Ultrasonic-assisted catalytic PMS treatment reactor for tank washing water and its application

Abstract

This invention discloses an ultrasound-assisted catalytic PMS reactor for treating tank cleaning water and its application. The ultrasound-assisted catalytic PMS reactor for treating tank cleaning water includes a bioreactor and at least one ultrasonic probe for ultrasonically oscillating the interior of the bioreactor. PMS and a ruthenium-doped manganese hydroxide catalyst are added to the ultrasound-assisted catalytic PMS reactor to degrade wastewater containing pollutants. Ultrasound can affect the free radicals generated in the PMS and the active groups in the ruthenium-doped manganese hydroxide catalyst, playing an auxiliary or synergistic role in the catalytic and ultrasonic processes, thereby greatly improving the degradation and mineralization of pollutants and achieving the goal of highly efficient pollutant degradation.

Description

Technical Field

[0001] This invention belongs to the field of water treatment technology, specifically relating to an ultrasonic-assisted catalytic PMS reactor for treating tank washing water and its application. Background Technology

[0002] Polluted wastewater not only contains recalcitrant organic pollutants and cleaning agents used for cleaning ship holds, but also exhibits complex and variable compositions across different ports, making it difficult for existing wastewater treatment technologies to meet discharge standards. Advanced oxidation processes (AOPs) are an effective method for degrading macromolecular organic pollutants. However, traditional AOP technologies typically include photocatalytic oxidation, electrochemical oxidation, ozone oxidation, and catalytic wet oxidation. These technologies still suffer from limitations such as high energy consumption, weak degradation capacity, and susceptibility to equipment corrosion. In contrast, PMS oxidation technology is one of the most widely used new AOP technologies. The sulfate radicals produced have high redox potentials and longer lifetimes compared to hydroxyl radicals, and do not cause secondary pollution. PMS activated by a catalyst retains its high oxidizing capacity while also improving its reaction selectivity. Currently, catalyst-activated persulfate processes are widely used for treating polluted wastewater, but they still suffer from poor adaptability to water quality requirements, low removal rates, and high costs. In recent years, the advanced oxidation combined with ultrasonic processes has shown great potential in improving the removal and mineralization of recalcitrant pollutants, enabling continuous detoxification of pollutants. In a typical direct composite system, the catalyst for activation is first added to the system and mixed using magnetic stirring. When adsorption reaches equilibrium, persulfate is added for further activation, resulting in the production of SO₂. 4- The oxidation and degradation of · and ·OH are carried out simultaneously, while ultrasonic catalysis is performed outside the reactor to promote the oxidation reaction.

[0003] Ultrasound can induce cavitation and eddy currents, creating microbubbles and eddies within liquids, thereby achieving mixing and homogenization. Currently, ultrasound-assisted technology has been used for denitrification, dechlorination, and the degradation of dyes and pollutants, demonstrating its potential in practical wastewater treatment. However, research indicates that this technology is susceptible to the effects of equipment and environmental factors, leading to unstable pollutant degradation and reduced pollutant removal efficiency. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide an ultrasonic-assisted catalytic PMS reactor for treating tank cleaning water.

[0005] Another objective of this invention is to provide a tank washing water treatment system. This system involves introducing advanced oxide permonosulfate (PMS) into an ultrasonic-assisted catalytic PMS tank washing water treatment reactor. The reactor utilizes a ruthenium-doped manganese hydroxyl oxide catalyst and ultrasound to jointly promote the degradation of pollutant-containing wastewater. Ultrasound not only affects the active groups in the ruthenium-doped manganese hydroxyl oxide catalyst, but also generates cavitation and eddy current effects, separating organic matter from the solid surface in the wastewater, thereby achieving efficient degradation. The system can treat one or more of the following pollutants: phenol, ciprofloxacin, 1-naphthylamine, tetracycline, and rhodamine B.

[0006] The objective of this invention is achieved through the following technical solution.

[0007] An ultrasonic-assisted catalytic PMS treatment reactor for tank washing water includes: a bioreactor and at least one ultrasonic probe for ultrasonically oscillating the interior of the bioreactor, wherein the ultrasonic frequencies generated by all ultrasonic probes inside the bioreactor are 10-100 Hz.

[0008] In the above technical solution, the bioreactor includes: a reaction chamber, an inlet formed at the upper part of the reaction chamber, and an outlet formed at the lower part of the reaction chamber.

[0009] In the above technical solution, the bioreactor further includes: an aeration pump and an aeration disc installed in the reaction chamber. The aeration pump is located outside the reaction chamber, and the aeration pump and the aeration disc are connected by a pipeline and a gas flow meter is installed on the pipeline.

[0010] In the above technical solution, the top surface of the reaction chamber is open.

[0011] In the above technical solution, a frustum-shaped baffle is installed inside the reaction chamber. The baffle gradually narrows from top to bottom, and the aeration disc is fixed to the lower surface of the frustum-shaped baffle.

[0012] In the above technical solution, the water outlet is located above the baffle.

[0013] In the above technical solution, both the aeration plate and the reaction chamber are cylindrical, and the radius ratio of the aeration plate and the reaction chamber is 1:(3-5).

[0014] In the above technical solution, the ratio of the diameter of the reaction chamber to the height of the reaction chamber is 1:(3-5).

[0015] In the above technical solution, when there are multiple ultrasonic probes, the multiple ultrasonic probes are divided into multiple groups, and each group of ultrasonic probes is arranged along the height direction of the reaction chamber.

