Treatment method of petrochemical and biochemical effluent

Abstract

The invention relates to a petrochemical biochemical effluent treatment method which comprises the following steps: S1, introducing petrochemical biochemical effluent to be treated into a membrane catalytic ozonation unit for treatment to obtain a first product; s2, the first product water is introduced into a biological activated carbon unit and sequentially flows through an activated carbon catalytic ozonation zone, a biological activated carbon aerobic zone and a biological activated carbon anoxic zone to be treated, and second product water is obtained. The problems of low ozone utilization rate, long treatment process flow, high overall energy consumption and the like in the existing biochemical effluent treatment and recycling process in the petrochemical industry can be solved.

Description

Technical Field

[0001] This disclosure relates to the field of petrochemical wastewater treatment technology, specifically to a method for treating petrochemical biochemical effluent. Background Technology

[0002] A common process for treating petrochemical wastewater involves adding pretreatment and dual-membrane (ultrafiltration and reverse osmosis) units to the existing treatment system. Freshwater is often reused as makeup water for circulating water (Water Management Technical Requirements Part 2: Circulating Water) (Q / SH0628.2-2014) or as influent for chemical treatment. Concentrated wastewater generally requires further treatment to meet the requirements of the "Emission Standard of Pollutants for Petroleum Refining Industry" (GB31570-2015). However, this treatment method has disadvantages such as a long treatment process, high cost per ton of water treated, and large footprint.

[0003] Existing similar improvement measures or research include increasing the efficiency of a specific treatment unit or integrating equipment for treatment. For example, Wen Xianghua et al. (ZL 202111395450.1) disclosed a ceramic catalytic membrane and its preparation method and application. The ceramic catalytic membrane includes: a ceramic membrane; a manganese-based composite metal oxide, wherein the manganese-based composite metal oxide is loaded on the surface of the ceramic membrane and / or within the membrane pores, and the manganese-based composite metal oxide includes at least one of cerium, iron, and cobalt. Through the synergistic effect of electron pairs on the catalytic membrane, the oxygen hole content and electron transfer rate are increased, thereby improving the ozone utilization efficiency. Wu Zhuoyuan et al. (ZL 201510595972.4) disclosed an ozone-biological activated carbon integrated wastewater deep treatment method and device. It includes an ozone oxidation reaction zone, an ozone catalytic oxidation zone, a three-phase separation zone, and a biological activated carbon reaction zone. The integrated design improves ozone utilization efficiency and couples biological activated carbon technology. Qiu et al. (201710547121.1) disclosed an integrated ozone-coupled ceramic membrane bioreactor and its treatment process. It includes an ozonation reaction zone, an anoxic reaction zone, an anaerobic reaction zone, and an aerobic ceramic membrane MBR. By organically combining ozone oxidation, traditional nitrogen and phosphorus removal processes, and the MBR process, ozone oxidation alters the molecular structure and reduces the molecular weight of organic matter in the secondary effluent, thereby improving the biodegradability of organic matter and ensuring the effective operation of subsequent treatment processes.

[0004] However, current technologies for treating and reusing wastewater from the petrochemical industry still suffer from low ozone utilization rates. Furthermore, given the current constraints on refinery land use, there is a lack of research on how to provide a short-process treatment and reuse technology suitable for the biochemical effluent from the petrochemical industry and reduce energy consumption. Summary of the Invention

[0005] The purpose of this disclosure is to provide a method for treating petrochemical biochemical effluent, which can solve the problems of low ozone utilization, long treatment process and high overall energy consumption in the existing petrochemical biochemical effluent treatment and reuse process.

[0006] To achieve the above objectives, this disclosure provides a method for treating petrochemical and biochemical effluent, comprising the following steps: S1. The petrochemical and biochemical effluent to be treated is introduced into the membrane catalytic ozone oxidation unit for treatment to obtain the first product water; S2. The first product water is introduced into the biological activated carbon unit and sequentially flows through the activated carbon catalytic ozone oxidation zone, the biological activated carbon aerobic zone, and the biological activated carbon anoxic zone for treatment to obtain the second product water.

[0007] Optionally, the turbidity of the petrochemical biochemical effluent to be treated is below 12 NTU, the COD concentration is below 70 mg / L, the phosphate concentration is below 0.5 mg / L, the total nitrogen concentration is below 20 mg / L, and the BOD concentration is below 14 mg / L.

[0008] Optionally, in step S1, the membrane catalytic ozone oxidation unit includes a catalytic flat ceramic membrane; the catalytic flat ceramic membrane includes a support layer and a membrane layer that are bonded together, the support layer and / or the membrane layer including a first catalytic active component; and multiple parallel hollow channels are formed within the membrane layer of the catalytic flat ceramic membrane, the outlet ports of the multiple hollow channels are respectively connected to the filtered water outlet channel, the support layer is close to the hollow channels; the outlet of the filtered water outlet channel is connected to the biological activated carbon unit via a suction pump; Preferably, the support layer and the film layer are made of α-alumina; Preferably, the first catalytically active component is selected from one or more of MnO2, Fe2O3, and CuO; preferably, based on the total weight of the catalytic flat ceramic membrane, the content of the first catalytically active component is 0.5-4% by weight, more preferably 2-3% by weight. Optionally, the catalytic flat ceramic membrane has a porous structure, the pore size of the membrane layer is 50~200 nm, preferably 50~100 nm; the pore size of the support layer is 1~20 μm, preferably 5~15 μm; The thickness of the catalytic flat ceramic membrane is 3~10 mm, preferably 5~7 mm; the diameter of the hollow channel is 2~4 mm, preferably 2.5~3.5 mm.

[0009] Optionally, the membrane catalytic ozone oxidation unit includes a shell, a first aeration device, and a membrane pore micro / nano reactor. The membrane pore micro / nano reactor includes the catalytic flat ceramic membrane. Preferably, the membrane pore micro / nano reactor includes multiple catalytic flat ceramic membranes connected in parallel. The filtered water outlet channels of the multiple catalytic flat ceramic membranes converge and are connected to the suction pump. The membrane pore micro-nano reactor is placed inside the shell. The catalytic plate ceramic membrane allows the effluent to be treated and ozone to enter the hollow channels inside the catalytic plate ceramic membrane through the pores on the catalytic plate ceramic membrane and carry out the ozone oxidation reaction. The petrochemical and biochemical effluent after the ozone oxidation reaction flows out through the filtered water effluent channel and is connected to the biological activated carbon unit through the suction pump. The first aeration device is located near the bottom of the shell, and the membrane pore micro / nano reactor is located above the first aeration device. The first aeration device is provided with aeration holes. Optionally, the inlet of the petrochemical biochemical effluent is located at the bottom of the shell of the membrane catalytic ozone oxidation unit.

[0010] Optionally, the process conditions of the membrane catalytic ozone oxidation unit include: a membrane flux of 20~150 L / m 2 h, preferably 30~100 L / m 2 •h; the ozone dosage is 1~100 mg / L, preferably 5~30 mg / L, and the residence time of the petrochemical and biological effluent is 0.5~4 h, preferably 1~2 h.

[0011] Optionally, in step S2, the activated carbon catalytic ozone oxidation zone includes a first packing material, which includes a first activated carbon and a second catalytic active component; the second catalytic active component is selected from one or more of Fe2O3, CuO, and MnO2; preferably, based on the total weight of the first packing material, the content of the second catalytic active component is 0.1~3% by weight, preferably 0.5~2% by weight. The aerobic zone of the biological activated carbon includes a second packing material, a first aerobic microorganism, and nitrifying bacteria. The second packing material includes a second activated carbon. Preferably, based on the volume of the first product water, the dosage of the first aerobic bacteria is 1000~5000 mg / L, more preferably 2000~3000 mg / L; the dosage of the nitrifying bacteria is 500~1000 mg / L, more preferably 600~800 mg / L. The anoxic zone of the biological activated carbon includes a third packing material, a second aerobic microorganism, and denitrifying bacteria; along the flow direction of the petrochemical biochemical effluent, the second aerobic microorganism is positioned upstream of the denitrifying bacteria; the third packing material includes a third activated carbon; preferably, based on the volume of the first product water, the dosage of the second aerobic microorganism is 100~800 mg / L, more preferably 300~600 mg / L; the dosage of the denitrifying bacteria is 500~2000 mg / L, more preferably 1000~1500 mg / L; Optionally, the first activated carbon, the second activated carbon, and the third activated carbon are each independently selected from coal-based columnar activated carbon; more preferably, the first activated carbon, the second activated carbon, and the third activated carbon have an iodine value greater than 800 mg / g, a diameter of 1~2 mm, and a length of 2~5 mm.

[0012] Optionally, in the biological activated carbon unit, the activated carbon catalytic ozone oxidation zone, the biological activated carbon aerobic zone, and the biological activated carbon anoxic zone are arranged sequentially from top to bottom; there is a gap between the top of the activated carbon catalytic ozone oxidation zone and the top of the shell of the biological activated carbon unit, and the first product water inlet of the biological activated carbon unit is located on the side wall of the gap; Preferably, the packing volume ratio of the packing material in the activated carbon catalytic ozone oxidation zone, the biological activated carbon aerobic zone, and the biological activated carbon anoxic zone is 1:2~5:1~3, more preferably 1:3~4:1.5~2.5; Preferably, the aerobic zone of the bio-activated carbon is provided with a second aeration device for introducing air; optionally, the second aeration device is located at the bottom of the aerobic zone of the bio-activated carbon, and the aeration holes of the second aeration device face the top of the aerobic zone of the bio-activated carbon.

