Ozone mass transfer strengthening application of hydrophobic modification of tubular ceramic membrane based on polydimethylsiloxane in ozone membrane contact reactor

Abstract

The invention relates to the technical field of ceramic membrane water treatment, in particular to application of hydrophobic modification of a tubular ceramic membrane based on polydimethylsiloxane to ozone mass transfer enhancement in an ozone membrane contact reactor. The modification method comprises the following steps: cleaning inner and outer surfaces of an original tubular ceramic membrane; preparing a PDMS (Polydimethylsiloxane) normal hexane solution; modifying the inner and outer surfaces of the tubular ceramic membrane by using a PDMS solution; performing vacuum drying on the membrane material; and cooling at room temperature. The hydrophobic modification method of the ceramic membrane provided by the invention is simple in process, low in raw material cost and free of secondary pollution. The modified tubular ceramic membrane has good hydrophobicity, and the measured contact angle of the membrane surface is greater than # imgabs0 #. The ozone membrane contact reactor constructed by utilizing the hydrophobic ceramic membrane has efficient ozone mass transfer performance, and the ozone concentration of effluent can reach 4.65 mg / L when the ozone membrane contact reactor is operated under the optimal working condition.

Description

Technical Field

[0001] The invention relates to the technical field of ceramic membrane water treatment, and in particular to an application of hydrophobic modification of a tubular ceramic membrane based on polydimethylsiloxane in ozone mass transfer enhancement in an ozone membrane contact reactor. Background Art

[0002] Ceramic membranes are widely used in the wastewater treatment industry due to their good mechanical strength, stable chemical properties, high temperature resistance, corrosion resistance and large specific surface area. Among them, the coupling of ceramic membrane separation and ozone technology can form a synergistic effect, using catalytic oxidation and mass transfer enhancement to improve the removal efficiency of refractory organic matter in chemical industry wastewater, reduce environmental hazards and achieve resource recovery. The operating devices of existing coupling technologies mainly include pre-ozone oxidation coupled membrane filtration, in-situ ozone aeration coupled membrane filtration and ozone ceramic membrane contact reactor. The main reaction mechanisms include direct ozone oxidation (addition / ring-opening reaction), ozone catalytic oxidation (active oxygen mineralization of organic matter), selective layer physical screening and membrane mass transfer. In the membrane contact reactor, the ozone mixed gas and wastewater are cross-transferred through the ceramic membrane wall as a physical barrier, and the ozone molecules diffuse into the water body from the wall membrane pores, dissolve and then oxidize to remove pollutants in the water. Since the membrane contact reactor prepared by the ceramic membrane has excellent ozone resistance, mechanical strength and mass transfer diffusion area, and the reactor occupies a small area, the process is simple, and the oxidation and degradation capacity is high, it can achieve efficient and rapid treatment of chemical wastewater.

[0003] However, the hydrophilicity of the surface of commercial ceramic membranes can easily cause the liquid phase to penetrate into the gas phase through the membrane pores, which hinders mass transfer. Liquid phase penetration may occur during long-term operation, leading to equipment failure. How to hydrophobically modify the surface of ceramic membranes, reduce membrane pore wetting, and improve mass transfer efficiency has become a key technical problem that needs to be urgently solved in the ceramic membrane coupled ozone process. According to literature reports, the current mainstream ceramic membrane hydrophobic modification processes are divided into the following types: graft polymerization, vapor deposition, and super-hydrophobic modification. Among them, graft polymerization is to react the modified monomer or functional group with the -OH on the membrane surface to graft hydrophobic groups. Commonly used hydrophobic modification reagents include fluoroalkylsiloxanes, alkylchlorosilanes, organic acids, etc. Vapor phase precipitation refers to the deposition of substances such as silane coupling agents in gaseous form on the surface of ceramic membranes under certain temperature and pressure conditions to form a thin film. Superhydrophobic modification usually refers to loading a hydrophobic layer similar to plastic on the surface of the ceramic membrane. The ingredients can be polyethylene terephthalate (PET), polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF) or polydimethylsiloxane (PDMS).

