Method for treating organophosphonic acid wastewater by using supported copper monatomic catalyst
By activating persulfate with a supported copper single-atom catalyst, the problem of metal ion loss in organophosphonic acid wastewater treatment was solved, achieving efficient, stable, and widely applicable organophosphonic acid degradation suitable for complex water quality environments.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SHANGHAI JIAOTONG UNIV
- Filing Date
- 2025-06-23
- Publication Date
- 2026-07-24
Smart Images
Figure CN120664679B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of wastewater treatment technology, specifically relating to a method for treating organophosphonic acid wastewater using a supported copper single-atom catalyst. Background Technology
[0002] Organophosphonic acids are an important phosphorus-containing pollutant in water bodies, and their accumulation in natural water bodies can lead to a series of environmental hazards. Traditional inorganic phosphorus removal technologies are ineffective in removing organophosphonic acids; therefore, it is essential to develop efficient organophosphonic acid removal technologies that can completely degrade organophosphonic acids into easily treatable inorganic phosphorus.
[0003] Currently, advanced oxidation techniques based on homogeneous copper are considered an effective method for removing organophosphonates. This method achieves organophosphonate degradation by selectively generating trivalent copper (Cu(III)) in the activated peroxide reaction, as documented in papers such as "Self-Enhanced Selective Oxidation of Phosphonate into Phosphate by Cu(II) / H2O2: Performance, Mechanism, and Validation" (Environmental Science & Technology) and "Efficient degradation of phosphonate via trace Cu(II) mediated activation of peroxymonosulfate" (Process Safety and Environmental Protection). However, advanced oxidation techniques based on homogeneous copper cannot be used for practical organic wastewater treatment due to the problem of metal ion loss.
[0004] Among many copper-based catalysts, copper single-atom catalysts have advantages such as high atom utilization, well-defined active site structure, and the ability to regulate structure from a molecular design perspective. Compared with copper-based oxides and hydroxides, they can better control the dissolution of metal ions, thereby achieving a single heterogeneous reaction.
[0005] For example, CN114505087A discloses the preparation of a copper single-atom catalyst and its application in the degradation of organic pollutants, specifically for the degradation of easily oxidized phenolic compounds and oxygen- or nitrogen-containing heterocyclic compounds, including bisphenol A (BPA), phenol, 2,4-dichlorophenol (DCP), ciprofloxacin (CIP), or rhodamine B (RhB). However, the materials used in this prior art are mainly suitable for easily oxidized phenolic compounds, and it primarily targets the activation of PDS to achieve advanced oxidation processes for the degradation of organic pollutants. Furthermore, this scheme uses nitrogen-doped graphene as a carrier for copper single atoms, which does not possess the characteristics of interacting with organophosphonic acids. Therefore, when dealing with organophosphonic acid wastewater, this carrier cannot produce a synergistic effect, resulting in a relatively low overall treatment efficiency.
[0006] For example, CN118847115A discloses a Cu1 / TiO2 single-atom catalyst and its preparation method, which is prepared by hydrothermal reaction and used for photocatalytic degradation of organophosphate DMMP. However, this method mainly targets the degradation of DMMP and requires additional energy for degradation, making it relatively dependent on the external environment and lacking universality in various natural environments. Furthermore, the nitrogen atom catalyst disclosed in this prior art needs to be prepared by hydrothermal reaction, which involves strict production conditions, high difficulty, and high cost.
[0007] This indicates a current lack of research on heterogeneous copper-based catalysts for organophosphonic acids in advanced oxidation technologies. Therefore, developing heterogeneous copper-based advanced oxidation technologies, improving their resistance to matrix interference, and achieving selective oxidation of organophosphonic acids are of great significance for advanced water treatment. Summary of the Invention
[0008] The purpose of this invention is to provide a method for treating organophosphonic acid wastewater using a supported copper single-atom catalyst, thereby addressing at least one of the aforementioned problems. This method solves the issue of unrecoverable metal ions in existing advanced oxidation processes for organophosphonic acid wastewater treatment. This solution provides an advanced oxidation technology for organophosphonic acid wastewater, achieving highly efficient and deep degradation of organophosphonic acids in the wastewater. It is adaptable to wastewater with a wide pH range, and after multiple degradation processes, the metal leaching content is extremely low (0.0015 mg / L), exhibiting strong anti-interference and high selectivity.