[0016] In the above technical solution, multiple fixing holes are formed on the reaction chamber, each fixing hole passes through an ultrasonic probe, and the outer end of each ultrasonic probe is fixed on an ultrasonic support, which is located outside the reaction chamber.

[0017] In the above technical solution, a sealing ring is provided at each fixing hole to seal the ultrasonic probe and the reaction chamber.

[0018] A tank cleaning water treatment system includes: an ultrasonic-assisted catalytic PMS treatment reactor for tank cleaning water, PMS, and a ruthenium-doped manganese hydroxyl oxide catalyst. The preparation method of the ruthenium-doped manganese hydroxyl oxide catalyst includes: mixing nano-manganese hydroxyl oxide, a ruthenium source, and water at room temperature until homogeneous; reacting hydrothermally at 160–180°C for 6–8 hours; filtering to obtain a first precipitate; washing and drying the first precipitate to obtain the ruthenium-doped manganese hydroxyl oxide catalyst. The mass fraction of the nano-manganese hydroxyl oxide to the molar fraction of ruthenium in the ruthenium source is 30:(7–9), where the mass fraction is in mg and the molar fraction is in mol.

[0019] In the above technical solution, the ruthenium source is ruthenium trichloride or ruthenium oxide.

[0020] In the above technical solution, the method of mixing nano-manganese hydroxyoxide, ruthenium source and water to uniformity is as follows: mix nano-manganese hydroxyoxide and water, stir for 20-40 minutes until uniform to obtain solution A, mix solution A and ruthenium source, and sonicate for 20-40 minutes until uniform.

[0021] In the above technical solution, the nano-hydroxy manganese oxide has a nanowire structure with a diameter of 10-15 nm.

[0022] In the above technical solution, the mass fraction of the nano-manganese hydroxyoxide and the volume fraction of water are (0.5-5):1, where the mass fraction is in mg and the volume fraction is in mL.

[0023] In the above technical solution, the drying temperature is 50-70℃ and the drying time is 8-12h.

[0024] The method for preparing the nano-manganese hydroxyl oxide in the above technical solution includes the following steps:

[0025] Step 1: Mix potassium permanganate, sodium citrate and water, and stir until homogeneous to obtain a uniform dispersion. The ratio of the molar amount of potassium permanganate, the molar amount of sodium citrate and the volume fraction of water in Step 1 is (0.0015~0.003):(0.0005~0.001):(20~40). The molar amount is in mol and the volume fraction is in mL.

[0026] In step 1, the stirring time is 20 to 40 minutes.

[0027] Step 2: The uniform dispersion is subjected to hydrothermal reaction at 160-180℃ for 24-26 hours, washed, and dried to obtain a yellow powder, which is nano-manganese hydroxyl oxide.

[0028] In step 2, the drying temperature is 50–70°C, and the drying time is 8–12 hours.

[0029] In the above technical solution, the washing agent used is water and anhydrous ethanol.

[0030] The above-mentioned method of using the tank washing water treatment system includes: introducing wastewater containing pollutants into the reaction chamber of the ultrasonic-assisted catalytic PMS treatment tank washing water reactor, adding ruthenium-doped manganese hydroxyl oxide catalyst, starting the aeration disc and ultrasonic probe, adding PMS after adsorption and desorption equilibrium is reached, and continuing to keep the aeration disc and ultrasonic probe working.

[0031] The ratio of the volume fraction of the wastewater to be treated, the molar fraction of PMS, and the mass fraction of the ruthenium-doped manganese hydroxyl oxide catalyst is (30-70): (0.00020-0.00030): (20-30), where the volume fraction is in mL, the mass fraction is in mg, and the molar fraction is in mol.

[0032] In the above-described method of use, the contaminant is one or more of phenol, ciprofloxacin, 1-naphthylamine, tetracycline, and rhodamine B.

[0033] In the above method of use, the aeration is air, and the aeration rate of the aeration disc is 2.5 to 3 L / min.

[0034] In the above-described method of use, the concentration of pollutants in the wastewater to be treated is 30–70 mg / L.

[0035] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0036] 1. The ruthenium-doped manganese hydroxyoxide catalyst of the present invention has high catalytic activity, with a degradation efficiency of up to 100% for phenol and high degradation efficiency for various pollutants. It also has good stability, and after 5 cycles of testing, the ruthenium-doped manganese hydroxyoxide catalyst still maintains high catalytic degradation activity.

[0037] 2. This invention uses a hydrothermal method to prepare nano-manganese hydroxyoxide, and then prepares a ruthenium-doped manganese hydroxyoxide catalyst (Ru-MnOOH) by doping the nano-manganese hydroxyoxide with ruthenium. The preparation method of this invention has the advantages of fewer raw material types, relatively low cost, green and environmentally friendly, simple process and mild conditions.

