A process and device for treating high-concentration organic wastewater by coupling advanced oxidation method with biological method

Abstract

The present invention discloses a process and device for treating high-concentration organic wastewater by coupling an advanced oxidation process with a biological process. The process of the present application is as follows: the high-concentration organic wastewater and air are preheated separately and then introduced into a catalytic combustion reactor to carry out a catalytic combustion reaction. The treated wastewater vapor is sent into a bioreactor after heat exchange and condensation to be treated by an activated sludge process. The treated wastewater can meet the discharge standards. After the catalyst in the first catalytic burner is deactivated, it can be switched to the second catalytic burner for reaction. The deactivated catalyst can be regenerated in situ at high temperature by introducing air. The present invention solves the problems of large footprint and high energy consumption of common high-concentration organic wastewater treatment methods by combining electromagnetic heating technology, catalytic combustion technology and biological activated sludge treatment technology, and realizes efficient treatment of high-concentration organic wastewater. The chemical oxygen demand of the treated wastewater can meet the secondary discharge standard of industrial wastewater.

Description

Technical Field

[0001] The invention belongs to the technical field of industrial wastewater treatment, and specifically relates to a process and a device for treating high-concentration organic wastewater by using an advanced oxidation method coupled with a biological method. Background Art

[0002] Wastewater generated in the chemical, coal chemical, pharmaceutical and other industries has the characteristics of high concentration, high toxicity, complex composition, and difficulty in being directly degraded by microorganisms. The chemical oxygen demand (COD) of these high-concentration organic wastewaters is usually above 20,000 mg / L, and the COD of some wastewaters can reach hundreds of thousands of mg / L. Therefore, it is urgent to solve the problem of efficient treatment of high-concentration organic wastewater.

[0003] At present, common wastewater treatment processes mainly include advanced oxidation, physical and chemical methods, and biological methods. Advanced oxidation methods include photocatalytic oxidation, ozone oxidation, etc., which convert organic matter into carbon dioxide and water under the conditions of highly active oxidizing substances. Physical and chemical methods include adsorption, coagulation, etc., which use adsorption and other effects to condense organic matter to achieve purification. Biological methods include aerobic biological treatment, anaerobic biological treatment, etc., which use microorganisms to decompose organic matter into inorganic components. There are shortcomings in the treatment of high-concentration wastewater. Advanced oxidation methods usually use a large amount of oxidants, which is too expensive; physical and chemical methods cannot completely purify wastewater; biological methods usually have a long treatment cycle, and high-concentration wastewater has too high COD, and direct biological treatment will cause biological hypoxia and death. Therefore, if the two wastewater treatment technologies can be coupled to treat high-concentration organic wastewater, while reducing energy consumption, it can also ensure efficient and thorough treatment of wastewater. Summary of the invention

[0004] In view of the above technical problems existing in the prior art, the object of the present invention is to provide a process and device for treating high-concentration organic wastewater by coupling an advanced oxidation process with a biological process.

[0005] The process for treating high-concentration organic wastewater by an advanced oxidation method coupled with a biological method is characterized by comprising the following steps:

[0006] 1) Purification of high-concentration organic wastewater: Under the conveying action of the feed pump, the high-concentration organic wastewater enters the cold fluid channel of the heat exchanger through the liquid flow meter for heat exchange, and then passes through the first preheater for secondary preheating to form wastewater steam from the high-concentration organic wastewater. The wastewater steam and the air passing through the second preheater are introduced into the first catalytic burner filled with a catalyst for purification reaction. The purified high-temperature steam flows into the hot fluid channel of the heat exchanger for heat exchange with the high-concentration organic wastewater, and is stored in the product tank after condensation by the condenser. The organic wastewater in the product tank is discharged into the bioreactor for activated sludge treatment, and the wastewater after secondary treatment can be discharged as purified wastewater;

[0007] 2) Catalyst regeneration: After the catalyst in the first catalytic burner is deactivated, the wastewater vapor is switched to the second reaction route, that is, it enters the second catalytic burner filled with catalyst together with air for purification reaction. The purified high-temperature steam flows into the hot fluid channel of the heat exchanger to exchange heat with high-concentration organic wastewater. Air is introduced into the first catalytic burner at 500-600°C for regeneration and activation. The discharged regenerated tail gas can be centrally purified.