[0009] The objective of this invention is achieved through the following technical solution:
[0010] A method for treating organophosphonic acid wastewater using a supported copper single-atom catalyst involves adding persulfate and the supported copper single-atom catalyst to the organophosphonic acid wastewater to degrade the organophosphonic acid.
[0011] The supported copper single-atom catalyst is a metal oxide supported with copper single atoms, wherein the loading amount of copper single atoms is 1-10 wt% of the total weight of the catalyst.
[0012] Preferably, the organophosphonic acid is one or more selected from hydroxyethylidene diphosphonic acid, aminotrimethylenephosphonic acid, ethylenediaminetetramethylenephosphonic acid, and diethylenetriaminepentamethylidenephosphonic acid.
[0013] Preferably, the persulfate is a permonosulfate with an asymmetric structure.
[0014] Preferably, the metal oxide is one or more of zirconium dioxide, titanium dioxide, and zinc oxide.
[0015] Preferably, the supported copper single-atom catalyst is prepared by the following method:
[0016] Step 1: Disperse the metal oxide in ultrapure water using ultrasound, and add a copper source dropwise to the suspension to form solution A;
[0017] Step 2: Add ammonia solution dropwise to solution A to carry out the reaction and adjust the pH of the solution. Separate the precipitate, wash and dry it to obtain the precursor;
[0018] Step 3: Calcine the precipitate in air, wash and dry it to obtain the supported copper single-atom catalyst.
[0019] Preferably, in step one, the copper source is one or both of copper chloride and copper nitrate.
[0020] Preferably, in step one, the concentration of the metal oxide in solution A is 5 g / L, and the concentration of the copper source is 50-300 mg / L.
[0021] Preferably, step two includes one or more of the following:
[0022] i) The concentration of the ammonia solution is 1-4 mol / L;
[0023] ii) The reaction time is 2-5 hours;
[0024] iii) The pH of the solution is adjusted to 9-9.5.
[0025] Preferably, step three includes one or both of the following:
[0026] i) The calcination temperature is 400-600℃;
[0027] ii) The drying temperature is 80-100℃ and the time is 24-48h.
[0028] Preferably, the supported copper single-atom catalyst activates persulfate in organophosphonic acid wastewater at pH=9 and completes the degradation of organophosphonic acid within 30 min;
[0029] in,
[0030] The supported copper single-atom catalyst is zirconium dioxide supported with copper single atoms, and the loading of copper single atoms is 6 wt% of the total weight of the catalyst; the dosage of the supported copper single-atom catalyst is 0.01-1 g / L.
[0031] The persulfate is permonosulfate, and the dosage of the persulfate is 0.1-5 mmol / L.
[0032] The concentration of organophosphonic acids (such as hydroxyethylidene diphosphonic acid) in organophosphonic acid wastewater is 0.01-0.5 mmol / L.
[0033] The working principle of this invention is as follows:
[0034] First, the -PO(OH)₂ group in the organophosphonic acid molecule coordinates with the metal site in the Cu-metal oxide, forming a surface complex (Cu(II)-metal oxide-organophosphonic acid complex). This Cu(II)-metal oxide-organophosphonic acid complex modulates the electron density of Cu, making it more favorable for reaction with persulfate. In the presence of persulfate, Cu(II)-metal oxide-organophosphonic acid is oxidized to Cu(III)-metal oxide-organophosphonic acid. Subsequently, the highly reactive Cu(III)-metal oxide-organophosphonic acid complex spontaneously decomposes into Cu(II) and PO₄⁻ via ligand-to-metal charge transfer (LMCT) process. 3 The regenerated Cu(II) then coordinates with another organophosphonic acid molecule to begin the next catalytic cycle.