[0038] 3. Compared with traditional persulfate oxidation technology, this invention avoids over-catalytic oxidation, saving the time and space required for the reaction. Ultrasound can affect the free radicals generated in PMS and the active groups in the ruthenium-doped manganese hydroxide catalyst, playing an auxiliary or synergistic role in the catalytic and ultrasonic processes, thereby greatly improving the degradation of pollutants and achieving the goal of highly efficient pollutant degradation. Attached Figure Description

[0039] Figure 1 X-ray diffraction patterns of MnOOH in Comparative Example 1 and the ruthenium-doped manganese hydroxyl oxide catalyst prepared in Example 1;

[0040] Figure 2 Image a is a scanning electron microscope image of MnOOH from Comparative Example 1. Figure 2 b is a scanning electron microscope image of the ruthenium-doped manganese hydroxyl oxide catalyst prepared in Example 1;

[0041] Figure 3 A transmission electron microscope image of the ruthenium-doped manganese hydroxyl oxide catalyst prepared in Example 1;

[0042] Figure 4 A high-resolution atomic transmission electron microscope image of the ruthenium-doped manganese hydroxyl oxide catalyst prepared in Example 1;

[0043] Figure 5 Energy dispersive X-ray elemental mapping image of the ruthenium-doped manganese hydroxyl oxide catalyst prepared in Example 1;

[0044] Figure 6 The graph shows a comparison of the degradation effects of PMS on phenol by MnOOH (Comparative Example 1), MnO (Comparative Example 2), ruthenium-doped manganese oxide catalyst (Comparative Example 3), and ruthenium-doped manganese hydroxyl oxide catalyst (Comparative Example 1).

[0045] Figure 7The graph shows the cycle performance test results of the ruthenium-doped manganese hydroxyoxide catalyst prepared in Example 1 activating PMS to degrade phenol.

[0046] Figure 8 The graph shows a comparison of the effects of the ruthenium-doped manganese hydroxyl oxide catalysts prepared in Examples 1-6 on the activation of PMS for phenol degradation.

[0047] Figure 9 This is a comparison chart showing the effect of the ruthenium-doped manganese hydroxyl oxide catalyst prepared in Example 1 on activating PMS to degrade different pollutants;

[0048] Figure 10 'a' represents the specific surface area diagram of MnOOH in Comparative Example 1 and the ruthenium-doped manganese hydroxyl oxide catalyst prepared in Example 1. Figure 10 b represents the pore size distribution of MnOOH in Comparative Example 1 and the ruthenium-doped manganese hydroxyl oxide catalyst prepared in Example 1.

[0049] Figure 11 Infrared absorption spectra of MnOOH in Comparative Example 1 and the ruthenium-doped manganese hydroxyl oxide catalyst prepared in Example 1;

[0050] Figure 12 Electrochemical impedance spectroscopy of MnOOH in Comparative Example 1 and the ruthenium-doped manganese hydroxyl oxide catalyst prepared in Example 1;

[0051] Figure 13 Transient current spectra of MnOOH in Comparative Example 1 and the ruthenium-doped manganese hydroxyl oxide catalyst prepared in Example 1;

[0052] Figure 14 A schematic diagram of the structure of a reactor for ultrasonic-assisted catalytic PMS treatment of tank washing water;

[0053] Figure 15 The figures show the fitting curves of the degradation kinetics of phenol by the ruthenium-doped manganese hydroxyoxide catalysts prepared in Examples 1-6.

[0054] Figure 16 This is a comparison chart of the degradation effects of phenol on Examples 9 and 11;

[0055] Figure 17 This is a comparison chart of the degradation effects of phenol on Examples 12 and 13.

[0056] Among them, 1 is the water inlet, 2 is the ultrasonic support, 3 is the ultrasonic probe, 4 is the aeration disc, 5 is the gas flow meter, 6 is the reaction chamber, 7 is the water outlet, 8 is the baffle, and 9 is the aeration pump. Detailed Implementation

[0057] The technical solution of the present invention will be further described below with reference to specific embodiments.

[0058] The raw material information involved in the following examples is as follows:

[0059] Ruthenium trichloride: Shanghai Aladdin Biochemical Technology Co., Ltd.; Sodium citrate: Shanghai Aladdin Biochemical Technology Co., Ltd.; Anhydrous ethanol: Tianjin Fengchuan Chemical Reagent Technology Co., Ltd.; Ammonium sulfate: Shanghai Aladdin Biochemical Technology Co., Ltd.; Potassium permanganate: Tianjin Xintong Fine Chemical Co., Ltd.

[0060] The instrument information involved in the following embodiments is as follows:

[0061] Electronic balance: BMS-220.4, Shanghai, China; High-speed centrifuge: TG16-WS, Hunan, China; Drying oven (forced air drying oven): 101 series, Shanghai, China; Ultrasonic cleaner: KQ-250B, Kunshan, China; Magnetic stirrer: SN-MS-3D, Shanghai, China; High-performance liquid chromatograph: Agilent 1260, USA.

[0062] Examples 1-6

[0063] A method for preparing a ruthenium-doped manganese hydroxyoxide catalyst includes: mixing nano-sized manganese hydroxyoxide with a diameter of 10-15 nm with water at room temperature, stirring for 30 min until homogeneous to obtain solution A; mixing solution A with a ruthenium source, sonicating for 30 min until homogeneous, and hydrothermally reacting at 180℃ for 6 h; filtering to obtain a first precipitate; washing the first precipitate three times each with deionized water and anhydrous ethanol, and drying in a drying oven at 60℃ for 12 h to obtain the ruthenium-doped manganese hydroxyoxide catalyst (Ru-MnOOH), wherein the ruthenium source is ruthenium trichloride, the mass fraction of nano-sized manganese hydroxyoxide to the molar fraction of ruthenium in the ruthenium source is X (mass fraction in mg, molar fraction in mol), and the mass fraction of nano-sized manganese hydroxyoxide to the volume fraction of water is 5:1 (mass fraction in mg, volume fraction in mL). The values ​​of X are shown in Table 1.