[0013] Optionally, in step S2, the treatment conditions in the bio-activated carbon unit include: The processing temperature is 15~35℃, preferably 20~30℃; the total residence time of the first product water is 3~9 h, preferably 5~7 h; the flow rate of the first product water is 5~10 L / min, preferably 8~9 L / min. Optionally, the residence time of the first product water in the activated carbon catalytic ozone oxidation zone is 0.5-2 h, preferably 1-1.5 h; the residence time in the aerobic zone of the biological activated carbon is 1-5 h, preferably 2-4 h; and the residence time in the anoxic zone of the biological activated carbon is 1-3 h, preferably 1.5-2 h. Optionally, the air aeration rate is 1~4 L / min, preferably 1.5~3.0 L / min, based on the packing material in the aerobic zone of the bio-activated carbon per cubic meter; More preferably, the dissolved oxygen in the aerobic zone of the bio-activated carbon is 1~8 mg / L, more preferably 2~4 mg / L; the dissolved oxygen in the anoxic zone of the bio-activated carbon is 0.1~0.8 mg / L, more preferably 0.2~0.5 mg / L.

[0014] Optionally, a pipeline mixer is provided on the pipeline that introduces biochemical wastewater into the membrane catalytic ozone oxidation unit. The pipeline mixer includes a reagent inlet so that the biochemical wastewater enters the pipeline mixer and is treated after contacting the reagent. Preferably, the method further includes: The effluent from the petrochemical and biochemical processes to be treated undergoes water quality testing via an online water quality monitoring and automatic control unit. Based on the test results, the dosage of chemicals in the pipeline mixer is automatically adjusted. Then, the effluent from the pipeline mixer flows into the membrane catalytic ozone oxidation unit. The water quality test indicators include the turbidity and phosphate concentration of the effluent. The dissolved oxygen in the biological activated carbon unit is tested using an online water quality monitoring and automatic control unit, and the air aeration rate in the biological activated carbon unit is adjusted based on the dissolved oxygen test results.

[0015] Optionally, the method includes: When the online water quality monitoring and automatic control unit displays that the turbidity of the effluent to be treated is 4~12 NTU and / or the phosphate concentration is 0.3~0.5 mg / L, the online monitoring and automatic control unit controls the dosing system on the incoming water pipeline to be turned on, so as to add chemicals to the effluent to be treated introduced through the incoming water pipeline; optionally, the chemicals include one or more of coagulants and phosphorus removal agents; optionally, the coagulant is selected from one or more of PAC, PFS and PAFC, preferably PAC; preferably, the dosage of the chemicals is (1×turbidity + 2.5×phosphate concentration - 8) mg / L.

[0016] Optionally, a first dissolved oxygen testing position is provided in the middle of the aerobic zone of the biological activated carbon, and a second dissolved oxygen testing position is provided in the lower part of the anoxic zone of the biological activated carbon; the method includes: The dissolved oxygen levels in the effluent from the biological activated carbon unit were tested at the first and second dissolved oxygen testing locations using an online water quality monitoring and automatic control unit. When the dissolved oxygen concentration at the first testing location was below 2 mg / L, the aeration rate of the air in the biological activated carbon unit was adjusted to (0.5 × treated water volume) m³ / h, based on the water volume in the biological activated carbon unit. 3 / h; And / or, when the dissolved oxygen concentration at the second dissolved oxygen test location is above 0.5 mg / L, reduce the aeration rate in the aerobic zone of the bio-activated carbon.

[0017] Optionally, the method further includes: The second product water obtained from the biological activated carbon unit enters the protection unit, flows through the softener and the security filter in sequence for treatment, and then enters the reverse osmosis unit for treatment to obtain reverse osmosis desalinated water and reverse osmosis concentrate.

[0018] Through the above technical solution, this disclosure provides a method for treating petrochemical biochemical effluent. By setting up a membrane catalytic ozone oxidation unit, coupling ozone oxidation, membrane catalysis, and membrane filtration, the ozone utilization rate is improved, the ozone dosage and generator energy consumption are reduced, and the process is shortened. The membrane catalytic effluent enters a biological activated carbon unit, organically combining the membrane catalytic ozone oxidation and biological activated carbon units. The biological activated carbon is designed with partitions to fully utilize the residual ozone and dissolved oxygen in the ozone effluent, achieving the dual purpose of carbon and nitrogen removal, improving ozone utilization rate, reducing aeration, and lowering costs. Compared with the traditional "ozone oxidation + biochemical" process, which requires a buffer tank after the ozone oxidation reaction to allow residual ozone to decompose on its own, this disclosure utilizes residual ozone in the water within the activated carbon catalytic zone, improving ozone utilization rate and saving land area.

[0019] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description

[0020] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings: Figure 1 A schematic diagram of an apparatus for treating petrochemical and biochemical effluent provided in this disclosure; Figure 2 This is a flowchart of a method for treating petrochemical and biochemical effluent provided in this disclosure.

[0021] Figure Labels L1-PLC upper unit system, L2-Petrochemical and biochemical effluent, L3-Reagents, L4-Ozone, L5-Fresh water, L6-Concentrated water; 1-Membrane catalytic ozone oxidation unit, 2-Biological activated carbon unit, 3-Safety unit, 4-Reverse osmosis unit, 5-Activated carbon catalytic ozone oxidation zone, 6-Biological activated carbon aerobic zone, 7-Biological activated carbon anoxic zone. Detailed Implementation

[0022] The following provides a detailed description of specific embodiments of this disclosure. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit this disclosure. The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values; these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0023] This disclosure provides a method for treating petrochemical and biochemical effluent, comprising the following steps: S1. The petrochemical and biochemical effluent to be treated is introduced into the membrane catalytic ozone oxidation unit for treatment to obtain the first product water; S2. The first product water is introduced into the biological activated carbon unit and sequentially flows through the activated carbon catalytic ozone oxidation zone, the biological activated carbon aerobic zone, and the biological activated carbon anoxic zone for treatment to obtain the second product water.

[0024] This disclosure provides a method for treating petrochemical biochemical effluent. By setting up a membrane catalytic ozone oxidation unit, coupling ozone oxidation, membrane catalysis, and membrane filtration, the ozone utilization rate is improved, the ozone dosage and generator energy consumption are reduced, and the process is shortened. The membrane catalytic effluent enters a biological activated carbon unit, organically combining the membrane catalytic ozone oxidation and biological activated carbon units. The biological activated carbon is designed with separate zones to fully utilize the residual ozone and dissolved oxygen in the ozone effluent, achieving the dual purpose of carbon and nitrogen removal, improving ozone utilization, reducing aeration, and lowering costs. Specifically, the first product water from the membrane catalytic ozone oxidation unit enters the activated carbon catalytic ozone oxidation zone, where the residual ozone in the first product water undergoes catalytic reaction and is oxidized by activated carbon catalytic ozone oxidation. The first product water after treatment has a high dissolved oxygen level (ozone oxidation improves the biodegradability of the first product water, i.e., increases the BOD / COD ratio); after entering the aerobic zone of biological activated carbon, oxygen is consumed by aerobic microorganisms and nitrifying bacteria (engineered bacteria), reducing the COD value and converting a small amount of NH4 into NO3 (especially the inoculated engineered bacteria preferentially consume the recalcitrant BOD, so that in the subsequent denitrification process in the anoxic zone of activated carbon, a portion of BOD is still retained for total nitrogen removal), and the dissolved oxygen level gradually decreases; then the petrochemical biological effluent enters the anoxic zone of activated carbon, where aerobic microorganisms further consume oxygen, reducing the dissolved oxygen level to a level suitable for denitrifying microorganisms to function, thereby achieving the nitrogen removal effect.

[0025] Compared with the traditional "ozone oxidation + biochemical" process, which involves designing a buffer tank after the ozone oxidation reaction to allow residual ozone to decompose on its own, this disclosure utilizes residual ozone in the water within an activated carbon catalytic zone, thereby improving ozone utilization and saving land area.

[0026] In one specific embodiment, the turbidity of the petrochemical biochemical effluent to be treated is below 12 NTU, the COD concentration is below 70 mg / L, the phosphate concentration is below 0.5 mg / L, the total nitrogen concentration is below 20 mg / L, and the BOD concentration is below 14 mg / L. The petrochemical biochemical effluent used in this disclosure can come from wastewater from any unit of an existing petrochemical plant, making it widely applicable. Three-dimensional fluorescence analysis shows that the biochemical effluent contains a high amount of humic and fulvic acid substances. According to liquid chromatography-organic carbon detection (LC-OCD) data, the dissolved organic carbon in the biochemical effluent includes hydrophilic and hydrophobic organic carbon, with hydrophilic organic carbon (humus and small molecule neutral substances) accounting for more than 50% by weight and hydrophobic organic carbon accounting for 25% by weight. Furthermore, the method provided in this disclosure is applicable to effluent that has already undergone aerobic biochemical treatment, and the total nitrogen is mainly nitrate nitrogen with very low ammonia nitrogen content.