[0035] Compared with the prior art, the present invention has the following beneficial effects:
[0036] This invention provides a method for degrading organophosphonic acids in water using a supported copper single-atom catalyst activated by persulfate (PMS). This method is carried out at room temperature and pressure, is simple to operate, requires no external energy input, and has a wide pH adaptability range, showing great promise for the treatment of water bodies contaminated by organophosphonic acids.
[0037] 1. Wide range of applications: Copper single-atom catalysts supported on different metal oxide supports can activate PMS and achieve 100% degradation of organophosphonic acid HEDP. Among them, the prepared Cu-ZrO2 catalyst has the best activation effect on PMS, can effectively degrade a variety of organophosphonic acids, and has a good effect on organophosphonic acid HEDP within a wide pH range (6-10).
[0038] 2. Superior catalytic performance: The prepared copper single-atom catalyst Cu-ZrO2, when activated by PMS at pH=9, can achieve 100% degradation of organophosphonic acid (HEDP) within 30 min. Compared with the homogeneous Cu(II) / PMS system, the HEDP degradation efficiency is significantly improved.
[0039] 3. Excellent stability: The single-atom catalyst Cu-ZrO2 activated PMS still maintains a degradation efficiency of over 95% after 6 cycles of degradation of organophosphonic acid, and the leaching content of metallic Cu is extremely low (0.0015 mg / L).
[0040] 4. High selectivity for interference: In Cl-, SO4 2 -, NO3-, CO3 2 Under conditions of coexistence of competing anions such as humic acid, the degradation efficiency of organophosphonic acid HEDP in the Cu-ZrO2 activated PMS system still reaches 95%, making it suitable for complex water quality environments.
[0041] Compared to the existing technology CN114505087A, this method utilizes metal sites in the metal oxide support that possess specific binding capabilities for organophosphonic acids. These sites can serve as binding sites for organophosphonic acids, thus facilitating their adsorption onto the catalyst surface, shortening the interaction distance between the active material and the organophosphonic acid, and enhancing the degradation efficiency. Furthermore, compared to the symmetrical structure of PDS, the asymmetric structure of PMS is more easily activated by copper single atoms to generate active materials, further improving the degradation efficiency of organophosphonic acids.
[0042] Compared to CN118847115A, this method does not require strict hydrothermal conditions. It only involves simple adsorption precipitation followed by calcination, resulting in a simple preparation process, low production cost, and suitability for large-scale mass production. Furthermore, this method exhibits excellent degradation effects on various organophosphonic acids in water, maintaining extremely high degradation efficiency under various interfering factors, making it adaptable to the treatment of organophosphonic acid wastewater in complex natural environments. Attached Figure Description
[0043] Figure 1 The effect of applying copper single-atom catalysts with three different metal oxide supports in Example 1 to activate PMS for the degradation of organophosphonic acid HEDP is shown in the figure.
[0044] Figure 2 The graphs show the degradation effects of different systems on HEDP in Application Example 1 and Comparative Example 1.
[0045] Figure 3 The graph shows the effect of 6 cycles of HEDP degradation using the Cu-ZrO2 / PMS system in Example 2.
[0046] Figure 4 The graph shows the degradation effect of Cu-ZrO2 activated PMS on different organophosphonic acids in Comparative Example 3.
[0047] Figure 5 The graph shows the degradation effect of HEDP by the Cu-ZrO2 / PMS system and the homogeneous Cu(II) / PMS system under different pH conditions in Application Example 6. Detailed Implementation
[0048] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.
[0049] Unless otherwise specified, the reagents used in the following description are commercially available products commonly used in the field, the methods used are known in the field, and any other matters not covered herein may be handled using existing technologies.