[0008] The process for treating high-concentration organic wastewater by an advanced oxidation method coupled with a biological method is characterized in that the initial COD of the high-concentration organic wastewater is between 20,000 mg / L and 100,000 mg / L, and its COD can be reduced by more than 98% after catalytic combustion treatment. The organic wastewater stored in the product tank after catalytic combustion treatment is further treated by an activated sludge method, and its COD can be further reduced by more than 90%.

[0009] The process for treating high-concentration organic wastewater by coupling an advanced oxidation process with a biological process is characterized in that the first catalytic burner or the second catalytic burner is heated by electromagnetic heating, the temperature for the purification reaction is 200-400°C, and the catalyst filled therein is a foamed nickel monolithic catalyst or a foamed iron monolithic catalyst.

[0010] The process for treating high-concentration organic wastewater by coupling an advanced oxidation process with a biological process is characterized in that the nickel foam monolithic catalyst uses a whole piece of nickel foam as a carrier, and Al is first deposited on the carrier. 2 O 3 Reload Fe 2 O 3 , whose composition structure is Fe 2 O 3 / Al 2 O 3 / Foam Nickel,Al 2 O 3 The deposition amount accounts for Al 2 O 3 35-45% of the total mass of Fe and nickel foam 2 O 3 Loading amount of Fe 2 O 3 、Al 2 O 3 5-15% of the total mass of the three components;

[0011] The foam iron monolithic catalyst uses a whole piece of foam iron as a carrier, and first deposits Al on the carrier. 2 O 3 Reload Fe 2 O 3 , whose composition structure is Fe 2 O3 / Al 2 O 3 / Foam iron, Al 2 O 3 The deposition amount accounts for Al 2 O 3 35-45% of the total mass of Fe and foam iron, 2 O 3 Loading amount of Fe 2 O 3 、Al 2 O 3 5 to 15% of the total mass of the three together with foamed iron.

[0012] Furthermore, the preparation of the catalyst includes: firstly, pre-treating the foam metal, placing the whole foam metal in ethanol, 1mol / L HCl, 1mol / L NaOH, and deionized water solutions in turn for ultrasonic cleaning, and drying for use. Then, the coating is loaded, the foam metal is immersed in nano-alumina sol for 1 hour, taken out and dried for 2 hours, and calcined in a muffle furnace at 450°C for 4 hours, and the steps are repeated until the coating loading is 40%, where the loading is the mass of the coating to the substrate. Finally, the active component is loaded, and the foam metal with the coating loaded is placed in 1mol / LFe(NO 3 ) 3 The solution was immersed in excess for 1 hour, taken out and dried for 2 hours, and calcined in a muffle furnace at 500℃ for 5 hours. The steps were repeated until Fe 2 O 3 The load reaches the target value.

[0013] The process for treating high-concentration organic wastewater by coupling an advanced oxidation process with a biological process is characterized in that the bioreactor adopts an activated sludge process for treatment, is equipped with an aeration system and a PLC automatic control system, and the PLC automatic control system controls the operation cycle of the bioreactor. Each time high-concentration organic wastewater is introduced, aeration is performed for 150 to 300 minutes. After the aeration is completed, precipitation is performed to put the mixed liquid in a static state for subsequent separation. After the precipitation is completed, the supernatant is discharged, and the discharged supernatant is the purified wastewater. After the drainage is completed, the wastewater is allowed to stand, and the sludge that is left to stand is the return sludge of the next cycle. The operating temperature of the whole process is (25±5)°C, the pH of the wastewater is 7 to 8, and the dissolved oxygen content during aeration is 2 to 3 mg / L.

[0014] The process for treating high-concentration organic wastewater by coupling an advanced oxidation process with a biological process is characterized in that the aeration time of each treatment cycle is 200 to 240 minutes, the sedimentation time is 20 to 60 minutes, and the standing time is 10 to 30 minutes.

[0015] The process for treating high-concentration organic wastewater by coupling an advanced oxidation process with a biological process is characterized in that the bioreactor inoculated sludge is aerobic sludge particles, and after each introduction of high-concentration organic wastewater, the suspended solid concentration MLSS of the activated sludge inside the bioreactor reaches 3000-4000 mg / L.