[0004] PDMS is a high molecular polymer with the chemical formula (C2H6OSi) n, with heat resistance and cold resistance, small viscosity change with temperature, small surface tension, high thermal conductivity and good hydrophobicity. It also has high shear resistance and can be used for a long time at -50℃~200℃. The PDMS precursor is used to construct a hydrophobic layer on the surface of the ceramic membrane. The process operation is simple, the reaction conditions are mild, the product is stable, and it has little effect on the performance of the ceramic membrane. Therefore, PDMS is selected as a modifier for hydrophobic modification of the membrane surface, in order to develop a modification technology with low cost, controllable process, good modification effect, and can promote the coupling of efficient mass transfer of membrane materials and ozone oxidation process, solve potential process problems, and provide advice or guidance for the treatment of difficult-to-degrade organic matter in chemical wastewater. Summary of the invention

[0005] In order to solve the technical problems of mass transfer blockage and liquid phase penetration in ozone ceramic membrane contact reactor, the present invention provides an application of ozone mass transfer enhancement in ozone membrane contact reactor based on hydrophobic modification of tubular ceramic membranes with polydimethylsiloxane. The present invention uses a precursor to configure a polydimethylsiloxane (PDMS) organic solution to construct a hydrophobic layer on the surface of the ceramic membrane, improve the hydrophobicity of the membrane material, reduce the mass transfer resistance, enhance the reactor ozone mass transfer efficiency and wastewater treatment energy efficiency, and realize the application of ozone ceramic membrane contact reactor in organic matter degradation.

[0006] The first object of the present invention is to provide an application of hydrophobic modification of tubular ceramic membrane based on polydimethylsiloxane in ozone membrane contact reactor for enhancing ozone mass transfer.

[0007] In some embodiments of the present invention, the method for hydrophobic modification of tubular ceramic membranes is as follows: Provide original tubular ceramic membrane and clean and dry it; The original tubular ceramic membrane is placed in a polydimethylsiloxane (PDMS)-based modification solution to modify the inner and outer surfaces of the tubular ceramic membrane, and then vacuum dried and cooled to obtain a hydrophobic modified tubular ceramic membrane.

[0008] In some embodiments of the present invention, the original tubular ceramic membrane is a tubular single channel; the outer diameter of the membrane tube is 12~16 mm, the inner diameter is 8~12 mm, and the length is 200~300 mm. The main component of the membrane material is aluminum oxide, and the pore size is 1~3 μm; the outer side of the ceramic membrane is a support layer, and the inner side is a filter layer, and the thickness of the filter layer is greater than 30 μm.

[0009] In some embodiments of the present invention, the steps of cleaning and drying are as follows: prepare a 3 M NaOH solution, immerse the original tubular ceramic membrane in the NaOH solution for 10 to 15 min; then rinse with deionized water until the inner and outer surfaces are neutral, and place in a 60° C. oven to dry for 12 h for use.

[0010] In some embodiments of the present invention, the polydimethylsiloxane (PDMS) modified solution is prepared by the following method: The PDMS precursor is dissolved in an organic solvent and stirred to obtain the PDMS precursor; wherein the PDMS precursor comprises agent A of Dow Corning Sylgard 186: an elastic base (part-A: Sylgard 186 elastomer base) and agent B: a curing agent (part-B: Sylgard 186 curing agent).

[0011] In some embodiments of the present invention, the mass concentration of the elastic substrate is 0.5% to 3%, and the mass concentration of the curing agent is 0.05% to 0.3%; The stirring time is 1~2 h, and the stirring speed is 400~800 rpm.

[0012] In some embodiments of the present invention, the organic solvent is selected from n-hexane.

[0013] In some embodiments of the present invention, the tubular ceramic membrane is horizontally immersed in the polydimethylsiloxane modified solution, rotated for 5 to 10 minutes to ensure that the inner and outer surfaces of the membrane are evenly in contact with the polydimethylsiloxane modified solution, and then pulled out of the solution.

[0014] In some embodiments of the present invention, the parameters of the ozone membrane contact reactor are: air inlet flow rate is 0.50~1.25 L / min, water inlet flow rate is 0.06~0.24 L / min, inlet ozone concentration is 20~35 mg / L, and under the optimal reaction conditions, the reactor outlet water ozone concentration is 4.65 mg / L.