[0050] A method for removing organophosphonic acids (especially HEDP) from water using a supported copper single-atom catalyst:
[0051] The supported copper single-atom catalyst used is supported on a metal oxide, with copper supported on the metal oxide in single-atom form, and the loading of Cu is 1-10 wt% based on the total weight of the catalyst.
[0052] The preparation method of this supported copper single-atom catalyst is as follows:
[0053] Step 1: Disperse the metal oxide in ultrapure water using ultrasound, and while stirring vigorously, slowly add copper solution dropwise to the suspension to form solution A;
[0054] Step 2: Prepare an ammonia solution;
[0055] Step 3: Add ammonia solution dropwise to solution A to adjust the pH of the solution;
[0056] Step four: Filter the precipitate formed in step three, wash it with water, and dry it.
[0057] Finally, the precursor was calcined in air, washed repeatedly with anhydrous ethanol and ultrapure water, and dried in an oven to obtain a supported copper single-atom catalyst.
[0058] in,
[0059] In step one, solution A is prepared by dissolving a metal oxide and a divalent copper source in water; the metal oxide is one or more of zirconium dioxide (ZrO2), titanium dioxide (TiO2), and zinc oxide (ZnO); the divalent copper source is copper chloride and / or copper nitrate. The amount of metal oxide in solution A is 5 g / L, and the amount of copper source is 50-300 mg / L.
[0060] In step two, the concentration of the ammonia solution is 1-4 mol / L.
[0061] In step three, the pH is adjusted to a range of 9-9.5, and the reaction time is 2-5 hours.
[0062] In step four, the calcination temperature is 400-600℃; washing is performed until neutral; the drying temperature is 80-100℃; and the drying time is 24-48 hours.
[0063] This supported copper single-atom catalyst degrades organophosphonic acid (OPA) in wastewater by activating persulfate with an asymmetric structure. The degradation process is carried out at ambient temperature and pressure, is simple to operate, requires no external energy input, and has a wide pH adaptability range, showing great promise for the treatment of water bodies polluted by OPA. The OPA is one or more of the following: hydroxyethylidene diphosphonic acid (HEDP), aminotrimethylenephosphonic acid (ATMP), ethylenediaminetetramethylenephosphonic acid (EDTMP), and diethylenetriaminepentamethylidene phosphonic acid (DTPMP). Specifically, excellent OPA degradation results can be achieved when the concentration of OPA (such as HEDP) in the wastewater is 0.01-0.5 mmol / L, the dosage of the supported copper single-atom catalyst is 0.01-1 g / L, and the dosage of persulfate is 0.1-5 mmol / L.
[0064] Common metal oxides (such as ZrO2, TiO2, and ZnO) are ideal support materials for preparing single-atom catalysts due to their superior structural stability, wide pH range, and good metal loading capacity. Since the chemical environment of copper sites on the surface of heterogeneous catalysts is much more complex than that of homogeneous copper ions, the catalytic performance of copper sites is affected by the support. Furthermore, the interaction between the support and phosphonic acid groups influences the formation and structure of surface complexes. In the preferred embodiment of this scheme, ZrO2 is a promising candidate as the preferred support due to its strong affinity for phosphonic acid groups in organophosphonic acids. The Zr in the metal support forms a strong complex structure with the organophosphonic acid, thereby affecting the electronic structure and catalytic activity of the active sites, while simultaneously exposing more copper sites for PMS activation.
[0065] This method is characterized by the efficient activation of persulfate by a copper single-atom catalyst supported on a metal oxide, generating high-valence Cu(III), which then undergoes intramolecular electron transfer to degrade organophosphonic acids. This method can efficiently remove organophosphonic acids from water, achieving 100% removal rates for various organophosphonic acids within 120 minutes at pH 9. This invention solves the problems of secondary metal ion pollution and slow Cu(II) / Cu(I) cycling in copper-based homogeneous advanced oxidation technologies. Furthermore, this method has advantages such as rapid Cu(III) generation, high pollutant removal efficiency, wide pH applicability, and strong anti-interference capabilities, making it particularly suitable for treating water bodies contaminated with organophosphonic acids.