[0016] The device used in the process of treating high-concentration organic wastewater by an advanced oxidation method coupled with a biological method is characterized in that it includes a feed pump, a liquid flow meter, a heat exchanger, a first preheater, a first catalytic burner and a second catalytic burner arranged in parallel, a condenser, a product tank and a bioreactor; the cold fluid channel inlet of the heat exchanger is connected to the feed pump through a liquid flow meter pipeline, the cold fluid channel outlet of the heat exchanger is connected to the inlet of the first preheater by a pipeline, and the outlet of the first preheater is divided into two paths, one path is connected to the top of the first catalytic burner by a pipeline through a second valve, and the other path is connected to the second catalytic burner through a third valve. The top of the burner is connected by a pipeline; the bottom outlet of the first catalytic burner is divided into two paths, one path discharges the regenerated tail gas through the fifth valve, and the other path is connected to the inlet of the hot fluid channel of the heat exchanger by a pipeline through the fourth valve; the bottom outlet of the second catalytic burner is divided into two paths, one path discharges the regenerated tail gas through the sixth valve, and the other path is connected to the inlet of the hot fluid channel of the heat exchanger by a pipeline through the seventh valve; the high-temperature steam flowing into the inlet of the hot fluid channel of the heat exchanger is used as a heat source to heat the high-concentration organic wastewater; the outlet of the hot fluid channel of the heat exchanger is connected to the product tank by a pipeline through the condenser; the bioreactor and the product tank are connected by a pipeline.

[0017] The device used in the process of treating high-concentration organic wastewater by an advanced oxidation process coupled with a biological process is characterized in that it also includes a second preheater, air is introduced into the inlet end of the second preheater, and the outlet of the second preheater is divided into two paths, which are respectively connected to the top inlet of the first catalytic burner and the top inlet of the second catalytic burner by pipelines through the eighth valve and the ninth valve.

[0018] Beneficial effects of the present invention:

[0019] 1) The present invention uses an advanced oxidation method coupled with a biological method to efficiently reduce COD in high-concentration organic wastewater. After the high-concentration wastewater passes through a catalytic burner, the COD can be reduced from 100,000 mg / L to less than 2,000 mg / L, and then after passing through a bioreactor, the COD can be reduced to less than 200 mg / L, ensuring a high COD removal rate.

[0020] 2) The present invention uses a recycled steam heat source to send the wastewater vapor after catalytic combustion into the hot fluid channel for heat exchange, and conducts countercurrent heat exchange with the high-concentration organic wastewater in the cold fluid channel. The wastewater vapor after heat exchange is condensed and transported through pipelines to the subsequent device for reaction. The heat load of the first preheater is reduced, and the energy consumption is greatly reduced.

[0021] 3) The catalytic combustion reactor adopts electromagnetic heating, combined with foamed nickel or foamed iron as a whole catalyst. Compared with electric heating, electromagnetic heating is overall heating, with fast heating speed, small heat loss, high thermal efficiency, safety and environmental protection. The filled foam metal catalyst has higher mechanical strength than traditional catalysts, more stable catalyst properties, less prone to coking, more stable bed temperature and higher catalytic efficiency. At the same time, the catalyst is regenerated in situ to ensure the continuous and stable operation of the device.

[0022] 4) Compared with the currently commonly used wastewater treatment technologies at home and abroad, the present invention has the advantages of low energy consumption, high efficiency and stable operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A device for treating high-concentration organic wastewater by coupling the advanced oxidation method with the biological method of the present application;

[0024] Figure 1 In: 1-feed pump, 21-first valve, 22-second valve, 23-third valve, 24-fourth valve, 25-fifth valve, 26-sixth valve, 27-seventh valve, 28-eighth valve, 29-ninth valve, 210-tenth valve, 211-eleventh valve, 3-liquid flow meter, 4-heat exchanger, 5-preheater, 6-first catalytic burner, 7-second catalytic burner, 8-second preheater, 9-condenser, 10-product tank, 11-bioreactor. DETAILED DESCRIPTION

[0025] The present invention will be further described below in conjunction with specific embodiments, but the protection scope of the present invention is not limited thereto.

