Industrial wastewater catalytic oxidation treatment process

Abstract

The invention discloses an industrial wastewater catalytic oxidation treatment process, which relates to the technical field of industrial wastewater treatment, and comprises the following steps: 1, pretreatment detoxification: removing suspended solids, colloids, oils, heavy metals and part of high-toxicity substances (such as phenols) through an arranged grating and a precision filter, adjusting water quality and water quantity, ensuring stable operation of a subsequent unit, and removing impurities in the subsequent unit; meanwhile, the intermittent drainage characteristic of chemical production is adapted; step 2, graded catalytic oxidation: the pretreated detoxified wastewater is subjected to graded cracking of different refractory groups through a multi-stage catalytic tower, the biodegradability is greatly improved (B / C is increased from less than 0.2 to more than 0.5), COD is removed, and toxic substances are reduced; and 3, carrying out conditioning and disinfection: carrying out conditioning and catalytic oxidation on the wastewater subjected to graded catalytic oxidation in the step 2, so as to reduce residual toxicity and meet the requirements of poison-resistant biological treatment. The oxidation rate and the oxidation speed can be further improved through the steps.

Description

Technical Field

[0001] This invention relates to the field of industrial wastewater treatment technology, specifically to a catalytic oxidation treatment process for industrial wastewater. Background Technology

[0002] Industrial wastewater treatment is a technological system for treating pollutant-containing wastewater generated in industrial production. It encompasses physical, biological, and chemical methods, adhering to principles such as source reduction and recycling to achieve resource recovery and pollution control. Its core methods include physical methods (gravity separation, flotation), biological methods (activated sludge process, biofilm process), and chemical methods (coagulation, oxidation-reduction), and are divided into primary treatment for removing suspended solids, secondary treatment for degrading organic matter, and tertiary treatment for deep purification.

[0003] Existing industrial wastewater catalytic oxidation treatment processes typically employ catalytic towers to treat industrial wastewater. These towers include ozone generation units, ozone catalytic oxidation units, and subsequent separation units. The strong oxidizing properties of ozone decompose organic matter in the wastewater. However, in practical applications, existing catalytic oxidation processes have several problems. Firstly, the ozone distribution within the catalytic tower is often uneven, leading to incomplete oxidation in some areas and affecting the overall oxidation effect. Secondly, existing catalytic oxidation processes have limited ability to break down different recalcitrant radicals, making it difficult to significantly improve the biodegradability of the wastewater to an ideal level, thus limiting the efficiency of subsequent biological treatment units. Summary of the Invention

[0004] The purpose of this invention is to provide a catalytic oxidation treatment process for industrial wastewater to solve the problems mentioned in the background art.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A catalytic oxidation treatment process for industrial wastewater includes the following steps: The first step is pretreatment and detoxification: suspended solids, colloids, oils, heavy metals and some highly toxic substances (such as phenols) are removed by setting up a bar screen and a precision filter, the water quality and quantity are adjusted to ensure the stable operation of subsequent units, and at the same time adapt to the intermittent drainage characteristics of chemical production. The second step is staged catalytic oxidation: the pretreated and detoxified wastewater is passed through a multi-stage catalytic tower to break down different recalcitrant groups, which greatly improves its biodegradability (B / C ratio increases from <0.2 to >0.5), removes COD, and reduces toxic substances; The third step is to adjust and disinfect the wastewater after the catalytic oxidation in the second step. This will reduce the remaining toxicity and meet the requirements of toxic biological treatment. The fourth step is toxic biological treatment: using domesticated special microorganisms to degrade small molecule organic matter and further remove pollutants such as COD, BOD, and ammonia nitrogen; The second step above requires the use of an industrial wastewater catalytic oxidation treatment device, which includes a primary tower and a secondary tower connected in series. The primary tower and the secondary tower are equipped with a first distribution mechanism and a second distribution mechanism, respectively.

[0006] A further improvement of the technical solution of the present invention is that: multiple retention hoppers are connected inside the primary column, and the multiple retention hoppers are connected to each other through a first infusion pipe; a conical hopper is fixedly connected to the inner wall of the primary column, and the conical hopper is located below the multiple retention hoppers.

[0007] A further improvement of the technical solution of the present invention is that: an ozone generator is installed on the outer wall of the first-stage tower, a main gas pipe is connected to the ozone generator, the main gas pipe extends into the interior of the first-stage tower, a branch pipe is provided inside the first-stage tower, the main gas pipe and the branch pipe are connected, an annulus is provided above the residence hopper and the conical hopper, the branch pipe and the annulus are connected, and an air outlet is provided on the annulus.