[0066] Example 1
[0067] A supported copper single-atom catalyst: the support is ZrO2, and the copper loading is 1 wt%;
[0068] The method for preparing this supported copper single-atom catalyst includes the following steps:
[0069] Step 1: Dissolve the metal oxide and divalent copper source in water to obtain solution A;
[0070] Step 2: Dissolve ammonia in water to obtain solution B;
[0071] Step 3: Add solution B dropwise to solution A to obtain a metal precipitate, and adjust the solution to maintain a certain pH value;
[0072] Step 4: Filter the precipitate obtained in Step 3, wash it with water, and dry it.
[0073] Finally, the precursor was calcined in air, washed repeatedly with anhydrous ethanol and ultrapure water, and then dried in an oven to obtain a supported copper single-atom catalyst.
[0074] In step one, the metal oxide is ZrO2 with a content of 5 g / L; the divalent copper source is copper nitrate with a content of 50 mg / L; the concentration of ammonia water is 1 mol / L; in step three, the pH is adjusted and maintained at 9; the reaction time in step three is 2 h; in step four, the precipitate is washed until neutral; and in step four, the drying temperature is 80℃ and the drying time is 24 h.
[0075] Example 2
[0076] A supported copper single-atom catalyst: the support is TiO2, and the copper loading is 2wt%;
[0077] The method for preparing this supported copper single-atom catalyst includes the following steps:
[0078] Step 1: Dissolve the metal oxide and divalent copper source in water to obtain solution A;
[0079] Step 2: Dissolve ammonia in water to obtain solution B;
[0080] Step 3: Add solution B dropwise to solution A to obtain a metal precipitate, and adjust the solution to maintain a certain pH value;
[0081] Step 4: Filter the precipitate obtained in Step 3, wash it with water, and dry it.
[0082] Finally, the precursor was calcined in air, washed repeatedly with anhydrous ethanol and ultrapure water, and then dried in an oven to obtain a supported copper single-atom catalyst.
[0083] In step one, the metal oxide is TiO2 with a content of 5 g / L; the divalent copper source is copper nitrate with a content of 100 mg / L; the concentration of ammonia water is 2 mol / L; in step three, the pH is adjusted and maintained at 9; the reaction time in step three is 3 h; in step four, the precipitate is washed until neutral; the drying temperature in step four is 90℃ and the drying time is 24 h.
[0084] Example 3
[0085] A supported copper single-atom catalyst: the support is ZnO, and the copper loading is 4 wt%;
[0086] The method for preparing this supported copper single-atom catalyst includes the following steps:
[0087] Step 1: Dissolve the metal oxide and divalent copper source in water to obtain solution A;
[0088] Step 2: Dissolve ammonia in water to obtain solution B;
[0089] Step 3: Add solution B dropwise to solution A to obtain a metal precipitate, and adjust the solution to maintain a certain pH value;
[0090] Step 4: Filter the precipitate obtained in Step 3, wash it with water, and dry it.
[0091] Finally, the precursor was calcined in air, washed repeatedly with anhydrous ethanol and ultrapure water, and then dried in an oven to obtain a supported copper single-atom catalyst.
[0092] In step one, the metal oxide is ZnO with a content of 5 g / L; the divalent copper source is copper nitrate with a content of 200 mg / L; the concentration of ammonia water is 3 mol / L; in step three, the pH is adjusted and maintained at 9; the reaction time in step three is 4 h; in step four, the precipitate is washed until neutral; the drying temperature in step four is 100℃ and the drying time is 36 h.