[0026] Example: Control Figure 1

[0027] A device for treating high-concentration organic wastewater by an advanced oxidation process coupled with a biological process comprises a feed pump 1, a liquid flow meter 3, a heat exchanger 4, a first preheater 5, a first catalytic burner 6 and a second catalytic burner 7 arranged in parallel, a condenser 9, a product tank 10, and a bioreactor 11.

[0028] High-concentration organic wastewater is introduced into the inlet of the feed pump 1, and the outlet of the feed pump 1 is connected to the cold fluid channel of the heat exchanger 4 through the first valve 21 and the liquid flowmeter 3. The cold fluid channel of the heat exchanger 4 is connected to the inlet of the first preheater 5 by a pipeline, and the outlet of the first preheater 5 is divided into two paths, one of which is connected to the top of the first catalytic burner 6 by a pipeline through the second valve 22, and the other is connected to the top of the second catalytic burner 7 by a pipeline through the third valve 23. In the actual application process, the first catalytic burner 6 and the second catalytic burner 7 alternately perform catalytic combustion reaction and regeneration. When one is in a reaction state for removing organic matter in wastewater vapor, the other is fed with air for heating and regeneration.

[0029] The hot fluid channel inlet of the heat exchanger 4 is divided into two paths, one of which is connected to the bottom outlet of the first catalytic burner 6 by a pipeline through the fourth valve 24, and the other is connected to the bottom outlet of the second catalytic burner 7 by a pipeline through the seventh valve 27. The high-temperature steam flowing out of the hot fluid channel outlet of the heat exchanger 4 is used as a heat source to heat the high-concentration organic wastewater. A first branch pipe is also connected to the pipeline between the bottom outlet of the first catalytic burner 6 and the fourth valve 24, and a fifth valve 25 is provided on the first branch pipe; a second branch pipe is also connected to the pipeline between the bottom outlet of the second catalytic burner 7 and the seventh valve 27, and a sixth valve 26 is provided on the second branch pipe.

[0030] The bioreactor 11 is connected to the condenser 9 through the tenth valve 210 and the product tank 10, and the wastewater vapor after catalytic combustion is sent to the bioreactor 11 after heat exchange and condensation. The bioreactor 11 adopts the activated sludge method for treatment, and is equipped with an aeration system and a PLC automatic control system. In practical applications, the PLC automatic control system controls the operation cycle of the SBR. After each high-concentration organic wastewater is introduced, aeration is performed for 150 to 300 minutes. After the aeration is completed, precipitation is performed to make the mixed liquid in a static state for subsequent separation. After the precipitation is completed, the supernatant is discharged, and the discharged supernatant is the purified wastewater. After the drainage is completed, it is allowed to stand, and the sludge that is left to stand is the return sludge of the next cycle. The operating temperature of the whole process is (25±5)℃, the pH of the wastewater is 7 to 8, and the dissolved oxygen content during aeration is 2 to 3 mg / L.

[0031] Furthermore, in one treatment cycle: water intake for 60 minutes, aeration for 240 minutes, sedimentation for 30 minutes, drainage for 15 minutes, and standing for 15 minutes, a total of 6 hours. Water intake was 4 times a day, and the water intake was 1.5L each time.

[0032] Furthermore, the inoculated sludge of the bioreactor 11 is aerobic sludge particles. After each introduction of high-concentration organic wastewater, the suspended solid concentration MLSS of the activated sludge inside the bioreactor reaches 3000-4000 mg / L.

[0033] Comparison Figure 1 The device of the present application also includes a second preheater 8, air is introduced into the inlet end of the second preheater 8, and the outlet of the second preheater 8 is divided into two paths, which are respectively connected to the top inlet of the first catalytic burner 6 and the top inlet of the second catalytic burner 7 by pipelines through the eighth valve 28 and the ninth valve 29, so as to respectively introduce the hot air preheated by the second preheater 8.

[0034] At the start-up stage of the device, fresh steam is used as the heat source for heating high-concentration organic wastewater or directly heated by a preheater. After the device runs stably, the heat of the high-temperature steam flowing out of the hot fluid channel outlet of the heat exchanger is recovered.