[0027] In a preferred embodiment, the membrane catalytic ozone oxidation unit includes a catalytic flat ceramic membrane; The catalytic flat-plate ceramic membrane includes a support layer and a membrane layer that are bonded together. The support layer and / or the membrane layer includes a first catalytically active component. Multiple parallel hollow channels are formed within the membrane layer of the catalytic flat-plate ceramic membrane. The outlet ports of these hollow channels converge into a filtered water outlet channel. The support layer is located close to the hollow channels. The outlet of the filtered water outlet channel is connected to the biological activated carbon unit via a suction pump. In this disclosure, the membrane layer on the outside provides filtration, while the internal support layer provides support. The first catalytically active component is provided on the support layer and the membrane layer to catalytically oxidize the petrochemical and biochemical effluent. The suction pump draws the filtered water, after catalytic reaction, from inside the catalytic flat-plate ceramic membrane to the biological activated carbon unit, creating a negative pressure in the hollow structure of the catalytic flat-plate ceramic membrane. This facilitates the entry of the petrochemical and biochemical effluent to be treated into the hollow channels within the membrane catalytic ozone oxidation unit through the membrane layer and the support layer. In the activated carbon catalytic ozone oxidation zone, the residual ozone in the first product water is mainly decomposed by metal-loaded activated carbon, reducing the dissolved ozone concentration in the first product from 0.5~1 mg / L to below 0.1 mg / L. This weakens or essentially eliminates the oxidizing effect of ozone on the microorganisms in the subsequent biological activated carbon. At the same time, some of the oxygen produced by ozone decomposition dissolves in the first product water, increasing the dissolved oxygen concentration and helping to save on subsequent aeration.

[0028] In one embodiment, the support layer and the film layer are made of α-alumina; Preferably, the first catalytically active component is selected from one or more of MnO2, Fe2O3, and CuO; preferably, based on the total weight of the catalytic flat ceramic membrane, the content of the first catalytically active component is 0.5-4% by weight, more preferably 2-3% by weight. Optionally, the catalytic flat ceramic membrane has a porous structure, the pore size of the membrane layer is 50~200 nm, preferably 50~100 nm; the pore size of the support layer is 1~20 μm, preferably 5~15 μm; The thickness of the catalytic flat ceramic membrane is 3-10 mm, preferably 5-7 mm; the diameter of the hollow channel is 2-4 mm, preferably 2.5-3.5 mm.

[0029] In one specific implementation, such as Figure 1 As shown, the membrane catalytic ozone oxidation unit includes a shell, a first aeration device, and a membrane pore micro-nano reactor. The membrane pore micro-nano reactor includes the catalytic flat ceramic membrane. Preferably, the membrane pore micro-nano reactor includes multiple catalytic flat ceramic membranes connected in parallel. The filtered water outlet channels of the multiple catalytic flat ceramic membranes converge and are connected to the suction pump. The membrane pore micro-nano reactor is placed inside the shell. The catalytic plate ceramic membrane allows the effluent to be treated and ozone to enter the hollow channels inside the catalytic plate ceramic membrane through the pores on the catalytic plate ceramic membrane and carry out the ozone oxidation reaction. The petrochemical and biochemical effluent after the ozone oxidation reaction flows out through the filtered water effluent channel and is connected to the biological activated carbon unit through the suction pump. The first aeration device is located near the bottom of the shell, and the membrane pore micro / nano reactor is located above the first aeration device. The first aeration device is provided with aeration holes. Optionally, the inlet of the petrochemical biochemical effluent is located at the bottom of the shell of the membrane catalytic ozone oxidation unit. The outlet of the first product water is located at the upper part of the shell of the membrane catalytic ozone oxidation unit. Optionally, a slag discharge port is also provided at the bottom of the shell of the membrane catalytic ozone oxidation unit.

[0030] In the membrane catalytic ozone oxidation unit, catalytic ozone oxidation and the synergistic oxidation of various free radicals occur, thereby reducing or completely mineralizing the recalcitrant organic matter in the effluent, which is beneficial for subsequent treatment. Its working principle mainly relies on membrane surface catalysis and membrane pore catalysis, especially utilizing the "confined effect" on the membrane micro- and nano-pores to generate free radicals. Within these micro- and nano-pores, the collision probability of ozone, active free radicals, and pollutants increases, resulting in a synergistic effect and improving ozone utilization. In this unit, the COD removal rate is approximately 40%, and the dissolved organic carbon removal rate is approximately 30%. A comparison of the organic carbon composition of the influent and effluent shows that the proportion of hydrophilic organic carbon increases by approximately 3%–10%, while the proportion of hydrophobic organic carbon decreases by 3%–10%, improving biodegradability. Simultaneously, the removal of humic acids and fulvic acids in the wastewater is significant. The ozone utilization rate reaches as high as 95%.

[0031] In one embodiment, the process conditions of the membrane catalytic ozone oxidation unit include: a membrane flux of 20~150 L / m³. 2 h, preferably 30~100 L / m 2 The ozone dosage is 1~100 mg / L, preferably 5~30 mg / L, and the residence time of the petrochemical and biochemical effluent is 0.5~4 h, preferably 1~2 h. Treating the petrochemical and biochemical effluent in the membrane catalytic ozone oxidation unit according to the process conditions described in this embodiment, especially according to the preferred process conditions, can achieve better treatment results.

[0032] In one embodiment, in step S2, the activated carbon catalytic ozone oxidation zone includes a first packing material, which includes a first activated carbon and a second catalytic active component; the second catalytic active component is selected from one or more of Fe2O3, CuO, and MnO2; preferably, based on the total weight of the first packing material, the content of the second catalytic active component is 0.1~3% by weight, more preferably 0.5~2% by weight; in this disclosure, the first activated carbon in the activated carbon catalytic ozone oxidation zone is loaded with a catalytic active component for catalyzing the reaction of residual ozone; The aerobic zone of the bio-activated carbon includes a second packing material, a first aerobic microorganism, and nitrifying bacteria. The second packing material includes a second activated carbon, which can serve as a carrier for microbial growth. The first aerobic microorganism and nitrifying bacteria in this disclosure can be conventional species in the art and can be purchased through ordinary commercial channels. The first aerobic microorganism can be selected from one or more of the genera *Bacillus*, *Trichophyton*, *Arthrobacter*, *Micrococcus*, *Pseudomonas*, *Pediococcus*, *Achromobacter*, *Flavobacterium*, *Mycobacterium*, *Flavobacterium*, and *Oligotrophomonas*. The nitrifying bacteria can be selected from conventional species such as *Helicobacter*. Preferably, based on the volume of the first product water, the dosage of the first aerobic bacteria is 1000~5000 mg / L, preferably 2000~3000 mg / L; the dosage of the nitrifying bacteria is 500~1000 mg / L, preferably 600~800 mg / L. The anoxic zone of the biological activated carbon includes a third packing material, a second aerobic microorganism, and denitrifying bacteria. The third packing material includes a third activated carbon, which can serve as a carrier for microbial growth. The second aerobic microorganism is the same species as the microorganism in the first aerobic zone. The denitrifying bacteria can be conventional species in the art and can be purchased through ordinary commercial channels. The denitrifying bacteria can be selected from one or more of denitrifying bacilli, Stenotrophomonas, and Aeromonas fluorescens. Preferably, based on the volume of the first product water, the dosage of the second aerobic microorganism is 100-800 mg / L, preferably 300-600 mg / L; the dosage of the anoxic bacteria (denitrifying bacteria) is 500-2000 mg / L, preferably 1000-1500 mg / L. When the packing of each reaction zone in the biological activated carbon unit is set within the range provided in this embodiment, a better treatment effect can be achieved.

[0033] In one specific embodiment, the first activated carbon, the second activated carbon, and the third activated carbon are each independently selected from coal-based columnar activated carbon; more preferably, the first activated carbon, the second activated carbon, and the third activated carbon have an iodine value greater than 800 mg / g, a diameter of 1~2 mm, and a length of 2~5 mm.

[0034] In one implementation, such as Figure 1 As shown, in the bio-activated carbon unit, the activated carbon catalytic ozone oxidation zone, the bio-activated carbon aerobic zone, and the bio-activated carbon anoxic zone are arranged sequentially from top to bottom. A gap exists between the top of the activated carbon catalytic ozone oxidation zone and the top of the shell of the bio-activated carbon unit. The first product water inlet of the bio-activated carbon unit is located on the side wall of this gap. The first product water from the membrane catalytic ozone oxidation unit enters the top gap of the bio-activated carbon unit from the top and flows sequentially through the activated carbon catalytic ozone oxidation zone, the bio-activated carbon aerobic zone, and the bio-activated carbon anoxic zone under gravity for treatment. In the activated carbon catalytic ozone oxidation zone: the main function is to utilize metal-loaded activated carbon to catalytically decompose the residual ozone in the first product water, thereby reducing the dissolved ozone concentration in the first product from 0.5~1 mg / L to below 0.1 mg / L. This weakens or essentially eliminates the oxidizing effect of ozone on the microorganisms in the subsequent biological activated carbon. At the same time, some of the oxygen produced by ozone decomposition dissolves in the first product water, increasing the dissolved oxygen concentration and helping to save on subsequent aeration.