[0064] Table 1

[0065] Example X Example 1 15：4 Example 2 (for comparison) 15：1 Example 3 (for comparison) 15：2 Example 4 (for comparison) 5：1 Example 5 (for comparison) 3：1 Example 6 (for comparison) 3：2

[0066] The method for preparing the above-mentioned nano-manganese hydroxyoxide includes the following steps:

[0067] Step 1: Mix potassium permanganate, sodium citrate and water, and stir for 30 minutes until homogeneous to obtain a uniform dispersion. The ratio of the molar amount of potassium permanganate, the molar amount of sodium citrate and the volume fraction of water in Step 1 is 0.0009:0.0003:10. The molar amount is expressed in mol and the volume fraction is expressed in mL.

[0068] Step 2: The uniform dispersion was transferred to a stainless steel high-pressure reactor with a polytetrafluoroethylene liner and hydrothermally reacted at 180°C for 24 hours. The mixture was then washed three times each with deionized water and anhydrous ethanol, and dried in a drying oven at 60°C for 12 hours to obtain a yellow powder, which was nano-manganese hydroxyl oxide.

[0069] Comparative Example 1

[0070] One type of MnOOH is the nano-manganese hydroxy oxide obtained by the "method for preparing the above-mentioned nano-manganese hydroxy oxide" in Example 1.

[0071] Comparative Example 2

[0072] A method for preparing MnO includes the following steps:

[0073] Step 1: Mix potassium permanganate, ammonium sulfate and water, and stir for 30 minutes until homogeneous to obtain a uniform dispersion. The ratio of the molar amount of potassium permanganate, the molar amount of ammonium sulfate and the volume fraction of water in Step 1 is 0.02:0.01:70. The molar amount is expressed in mol and the volume fraction is expressed in mL.

[0074] Step 2: The uniform dispersion was transferred to a stainless steel high-pressure reactor with a polytetrafluoroethylene liner and hydrothermally reacted at 180°C for 24 hours. After cooling to room temperature, the mixture was washed, dried, heated to 400°C in air at a rate of 2°C / min, and calcined at 400°C for 4 hours to obtain MnO (powder).

[0075] Comparative Example 3

[0076] A method for preparing a ruthenium-doped manganese oxide catalyst includes: mixing MnO (powder) prepared in Comparative Example 2 with water at room temperature, stirring for 30 min until homogeneous to obtain a first solution; mixing the first solution with ruthenium trichloride, sonicating for 30 min until homogeneous, hydrothermally reacting at 180℃ for 6 h, filtering to obtain a second precipitate; washing the second precipitate alternately with deionized water and anhydrous ethanol 3 times each, and drying in a drying oven at 60℃ for 12 h to obtain a ruthenium-doped manganese oxide catalyst (Ru-MnO), wherein the mass ratio of MnO (powder) to the molar ratio of ruthenium in ruthenium trichloride is 15:4, with mass parts in mg and molar parts in mol; and the mass ratio of MnO (powder) to the volume ratio of water is 5:1, with mass parts in mg and volume parts in mL.

[0077] Figure 1 X-ray diffraction patterns of MnOOH (Comparative Example 1) and the ruthenium-doped manganese hydroxyl oxide catalyst prepared in Example 1. Figure 1 It can be seen that there is no significant difference in the diffraction peak curves of the MnOOH catalyst in Comparative Example 1 and the ruthenium-doped manganese hydroxyoxide catalyst prepared in Example 1. The diffraction peaks of the MnOOH catalyst in Comparative Example 1 and the ruthenium-doped manganese hydroxyoxide catalyst prepared in Example 1 can be indexed as MnOOH, which matches well with the standard data in PDF:88-0649. The possible reason for the absence of a peak for ruthenium is that ruthenium was successfully incorporated into the interstitial sites of the MnOOH lattice. The peak shape is sharp and the peak intensity is high, indicating that the ruthenium-doped manganese hydroxyoxide catalyst prepared in Example 1 has good crystallinity. However, the peak value of the diffraction peak of the ruthenium-doped manganese hydroxyoxide catalyst prepared in Example 1 is lower. This may be because ruthenium doping leads to an increase in cell volume, and the atomic bond orbitals are located in the direction of the transition metal ion, resulting in electron repulsion due to the presence of additional electrons generated together with oxygen vacancies.

[0078] Figure 2 Image a is a scanning electron microscope image of MnOOH from Comparative Example 1. Figure 2 Image b is a scanning electron microscope image of the ruthenium-doped manganese hydroxyl oxide catalyst prepared in Example 1. Figure 2 In sample a, MnOOH from Comparative Example 1 exhibits a distinct nanowire morphology. Figure 2 Figure b shows that doping manganese hydroxyl oxide with ruthenium metal did not change the morphology of the MnOOH nanowires.

[0079] Figure 3 This is a transmission electron microscope (TEM) image of the ruthenium-doped manganese hydroxide catalyst prepared in Example 1. From... Figure 3 It can be seen that the ruthenium-doped manganese hydroxyl oxide catalyst has a nanowire structure.

[0080] Figure 4 A high-resolution atomic transmission electron microscope (TEM) image of the ruthenium-doped manganese hydroxide catalyst prepared in Example 1. Figure 4 It can be seen that the interplanar spacing of the ruthenium-doped manganese hydroxyoxide catalyst is 0.341 nm, and the lattice stripes are ordered, corresponding to the (-111) plane of the ruthenium-doped manganese hydroxyoxide catalyst.