[0093] Example 4
[0094] A supported copper single-atom catalyst: the support is ZrO2, and the copper loading is 4 wt%;
[0095] The method for preparing this supported copper single-atom catalyst includes the following steps:
[0096] Step 1: Dissolve the metal oxide and divalent copper source in water to obtain solution A;
[0097] Step 2: Dissolve ammonia in water to obtain solution B;
[0098] Step 3: Add solution B dropwise to solution A to obtain a metal precipitate, and adjust the solution to maintain a certain pH value;
[0099] Step 4: Filter the precipitate obtained in Step 3, wash it with water, and dry it.
[0100] Finally, the precursor was calcined in air, washed repeatedly with anhydrous ethanol and ultrapure water, and then dried in an oven to obtain Cu-ZrO2.
[0101] In step one, the metal oxide is ZrO2 with a content of 5 g / L; the divalent copper source is copper nitrate with a content of 200 mg / L; the concentration of ammonia water is 4 mol / L; in step three, the pH is adjusted and maintained at 9; the reaction time in step three is 4 h; in step four, the precipitate is washed until neutral; the drying temperature in step four is 80℃ and the drying time is 24 h.
[0102] Example 5
[0103] A supported copper single-atom catalyst: the support is ZrO2, and the copper loading is 6 wt%;
[0104] The method for preparing this supported copper single-atom catalyst includes the following steps:
[0105] Step 1: Dissolve the metal oxide and divalent copper source in water to obtain solution A;
[0106] Step 2: Dissolve ammonia in water to obtain solution B;
[0107] Step 3: Add solution B dropwise to solution A to obtain a metal precipitate, and adjust the solution to maintain a certain pH value;
[0108] Step 4: Filter the precipitate obtained in Step 3, wash it with water, and dry it.
[0109] Finally, the precursor was calcined in air, washed repeatedly with anhydrous ethanol and ultrapure water, and then dried in an oven to obtain Cu-ZrO2.
[0110] In step one, the metal oxide is ZrO2 with a content of 5 g / L; the divalent copper source is copper nitrate with a content of 300 mg / L; the concentration of ammonia water is 4 mol / L; in step three, the pH is adjusted and maintained at 9.5; the reaction time in step three is 5 h; in step four, the precipitate is washed until neutral; the drying temperature in step four is 100℃ and the drying time is 48 h.
[0111] Application Example 1
[0112] Preparation of supported copper single-atom catalysts: The supports were ZrO2, TiO2 and ZnO, and the copper loading was 6 wt% in each case;
[0113] The method for preparing this supported copper single-atom catalyst includes the following steps:
[0114] Step 1: Dissolve the metal oxide and divalent copper source in water to obtain solution A;
[0115] Step 2: Dissolve ammonia in water to obtain solution B;
[0116] Step 3: Add solution B dropwise to solution A to obtain a metal precipitate, and adjust the solution to maintain a certain pH value;
[0117] Step 4: Filter the precipitate obtained in Step 3, wash it with water, and dry it.
[0118] Finally, the precursor was calcined in air, washed repeatedly with anhydrous ethanol and ultrapure water, and then dried in an oven to obtain a copper single-atom catalyst.
[0119] In step one, the metal oxides in solution A are ZrO2, TiO2, and ZnO, with a concentration of 5 g / L; the divalent copper source is copper nitrate with a concentration of 200 mg / L; the concentration of ammonia is 4 mol / L; in step three, the pH is adjusted and maintained at 9.5; the reaction time in step three is 5 h; in step four, the precipitate is washed until neutral; and in step four, the drying temperature is 80℃ and the drying time is 24 h.
[0120] The performance of three catalysts (Cu-ZrO2, Cu-TiO2, and Cu-ZnO) prepared in Example 1 for HEDP degradation using activated PMS was tested. The HEDP concentration was 0.1 mmol / L, the catalyst dosage was 0.2 g / L, and the PMS dosage was 2 mmol / L. At wastewater pH 9, after a reaction time of 60 minutes, all three catalysts achieved 100% removal rate of the organophosphonic acid HEDP in the presence of PMS. The Cu-ZrO2 / PMS system showed the best degradation effect on organophosphonic acid. Figure 1 As shown, a 100% removal rate was achieved in approximately 30 minutes.