[0015] The above technical solution of the present invention has the following advantages compared with the prior art: (1) The present invention provides a novel hydrophobic modification scheme for tubular ceramic membranes. The scheme is easy to operate, has a controllable process, and has a good modification effect, thereby effectively broadening the hydrophobic modification pathways for tubular ceramic membranes.

[0016] (2) The present invention combines the high mechanical strength, stable chemical properties, high temperature resistance, corrosion resistance and large specific surface area of ​​ceramic membranes with the heat and cold resistance, small viscosity change with temperature, low surface tension, high thermal conductivity and good hydrophobicity of PDMS materials. The prepared modified ceramic membrane can operate stably for a long time under complex process conditions, providing a practical development prospect for industrial wastewater treatment.

[0017] (3) Compared with several traditional modification processes, the present invention has better hydrophobic modification effect on tubular single-channel ceramic membranes, fewer implementation steps, and the selected reagents are all commercialized and low in price, so the modification cost is relatively low.

[0018] (4) The present invention maintains the physicochemical properties of tubular ceramic membranes as mass transfer mediating structures, and the modified hydrophobic membrane can be used in membrane contact reactors for gas mass transfer. Because the liquid phase is not easy to penetrate into the membrane pores, the mass transfer resistance of the membrane wall is small, and the ozone molecules in the gas phase use the concentration gradient as a driving force to diffuse and transfer into the water body. Dissolved ozone has strong oxidizing properties and can decompose to produce active free radicals in an alkaline environment, thereby effectively oxidizing, degrading and mineralizing organic pollutants in the water body, further expanding the application potential of ceramic membranes in water treatment technology.

[0019] (5) The ozone membrane contact reactor prepared by the modified tubular ceramic membrane of the present invention can not only overcome the problems of liquid flooding and bubbles generated by traditional ozone mass transfer components, but also has high mass transfer efficiency, mechanical strength and resistance to ozone corrosion, and is suitable for the oxidative removal of difficult-to-degrade organic matter in chemical wastewater. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific embodiments of the present invention in conjunction with the accompanying drawings, wherein: Figure 1 The contact angle diagrams of different hydrophobic modified films of Example 1 of the present invention and the comparative example; Figure 2 This is a graph of different outlet water ozone concentrations of Example 1 of the present invention and the comparative example; Figure 3 The figure is the effect of hydrophobic modification and PDMS mass concentration on the effluent ozone concentration in Example 2 of the present invention; wherein (a) is the effect of the number of hydrophobic modifications on the effluent ozone concentration; (b) is the effect of PDMS mass concentration on the effluent ozone concentration; Figure 4 Characterization diagrams of the ceramic membrane before and after modification of Example 3 of the present invention; wherein (a) is a scanning electron microscope image of the original ceramic membrane; (b) is a scanning electron microscope image of the PDMS hydrophobic modified ceramic membrane; Figure 5 The structure diagram of the hydrophobic modified membrane and ozone membrane contact reactor of the present invention; Figure 6 Graphs showing the influence of different factors on the ozone mass transfer effect in Example 4 of the present invention; wherein, (a) is a graph showing the influence of water inlet flow rate on the ozone mass transfer effect; (b) is a graph showing the influence of air inlet flow rate on the ozone mass transfer effect; (c) is a graph showing the influence of air inlet ozone concentration on the ozone mass transfer effect; and (d) is a graph showing the long-term operation results of the ozone membrane contact reactor. DETAILED DESCRIPTION

[0021] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0022] Example 1

[0023] This embodiment provides a PDMS super-hydrophobic modification method, which is specifically as follows: The original ceramic membrane is provided in the form of a tubular single channel with 1 channel; the outer diameter of the membrane tube is 12 mm, the inner diameter is 8 mm, and the length is 200 mm; the outer side of the ceramic membrane is a support layer, and the inner side is a filter layer, and the filter layer thickness is greater than 30 μm. The main component of the membrane material is aluminum oxide, and the pore size is about 1 μm.