[0035] The process steps of using the device of the present application to treat high-concentration organic wastewater by advanced oxidation coupled biological method are as follows:

[0036] 1) Vaporization of high-concentration organic wastewater: Under the conveying action of the feed pump 1, the high-concentration organic wastewater enters the heat exchanger 4 and the first preheater 5 through the first valve 21 and the liquid flowmeter 3 in turn for heat exchange, and then is heated to 200°C to 400°C by the first preheater 5, and is passed into the first catalytic burner 6 through the second valve 22. At the same time, the hot air of the second preheater 8 is also passed into the first catalytic burner 6 through the eighth valve 28 for purification reaction. The purified high-temperature steam flows into the hot fluid channel of the heat exchanger 4 for heat exchange, and is used as a heat source to heat the high-concentration organic wastewater, and is condensed by the condenser 9 and discharged into the bioreactor 11 for activated sludge treatment. The wastewater after secondary treatment is discharged as purified wastewater;

[0037] 2) Catalyst regeneration: After the catalyst in the first catalytic burner 6 is deactivated, the wastewater is switched to the second reaction route, that is, the third valve 23 is opened and the second valve 22 is closed to control the wastewater steam to enter the second catalytic burner 7 for purification reaction. The purified high-temperature steam flows into the hot fluid channel of the heat exchanger 4 for heat exchange, and then serves as a heat source to heat the high-concentration organic wastewater; air is introduced into the first catalytic burner 6 at 500-600°C for regeneration and activation, and the discharged regeneration tail gas can be centrally purified.

[0038] At the same time, during the regeneration of the catalyst in step 2), the fifth valve 25 and the eighth valve 28 are opened, and the fourth valve 24 is closed. Two streams of preheated hot air are discharged through the second preheater 8, one of which is used for the regeneration of the catalyst, that is, it is introduced into the first catalytic burner 6 and regenerated and activated at a temperature of 500-600° C. The bottom outlet of the first catalytic burner 6 discharges the regenerated tail gas through the fifth valve 25. The regenerated tail gas discharged from the first catalytic burner 6 can be centrally purified, for example, by absorbing the regenerated tail gas using an absorbing liquid. The second stream of hot air discharged from the second preheater 8 is introduced into the second catalytic burner 7 for reaction.

[0039] The preparation of the catalyst in the present invention includes: firstly, pre-treating the foam metal, placing the foam metal in ethanol, 1mol / L HCl, 1mol / L NaOH, and deionized water solutions, ultrasonically cleaning the foam metal, and drying it for use. Then, loading the coating, placing the foam metal in a nano-alumina sol (Al 2 O 3 The coating was immersed in 15% (mass fraction) for 1 hour, taken out and dried for 2 hours, and calcined in a muffle furnace at 450°C for 4 hours. The steps were repeated until the coating loading was 40%, where the loading was the mass of the coating to the substrate. Finally, the active component was loaded. The foam metal with the coating loaded was placed in 1 mol / LFe (NO 3 ) 3 The solution was immersed in excess for 1 hour, taken out and dried for 2 hours, and calcined in a muffle furnace at 500℃ for 5 hours. The steps were repeated until Fe 2 O 3 The load reaches the target value.

[0040] Embodiment 1:

[0041] According to Figure 1 The device shown is used to treat high-concentration organic wastewater by using an advanced oxidation method coupled with a biological method:

[0042] The first catalytic burner 6 and the second catalytic burner 7 are filled with a foamed nickel monolithic catalyst (whose composition is 10 wt % Fe 2 O 3 / 40wt%Al 2 O 3 / Foam nickel, the size of foam nickel is 10cm*10cm*5cm, Al 2 O 3 The loading amount is Al 2 O 3 and the weight ratio of nickel foam, Fe 2 O 3 The loading amount is iron oxide and Al 2 O 3 The bioreactor is SBR, and the inoculated sludge is aerobic sludge particles.