[0008] A further improvement of the technical solution of the present invention is that: the outlet end of the first infusion tube is located above the conical hopper, a valve is installed on the outer wall of the first infusion tube, the valve is located below the retention hopper, and multiple inlets are opened on the first infusion tube, the inlets being located above the retention hopper.

[0009] A further improvement of the technical solution of the present invention is that: a distribution hopper is slidably connected inside the primary tower, a plurality of slide rails are fixedly connected to the inner wall of the primary tower, the distribution hopper and the slide rails are slidably connected, a filter screen is connected to the surface of the distribution hopper, a plurality of round holes are opened on the distribution hopper, a plurality of connecting pipes communicating with the round holes are fixedly connected to the surface of the distribution hopper, and the connecting pipes extend to the top of the uppermost retention hopper.

[0010] A further improvement of the technical solution of the present invention is that: multiple connecting frames are fixedly connected between the primary tower and the secondary tower, multiple stagnant hoppers are provided in the secondary tower, and a second infusion pipe is connected between the multiple stagnant hoppers, and the second infusion pipe is connected to the conical hopper.

[0011] A further improvement of the technical solution of the present invention is that: the second distribution mechanism includes a connecting pipe, which is inserted into the interior of the secondary tower and extends to the outside. One end of the connecting pipe located on the outside is connected to a liquid inlet pipe. One end of the liquid inlet pipe is open, and the other end of the liquid inlet pipe is closed. Multiple liquid distribution pipes are provided inside the secondary tower. Multiple liquid outlet holes are provided on the liquid distribution pipes. The end of the connecting pipe located inside the secondary tower is connected to the liquid distribution pipes.

[0012] Due to the adoption of the above technical solution, the technical progress achieved by the present invention compared with the prior art is as follows: The present invention provides an industrial wastewater catalytic oxidation treatment process. Through the cooperation of the multi-stage tower and the first distribution mechanism and the second distribution mechanism, the wastewater can be fully contacted with the catalyst during the treatment process, achieving the effect of hierarchical catalytic oxidation, effectively cracking different refractory groups, greatly improving the biodegradability of the wastewater, converting the originally difficult-to-treat industrial wastewater into a water quality state that can be further biologically treated, and creating good conditions for subsequent steps such as poison-resistant biological treatment. In addition, for the industrial wastewater catalytic oxidation treatment equipment supporting this process, each component works together. For example, the settings of multiple residence hoppers, conical hoppers, material distribution hoppers, and ozone generators in the first-stage tower, as well as the cooperation of the liquid retention hopper and the second distribution mechanism in the second-stage tower, enable the equipment to efficiently and stably complete the wastewater treatment task during operation. The overall process and equipment have significant advantages and good application prospects in treating industrial wastewater. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a three-dimensional structural schematic diagram of the present invention; Figure 2 is an internal structural schematic diagram of the present invention; Figure 3 is a partial sectional structural schematic diagram of the present invention; Figure 4 For the present invention Figure 3 is an enlarged structural schematic diagram at A in

[0014] In the figure: 1, first-stage tower; 2, second-stage tower; 3, ozone generator; 4, material distribution hopper; 5, residence hopper; 6, conical hopper; 7, first distribution mechanism; 71, main air pipe; 72, branch pipe; 73, ring; 74, air outlet hole; 8, second distribution mechanism; 81, liquid inlet pipe; 82, connecting pipe; 83, liquid separation pipe; 84, liquid outlet hole; 9, liquid retention hopper; 10, connecting frame; 11, communicating pipe; 12, filter screen; 13, slide rail; 14, liquid inlet; 15, valve; 16, upper cover; 17, round hole; 18, first infusion pipe; 19, second infusion pipe. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0015] The following further describes the present invention in detail with reference to the embodiments: Embodiment 1 As Figure 1-4 shown, the present invention provides an industrial wastewater catalytic oxidation treatment process, including the following steps: The first step is pretreatment and detoxification: suspended solids, colloids, oils, heavy metals and some highly toxic substances (such as phenols) are removed by setting up a bar screen and a precision filter, the water quality and quantity are adjusted to ensure the stable operation of subsequent units, and at the same time adapt to the intermittent drainage characteristics of chemical production. A mechanical bar screen (0.5~1 mm gap) + a precision filter (50 μm pore size) is used to remove suspended solids unique to chemical production, such as plastic particles, catalyst residues, and resin fragments, to prevent clogging of the catalytic oxidation tower packing.