[0081] Figure 5 Energy-dispersive X-ray elemental mapping (EDXEM) image of the ruthenium-doped manganese hydroxide catalyst prepared in Example 1. Figure 5 It can be seen that Mn, O and Ru elements are uniformly dispersed, which indicates the successful synthesis of the ruthenium-doped manganese hydroxyl oxide catalyst in Example 1.

[0082] The method for activating PMS to degrade pollutants is as follows: 25 mg of catalyst is dispersed in 50 mL of an aqueous solution of the pollutant at pH = 6 to obtain a suspension. The suspension is vigorously stirred at 800 r / min for 15 min to reach adsorption / desorption equilibrium. 0.25 mmol of PMS is added to prepare a reaction solution, and the activation of PMS to degrade the pollutant is initiated. At different activation times of PMS, 1 mL of the reaction solution is filtered through a 0.22 μm filter to remove suspended solids, yielding a test solution. The test solution is then analyzed using high-performance liquid chromatography (HPLC) to calculate the degradation efficiency. The pollutant is phenol, and the concentration of the pollutant in the aqueous solution is 50 mg / L. The catalyst is one of the following: the ruthenium-doped manganese oxide catalyst prepared in Examples 1-6, MnOOH in Comparative Example 1, MnO prepared in Comparative Example 2, and the ruthenium-doped manganese oxide catalyst prepared in Comparative Example 3.

[0083] Degradation efficiency (removal rate) = 1 - (test concentration / initial concentration), where the initial concentration is the pollutant concentration in the test solution at minute 0 after adsorption / desorption equilibrium, and the test concentration is the pollutant concentration in the test solution at minute t after adsorption / desorption equilibrium.

[0084] In the method of catalytically activated PMS for pollutant degradation, when ruthenium-doped manganese oxyhydroxide catalyst is used to activate PMS for pollutant degradation, 1 mL of reaction solution is taken at 0, 20, 40, 60, 80, 100, 120, 140, 160, and 180 s after adsorption / desorption equilibrium. When MnOOH or MnO is used to activate PMS for pollutant degradation, 1 mL of reaction solution is taken at 0, 60, 120, 180, 240, and 300 s after adsorption / desorption equilibrium. When ruthenium-doped manganese oxide catalyst is used to activate PMS for pollutant degradation, 1 mL of reaction solution is taken at 0, 20, 40, 60, 120, 180, 240, and 300 s after adsorption / desorption equilibrium.

[0085] Figure 6 This is a comparison chart (vertical axis: "1-degradation efficiency") of the activated PMS catalysts for phenol, obtained from MnOOH in Comparative Example 1, MnO prepared in Comparative Example 2, ruthenium-doped manganese oxide catalyst prepared in Comparative Example 3, and ruthenium-doped manganese hydroxide catalyst prepared in Example 1. Figure 6 As can be seen, after adsorption / desorption equilibrium and the addition of 0.25 mmol PMS, the degradation efficiency of MnOOH in Comparative Example 1 was 4.34% for phenol at 60 s and 26.6% for 300 s; the degradation efficiency of MnO prepared in Comparative Example 2 was 29.55% for phenol at 60 s and 82.19% for 300 s; the degradation efficiency of ruthenium-doped manganese oxide catalyst prepared in Comparative Example 3 was 69.27% ​​for phenol at 60 s and 100% for phenol at 240 s; while the degradation efficiency of ruthenium-doped manganese oxide catalyst prepared in Example 1 was 100% for phenol at 60 s. Compared with Comparative Examples 1-3, the degradation efficiency of ruthenium-doped manganese oxide catalyst prepared in Example 1 was greatly improved.

[0086] Figure 7 This is a cycle performance test graph (vertical axis: "1-degradation efficiency") of the ruthenium-doped manganese hydroxyoxide catalyst prepared in Example 1 activating PMS for phenol degradation. Five cycles were performed according to the aforementioned "Method for Catalyst Activation of PMS for Pollutant Degradation". The catalyst was the ruthenium-doped manganese hydroxyoxide catalyst prepared in Example 1. After each cycle, the catalyst was recovered, washed with deionized water, and dried at 60°C for use in the next cycle. Figure 7 As shown, the ruthenium-doped manganese hydroxyl oxide catalyst prepared in Example 1, at the 100s of the fifth cycle ( Figure 7 The degradation efficiency of phenol (with the horizontal axis marked "500") can still reach 100%, which indicates that the catalytic system of PMS activated by the ruthenium-doped manganese hydroxyl oxide catalyst prepared in Example 1 has good stability and feasibility.

[0087] The ruthenium-doped manganese hydroxyl oxide catalysts prepared in Examples 1-6 were used to degrade phenol according to the aforementioned "Method for Catalyst Activation of PMS to Degrade Pollutants". A comparison chart of the effects of the ruthenium-doped manganese hydroxyl oxide catalysts prepared in Examples 1-6 on activating PMS to degrade phenol was obtained, as shown in the figure. Figure 8 As shown (the vertical axis represents "1 - degradation efficiency"). From Figure 8It can be seen that from Examples 2, 3, and 4 to Example 1, the degradation efficiency of phenol by the ruthenium trichloride-doped manganese hydroxyl oxide catalyst gradually increases with the increase of ruthenium trichloride content. However, from Examples 1 and 5 to Example 6, when the ruthenium trichloride content increases to a certain extent, the degradation efficiency decreases with the continuous increase of ruthenium trichloride mass. The ruthenium-doped manganese hydroxyl oxide catalyst prepared in Example 1 has the highest degradation efficiency, reaching 100% within 60 seconds. Figure 15 The graphs show the degradation kinetics curves of phenol degradation by the ruthenium-doped manganese hydroxyoxide catalysts prepared in Examples 1-6.