[0043] The temperatures of the first preheater 5 and the first catalytic burner 6 are raised to 300° C. by electric heating and electromagnetic heating respectively, and fresh steam is first used as a heat source to heat the high-concentration wastewater. After the device is stable, it is transported by the feed pump 1, and the biodiesel glyceride esterification production wastewater enters the heat exchanger 4 through the first valve 21 and the liquid flow meter 3 for vaporization. The generated wastewater steam is heated to 300°C through the cold fluid channel of the heat exchanger and the first preheater 5, and then passes into the first catalytic burner 6 through the second valve 22. At the same time, the hot air preheated from the second preheater 8 passes into the first catalytic burner 6 through the eighth valve 28 for purification reaction. The purified 300°C high-temperature steam is discharged from the bottom of the first catalytic burner 6 and enters the hot fluid channel of the heat exchanger 4 through the fourth valve 24. The purified 300°C high-temperature steam exchanges heat with the wastewater in the heat exchanger 4. After heat exchange, the temperature of the wastewater flowing out of the cold fluid channel of the heat exchanger 4 rises to 250°C, and the temperature of the high-temperature steam flowing out of the hot fluid channel of the heat exchanger 4 drops to 145°C. The 145°C flowing out of the hot fluid channel of the heat exchanger 4 is stored in the product tank 10 after condensation. When the water volume in the product tank 10 reaches a certain amount, it is transported to the bioreactor 11. After being treated by the biological sludge method, it can be discharged as purified wastewater.

[0044] After the catalyst in the first catalytic burner 6 is deactivated, the third valve 23 is opened and the second valve 22 is closed, and two streams of preheated hot air are discharged through the second preheater 8, one of which is used for catalyst regeneration and the second is used for reaction. The waste water vapor and the second stream of hot air discharged from the second preheater 8 enter the second catalytic burner 7 together for purification reaction. The hot air for regeneration discharged from the second preheater 8 is passed into the first catalytic burner 6 and regenerated and activated at 550°C. The regenerated tail gas is discharged after passing through the seventh valve 27, and then subjected to centralized purification treatment to realize continuous operation of the device.

[0045] Under the control of the PLC system, bioreactor 12 passes 1.5L of purified wastewater into the bioreactor, and the water inlet time is 60min. After the water inlet is completed, aeration operation is carried out to even out the water quality and water volume, and the aeration time is 240min. After the aeration is completed, precipitation is carried out to make the mixed liquid in a static state for subsequent separation, and the precipitation time is 30min. After the precipitation is completed, the upper clear liquid is discharged, the drainage time is 15min, and the supernatant drainage volume is 1.5L. After the drainage is completed, it is allowed to stand, and the sludge that has been left to stand is the return sludge for the next cycle, and the standing time is 15min. One cycle is 6h in total, and water can be inlet 4 times a day. The reaction temperature is (25±1)℃, the wastewater pH is 7-8, and the dissolved oxygen content during aeration is 2-3mg / L.

[0046] The inoculated sludge of the bioreactor 11 is aerobic sludge particles. After each introduction of high-concentration organic wastewater, the suspended solid concentration MLSS of the activated sludge inside the bioreactor reaches 3500 mg / L.

[0047] After catalytic combustion treatment, the chemical oxygen demand (COD) of biodiesel glycerol esterification wastewater is reduced from the initial 100,000 mg / L to below 2,000 mg / L, and can be further reduced to 200 mg / L after biological treatment. The comprehensive removal rate reaches more than 99.8%, and the wastewater COD meets the secondary discharge standard for industrial wastewater.

[0048] According to the implementation process of Example 1, if the biodiesel glycerol esterification wastewater with an initial COD of 100,000 mg / L is put into the bioreactor 11 for activated sludge treatment, aerobic bacteria will die due to lack of oxygen, making it difficult to achieve good experimental results.

[0049] Embodiment 2:

[0050] According to Figure 1 The device shown in the figure is used to continuously treat high-concentration organic wastewater. The operation steps are repeated in Example 1, except for the following two points:

[0051] 1. The catalysts of the first catalytic burner and the second catalytic burner were replaced with foamed iron monolithic catalysts (10 wt% Fe 2 O 3 / 40wt%Al 2 O 3 / Foam iron, the size of the foam iron is 10cm*10cm*5cm, Al 2 O 3 The loading amount is Al 2 O 3 The weight ratio of Fe to foam iron, 2 O 3 The loading amount is iron oxide and Al 2 O 3 The weight ratio of foamed iron);

[0052] 2. The wastewater raw material is replaced with oil epoxidation reaction wastewater with an initial chemical oxygen demand of about 20,000 mg / L (i.e., wastewater produced by epoxidation reaction of biodiesel, formic acid and hydrogen peroxide), and the remaining operating steps are the same as those in Example 1.