[0016] The second step is staged catalytic oxidation: the pretreated and detoxified wastewater is passed through a multi-stage catalytic tower to break down different recalcitrant groups, which greatly improves its biodegradability (B / C ratio increases from <0.2 to >0.5), removes COD, and reduces toxic substances; The system employs a series design of a primary ozone catalytic oxidation tower and a secondary hydrogen peroxide catalytic oxidation tower. The tower bodies are made of 316L stainless steel (resistant to acids, alkalis, and ozone corrosion) and filled with specialized catalyst packing. Wastewater flows counter-currently from top to bottom, contacting the oxidant. Compared to single catalytic oxidation, this staged design increases ozone utilization by over 50% and reduces hydrogen peroxide dosage by 30%, while avoiding the "incomplete oxidation" problem of recalcitrant substances in single oxidation processes. The subsequent toxic-resistant biological treatment unit uses domesticated special microorganisms to thoroughly mineralize small-molecule organic matter, while the advanced treatment and salt separation unit ensures effluent quality and resource utilization.

[0017] The third step is to adjust and disinfect the wastewater after the catalytic oxidation in the second step. This will reduce the remaining toxicity and meet the requirements of toxic biological treatment. The fourth step is toxic biological treatment: using domesticated special microorganisms to degrade small molecule organic matter and further remove pollutants such as COD, BOD, and ammonia nitrogen; The second step above requires the use of an industrial wastewater catalytic oxidation treatment device, which includes a primary tower 1 and a secondary tower 2 connected in series. The primary tower 1 and the secondary tower 2 are equipped with a first distribution mechanism 7 and a second distribution mechanism 8, respectively.

[0018] like Figure 3 As shown, the primary tower 1 is connected to multiple retention hoppers 5, which are connected to each other by a first infusion pipe 18. A conical hopper 6 is fixedly connected to the inner wall of the primary tower 1, and the conical hopper 6 is located below the multiple retention hoppers 5. The top of the primary tower 1 is threadedly connected to a top cover 16.

[0019] like Figure 3-4As shown, an ozone generator 3 is installed on the outer wall of the first-stage tower 1. A main gas pipe 71 is connected to the ozone generator 3. The main gas pipe 71 extends into the interior of the first-stage tower 1. A branch pipe 72 is provided inside the first-stage tower 1. The main gas pipe 71 and the branch pipe 72 are connected. An annular ring 73 is provided above the residence hopper 5 and the conical hopper 6. The branch pipe 72 and the annular ring 73 are connected. An air outlet 74 is provided on the annular ring 73.

[0020] The ozone generator 3 and the first distribution mechanism 7 can evenly distribute ozone in multiple stages within the primary tower 1, thereby improving oxidation efficiency and oxidation rate. Ozone is generated by the ozone generator 3 and then transported through the main gas pipe 71 to the branch pipe 72 inside the primary tower 1. The branch pipe 72 then transports the ozone to the annular ring 73, and finally, it is evenly released from the outlet 74 on the annular ring 73 into various locations within the primary tower 1, ensuring full contact with the wastewater for catalytic oxidation. This multi-stage ozone distribution method allows the ozone to come into more thorough contact with recalcitrant substances in the wastewater, greatly enhancing the catalytic oxidation effect, effectively removing COD and reducing toxic substances in the wastewater, and providing more favorable water quality conditions for subsequent treatment steps.

[0021] like Figure 2-3 As shown, the outlet end of the first infusion tube 18 is located above the conical hopper 6. A valve 15 is installed on the outer wall of the first infusion tube 18. The valve 15 is located below the retention hopper 5. The first infusion tube 18 has multiple inlet ports 14, which are located above the retention hopper 5.

[0022] Meanwhile, the design of multiple retention hoppers 5 within the primary tower 1 extends the residence time of wastewater within the primary tower 1, further ensuring the full progress of catalytic oxidation. Furthermore, the multiple retention hoppers 5 are connected by a first liquid delivery pipe 18. Multiple inlets 14 on the first liquid delivery pipe 18 are located above the retention hoppers 5, and the outlet end is located above the conical hopper 6. A valve 15 is installed on the outer wall below the retention hoppers 5. This design allows for flexible control of the wastewater flow and its residence within each retention hopper 5, enabling precise adjustments based on the actual wastewater treatment requirements. This ensures that each stage of catalytic oxidation achieves optimal results, improving the stability and reliability of the entire industrial wastewater catalytic oxidation treatment process.