[0088] The ruthenium-doped manganese hydroxyoxide catalyst prepared in Example 1 was used to degrade pollutants according to the aforementioned "Method for Degrading Pollutants by Activating PMS with Catalyst". The pollutants were one of ciprofloxacin, 1-naphthylamine, tetracycline, and rhodamine B. Test solutions were taken from the reaction solutions at 60s and 300s after the addition of PMS. A comparison of the effects of the ruthenium-doped manganese hydroxyoxide catalyst prepared in Example 1 on activating PMS to degrade different pollutants is shown in the figure below. Figure 9 As shown (vertical axis represents "removal rate (%)"). From Figure 9 It can be seen that, at 300s after adsorption / desorption equilibrium and the addition of PMS, the ruthenium-doped manganese hydroxyl oxide catalyst (Ru-MnOOH) prepared in Example 1 can maintain good activity and stability. The removal rates of ciprofloxacin, 1-naphthylamine, tetracycline and rhodamine B are all 100%, and it has extremely high degradation efficiency for a variety of pollutants, showing good prospects for practical application.

[0089] Figure 10 'a' represents the specific surface area diagram of MnOOH in Comparative Example 1 and the ruthenium-doped manganese hydroxyl oxide catalyst prepared in Example 1. Figure 10 b represents the pore size distribution of MnOOH in Comparative Example 1 and the ruthenium-doped manganese hydroxyl oxide catalyst prepared in Example 1. Nitrogen adsorption-desorption isotherms were measured using a Quantachrome Autosorb iQ-MP analyzer, and the specific surface area and pore size distribution were analyzed using the BJH and BET methods. Figure 10 As shown in Figure a, the nitrogen adsorption-desorption isotherms of both the MnOOH in Comparative Example 1 and the ruthenium-doped manganese hydroxyl oxide catalyst prepared in Example 1 exhibit type IV curves, showing a hysteresis loop. The shape of the hysteresis loop is close to that of type H3, indicating that both the MnOOH in Comparative Example 1 and the ruthenium-doped manganese hydroxyl oxide catalyst prepared in Example 1 possess a mesoporous structure. However, compared to Example 1, the H3-type hysteresis loop of Comparative Example 1 is smaller. Figure 10 As shown in b, the specific surface area of ​​MnOOH in Comparative Example 1 is 22.8580 m². 2 g-1 The ruthenium-doped manganese hydroxyl oxide catalyst prepared in Example 1 has a specific surface area of ​​121.6751 m². 2 g -1 The ruthenium-doped manganese hydroxyoxide catalyst prepared in Example 1 exhibits a mesoporous structure with a large specific surface area.

[0090] Figure 11 Infrared absorption spectra of MnOOH (Comparative Example 1) and the ruthenium-doped manganese hydroxyl oxide catalyst prepared in Example 1 are shown. The infrared absorption spectra were measured using a Nicolet iS50 Fourier transform infrared spectrometer via the KBr pellet method. Figure 11 As shown, the spectra are at 1085, 1117, and 1150 cm⁻¹. -1 The characteristic peaks represent the bending vibrations of γ-OH, δ-2-OH, and δ-1-OH, respectively; the spectrum is at 2692 cm⁻¹. -1 The characteristic peaks are caused by the OH stretching vibration, which is related to the OH···O hydrogen bonds in MnOOH; the spectrum is at 2078 cm⁻¹. -1 The characteristic peak is at 2692 cm⁻¹ -1 Characteristic peaks of OH stretching combination; spectra at 447, 488, and 592 cm⁻¹ -1 The characteristic peaks are attributed to Mn-O stretching vibrations; the spectrum is at 3422 cm⁻¹ -1 The characteristic peaks are attributed to the stretching vibration of -OH; because ruthenium-doped manganese hydroxyl oxide catalysts exhibit a high surface area-to-volume ratio, the peaks at 1396, 1553, and 1845 cm⁻¹ are due to this. -1 The characteristic peaks are attributed to trace amounts of water and carbon dioxide. The characteristic peak positions of MnOOH in Comparative Example 1 and the ruthenium-doped manganese hydroxyl oxide catalyst prepared in Example 1 are basically the same, and no unique functional groups were detected on the ruthenium-doped manganese hydroxyl oxide catalyst prepared in Example 1.

[0091] Electrochemical impedance spectroscopy (EIS) and transient current response were performed using a CHI 660D electrochemical workstation, an electrolytic cell, and a three-electrode system.

[0092] The electrolytic cell contains an electrolyte (the first electrolyte for electrochemical impedance spectroscopy and the second electrolyte for transient current response spectroscopy). The first electrolyte contains Na₂SO₄ as the electrolyte and water as the solvent, with a concentration of 0.5 mol·L⁻¹. -1The three-electrode system includes a counter electrode, a reference electrode, and a working electrode. A platinum sheet is used as the counter electrode, and an Ag / AgCl electrode is used as the reference electrode. The working electrode is prepared as follows: 4 mg of catalyst and 20 μL of naphthol are diffused in 1 mL of anhydrous ethanol and sonicated for 30 min to obtain a mixture. This mixture is then coated onto an indium tin oxide (ITO) glass electrode and dried in an oven at 60 °C for 8 hours to obtain an electrode with an area of ​​2.75 cm². 2 The working electrode is a catalyst, which is either MnOOH in Comparative Example 1 or the ruthenium-doped manganese hydroxyl oxide catalyst prepared in Example 1.