[0035] For the aerobic zone of biological activated carbon: This zone is inoculated with bioengineered bacterial agents (the aforementioned aerobic microorganisms). These agents can use the recalcitrant COD in the water as an energy (carbon source) to further biodegrade organic matter in the wastewater. Utilizing the biochemical action of the bioengineered bacterial agents, the COD removal rate of the influent and effluent is approximately 30-40% by weight, the dissolved organic carbon removal rate is approximately 30-40% by weight, and humic acid and fulvic acid substances in the wastewater are significantly removed. Simultaneously, a comparison of the organic carbon composition of the influent and effluent shows that the proportion of hydrophilic organic carbon increases slightly (0.5-1% by weight), while the proportion of hydrophobic organic carbon decreases slightly (0.5-1% by weight). It is generally understood that hydrophilic organic carbon is more easily absorbed, utilized, and degraded by conventional microorganisms; however, for the aerobic zone of biological activated carbon inoculated with engineered bacterial agents, the data shows that while all types of organic carbon decrease proportionally, the decrease in hydrophobic organic carbon is more significant, which is related to the characteristics of these engineered bacteria. The biochemical results of the aerobic zone set up in this disclosure make it possible to perform post-denitrification without supplementing the carbon source, thus achieving the effect of coupled application.

[0036] In the anoxic zone of the biological activated carbon, some aerobic microorganisms still exist in the upper part of the zone, further consuming dissolved oxygen in the water. When the dissolved oxygen is less than 0.5 mg / L, the activity of denitrifying bacteria is high, achieving partial carbon and nitrogen removal through denitrification. For this wastewater quality, the total nitrogen removal rate is approximately 20% by weight. This distribution of biological activated carbon zones eliminates the need for additional carbon sources while achieving a certain level of nitrogen removal, creating favorable conditions for subsequent wastewater reuse.

[0037] In one embodiment, the packing volume ratio of the packing material in the activated carbon catalytic ozone oxidation zone, the biological activated carbon aerobic zone, and the biological activated carbon anoxic zone is 1:2~5:1~3, preferably 1:3~4:1.5~2.5. This packing volume ratio enables better "ozone + biochemical" coupled treatment of petrochemical biochemical effluent in the biological activated carbon unit.

[0038] In one specific embodiment, packing support plates can be independently installed at the bottom of the activated carbon catalytic ozone oxidation zone, the biological activated carbon aerobic zone, and the biological activated carbon anoxic zone, so as to improve the support for the packing when a large amount of packing is loaded in a large-volume reactor.

[0039] In one embodiment, in step S2, the treatment conditions in the bio-activated carbon unit include: The processing temperature is 15~35 ℃, preferably 20~30 ℃; the total residence time of the first product water is 1~5 h, preferably 2~4 h; the flow rate of the first product water is 5~10 L / min, preferably 8~9 L / min; Optionally, the residence time of the first product water in the activated carbon catalytic ozone oxidation zone is 0.5-2 h, preferably 1 h; the residence time in the aerobic zone of the biological activated carbon is 1-5 h, preferably 2-4 h; and the residence time in the anoxic zone of the biological activated carbon is 1-3 h, preferably 2 h. Optionally, the air aeration rate is 1~4 L / min, preferably 1.5~3.0 L / min, based on the packing material per unit volume (per cubic meter) in the aerobic zone of the bio-activated carbon. More preferably, the dissolved oxygen in the aerobic zone of the biological activated carbon is 1~8 mg / L, more preferably 2~4 mg / L; the dissolved oxygen in the anoxic zone of the biological activated carbon is 0.1~0.8 mg / L, more preferably 0.2~0.5 mg / L. Treating petrochemical biochemical effluent according to the process conditions of this embodiment, especially the preferred process conditions, can achieve better treatment results.

[0040] In a preferred embodiment, such as Figure 1 As shown, a pipeline mixer is installed on the pipeline that introduces biochemical wastewater into the membrane catalytic ozone oxidation unit. The pipeline mixer includes a reagent inlet so that the biochemical wastewater enters the pipeline mixer and comes into contact with the reagent for treatment.

[0041] In a preferred embodiment, the method further includes: The effluent from the petrochemical and biochemical processes to be treated undergoes water quality testing via an online water quality monitoring and automatic control unit. Based on the test results, the dosage of chemicals in the pipeline mixer is automatically adjusted. Then, the effluent from the pipeline mixer flows into the membrane catalytic ozone oxidation unit. The water quality test indicators include the turbidity and phosphate concentration of the effluent. The dissolved oxygen level in the biological activated carbon unit is tested using an online water quality monitoring and automatic control unit, and the air aeration rate in the biological activated carbon unit is adjusted based on the dissolved oxygen test results. This disclosure utilizes an online water quality monitoring and automatic control system to quickly and flexibly adjust the process dosage and aeration rate, achieving the purpose of turbidity and phosphorus removal from the incoming water, precisely controlling the reagents and aeration rate, and reducing reagent costs and energy consumption. In this disclosure, the online water quality monitoring and automatic control unit is controlled by a PLC host computer system.

[0042] In one specific embodiment, the method includes: When the online water quality monitoring and automatic control unit displays that the turbidity of the effluent to be treated is 4~12 NTU and / or the phosphate concentration is 0.3~0.5 mg / L, the online monitoring and automatic control unit controls the dosing system on the incoming water pipeline to be turned on, so as to add chemicals to the effluent to be treated introduced through the incoming water pipeline; optionally, the chemicals include one or more of coagulants and phosphorus removal agents; optionally, the coagulant is selected from one or more of PAC, PFS and PAFC, preferably PAC; preferably, the dosage of the chemicals is (1×turbidity + 2.5×phosphate concentration - 8) mg / L. According to the monitoring and control method in this embodiment, the overall treatment effect and treatment stability of the petrochemical biochemical effluent treatment process can be further improved.

[0043] In one specific embodiment, the aerobic zone of the bio-activated carbon is provided with a second aeration device for introducing air; optionally, the second aeration device is located at the bottom of the aerobic zone of the bio-activated carbon, and the aeration holes of the second aeration device face the top of the aerobic zone of the bio-activated carbon.

[0044] In one embodiment, a first dissolved oxygen testing position is provided in the middle of the aerobic zone of the bio-activated carbon, and a second dissolved oxygen testing position is provided in the lower part of the anoxic zone of the bio-activated carbon; the method includes: The dissolved oxygen levels in the effluent from the biological activated carbon unit were tested at the first and second dissolved oxygen testing locations using an online water quality monitoring and automatic control unit. When the dissolved oxygen concentration at the first testing location was below 2 mg / L, the aeration rate of the air in the biological activated carbon unit was adjusted to (0.5 × treated water volume) m³ / h, based on the water volume in the biological activated carbon unit. 3 / h, to maintain the dissolved oxygen level in the aerobic zone of the biological activated carbon; And / or, when the dissolved oxygen concentration at the second dissolved oxygen test location is above 0.5 mg / L, the aeration rate in the aerobic zone of the biological activated carbon is reduced to control the dissolved oxygen level in the anoxic zone of the biological activated carbon, which is suitable for denitrifying bacteria to treat petrochemical biological effluent.

[0045] In one implementation, such as Figure 1 As shown, the method also includes: The second product water obtained from the biological activated carbon unit enters the safeguard unit, flows sequentially through a softener and a security filter for treatment, and then enters the reverse osmosis unit for further treatment to obtain reverse osmosis desalination and reverse osmosis concentrate. This disclosure utilizes the safeguard unit and the reverse osmosis unit to optimize process parameters and permeability, achieving the recycling of reverse osmosis desalination and the compliant discharge of reverse osmosis concentrate. The concentrate no longer requires separate treatment equipment, saving land and investment.

[0046] In one specific embodiment, the softener in the protection unit is equipped with ion exchange resin, and the security filter is equipped with a PP cotton filter element; the reverse osmosis unit controls the water production rate to be 50%~75%, preferably 60%.

[0047] In one specific implementation, such as Figure 2 As shown, the method for treating petrochemical and biochemical effluent provided in this disclosure includes the following steps: S101. In the online water quality monitoring and automatic control unit: the turbidity and phosphate content of the petrochemical biochemical effluent to be treated are monitored, and the dosage of the reagent on the incoming water pipeline is adjusted in real time. The reagent is mixed through the pipeline mixer. The dissolved oxygen of the effluent to be treated at the first and second dissolved oxygen test positions in the biological activated carbon unit is tested, and the aeration rate of the air in the biological activated carbon unit is adjusted in real time. S102. In the membrane catalytic ozone oxidation unit: the petrochemical and biochemical effluent to be treated first enters the membrane catalytic ozone oxidation unit, which is equipped with ozone aeration (first aeration device) at the bottom. Ozone oxidation reaction occurs in the reaction tank of the membrane catalytic ozone oxidation unit, on the membrane surface of the catalytic flat ceramic membrane and in the membrane pores of the catalytic flat ceramic membrane, to obtain the first product water. S103. In the biological activated carbon unit: the effluent (first product water) from the membrane catalytic ozone oxidation unit enters the biological activated carbon unit from the top and is treated sequentially through the activated carbon catalytic ozone oxidation zone, the biological activated carbon aerobic zone, and the biological activated carbon anoxic zone to obtain the second product water. S104. In the protection unit and reverse osmosis unit: the water effluent (second product water) from the bottom of the biological activated carbon unit enters the ion exchange resin softener and PP filter cartridge security filter to ensure the turbidity of the influent and reduce scaling, and finally enters the reverse osmosis unit for treatment.