[0053] After treatment, the chemical oxygen demand of oil epoxidation reaction wastewater can be reduced from the initial 20,000 mg / L to below 500 mg / L after the first catalytic combustion treatment, and then to 50 mg / L after biological treatment. The removal rate is as high as over 99.9%, and the wastewater COD meets the first-level discharge standard for industrial wastewater.

[0054] The contents described in this specification are merely an enumeration of implementation forms of the inventive concept, and the protection scope of the present invention should not be regarded as being limited to the specific forms described in the embodiments.

Claims

1. A process for treating high-concentration organic wastewater by an advanced oxidation process coupled with a biological process, characterized in that The following steps are involved: 1) Purification of high-concentration organic wastewater: under the conveying action of the feed pump (1), the high-concentration organic wastewater enters the cold fluid channel of the heat exchanger (4) through the liquid flow meter (3) for heat exchange, and then passes through the first preheater (5) for secondary preheating, so that the high-concentration organic wastewater forms wastewater steam. The wastewater steam and the air that has passed through the second preheater are introduced into the first catalytic burner (6) filled with a catalyst for purification reaction. The purified high-temperature steam flows into the hot fluid channel of the heat exchanger (4) for heat exchange with the high-concentration organic wastewater, and is condensed by the condenser (9) and stored in the product tank (10). The organic wastewater in the product tank (10) is discharged into the bioreactor (11) for activated sludge treatment. The wastewater after secondary treatment can be discharged as purified wastewater; 2) Catalyst regeneration: After the catalyst in the first catalytic burner (6) is deactivated, the wastewater vapor is switched to the second reaction route, that is, it enters the second catalytic burner (7) filled with a catalyst together with air for purification reaction. The purified high-temperature steam flows into the hot fluid channel of the heat exchanger (4) to exchange heat with the high-concentration organic wastewater. Air is introduced into the first catalytic burner (6) at 500-600°C for regeneration and activation. The discharged regenerated tail gas can be centrally purified and treated; The initial COD of high-concentration organic wastewater is between 20,000 mg / L and 100,000 mg / L. The COD of the high-concentration organic wastewater can be reduced by more than 98% after catalytic combustion treatment. The organic wastewater stored in the product tank (10) after catalytic combustion treatment is further treated by an activated sludge process, which can further reduce the COD by more than 90%. The catalyst filled in the first catalytic burner (6) or the second catalytic burner (7) is a foamed nickel monolithic catalyst or a foamed iron monolithic catalyst; The nickel foam monolithic catalyst uses a whole piece of nickel foam as a carrier, first depositing Al2O3 on the carrier and then loading Fe2O3, and its composition structure is Fe2O3 / Al2O3 / nickel foam, the deposited amount of Al2O3 accounts for 35-45% of the total mass of Al2O3 and nickel foam, and the Fe2O3 loading amount accounts for 5-15% of the total mass of Fe2O3, Al2O3 and nickel foam; The foam iron monolithic catalyst uses a whole piece of foam iron as a carrier, first depositing Al2O3 on the carrier and then loading Fe2O3, and its composition structure is Fe2O3 / Al2O3 / foam iron, the deposited amount of Al2O3 accounts for 35-45% of the total mass of Al2O3 and foam iron, and the loaded amount of Fe2O3 accounts for 5-15% of the total mass of Fe2O3, Al2O3 and foam iron; The preparation of the catalyst includes: firstly, pre-treating the foam metal, placing the whole piece of foam metal in ethanol, 1 mol / L HCl solution, 1 mol / L NaOH solution, and deionized water solution in turn for ultrasonic cleaning, drying and setting aside, then loading the coating, immersing the foam metal in nano-alumina sol for 1 hour, taking it out and drying it for 2 hours, and calcining it in a muffle furnace at 450°C for 4 hours, repeating the steps until the coating loading is 40%, where the loading is the mass fraction of the coating in the matrix, and finally loading the active component, placing the foam metal loaded with the coating in 1 mol / L Fe(NO3)3 solution for excessive immersion for 1 hour, taking it out and drying it for 2 hours, and calcining it in a muffle furnace at 500°C for 5 hours, and repeating the steps until the Fe2O3 loading reaches the target value.

