effective retention time of the entire pool is 90h, and the nitrification liquor recirculation ratio is 200%.

[0094] 8) After biological treatment, the COD value of the mixed wastewater is significantly reduced. Before entering the pre-ultraviolet oxidation tank 2, in order to ensure the clarity of its effluent, it first enters the filtration and adsorption device 7 for filtration and adsorption treatment. The filtration and adsorption device 7 is an activated carbon adsorption fluidized bed. The activated carbon used is briquette crushed activated carbon. The activated carbon pore volume (including macropores) is 1.2 mL / g. Specifically, micropores and mesopores play the role of adsorption and biological regeneration, while nano-sized macropores play the role of biodegradation, forming an adsorption-regeneration equilibrium state.

[0095] 9) Pump the effluent from step 8) into the pre-UV oxidation tank 2. Utilize the UV / H2O2 advanced oxidation principle to consume residual H2O2 in the wastewater and degrade recalcitrant organic matter. The pre-UV oxidation tank 2 has the same structure as the post-UV oxidation tank 9, and the UV radiation dose is 800 mJ / cm². 2 However, at this point, the residual H2O2 in the wastewater has been completely consumed in steps 3) to 8), and cannot exert the advanced oxidation effect of UV / H2O2, but only exerts the UV oxidation effect.

[0096] The COD of the effluent at each stage of the HPPO wastewater treatment system provided in this comparative example is shown in Table 5 below:

[0097] Table 5

[0098]

[0099] Comparative Example 2

[0100] This comparative example provides a complete HPPO wastewater treatment system with the same water quality as in Example 1. The difference between Example 1 and Example 2 is that the sequential connection order of the devices in the treatment system is different. The specific steps are as follows:

[0101] 1) HP wastewater is collected through HP wastewater inlet W1 and pretreated in oil separator 1 (specifically, flotation tank) to remove a small amount of floating oil, resulting in a lower water transmittance (UVT). 254 nm The concentration of hydrogen peroxide is greater than 90%, and the residual hydrogen peroxide concentration is 400 mg / L.

[0102] 2) The effluent from step 1) is pumped into the pre-treatment ultraviolet oxidation tank 2. The recalcitrant organic matter in the HP wastewater is degraded using the UV / H2O2 advanced oxidation principle, and the residual hydrogen peroxide is consumed. The structure of this tank is the same as in Example 1, and the ultraviolet radiation dose is 800 mJ / cm². 2 .

[0103] 3) Pump the effluent from step 2) into the homogenizing tank 3, which is equipped with a stirring device and a PO wastewater inlet W2. The HP wastewater and the PO water that enters the homogenizing tank 3 through the PO wastewater inlet W2 are mixed evenly. The mixing ratio of HP wastewater to PO wastewater is 2:10.

[0104] 4) The turbidity of the mixed wastewater is higher than that of the single HP wastewater. Before entering the post-UV oxidation tank 9, it first enters the filtration and adsorption device 7 for filtration and adsorption treatment to ensure the clarity of the effluent. The filtration and adsorption device 7 is an activated carbon adsorption fluidized bed, and the activated carbon used is briquette-crushed activated carbon with a pore volume (including macropores) of 1.2 mL / g. Specifically, micropores and mesopores play a role in adsorption and biological regeneration, while nanopores play a role in biodegradation, forming an adsorption-regeneration equilibrium state. However, at this time, the COD value of the mixed wastewater is high, the operating load of the activated carbon adsorption fluidized bed increases sharply, and the organic matter removal efficiency and adsorption efficiency decrease significantly.

[0105] 5) The effluent from step 4) is fed into the water electrolysis ozone generator 8. Low-pressure water electrolysis generates high-concentration ozone water (3mg / L) in a short time, which fully oxidizes the pollutants in the influent and improves the water quality permeability.

[0106] 6) The effluent from step 5) is introduced into the post-UV oxidation tank 9 to further oxidize and degrade organic matter using the UV / O3 advanced oxidation principle. The pre-UV oxidation tank 2 has the same structure as the post-UV oxidation tank 9, and the UV radiation dose is 600 mJ / cm². 2 .

[0107] 7) Introduce the effluent from step 6) into hydrolysis acidification tank 4. The hydrolysis acidification reaction requires a wide pH range, and the mixed wastewater does not require additional pH adjustment. The actual treatment load of hydrolysis acidification tank 4 is 5.3 kg COD / m³. 3 •d, with an effective residence time of 12h, and equipped with a stirring device.

[0108] 8) The effluent from step 7) is introduced into EIC anaerobic reactor 5. The actual treatment load of EIC anaerobic reactor 5 is 2.3 kg COD / m³. 3 •d, with an effective residence time of 90h, operates using a high-efficiency vortex internal circulation mode, and maintains a temperature of around 36℃.

[0109] 9) The effluent from step 8) is introduced into the A / O biological treatment tank 6, which has the same structure as in Example 1. The actual treatment load of the A / O biological treatment tank 6 is 0.3 kg COD / m³. 3 •d, the effective retention time of the entire pool is 90h, and the nitrification liquor recirculation ratio is 200%.

[0110] The COD of the effluent at each stage of the HPPO wastewater treatment system provided in this comparative example is shown in Table 6 below:

[0111] Table 6

[0112]

[0113] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the protection scope of this invention.

Claims

1. A complete HPPO wastewater treatment system, characterized in that, The system includes an oil separator (1), a pre-ultraviolet oxidation tank (2), a homogenizing tank (3), a hydrolysis acidification tank (4), an EIC anaerobic reactor (5), an A / O biochemical tank (6), a filtration and adsorption device (7), an electrolytic water ozone generator (8), and a post-ultraviolet oxidation tank (9) arranged in sequence. The oil separator (1) is equipped with an HP wastewater inlet (W1), and the homogenizing tank (3) is equipped with a PO wastewater inlet (W2).

2. The full-process HPPO wastewater treatment system according to claim 1, characterized in that, The oil separator (1) is an air flotation tank.

3. The full-process HPPO wastewater treatment system according to claim 1, characterized in that, The hydrolysis acidification tank (4) is equipped with a stirring device.

4. The full-process HPPO wastewater treatment system according to claim 1, characterized in that, The A / O biological treatment tank (6) consists of an anaerobic zone, an anoxic zone, an aerobic zone and a sedimentation zone connected in sequence.

5. The full-process HPPO wastewater treatment system according to claim 4, characterized in that, The outlet of the aerobic zone is equipped with a nitrification liquid return channel that connects to the inlet of the anaerobic zone.

6. The full-process HPPO wastewater treatment system according to claim 1, characterized in that, The filtration and adsorption device (7) is an activated carbon adsorption fluidized bed.

7. The full-process HPPO wastewater treatment system according to claim 1, characterized in that, The pre-ultraviolet oxidation tank (2) consists of a tank body (10), a flow guide wall (11), and an open channel ultraviolet sterilizer (12). The post-ultraviolet oxidation tank (9) has the same structure as the pre-ultraviolet oxidation tank (2).

8. The full-process HPPO wastewater treatment system according to claim 7, characterized in that, The middle part of the pool (10) is separated by a guide wall (11) and the beginning and end of the guide wall (11) are open. Open channel type ultraviolet sterilizers (12) are provided on both sides of the guide wall (11).

9. The full-process HPPO wastewater treatment system according to claim 7 or 8, characterized in that, The pool body (10) is set in a 180° bend.

10. The full-process HPPO wastewater treatment system according to claim 7 or 8, characterized in that, The inlet (13) and outlet (14) of the pool body (10) are respectively located on both sides of one end of the guide wall (11).

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