[0023] Example 2 like Figure 3-4As shown, based on Embodiment 1, the present invention provides a technical solution: Preferably, a distributing hopper 4 is slidably connected inside the primary tower 1, and multiple slide rails 13 are fixedly connected to the inner wall of the primary tower 1. The distributing hopper 4 and the slide rails 13 are slidably connected. A filter screen 12 is connected to the surface of the distributing hopper 4. Multiple round holes 17 are opened on the distributing hopper 4. Multiple connecting pipes 11 communicating with the round holes 17 are fixedly connected to the surface of the distributing hopper 4. The connecting pipes 11 extend to the top of the uppermost dwelling hopper 5.

[0024] The combination of the feeding hopper 4, the slide rail 13, and the filter screen 12 enables the filtration of wastewater. When the filter screen 12 is affected by too many impurities, the top cover 16 can be opened easily to remove the feeding hopper 4 and clean the filter screen 12. The combination of the multiple round holes 17 and the connecting pipe 11 can evenly distribute the wastewater into the retention hopper 5 below.

[0025] like Figure 2 As shown, multiple connecting frames 10 are fixedly connected between the primary tower 1 and the secondary tower 2. Multiple stagnant water hoppers 9 are provided inside the secondary tower 2. A second infusion pipe 19 is connected between the multiple stagnant water hoppers 9. The second infusion pipe 19 is connected to the conical hopper 6.

[0026] like Figure 1-2 As shown, the second distribution mechanism 8 includes a connecting pipe 82, which is inserted into the interior of the secondary tower 2 and extends to the outside. One end of the connecting pipe 82 located on the outside is connected to a liquid inlet pipe 81. One end of the liquid inlet pipe 81 is open, and the other end of the liquid inlet pipe 81 is closed. The interior of the secondary tower 2 is provided with multiple liquid distribution pipes 83, and multiple liquid outlet holes 84 are opened on the liquid distribution pipes 83. The end of the connecting pipe 82 located inside the secondary tower 2 is connected to the liquid distribution pipes 83.

[0027] The combination of multiple stagnant hoppers 9 and a second distribution mechanism 8 enables hydrogen peroxide to be evenly distributed with wastewater at multiple points, thereby improving oxidation efficiency and rate. First, hydrogen peroxide is added to the inlet pipe 81. The hydrogen peroxide is then transported through the connecting pipe 82 to multiple distribution pipes 83 inside the secondary tower 2. Multiple outlet holes 84 on the distribution pipes 83 evenly disperse the hydrogen peroxide to various locations within the secondary tower 2, ensuring thorough mixing and contact with the wastewater that has undergone preliminary catalytic oxidation in the primary tower, facilitating further catalytic oxidation. This multi-point, even distribution of hydrogen peroxide allows for a more complete reaction with remaining recalcitrant substances in the wastewater, effectively enhancing the secondary catalytic oxidation effect, further removing COD and reducing toxic substances, resulting in deeper wastewater purification. This creates better conditions for subsequent conditioning, disinfection, and toxic biological treatment steps, ensuring the efficient and stable operation of the entire industrial wastewater catalytic oxidation treatment process and achieving better wastewater treatment results.

[0028] The working principle of this industrial wastewater catalytic oxidation treatment process is explained in detail below. First, a pretreatment detoxification step is performed, using mechanical bar screens and precision filters to remove various suspended solids, colloids, oils, heavy metals, and some highly toxic substances from the wastewater. Simultaneously, the water quality and quantity are adjusted to ensure stable operation of subsequent treatment units. Next, the wastewater enters a staged catalytic oxidation step. The pretreated wastewater passes sequentially through a primary ozone catalytic oxidation tower 1 and a secondary hydrogen peroxide catalytic oxidation tower 2. In the primary tower 1, ozone generated by the ozone generator 3 is evenly released into various locations within the tower through a first distribution mechanism 7, ensuring full contact with the wastewater for catalytic oxidation, effectively removing recalcitrant substances and improving biodegradability. In the secondary tower 2, hydrogen peroxide is evenly distributed at multiple points through a second distribution mechanism 8, further mixing and reacting with the wastewater that has undergone preliminary treatment in the primary tower 1, deeply removing COD and reducing toxic substances. Finally, a conditioning and disinfection step is performed to adjust the water quality of the catalytically oxidized wastewater, reducing residual toxicity and making it meet the requirements for toxic biological treatment. Finally, the process moves to the toxic biological treatment step, where domesticated special microorganisms are used to thoroughly mineralize small-molecule organic matter, further removing pollutants such as COD, BOD, and ammonia nitrogen from the wastewater, ultimately achieving efficient purification of industrial wastewater.