[0048] The present disclosure is further described in detail below through examples. All raw materials used in the examples are commercially available.

[0049] In the following examples and comparative examples, the catalytic flat-plate ceramic membrane was manufactured by Shenzhen Huayuan Environmental Technology Co., Ltd., with membrane dimensions of 250 mm × 6 mm × 1000 mm (L × W × H) and an effective membrane area of ​​0.5 m². 2 The device uses 20 membrane modules (20 catalytic flat ceramic membranes connected in parallel), totaling 10 m³. 2 .

[0050] The activated carbon carrier was purchased from Ningxia Huahui. The activated carbon had an iodine value greater than 800 mg / g, a diameter of 1.5 mm, and a length of 2-5 mm. The biochemical engineering bacteria agent was purchased from Zibo Lerui. The reverse osmosis membrane used is from Dow, model 4040.

[0051] In the following examples and comparative examples, the water quality of the petrochemical biochemical effluent to be treated is listed in Table 1.

[0052] Table 1

[0053] Example 1 use Figures 1-2 The short-process combined treatment and reuse technology and method shown are used to treat the effluent wastewater from a petrochemical biochemical plant: S101. In the online water quality monitoring and automatic control unit: the turbidity and phosphate content of the petrochemical biochemical effluent to be treated are monitored, and the dosage of the reagent on the inlet pipeline is adjusted in real time. The reagent is mixed through the pipeline mixer. The dissolved oxygen of the effluent to be treated at the first and second dissolved oxygen test positions in the biological activated carbon unit is tested, and the aeration rate of the air in the biological activated carbon unit is adjusted in real time. In step S101, the turbidity of the water sample monitored online is 10.5 NTU and the phosphate is 0.4 mg / L. The PAC dosing device is started, and the automatic control system calculates the dosage of 3.5 mg / L PAC by referring to the reagent dosage calculation formula (1×turbidity + 2.5×phosphate concentration - 8). S102. In the membrane catalytic ozone oxidation unit: the petrochemical and biochemical effluent to be treated first enters the membrane catalytic ozone oxidation unit, which is equipped with ozone aeration (first aeration device) at the bottom. Ozone oxidation reaction occurs in the reaction tank of the membrane catalytic ozone oxidation unit, on the surface of the catalytic flat ceramic membrane, and in the pores of the catalytic flat ceramic membrane, to obtain the first product water. The first product water collected by the catalytic flat ceramic membrane and sent to the filtered water outlet channel is then pumped out by a suction pump and sent to the biological activated carbon unit. In step S102, the catalytic flat ceramic membrane includes a support layer and a membrane layer. A flat ceramic membrane containing 2% by weight of MnO2 in both the support layer and the membrane layer is used (the base material of the support layer and the membrane layer is α-alumina, and the content of the first catalytic active component is 2% by weight based on the total weight of the catalytic flat ceramic membrane). The pore size of the ceramic membrane layer is 100 nm, the pore size of the support layer is 10 μm, the diameter of the hollow channels in the membrane is 3 mm, and the thickness of the entire catalytic flat ceramic membrane is 6 mm. mm; and the multi-layered parallel-connected flat ceramic membranes form a membrane pore micro / nano reactor in the membrane catalytic ozone oxidation unit; the process conditions of the membrane catalytic ozone oxidation unit include: membrane flux of 60 L / m 2 The ozone dosage was 10 mg / L, and the retention time of the petrochemical biochemical effluent was 2 hours. The COD of the effluent from membrane catalytic ozone oxidation (first product water) was 47.2 mg / L, the turbidity was 1.7 NTU, the phosphate content was 0.20 mg / L, the residual ozone content was 1.0 mg / L, and the dissolved oxygen content was 13.5 mg / L. S103. In the biological activated carbon unit: the effluent from the membrane catalytic ozone oxidation unit (first product water) enters the biological activated carbon unit from the top, and is treated sequentially through the activated carbon catalytic ozone oxidation zone, the biological activated carbon aerobic zone, and the biological activated carbon anoxic zone to obtain the second product water; in step S103, the first product water is sequentially passed through the activated carbon catalytic ozone oxidation zone, the biological activated carbon aerobic zone, and the biological activated carbon anoxic zone, wherein the activated carbon (first packing material) in the activated carbon catalytic ozone oxidation zone is activated carbon containing 2% by weight of Fe2O3 (second catalytic active component), the biological activated carbon aerobic zone includes the second packing material, the first aerobic microorganisms, and nitrifying bacteria, the second packing material includes the second activated carbon, the first aerobic microorganisms are Bacillus, and the nitrifying bacteria are Spirulina; based on the volume of the first product water, the dosage of the first aerobic bacteria is 3000 mg / L, and the dosage of the nitrifying bacteria is 600 mg / L. mg / L; the anoxic zone of the biological activated carbon includes a third packing material and a second aerobic microorganism (Bacillus) and denitrifying bacteria (Denitrifying Bacillus); along the flow direction of the petrochemical biochemical effluent, the second aerobic microorganism is located upstream of the denitrifying bacteria; the third packing material includes a third activated carbon; based on the volume of the first product water, the dosage of the second aerobic microorganism is 300 mg / L, and the dosage of the denitrifying bacteria is 1200 mg / L; the packing volume ratio of the packing material in the activated carbon catalytic ozone oxidation zone, the biological activated carbon aerobic zone, and the biological activated carbon anoxic zone is 1:3:2; the treatment conditions in the biological activated carbon unit include: a treatment temperature of 25 ℃; a total residence time of the first product water of 6 h; a flow rate of the first product water of 9 L / min; specifically, the residence time of the first product water in the activated carbon catalytic ozone oxidation zone is 1 h, the residence time in the biological activated carbon aerobic zone is 3 h, and the residence time in the biological activated carbon anoxic zone is 2 h. h; the air aeration rate is 1.5 L / min·m³, calculated based on the packing material per unit volume (per cubic meter) of biological activated carbon in the aerobic zone. -3 The average dissolved oxygen in the aerobic zone of the biological activated carbon was 3 mg / L; the dissolved oxygen in the anoxic zone of the biological activated carbon was 0.5 mg / L; the COD of the effluent (second product water) obtained from the biological activated carbon unit was 23.9 mg / L, the turbidity was 1.9 NTU, the phosphate was 0.16 mg / L, and the total nitrogen was 13.0 mg / L. S104. In the protection unit and reverse osmosis unit: the bottom effluent (second product water) of the biological activated carbon unit enters the ion exchange resin softener and PP filter cartridge security filter to ensure the turbidity of the influent and reduce scaling, and finally enters the reverse osmosis unit for treatment; in step S104, the reverse osmosis permeate is 60% by volume, and the resulting freshwater has a COD of 2.9 mg / L, a turbidity of 0.1 NTU, a phosphate of 0.03 mg / L, a total nitrogen of 1.7 mg / L, a pH of 7.9, and a conductivity of 476 μS / cm; the resulting concentrate has a COD of 50.4 mg / L, a turbidity of 3.0 NTU, a phosphate of 0.32 mg / L, a total nitrogen of 26.4 mg / L, a pH of 8.0, and a conductivity of 7838 μS / cm.

[0054] Comparative Example 1 use Figures 1-2 The short-process combined treatment and reuse technology and method shown are used to treat the effluent wastewater from a petrochemical biochemical plant: In step S101, the process conditions in the online water quality monitoring and automatic control unit are the same as in Example 1; In step S102, the difference from the membrane catalytic ozone oxidation unit in Example 1 is that neither the support layer nor the membrane layer of the flat ceramic membrane contains the first catalytically active component; the rest is the same as in Example 1. The COD of the membrane catalytic ozone oxidation effluent (first product water) is 54.2 mg / L, the turbidity is 1.7 NTU, the phosphate content is 0.20 mg / L, the residual ozone content is 2.0 mg / L, and the dissolved oxygen content is 13.5 mg / L. In step S103, the difference from the biological activated carbon unit in Example 1 is that the activated carbon (first packing) in the activated carbon catalytic ozone oxidation zone is activated carbon that does not contain the second catalytic active component, while the rest is the same as in Example 1. The COD of the biological activated carbon effluent (second product water) is 35.9 mg / L, the turbidity is 1.9 NTU, the phosphate is 0.18 mg / L, and the total nitrogen is 13.8 mg / L. In step S104, the reverse osmosis permeate is 60%, with a COD of 3.5 mg / L, turbidity of 0.1 NTU, phosphate of 0.03 mg / L, total nitrogen of 1.7 mg / L, pH of 7.9, and conductivity of 482 μS / cm; the concentrate has a COD of 73.4 mg / L, turbidity of 3.0 NTU, phosphate of 0.36 mg / L, total nitrogen of 28.0 mg / L, pH of 8.0, and conductivity of 7900 μS / cm.