[0024] Step 1, clean and dry the inner and outer surfaces of the original ceramic membrane: prepare 3 M NaOH solution for cleaning, soak the original ceramic membrane in the NaOH solution for 15 min; then rinse with deionized water until the inner and outer surfaces are neutral, and place in a 60°C oven to dry for 12 h for use; Step 2, prepare PDMS modified solution: select 100 g of n-hexane as solvent and PDMS precursor as solute. The precursor includes Dow Corning Sylgard 186 A agent: elastic base (part-A: Sylgard 186 elastomer base) and B agent: curing agent (part-B: Sylgard 186 curing agent); the mass concentration of part-A is 2% and the mass concentration of part-B is 0.02% during preparation; after the precursor is dissolved, the solution is magnetically stirred at room temperature for 2 h, and the stirring speed is 600 rpm.

[0025] Step 3: immerse the tubular ceramic membrane obtained in step 1 horizontally in the prepared PDMS solution, rotate for 5 minutes to ensure that the inner and outer surfaces of the membrane are in uniform contact with the solution, and then pull out the solution.

[0026] Step 4: Place the tubular ceramic membrane obtained in step 3 in a vacuum drying oven at 40 o C and dried under vacuum for 2 h.

[0027] Step 5: Cool the tubular ceramic membrane obtained in step 4 at room temperature for 12 h and store it in a dry place.

[0028] Step 6: After measuring the hydrophobic angle of the modified membrane surface, the modified membrane is made into a membrane contact reactor, and the hydrophobic modification effect is measured.

[0029] Comparative Example 1 This comparative example provides an untreated original ceramic membrane, wherein the original ceramic membrane is in the form of a tubular single channel with 1 channel; the outer diameter of the ceramic membrane tube is 12 mm, the inner diameter is 8 mm, and the length is 200 mm; the support layer of the ceramic membrane is about 10 μm thick, the filter layer is about 1 μm thick, and the main component is aluminum oxide; the pore size of the ceramic membrane is about 1 μm. After measuring the hydrophobic angle of the ceramic membrane surface, the ceramic membrane is made into a membrane contact reactor, and the hydrophobic modification effect is measured.

[0030] Comparative Example 2 This comparative example provides a graft polymerization method: Step 1: Clean the surface of the original ceramic membrane: rinse with deionized water for 10 minutes, then prepare 3M NaOH solution, soak the original ceramic membrane in the NaOH solution for 15 minutes, keep the membrane surface alkaline, and set aside.

[0031] Step 2: Use DMF to dissolve tris(trimethylsiloxy)silane to prepare a modified solution with a volume fraction of 1%; Step 3: immerse the tubular ceramic membrane obtained in step 1 horizontally in the prepared modified solution for 24 h to ensure that the inner and outer surfaces of the membrane are in uniform contact with the solution; Step 4: Dry the ceramic membrane obtained in step 3 in a vacuum drying oven at 80°C for 2 h; Step 5: Cool the ceramic membrane obtained in step 4 at room temperature for 12 h and store it in a dry place.

[0032] Step 6: After measuring the hydrophobic angle of the modified membrane surface, the modified membrane is made into a membrane contact reactor, and the hydrophobic modification effect is measured.

[0033] Comparative Example 3 This comparative example provides a vapor precipitation method: Step 1: Clean the surface of the original ceramic membrane: prepare a 3 M NaOH solution for cleaning, and soak the original ceramic membrane in the NaOH solution for 10 min; then rinse with deionized water until the surface is neutral, and place it in a 60°C oven to dry for 12 h for later use; Step 2: Select 75% alcohol as the solvent, dissolve the silane coupling agent (KH570, the volume ratio of solute to solvent is 1:3), and prepare a modified solution; Step 3: Take 4 mL of the modified solution and place it at the bottom of a 150 mL reactor. Suspend the ceramic membrane obtained in step 1 above the solution. Place the reactor in an oven at 150 °C for 3 h and cool to deposit. Step 4: Cool the ceramic membrane obtained in step 3 at room temperature for 12 h and store it in a dry place.

[0034] Step 5: After measuring the hydrophobic angle of the modified membrane surface, the modified membrane is made into a membrane contact reactor, and the hydrophobic modification effect is measured.

[0035] Performance Testing The hydrophobicity of the ceramic membrane obtained in Example 1 and Comparative Examples 1 to 3 and the ozone mass transfer performance of the corresponding ozone membrane contact reactor were tested. The hydrophobic angle and the ozone concentration of the reactor outlet water were measured as follows: Figure 1 and Figure 2 As shown: (1) Original ceramic membrane: The contact angle was measured to be 35 o ~45 o ; The outlet ozone concentration is 0.01 mg / L.