[0029] The present invention has been described in detail above. However, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, any modifications or improvements that do not depart from the spirit of the present invention are within the scope of protection of the present invention.

Claims

1. An industrial wastewater catalytic oxidation treatment process characterized by: Comprise the following steps: The first step, pretreatment detoxification: by setting the grid and precision filter to remove suspended solids, colloidal, oil, heavy metals and part of the high toxicity substances (such as phenolic), adjust the water quality and quantity, guarantee the stable operation of the subsequent unit, at the same time adapt to the intermittent drainage characteristics of chemical production; The second step, grading catalytic oxidation: the pretreated wastewater is broken down by multi-stage catalytic tower, which greatly improves the biodegradability (B / C from <0.2 to >0.5), removes COD and reduces toxic substances; The third step, adjustment and disinfection: the wastewater after catalytic oxidation in the second step is adjusted to reduce the remaining toxicity and meet the requirements of toxic biological treatment; The fourth step, toxic biological treatment: using domesticated special microorganisms to degrade small molecular organic matter, further remove COD, BOD, ammonia nitrogen and other pollutants; The second step above requires an industrial wastewater catalytic oxidation treatment device, which comprises a first tower (1) and a second tower (2), the first tower (1) and the second tower (2) are connected in series, and the first tower (1) and the second tower (2) are respectively provided with a first distribution mechanism (7) and a second distribution mechanism (8).

2. The industrial wastewater catalytic oxidation treatment device according to claim 1, characterized in that: A plurality of residence buckets (5) are connected to the first tower (1), a plurality of the residence buckets (5) are communicated through a first liquid inlet pipe (18), a conical bucket (6) is fixedly connected to the inner wall of the first tower (1), the conical bucket (6) is located below the plurality of residence buckets (5), and the top of the first tower (1) is threadedly connected with an upper cover (16).

3. The industrial wastewater catalytic oxidation treatment device according to claim 1, characterized in that: An ozone generator (3) is installed on the outer wall of the first tower (1), the ozone generator (3) is communicated with a main gas pipe (71), the main gas pipe (71) extends into the first tower (1), a branch pipe (72) is arranged in the first tower (1), the main gas pipe (71) and the branch pipe (72) are communicated, a ring (73) is arranged above the residence bucket (5) and the conical bucket (6), the branch pipe (72) and the ring (73) are communicated, and a gas outlet (74) is formed in the ring (73).

4. The industrial wastewater catalytic oxidation treatment device according to claim 2, characterized in that: The outlet end of the first liquid inlet pipe (18) is located above the conical bucket (6), a valve (15) is installed on the outer wall of the first liquid inlet pipe (18), the valve (15) is located below the residence bucket (5), a plurality of liquid inlets (14) are formed in the first liquid inlet pipe (18), and the liquid inlets (14) are located above the residence bucket (5).

5. The industrial wastewater catalytic oxidation treatment device according to claim 1, characterized in that: A distribution hopper (4) is slidably connected to the inside of the first tower (1), a plurality of sliding rails (13) are fixedly connected to the inner wall of the first tower (1), the distribution hopper (4) and the sliding rails (13) are slidably connected, a filter screen (12) is connected to the surface of the distribution hopper (4), a plurality of circular holes (17) are formed in the distribution hopper (4), a plurality of communication pipes (11) are fixedly connected to the surface of the distribution hopper (4) and communicated with the circular holes (17), and the communication pipes (11) extend to above the uppermost residence bucket (5).

6. The industrial wastewater catalytic oxidation treatment device according to claim 1, characterized in that: A plurality of connecting frames (10) are fixedly connected between the primary tower (1) and the secondary tower (2), a plurality of liquid retaining hoppers (9) are arranged in the secondary tower (2), a second liquid conveying pipe (19) is in communication between the plurality of liquid retaining hoppers (9), and the second liquid conveying pipe (19) is in communication with the conical hopper (6).

7. The industrial wastewater catalytic oxidation treatment process according to claim 1, characterized in that: The second distribution mechanism (8) comprises a connecting pipe (82), the connecting pipe (82) is inserted into the inside of the secondary tower (2) and extends to the outside, one end of the connecting pipe (82) located outside is in communication with a liquid inlet pipe (81), one end of the liquid inlet pipe (81) is open, the other end of the liquid inlet pipe (81) is closed, a plurality of liquid distribution pipes (83) are arranged in the inside of the secondary tower (2), a plurality of liquid outlet holes (84) are formed in the liquid distribution pipes (83), and one end of the connecting pipe (82) located in the inside of the secondary tower (2) is in communication with the liquid distribution pipes (83).

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