[0055] Comparative Example 2 use Figures 1-2 The short-process combined process and method shown are used to treat the effluent wastewater from a petrochemical biochemical plant. In step S101, the process conditions in the online water quality monitoring and automatic control unit are the same as in Example 1; In step S102, the treatment process of the membrane catalytic ozone oxidation unit is the same as in Example 1; the COD of the membrane catalytic ozone oxidation effluent (first product water) is 47.2 mg / L, the turbidity is 1.7 NTU, the phosphate is 0.20 mg / L, the residual ozone in the water is 1.0 mg / L, and the dissolved oxygen is 13.5 mg / L. In step S103, the difference from the biological activated carbon unit in Example 1 is that the activated carbon (first packing) in the activated carbon catalytic ozone oxidation zone is activated carbon that does not contain the second catalytic active component, while the rest is the same as in Example 1. The COD of the biological activated carbon effluent (second product water) is 27.3 mg / L, the turbidity is 1.9 NTU, the phosphate is 0.18 mg / L, and the total nitrogen is 13.7 mg / L. In step S104, the reverse osmosis permeate is 60%, with a COD of 3.3 mg / L, turbidity of 0.1 NTU, phosphate of 0.03 mg / L, total nitrogen of 1.7 mg / L, pH of 7.9, and conductivity of 476 μS / cm; the concentrate has a COD of 60.0 mg / L, turbidity of 3.0 NTU, phosphate of 0.36 mg / L, total nitrogen of 27.9 mg / L, pH of 8.0, and conductivity of 7838 μS / cm.

[0056] Comparing Comparative Example 2 with Comparative Example 1, Comparative Example 2 had the first catalytic active component loaded on the ceramic membrane, while Comparative Example 1 did not have the first catalytic active component loaded on the ceramic membrane. The COD and residual ozone content of the first product water treated by the membrane catalytic ozone oxidation unit in Comparative Example 2 were lower, basically reaching the same level as in Example 1. This indicates that loading the first catalytic active component in the membrane catalytic ozone oxidation unit is beneficial to reducing COD content. Further comparison of Comparative Example 2 with Example 1 shows that no second catalytic active component was loaded in the activated carbon catalytic ozone oxidation zone in Comparative Example 2. The COD content of the second product water after treatment by the biological activated carbon unit in Comparative Example 2 was higher, and the COD content of the final fresh water and concentrated water was also higher. This indicates that the treatment method provided in this disclosure in Example 1 can further reduce the COD in the effluent.

[0057] Comparative Example 3 use Figures 1-2 The short-process combined treatment and reuse technology and method shown are used to treat the effluent wastewater from a petrochemical biochemical plant: In step S101, the process conditions in the online water quality monitoring and automatic control unit are the same as in Example 1; In step S102, the difference from the membrane catalytic ozone oxidation unit in Example 1 is that neither the support layer nor the membrane layer of the flat ceramic membrane contains the first catalytically active component; the rest is the same as in Example 1. The COD of the membrane catalytic ozone oxidation effluent (first product water) is 54.2 mg / L, the turbidity is 1.7 NTU, the phosphate content is 0.20 mg / L, the residual ozone content is 2.0 mg / L, and the dissolved oxygen content is 13.5 mg / L. In step S103, the treatment process is the same as that of the biological activated carbon unit in Example 1. The COD of the biological activated carbon effluent (second product water) is 32.9 mg / L, the turbidity is 1.9 NTU, the phosphate is 0.17 mg / L, and the total nitrogen is 13.6 mg / L. In step S104, the reverse osmosis permeate is 60%, with a COD of 3.4 mg / L, turbidity of 0.1 NTU, phosphate of 0.03 mg / L, total nitrogen of 1.7 mg / L, pH of 7.9, and conductivity of 481 μS / cm; the concentrate has a COD of 67.4 mg / L, turbidity of 3.0 NTU, phosphate of 0.34 mg / L, total nitrogen of 27.8 mg / L, pH of 8.0, and conductivity of 7890 μS / cm.

[0058] Comparing Comparative Example 3 with Comparative Example 1, it can be seen that neither Comparative Example 3 nor Comparative Example 1 loaded the first catalytic active component in the membrane catalytic ozone oxidation unit. Therefore, the water quality of the first product water obtained from the membrane catalytic ozone oxidation units of Comparative Example 1 and 3 is similar. In Comparative Example 3, the second catalytic active component was loaded in the activated carbon catalytic ozone oxidation zone. Compared with Comparative Example 1 (without the second catalytic active component), the COD of the second product water obtained in the activated carbon catalytic ozone oxidation zone of Comparative Example 3 is lower, indicating that loading the second catalytic active component in the activated carbon catalytic ozone oxidation zone is more conducive to reducing COD. Further comparison of Comparative Example 3 with Example 1 shows that Example 1 introduced a first catalytically active component in the membrane catalytic ozone oxidation unit, resulting in a low COD in the first product water effluent. The COD of the second product water after treatment by the biological activated carbon unit in Example 1 was even lower, and the COD in the fresh water and concentrated water obtained by the overall process was also lower.

[0059] Example 2 use Figures 1-2 The short-process combined treatment and reuse technology and method shown are used to treat the effluent wastewater from a petrochemical biochemical plant: In step S101, the process conditions for the online water quality monitoring and automatic control unit are the same as in Example 1; In step S102, the membrane catalytic ozone oxidation unit differs from that in Example 1 in that it uses a flat ceramic membrane containing 1% by weight of MnO2 and 1% by weight of CuO in both the support layer and the membrane layer (the total content of the first catalytic active component is 2% by weight), while the rest is the same as in Example 1. The COD of the membrane catalytic ozone oxidation effluent (first product water) is 43.2 mg / L, the turbidity is 1.7 NTU, the phosphate content is 0.20 mg / L, the residual ozone content is 0.8 mg / L, and the dissolved oxygen content is 13.5 mg / L. In step S103, the treatment process conditions are the same as in Example 1. The COD of the biological activated carbon effluent (second product water) is 21.9 mg / L, the turbidity is 1.9 NTU, the phosphate is 0.17 mg / L, and the total nitrogen is 13.2 mg / L. In step S104, the reverse osmosis permeate is 60% by volume, with a freshwater COD of 2.8 mg / L, turbidity of 0.1 NTU, phosphate of 0.03 mg / L, total nitrogen of 1.7 mg / L, pH of 7.9, and conductivity of 470 μS / cm; the concentrate has a COD of 45.4 mg / L, turbidity of 3.0 NTU, phosphate of 0.34 mg / L, total nitrogen of 27.7 mg / L, pH of 8.0, and conductivity of 7810 μS / cm.

[0060] Example 3 This embodiment refers to the processing method in Embodiment 1, and the only difference from Embodiment 1 is: In step S102, a flat-plate ceramic membrane containing 0.8% by weight of MnO2 in both the support layer and the membrane layer is used (based on the total weight of the catalytic flat-plate ceramic membrane, the content of the first catalytic active component is 0.8% by weight), and the rest is the same as in Example 1. The COD of the membrane-catalyzed ozone oxidation effluent (first product water) is 48.9 mg / L, the turbidity is 1.7 NTU, the phosphate is 0.2 mg / L, the residual ozone in the water is 1.1 mg / L, and the dissolved oxygen is 13.5 mg / L; In step S103, the treatment process conditions are the same as in Example 1. The COD of the biological activated carbon effluent (second product water) is 25.3 mg / L, the turbidity is 1.9 NTU, the phosphate is 0.18 mg / L, and the total nitrogen is 13.6 mg / L. In step S104, the reverse osmosis permeate is 60% by volume, with a COD of 3.0 mg / L, turbidity of 0.1 NTU, phosphate of 0.03 mg / L, total nitrogen of 1.7 mg / L, pH of 7.9, and conductivity of 475 μS / cm; the concentrate has a COD of 52.7 mg / L, turbidity of 3.0 NTU, phosphate of 0.34 mg / L, total nitrogen of 27.8 mg / L, pH of 8.0, and conductivity of 7819 μS / cm.

[0061] Comparing Example 3 with Example 1, the content of the first catalytic active component in the support layer and membrane layer used in step S102 of Example 1 is within the preferred range (2-3% by weight) provided in this disclosure. The first product water obtained after treatment in step S102 of Example 1 has lower COD and lower residual ozone content. The COD in the fresh water and concentrated water obtained through the overall process is also lower, resulting in better treatment effect.

[0062] Example 4 This embodiment refers to the processing method in Embodiment 1, and the only difference from Embodiment 1 is: In step S102, a flat-plate ceramic membrane containing 0.2% by weight of MnO2 in both the support layer and the membrane layer is used (based on the total weight of the catalytic flat-plate ceramic membrane, the content of the first catalytic active component is 0.2% by weight), and the rest is the same as in Example 1. The COD of the membrane-catalyzed ozone oxidation effluent (first product water) is 51.2 mg / L, the turbidity is 1.7 NTU, the phosphate is 0.2 mg / L, the residual ozone in the water is 1.3 mg / L, and the dissolved oxygen is 13.5 mg / L; In step S103, the treatment process conditions are the same as in Example 1. The COD of the biological activated carbon effluent (second product water) is 30.1 mg / L, the turbidity is 1.9 NTU, the phosphate is 0.19 mg / L, and the total nitrogen is 13.9 mg / L. In step S104, the reverse osmosis permeate is 60% by volume, with a freshwater COD of 3.7 mg / L, turbidity of 0.1 NTU, phosphate of 0.03 mg / L, total nitrogen of 1.7 mg / L, pH of 7.9, and conductivity of 472 μS / cm; the concentrate has a COD of 61.4 mg / L, turbidity of 3.1 NTU, phosphate of 0.35 mg / L, total nitrogen of 28.7 mg / L, pH of 8.0, and conductivity of 7813 μS / cm.