[0036] (2) Graft modification: The contact angle was measured to be 35 o ~85 o ; The outlet ozone concentration is 0.2~0.3 mg / L.

[0037] (3) Vapor deposition: The contact angle was measured to be 43 o ~45 o ; The outlet ozone concentration is 0.1~0.2 mg / L.

[0038] (4) Super hydrophobic modification: The contact angle is measured to be 90 o ~100 o ; The outlet ozone concentration is 2.9~5.7 mg / L.

[0039] It can be seen that compared with the traditional modification methods of Comparative Examples 2 and 3, the super-hydrophobic modification of the tubular ceramic membrane based on PDMS provided by the present invention has a more significant modification effect, and the hydrophobic angle of the modified membrane surface can reach 100 o The effluent ozone concentration was significantly increased, which met the mass transfer requirements of the membrane contact reactor. Therefore, the PDMS superhydrophobic modification method was selected as the hydrophobic modification scheme for the tubular ceramic membrane.

[0040] Example 2

[0041] Determine the optimal modification formula and the optimal modification method: Based on the PDMS superhydrophobic modification method, this embodiment sets the mass concentration gradient of the PDMS precursor part-A to 0.5%, 1%, 2% and 3%, and the corresponding mass concentration gradient of part-B is 0.05%, 0.1%, 0.2% and 0.3%; the hydrophobic modification effect of the PDMS solution obtained by different mass concentration configurations is measured to determine the optimal modification formula.

[0042] Furthermore, after determining the optimal modification formula, a gradient was set for the number of hydrophobic modifications to be once (1X), twice (2X), four times (4X), and eight times (8X), and the hydrophobic modification effects of PDMS solutions obtained with different mass concentrations were measured to determine the optimal modification method.

[0043] The contact angle and mass transfer effect of the modified ceramic membrane obtained in this example are shown in Table 1 and Figure 3 As shown, it can be concluded that as the number of modification increases, the contact angle increases slightly (from 100 o Increased to 102 o ), but the mass transfer flux decreased. It is speculated that the multiple modifications caused a certain degree of blockage of the membrane pores, which hindered the diffusion process of ozone in the membrane pores. Increasing the mass concentration of PDMS solute can increase the contact angle and improve the mass transfer flux to a certain extent, but when the concentration increases from 2% to 3%, the increase in contact angle and flux is no longer significant. It is speculated that the effectively modified PDMS has reached its upper limit. Therefore, the optimal modification scheme is a 2% PDMS solution, which is modified once to form a hydrophobic layer.

[0044] Table 1 Contact angle measurement results of PDMS hydrophobic modified ceramic membrane

[0045] Example 3

[0046] According to the optimal modification scheme, a hydrophobic modified tubular ceramic membrane is prepared, and the modified ceramic membrane is used to prepare an ozone membrane contact reactor. In this embodiment, the reactor height is 200 mm, the reactor inner diameter is 25 mm, the reactor effective volume is 0.098 L, and the reactor membrane filling density is 51.2 m 2 / m 3 In the ozone ceramic membrane contact reactor, the gas flows from right to left along the reactor shell, and the liquid flows from left to right along the inner side of the ceramic tube. The ozone mass transfer adopts cross-flow mass transfer.

[0047] In this embodiment, the electron microscope image of the outer surface of the hydrophobic modified ceramic membrane is as follows: Figure 4 As shown, the structure of the ozone membrane contact reactor is as follows Figure 5 As shown. Figure 4 It can be seen that compared with the original ceramic membrane surface, the hydrophobic modified ceramic membrane successfully loads a PDMS hydrophobic layer on the surface of the ceramic particles of the membrane wall, and the hydrophobic layer will not cause the membrane pores to be completely blocked, which can effectively prevent the liquid phase from penetrating from the membrane pores, and at the same time enhance the mass transfer of ozone gas from the membrane pores to the liquid phase. Figure 5It can be seen that in the ozone ceramic membrane contact reactor, the gas flows from right to left along the reactor shell side, and the liquid flows from left to right along the ceramic tube side. The ozone mass transfer adopts cross-flow mass transfer. The ozone molecules diffuse into the liquid phase through the wall membrane pores and dissolve in the water body to form ozone water with strong oxidizing properties, which can effectively oxidize, degrade or mineralize organic pollutants in the water body.