[0093] The above three-electrode system was electrically connected to the CHI 660D electrochemical workstation and immersed in 200 mL of the first electrolyte solution. Figure 12 The electrochemical impedance spectroscopy (EIS) of the working electrode prepared using MnOOH from Comparative Example 1 and the ruthenium-doped manganese hydroxyl oxide catalyst prepared in Example 1 as catalysts is shown. Figure 12 As shown, compared with Comparative Example 1, the electrochemical impedance spectrum of the working electrode prepared using the ruthenium-doped manganese hydroxyoxide catalyst prepared in Example 1 as the catalyst exhibits a smaller semicircle, indicating that the charge transfer resistance of the ruthenium-doped manganese hydroxyoxide catalyst (Ru-MnOOH) prepared in Example 1 is low. This is because ruthenium doping promotes charge transport and separation and reduces the recombination rate of electron-hole pairs.

[0094] The above three-electrode system was electrically connected to the CHI 660D electrochemical workstation and immersed in 200 mL of the second electrolyte, which was a sodium sulfate aqueous solution with a sodium sulfate concentration of 0.1 M. At 200 s, 500 μL of PMS aqueous solution (the concentration of PMS in the PMS aqueous solution was 50 mM) was added, and at 400 s, 100 μL of phenol aqueous solution was added (that is, phenol aqueous solution was added 200 s after the addition of PMS, and the concentration of phenol in the phenol aqueous solution was 80 mg / L). Figure 13 The transient current spectrum corresponding to the working electrode prepared using MnOOH from Comparative Example 1 and the ruthenium-doped manganese hydroxyl oxide catalyst prepared in Example 1 as catalysts is shown. Figure 13 As shown, the working electrode prepared using the ruthenium-doped manganese hydroxyl oxide catalyst obtained in Example 1 as the catalyst exhibits a higher current response than that in Comparative Example 1, proving that ruthenium doping is beneficial for the effective separation of electron-hole pairs.

[0095] Example 7

[0096] like Figure 14As shown, an ultrasonic-assisted catalytic PMS treatment reactor for tank washing water includes: a bioreactor and 16 ultrasonic probes 3 for ultrasonically oscillating the interior of the bioreactor. The 16 ultrasonic probes 3 are divided into two groups, which are arranged opposite each other. Each group of ultrasonic probes 3 is arranged along the height direction of the reaction chamber 6. The ultrasonic frequencies generated by all ultrasonic probes 3 inside the bioreactor are one of 0 Hz, 50 Hz and 100 Hz.

[0097] Example 8

[0098] Based on Example 7, the bioreactor includes: a reaction chamber 6, which is a cylindrical cavity made of transparent plexiglass, with an inlet 1 formed at the upper part of the reaction chamber 6 and an outlet 7 formed at the lower part of the reaction chamber 6.

[0099] The bioreactor also includes an aeration pump 9 and an aeration disc 4 installed inside the reaction chamber 6. The aeration pump 9 is located outside the reaction chamber 6, and the aeration pump 9 and the aeration disc 4 are connected by a pipeline, on which a gas flow meter 5 is installed. The water inside the reaction chamber 6 flows from bottom to top under the action of the aeration disc 4, thereby promoting the reaction.

[0100] The top surface of reaction chamber 6 is open.

[0101] A frustum-shaped baffle 8 is installed inside the reaction chamber 6 (the top edge of the baffle 8 is connected to the inner wall of the reaction chamber 6). The baffle 8 gradually narrows from top to bottom. The aeration disc 4 is fixed on the lower surface of the frustum-shaped baffle. The reaction chamber 6, the aeration disc 4 and the baffle 8 are coaxially arranged.

[0102] The water outlet 7 is located above the baffle 8.

[0103] Both the explosion plate 4 and the reaction chamber 6 are cylindrical, and the ratio of their radii is 1:3.

[0104] The ratio of the diameter to the height of reaction chamber 6 is 1:3.

[0105] The reaction chamber 6 has 16 fixing holes, each through which an ultrasonic probe 3 passes. The outer end of each ultrasonic probe 3 is fixed to an ultrasonic support 2, which is located outside the reaction chamber 6. A sealing ring is provided at each fixing hole to seal the connection between the ultrasonic probe 3 and the reaction chamber 6. The insertion of the ultrasonic probe 3 into the reaction chamber 6 reduces ultrasonic wave attenuation, thereby improving energy transfer efficiency. The more uniform distribution of ultrasonic waves in the liquid contributes to a more uniform ultrasonic treatment effect and also isolates the process from external environmental interference, such as temperature changes and airflow, thus maintaining the stability of the ultrasonic treatment process.

[0106] Example 9

[0107] A tank cleaning water treatment system includes: an ultrasonic-assisted catalytic PMS treatment tank cleaning water reactor, PMS, and a ruthenium-doped manganese hydroxyl oxide catalyst.