2. The process for treating high-concentration organic wastewater by an advanced oxidation method coupled with a biological method as claimed in claim 1, characterized in that: The first catalytic burner (6) or the second catalytic burner (7) is heated by electromagnetic heating, and the temperature for the purification reaction is 200-400°C.

3. The process for treating high-concentration organic wastewater by an advanced oxidation method coupled with a biological method as claimed in claim 1, characterized in that: The bioreactor (11) adopts the activated sludge method and is equipped with an aeration system and a PLC automatic control system. The PLC automatic control system controls the operation cycle of the bioreactor. After each introduction of high-concentration organic wastewater, aeration is carried out for 150~300 minutes. After the aeration is completed, sedimentation is carried out to make the mixed liquid in a static state for subsequent separation. After the sedimentation is completed, the upper clear liquid is discharged. The discharged supernatant is the purified wastewater. After the drainage is completed, it is allowed to stand. The sludge that is left to stand is the return sludge for the next cycle. The operating temperature of the whole process is (25±5)℃, the pH of the wastewater is 7~8, and the dissolved oxygen content during aeration is 2~3 mg / L.

4. The process for treating high-concentration organic wastewater by an advanced oxidation method coupled with a biological method as claimed in claim 3, characterized in that: The aeration time of each treatment cycle is 200~240 min, the sedimentation time is 20~60 min, and the standing time is 10~30 min.

5. The process for treating high-concentration organic wastewater by an advanced oxidation method coupled with a biological method as claimed in claim 3, characterized in that: The inoculated sludge of the bioreactor (11) is aerobic sludge particles. After each introduction of high-concentration organic wastewater, the suspended solid concentration MLSS of the activated sludge inside the bioreactor reaches 3000~4000 mg / L.

6. The device used in the process of treating high-concentration organic wastewater by an advanced oxidation method coupled with a biological method as claimed in claim 1, characterized in that: The invention comprises a feed pump (1), a liquid flow meter (3), a heat exchanger (4), a first preheater (5), a first catalytic burner (6) and a second catalytic burner (7) arranged in parallel, a condenser (9), a product tank (10) and a bioreactor (11); the cold fluid channel inlet of the heat exchanger (4) is connected to the feed pump (1) through a pipeline of the liquid flow meter (3); the cold fluid channel outlet of the heat exchanger (4) is connected to the inlet of the first preheater (5) through a pipeline; the outlet of the first preheater (5) is divided into two paths, one of which is connected to the top of the first catalytic burner (6) through a pipeline through a second valve (22), and the other is connected to the top of the second catalytic burner (7) through a pipeline through a third valve (23); the bottom outlet of the first catalytic burner (6) is divided into two paths, one of which is connected to the regenerated exhaust gas through a fifth valve (25), and the other is connected to the top of the second catalytic burner (7) through a pipeline through a fourth valve (24); The valve (24) is connected to the inlet of the hot fluid channel of the heat exchanger (4) by a pipeline; the bottom outlet of the second catalytic burner (7) is divided into two paths, one path discharges the regenerated tail gas through the sixth valve (26), and the other path is connected to the inlet of the hot fluid channel of the heat exchanger (4) by a pipeline through the seventh valve (27); the high-temperature steam flowing into the inlet of the hot fluid channel of the heat exchanger (4) is used as a heat source to heat the high-concentration organic wastewater; the outlet of the hot fluid channel of the heat exchanger (4) is connected to the product tank (10) by a pipeline through the condenser (9); and the bioreactor (11) and the product tank (10) are connected by a pipeline.

7. The device used in the process of treating high-concentration organic wastewater by an advanced oxidation method coupled with a biological method as claimed in claim 6, characterized in that: It also includes a second preheater (8), air is introduced into the inlet end of the second preheater (8), and the outlet of the second preheater (8) is divided into two paths, which are respectively connected to the top inlet of the first catalytic burner (6) and the top inlet of the second catalytic burner (7) by pipelines through an eighth valve (28) and a ninth valve (29).

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