[0063] Comparing Example 4 with Example 3, the content of the first catalytic active component in the support layer and membrane layer used in step S102 of Example 3 is within the optimized range (0.5~4% by weight) provided in this disclosure. The content of the first catalytic active component in Example 4 is not within this optimized range. The COD in the first product water obtained after treatment in step S102 of Example 3 is lower, the residual ozone content in the water is also lower, and the COD in the fresh water and concentrated water obtained through the overall treatment process is lower, which has a better treatment effect.

[0064] Example 5 This embodiment refers to the processing method in Embodiment 1, and the only difference from Embodiment 1 is: In step S102, a flat ceramic membrane containing 8% by weight of MnO2 in both the support layer and the membrane layer is used (based on the total weight of the catalytic flat ceramic membrane, the content of the first catalytic active component is 8% by weight), and the rest is the same as in Example 1. The COD of the membrane-catalyzed ozone oxidation effluent (first product water) is 47.5 mg / L, the turbidity is 1.7 NTU, the phosphate is 0.2 mg / L, the residual ozone in the water is 0.9 mg / L, and the dissolved oxygen is 13.5 mg / L; In step S104, the reverse osmosis permeate is 60% by volume, with a freshwater COD of 3.3 mg / L, turbidity of 0.1 NTU, phosphate of 0.03 mg / L, total nitrogen of 1.7 mg / L, pH of 7.9, and conductivity of 476 μS / cm; the concentrate has a COD of 54.3 mg / L, turbidity of 3.0 NTU, phosphate of 0.35 mg / L, total nitrogen of 27.8 mg / L, pH of 8.0, and conductivity of 7815 μS / cm.

[0065] Comparing Example 5 with Example 3, the content of the first catalytic active component in the support layer and membrane layer used in step S102 of Example 3 is within the optimized range (0.5~4% by weight) provided in this disclosure. The content of the first catalytic active component in Example 5 is not within this optimized range. It is speculated that the content of the first catalytic active component is too high, which causes the highly active oxidative free radicals generated by catalytic ozone to react and affect the efficiency. The COD of the fresh water and concentrated water obtained by the overall treatment process in Example 3 is also lower.

[0066] Example 6 This embodiment refers to the processing method in Embodiment 1, and the only difference from Embodiment 1 is: In step S103, the packing volume ratio of the packing material in the activated carbon catalytic ozone oxidation zone, the biological activated carbon aerobic zone, and the biological activated carbon anoxic zone is 1:5:3; the rest is the same as in Example 1. The COD of the biological activated carbon effluent (second product water) is 25.5 mg / L, the turbidity is 1.9 NTU, the phosphate is 0.17 mg / L, and the total nitrogen is 14.0 mg / L. In step S104, the reverse osmosis permeate is 60% by volume, with a freshwater COD of 3.2 mg / L, turbidity of 0.1 NTU, phosphate of 0.04 mg / L, total nitrogen of 1.8 mg / L, pH of 7.9, and conductivity of 480 μS / cm; the concentrate has a COD of 52.5 mg / L, turbidity of 3.0 NTU, phosphate of 0.34 mg / L, total nitrogen of 29.5 mg / L, pH of 8.0, and conductivity of 7853 μS / cm.

[0067] Comparing Example 6 with Example 1, it can be seen that in step S103 of Example 1, the packing volume ratio of the packing material in the activated carbon catalytic ozone oxidation zone, the biological activated carbon aerobic zone, and the biological activated carbon anoxic zone is within the preferred range provided in this disclosure (1:3~4:1.5~2.5). The COD and total nitrogen of the second product water after treatment in step S103 of Example 1 are lower, and the COD and total nitrogen of the fresh water and concentrated water obtained through the overall treatment process are also lower.

[0068] Example 7 This embodiment refers to the processing method in Embodiment 1, and the only difference from Embodiment 1 is: In step S103, the packing volume ratio of the packing material in the activated carbon catalytic ozone oxidation zone, the biological activated carbon aerobic zone, and the biological activated carbon anoxic zone is 1:1:1; the rest is the same as in Example 1. The COD of the biological activated carbon effluent (second product water) is 26.1 mg / L, the turbidity is 1.9 NTU, the phosphate is 0.17 mg / L, and the total nitrogen is 14.2 mg / L. In step S104, the reverse osmosis permeate is 60% by volume, with a freshwater COD of 3.3 mg / L, turbidity of 0.1 NTU, phosphate of 0.04 mg / L, total nitrogen of 1.9 mg / L, pH of 7.9, and conductivity of 484 μS / cm; the concentrate has a COD of 53.5 mg / L, turbidity of 3.0 NTU, phosphate of 0.34 mg / L, total nitrogen of 29.9 mg / L, pH of 8.0, and conductivity of 7865 μS / cm.

[0069] Comparing Example 7 with Example 6, it can be seen that in step S103 of Example 6, the packing volume ratio of the packing material in the activated carbon catalytic ozone oxidation zone, the biological activated carbon aerobic zone, and the biological activated carbon anoxic zone is within the optimized range (1:2~5:1~3) provided in this disclosure. The COD and total nitrogen of the second product water after treatment in step S103 of Example 6 are lower, and the COD and total nitrogen of the fresh water and concentrated water obtained through the overall treatment process are also lower.

[0070] Example 8 This embodiment refers to the processing method in Embodiment 1, and the only difference from Embodiment 1 is: In step S102, the process conditions for the membrane catalytic ozone oxidation unit include: a membrane flux of 160 L / m³. 2 The ozone dosage was 10 mg / L, and the residence time of the petrochemical biochemical effluent was 0.75 h. The COD of the membrane catalytic ozone oxidation effluent (first product water) was 50.1 mg / L, the turbidity was 1.9 NTU, the phosphate was 0.3 mg / L, the residual ozone in the water was 1.4 mg / L, and the dissolved oxygen was 10.1 mg / L. In step S103, the treatment conditions in the biological activated carbon unit include: a treatment temperature of 10 ℃; a total residence time of the first product water of 2.25 h; a flow rate of the first product water of 24 L / min; specifically, the residence time of the first product water in the activated carbon catalytic ozone oxidation zone is 0.38 h; the residence time in the biological activated carbon aerobic zone is 1.13 h; the residence time in the biological activated carbon anoxic zone is 0.75 h; and the air aeration rate is 4 L / min·cm³ per unit volume of packing material in the biological activated carbon aerobic zone. -3 The dissolved oxygen in the aerobic zone of the biological activated carbon was 2.8 mg / L; the dissolved oxygen in the anoxic zone of the biological activated carbon was 0.9 mg / L; the COD of the effluent from the biological activated carbon (second product water) was 40.8 mg / L, the turbidity was 2.2 NTU, the phosphate was 0.27 mg / L, and the total nitrogen was 17.0 mg / L. In step S104, the reverse osmosis permeate is 60% by volume, with a freshwater COD of 4.3 mg / L, turbidity of 0.3 NTU, phosphate of 0.05 mg / L, total nitrogen of 2.0 mg / L, pH of 7.9, and conductivity of 500 μS / cm; the concentrate has a COD of 83.0 mg / L, turbidity of 3.5 NTU, phosphate of 0.58 mg / L, total nitrogen of 36.0 mg / L, pH of 8.0, and conductivity of 7760 μS / cm.

[0071] Comparing Example 8 with Example 1, it can be seen that Example 1, which treats petrochemical and biochemical effluent wastewater according to the preferred process conditions provided in this disclosure, has a better treatment effect. For example, the COD, total nitrogen, turbidity, conductivity and other indicators of the freshwater and concentrated water obtained through the overall treatment process are lower.

[0072] Comparative Example 4 The traditional "O3+BAF" process for treating biochemical effluent from a certain refining and chemical enterprise is adopted, with a treatment capacity of 120 m³. 3 The ozone dosage is 20-25 mg / L per hour, the biochemical retention time is 8 hours, and the existing "O3+BAF" process achieves a COD removal rate of 30.9%. The on-site treatment cost of the "O3+BAF" process is 2.44 yuan / t. The total area of ​​the main structures involved in the existing "O3+BAF" process is 469 m². 2 ; Side-line tests were conducted using the process disclosed herein, at a membrane flux of 60 L / (m²). 2 The ozone concentration is 10-15 mg / L, and the residence time of the biological activated carbon unit is 5 h. The COD removal rate is approximately 60%, and the wastewater treatment cost is 0.94 yuan / t. Compared with the current "O3+BAF" process, the process provided in this disclosure, based on a 120 m³ / h... 3 Based on the calculated processing capacity per hour, the area that can be saved after reuse and renovation is 126 m². 2 This saves 27% of the area.

[0073] The preferred embodiments of this disclosure have been described in detail above. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.

[0074] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0075] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A method for treating petrochemical and biochemical effluent, characterized in that, Includes the following steps: S1. The petrochemical and biochemical effluent to be treated is introduced into the membrane catalytic ozone oxidation unit for treatment to obtain the first product water; S2. The first product water is introduced into the biological activated carbon unit and sequentially flows through the activated carbon catalytic ozone oxidation zone, the biological activated carbon aerobic zone, and the biological activated carbon anoxic zone for treatment to obtain the second product water.