[0048] Example 4

[0049] The ozone mass transfer performance of the ozone membrane contact reactor prepared in Example 3 was measured. At the same time, the gradient of the inlet flow rate was set to 0.50 L / min, 0.75 L / min, 1.00 L / min, 1.25 L / min, the gradient of the inlet flow rate was set to 0.06 L / min, 0.12 L / min, 0.18 L / min, 0.24 L / min, and the gradient of the inlet ozone concentration was set to 20 mg / L, 25 mg / L, 30 mg / L, 35 mg / L; the outlet ozone concentration under different operating conditions was measured respectively to determine the optimal operating conditions. Finally, through long-term operation, the change of the outlet ozone concentration was observed and the stability of the reaction system was measured.

[0050] In this embodiment, under different operating conditions, the ozone effluent concentration, liquid phase mass transfer coefficient and system long-term operation measurement results are as follows: Figure 6 As shown in the figure. As can be seen from the figure, increasing the liquid phase, gas phase flow rate and inlet ozone concentration can significantly increase the mass transfer flux. However, the liquid phase mass transfer coefficient is only positively correlated with the gas-liquid flow rate and has nothing to do with the inlet ozone concentration. Taking into account factors such as the stability of the reaction system, operating costs and mass transfer effects, the optimal operating conditions are determined to be: inlet flow rate 1.00 L / min, inlet water flow rate 0.12 L / min, inlet ozone concentration 20 mg / L. At this time, the reactor outlet water ozone concentration is 4.65 mg / L.

[0051] In this embodiment, the long-term operation results of the system show that: the ozone effluent concentration is stable, the modified ceramic membrane has good tolerance, high mechanical strength, no significant damage to the hydrophobic layer, no liquid phase penetration, and no significant decrease in mass transfer flux. The operation is stable and meets the requirements of the ozone oxidation wastewater treatment process.

[0052] Obviously, the above embodiments are merely examples for clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the protection scope of the invention.

Claims

1. Application of hydrophobic modification of tubular ceramic membrane based on polydimethylsiloxane for ozone mass transfer enhancement in ozone membrane contact reactor; The method for hydrophobic modification of tubular ceramic membrane is as follows: Provide original tubular ceramic membrane and clean and dry it; The original tubular ceramic membrane is placed in a polydimethylsiloxane modification solution to modify the inner and outer surfaces of the tubular ceramic membrane to obtain a hydrophobic modified tubular ceramic membrane.

2. The use according to claim 1, It is characterized in that The original tubular ceramic membrane is a tubular single channel; the outer diameter of the membrane tube is 12-16 mm, the inner diameter is 8-12 mm, and the length is 200-300 mm. The main component of the membrane material is aluminum oxide, and the pore size is 1-3 μm.

3. The use according to claim 1, It is characterized in that The polydimethylsiloxane modified solution is prepared by the following method: The polydimethylsiloxane precursor is dissolved in an organic solvent and stirred to obtain the product; wherein the polydimethylsiloxane precursor includes Dow Corning Sylgard 186; and Dow Corning Sylgard 186 includes an elastic base and a curing agent.

4. The use according to claim 3, It is characterized in that The mass concentration of the elastic base is 0.5% to 3%, and the mass concentration of the curing agent is 0.05% to 0.3%; The stirring time is 1~2 h, and the stirring speed is 400~800 rpm.

5. The use according to claim 3, It is characterized in that The organic solvent is selected from n-hexane.

6. The use according to claim 1, It is characterized in that The tubular ceramic membrane was horizontally immersed in the polydimethylsiloxane modified solution and rotated for 5 to 10 minutes to ensure that the inner and outer surfaces of the membrane were evenly in contact with the polydimethylsiloxane modified solution, and then pulled out of the solution.

7. The use according to claim 1, It is characterized in that The parameters of the ozone membrane contact reactor are: air inlet flow rate is 0.50~1.25 L / min, water inlet flow rate is 0.06~0.24 L / min, inlet ozone concentration is 20~35 mg / L, and under the optimal reaction conditions, the reactor outlet water ozone concentration is 4.65 mg / L.

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