[0108] The ruthenium-doped manganese hydroxyl oxide catalyst prepared in Example 1 was used to degrade wastewater in a tank washing water treatment system. The process included: introducing wastewater into the reaction chamber 6 of the ultrasonic-assisted catalytic PMS treatment reactor in Example 8; adding the ruthenium-doped manganese hydroxyl oxide catalyst prepared in Example 1; starting the aeration disc 4 and ultrasonic probe 3 for stirring and ultrasonic dispersion; performing an adsorption reaction for 15 minutes; and adding PMS after adsorption-desorption equilibrium was reached. The aeration disc and ultrasonic probe were kept running for a degradation time t. The liquid level in the reaction chamber 6 was lower than the inlet temperature. At water inlet 1, the ratio of the volume fraction of the wastewater to be treated, the molar fraction of PMS, and the mass fraction of ruthenium-doped manganese oxyhydroxide catalyst is 50:0.00025:25. The volume fraction is expressed in mL, the mass fraction in mg, and the molar fraction in mol. The aeration rate of aeration disc 4 is 3 L / min (aeration is air). t is one of 20 s, 0 min, 1 min, 2 min, 3 min, 4 min, and 5 min. The pollutant in the wastewater to be treated is phenol, and the concentration of phenol in the wastewater to be treated is 50 mg / L.

[0109] Example 10 (as a comparison)

[0110] This example is basically the same as Example 9, except that the "ruthenium-doped manganese hydroxyl oxide catalyst prepared in Example 1" is replaced with MnOOH prepared in Comparative Example 1.

[0111] Example 11 (as a comparison)

[0112] It is basically the same as Example 9, except that the aeration disc 4 and the ultrasonic probe 3 are not activated.

[0113] Example 12 (as a comparison)

[0114] This example is basically the same as Example 9, except that the "ruthenium-doped manganese hydroxyl oxide catalyst prepared in Example 1" is replaced with "MnO prepared in Comparative Example 2".

[0115] Example 13 (as a comparison)

[0116] It is basically the same as Example 12, except that the aeration disc 4 and the ultrasonic probe 3 are not activated.

[0117] Figure 16This is a comparison chart of the degradation effects of phenol on Example 9 and Example 11 under ultrasonic frequency of 100 Hz and ultrasonic duration of 20 s. Figure 16 It can be seen that in Example 9, the phenol removal rate at 20s was 100%, and in Example 11, the phenol removal rate at 20s was 61%, which is almost consistent with the phenol removal rate of the ruthenium-doped manganese hydroxyl oxide catalyst prepared in Example 1 in the aforementioned "Method for Degrading Pollutants by Catalyst Activation of PMS". By comparing Example 9 and Example 11, it can be seen that the external ultrasonic strategy can enhance the PMS activation effect.

[0118] Figure 17 This is a comparison chart of the degradation effects of phenol on Example 12 under ultrasonic frequency of 100 Hz and ultrasonic duration of 4 min, and Example 13. Figure 17 It can be seen that in Example 12, the phenol removal rate was 100% after 4 minutes of degradation, and in Example 13, the phenol removal rate was 72% after 4 minutes of degradation.

[0119] The present invention has been described above by way of example. It should be noted that any simple modifications, alterations or other equivalent substitutions that can be made by those skilled in the art without creative effort without departing from the core of the present invention fall within the protection scope of the present invention.

Claims

1. A method of treating tank wash water, characterized by, The ultrasonic-assisted catalytic PMS treatment of cabin washing water reactor is used for promoting degradation of pollutants in the treated wastewater by the metal ruthenium-doped manganese hydroxyl oxide catalyst and ultrasonic waves, the ultrasonic waves have an influence on active groups in the metal ruthenium-doped manganese hydroxyl oxide catalyst, the ultrasonic waves separate organic substances in the treated wastewater from solid surfaces by cavitation and vortex effects, so that the system can realize efficient degradation, and the pollutants are one or more of phenol, ciprofloxacin, 1-naphthylamine, tetracycline and rhodamine B; The ultrasonic-assisted catalytic PMS treatment of cabin washing water reactor comprises a biological reactor and at least one ultrasonic probe (3) for ultrasonic treatment of the inside of the biological reactor; The biological reactor comprises a reaction cavity (6), a water inlet (1) is formed in the upper part of the reaction cavity (6), and a water outlet (7) is formed in the lower part of the reaction cavity (6); The biological reactor further comprises an aeration pump (9) and an aeration disc (4) installed in the reaction cavity (6), the aeration pump (9) is located outside the reaction cavity (6), the aeration pump (9) and the aeration disc (4) are connected by a pipeline, and a gas flow meter (5) is installed on the pipeline; A circular truncated cone baffle (8) is installed in the reaction cavity (6), the baffle (8) tapers from top to bottom, and the aeration disc (4) is fixed to the lower surface of the circular truncated cone baffle (8); The water outlet (7) is located above the baffle (8); The aeration disc (4) and the reaction cavity (6) are both cylindrical, and the radius ratio of the aeration disc (4) to the reaction cavity (6) is 1:(3-5); The diameter of the reaction cavity (6) to the height of the reaction cavity (6) is 1:(3-5).

2. The method of treating tank wash water according to claim 1, wherein, The top surface of the reaction cavity (6) is open.

3. The method of treating tank wash water according to claim 2, wherein, When the number of ultrasonic probes (3) is multiple, the multiple ultrasonic probes (3) are divided into multiple groups, and each group of ultrasonic probes (3) is arranged along the height direction of the reaction cavity (6).

4. The method of treating tank wash water according to claim 3, wherein, A plurality of fixing holes are formed on the reaction cavity (6), each fixing hole penetrates an ultrasonic probe (3), and each ultrasonic probe (3) is fixed to an ultrasonic support (2) at the outer end.

5. The method of treating tank wash water according to claim 4, wherein, A sealing ring is arranged at each fixing hole to seal between the ultrasonic probe (3) and the reaction cavity (6).

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