2. The method according to claim 1, characterized in that, The turbidity of the petrochemical biochemical effluent to be treated is below 12 NTU, the COD concentration is below 70 mg / L, the phosphate concentration is below 0.5 mg / L, the total nitrogen concentration is below 20 mg / L, and the BOD concentration is below 14 mg / L.

3. The method according to claim 1, characterized in that, In step S1, the membrane catalytic ozone oxidation unit includes a catalytic flat ceramic membrane; the catalytic flat ceramic membrane includes a support layer and a membrane layer that are bonded together, and the support layer and / or the membrane layer includes a first catalytic active component; and multiple parallel hollow channels are formed in the membrane layer of the catalytic flat ceramic membrane, the water outlets of the multiple hollow channels converge to the filtered water outlet channel, and the support layer is close to the hollow channels; the water outlet of the filtered water outlet channel is connected to the biological activated carbon unit via a suction pump; Preferably, the support layer and the film layer are made of α-alumina; Preferably, the first catalytically active component is selected from one or more of MnO2, Fe2O3, and CuO; preferably, based on the total weight of the catalytic flat ceramic membrane, the content of the first catalytically active component is 0.5-4% by weight, more preferably 2-3% by weight. Optionally, the catalytic plate ceramic membrane has a porous structure, wherein the pore size of the membrane layer is 50~200 nm, preferably 50~100 nm; the pore size of the support layer is 1~20 μm, preferably 5~15 μm; the thickness of the catalytic plate ceramic membrane is 3~10 mm, preferably 5~7 mm; and the diameter of the hollow channel is 2~4 mm, preferably 2.5~3.5 mm.

4. The method according to claim 3, characterized in that, The membrane catalytic ozone oxidation unit includes a shell, a first aeration device, and a membrane pore micro-nano reactor. The membrane pore micro-nano reactor includes the catalytic flat ceramic membrane. Preferably, the membrane pore micro-nano reactor includes multiple catalytic flat ceramic membranes connected in parallel. The filtered water outlet channels of the multiple catalytic flat ceramic membranes converge and are connected to the suction pump. The membrane pore micro-nano reactor is placed inside the shell. The catalytic plate ceramic membrane allows the effluent to be treated and ozone to enter the hollow channels inside the catalytic plate ceramic membrane through the pores on the catalytic plate ceramic membrane and carry out the ozone oxidation reaction. The petrochemical and biochemical effluent after the ozone oxidation reaction flows out through the filtered water effluent channel and is connected to the biological activated carbon unit through the suction pump. The first aeration device is located near the bottom of the shell, and the membrane pore micro / nano reactor is located above the first aeration device. The first aeration device is provided with aeration holes. Optionally, the inlet of the petrochemical biochemical effluent is located at the bottom of the shell of the membrane catalytic ozone oxidation unit.

5. The method according to claim 1, characterized in that, The process conditions for the membrane catalytic ozone oxidation unit include: membrane flux of 20~150 L / m 2 h, preferably 30~100 L / m 2 •h; the ozone dosage is 1~100 mg / L, preferably 5~30 mg / L, and the residence time of the petrochemical and biological effluent is 0.5~4 h, preferably 1~2 h.

6. The method according to claim 1, characterized in that, In step S2, the activated carbon catalytic ozone oxidation zone includes a first packing material, which comprises a first activated carbon and a second catalytic active component; the second catalytic active component is selected from one or more of Fe2O3, CuO, and MnO2; preferably, based on the total weight of the first packing material, the content of the second catalytic active component is 0.1~3% by weight, more preferably 0.5~2% by weight. The aerobic zone of the biological activated carbon includes a second packing material, a first aerobic microorganism, and nitrifying bacteria. The second packing material includes a second activated carbon. Preferably, based on the volume of the first product water, the dosage of the first aerobic bacteria is 1000~5000 mg / L, more preferably 2000~3000 mg / L; the dosage of the nitrifying bacteria is 500~1000 mg / L, more preferably 600~800 mg / L. The anoxic zone of the biological activated carbon includes a third packing material, a second aerobic microorganism, and denitrifying bacteria; along the flow direction of the petrochemical biochemical effluent, the second aerobic microorganism is positioned upstream of the denitrifying bacteria; the third packing material includes a third activated carbon; preferably, based on the volume of the first product water, the dosage of the second aerobic microorganism is 100~800 mg / L, more preferably 300~600 mg / L; the dosage of the denitrifying bacteria is 500~2000 mg / L, more preferably 1000~1500 mg / L; Optionally, the first activated carbon, the second activated carbon, and the third activated carbon are each independently selected from coal-based columnar activated carbon; more preferably, the first activated carbon, the second activated carbon, and the third activated carbon have an iodine value greater than 800 mg / g, a diameter of 1~2 mm, and a length of 2~5 mm.

7. The method according to claim 6, characterized in that, In the biological activated carbon unit, the activated carbon catalytic ozone oxidation zone, the biological activated carbon aerobic zone, and the biological activated carbon anoxic zone are arranged sequentially from top to bottom; there is a gap between the top of the activated carbon catalytic ozone oxidation zone and the top of the shell of the biological activated carbon unit, and the first product water inlet of the biological activated carbon unit is located on the side wall of the gap. Preferably, the packing volume ratio of the packing material in the activated carbon catalytic ozone oxidation zone, the biological activated carbon aerobic zone, and the biological activated carbon anoxic zone is 1:2~5:1~3, more preferably 1:3~4:1.5~2.5; Preferably, the aerobic zone of the bio-activated carbon is provided with a second aeration device for introducing air; optionally, the second aeration device is located at the bottom of the aerobic zone of the bio-activated carbon, and the aeration holes of the second aeration device face the top of the aerobic zone of the bio-activated carbon.

8. The method according to claim 7, characterized in that, In step S2, the processing conditions in the bio-activated carbon unit include: The processing temperature is 15~35℃, preferably 20~30℃; the total residence time of the first product water is 3~9 h, preferably 5~7 h; the flow rate of the first product water is 5~10 L / min, preferably 8~9 L / min. Optionally, the residence time of the first product water in the activated carbon catalytic ozone oxidation zone is 0.5-2 h, preferably 1-1.5 h; the residence time in the aerobic zone of the biological activated carbon is 1-5 h, preferably 2-4 h; and the residence time in the anoxic zone of the biological activated carbon is 1-3 h, preferably 1.5-2 h. Optionally, the air aeration rate is 1~4 L / min, preferably 1.5~3.0 L / min, based on the packing material in the aerobic zone of the bio-activated carbon per cubic meter; More preferably, the dissolved oxygen in the aerobic zone of the bio-activated carbon is 1~8 mg / L, more preferably 2~4 mg / L; the dissolved oxygen in the anoxic zone of the bio-activated carbon is 0.1~0.8 mg / L, more preferably 0.2~0.5 mg / L.

9. The method according to claim 1, characterized in that, A pipeline mixer is installed on the pipeline that introduces biochemical wastewater into the membrane catalytic ozone oxidation unit. The pipeline mixer includes a reagent inlet so that the biochemical wastewater enters the pipeline mixer and is treated after contacting the reagent. Preferably, the method further includes: The effluent from the petrochemical and biochemical processes to be treated undergoes water quality testing via an online water quality monitoring and automatic control unit. Based on the test results, the dosage of chemicals in the pipeline mixer is automatically adjusted. Then, the effluent from the pipeline mixer flows into the membrane catalytic ozone oxidation unit. The water quality test indicators include the turbidity and phosphate concentration of the effluent. The dissolved oxygen in the biological activated carbon unit is tested using an online water quality monitoring and automatic control unit, and the air aeration rate in the biological activated carbon unit is adjusted based on the dissolved oxygen test results.

10. The method according to claim 9, characterized in that, The method includes: When the online water quality monitoring and automatic control unit displays that the turbidity of the effluent to be treated is 4~12 NTU and / or the phosphate concentration is 0.3~0.5 mg / L, the online monitoring and automatic control unit controls the dosing system on the incoming water pipeline to be turned on, so as to add chemicals to the effluent to be treated introduced through the incoming water pipeline; optionally, the chemicals include one or more of coagulants and phosphorus removal agents; optionally, the coagulant is selected from one or more of PAC, PFS and PAFC, preferably PAC; preferably, the dosage of the chemicals is (1×turbidity + 2.5×phosphate concentration - 8) mg / L.

11. The method according to claim 9, characterized in that, A first dissolved oxygen testing position is provided in the middle of the aerobic zone of the bio-activated carbon, and a second dissolved oxygen testing position is provided in the lower part of the anoxic zone of the bio-activated carbon; the method includes: The dissolved oxygen levels in the effluent from the biological activated carbon unit were tested at the first and second dissolved oxygen testing locations using an online water quality monitoring and automatic control unit. When the dissolved oxygen concentration at the first testing location was below 2 mg / L, the aeration rate of the air in the biological activated carbon unit was adjusted to (0.5 × treated water volume) m³ / h, based on the water volume in the biological activated carbon unit. 3 / h; And / or, when the dissolved oxygen concentration at the second dissolved oxygen test location is above 0.5 mg / L, reduce the aeration rate in the aerobic zone of the bio-activated carbon.

12. The method according to claim 1, characterized in that, The method also includes: The second product water obtained from the biological activated carbon unit enters the protection unit, flows through the softener and the security filter in sequence for treatment, and then enters the reverse osmosis unit for treatment to obtain reverse osmosis desalinated water and reverse osmosis concentrate.

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