[0121] Comparative Example 1-1
[0122] PMS was activated by unloaded copper metal oxides ZrO2, TiO2 or ZnO, as well as by Cu-ZrO2, Cu-TiO2, Cu-ZnO alone (loading amount and preparation method are the same as in Application Example 1) or by the presence of degraded organophosphonic acid HEDP in PMS (i.e., the above substances were added to organophosphonic acid wastewater and tested under the same test conditions as in Application Example 1).
[0123] like Figure 2 As shown, in PMS systems activated by copper-free metal oxides ZrO2, TiO2, or ZnO, the degradation rate of organophosphonic acid HEDP is only 0.5%-5%, while Cu-ZrO2, Cu-TiO2, or Cu-ZnO alone have no degradation effect on HEDP. Furthermore, when PMS is present alone, the degradation rate of HEDP is only 15%. Therefore, only when the supported copper single-atom catalyst and PMS coexist and work synergistically can a better degradation effect on organophosphonic acids be achieved.
[0124] Comparative Examples 1-2
[0125] A copper-supported single-atom catalyst (Cu-C3N4) was prepared on carbon nitride (the specific loading and preparation method are the same as in Application Example 1, except that the main difference in the preparation method is that the metal oxide is replaced with carbon nitride in step one, while the rest remains the same). This catalyst was then used to activate PMS for the degradation of HEDP (tested under the same conditions as in Application Example 1). In the Cu-C3N4 / PMS system, with wastewater pH = 9, the HEDP degradation rate was 65% after 120 minutes of reaction, which was lower than that of the Cu-ZrO2 / PMS system. This is because the metal on the metal oxide support has a strong binding capacity for organophosphonic acids, making it easier to adsorb organophosphonic acids onto the catalyst surface, shortening the interaction distance with the active material, and improving the degradation effect of organophosphonic acids.
[0126] Application Example 2
[0127] A supported copper single-atom catalyst: the support is ZrO2, and the copper loading is 6 wt%;
[0128] The method for preparing this supported copper single-atom catalyst includes the following steps:
[0129] Step 1: Dissolve the metal oxide and divalent copper source in water to obtain solution A;
[0130] Step 2: Dissolve ammonia in water to obtain solution B;
[0131] Step 3: Add solution B dropwise to solution A to obtain a metal precipitate, and adjust the solution to maintain a certain pH value;
[0132] Step 4: Filter the precipitate obtained in Step 3, wash it with water, and dry it.
[0133] Finally, the precursor was calcined in air, washed repeatedly with anhydrous ethanol and ultrapure water, and then dried in an oven to obtain Cu-ZrO2.
[0134] In step one, the metal oxide is ZrO2 with a content of 5 g / L; the divalent copper source is copper nitrate with a content of 300 mg / L; the concentration of ammonia water is 4 mol / L; in step three, the pH is adjusted and maintained at 9.5; the reaction time in step three is 4 h; in step four, the precipitate is washed until neutral; the drying temperature in step four is 90℃ and the drying time is 24 h.
[0135] The samples prepared according to Example 2 were subjected to HEDP degradation performance tests using activated PMS. The HEDP concentration was 0.1 mmol / L, the catalyst dosage was 0.2 g / L, and the PMS dosage was 2 mmol / L. Results are shown below. Figure 3 As can be seen from the figure, when the wastewater pH=9, the prepared Cu-ZrO2 activated PMS still maintains a degradation efficiency of over 95% after 6 cycles of HEDP degradation, and the leaching content of metallic Cu is extremely low (0.0015 mg / L).
[0136] Application Example 3
[0137] A supported copper single-atom catalyst: the support is ZrO2, and the copper loading is 6 wt%;
[0138] The method for preparing this supported copper single-atom catalyst includes the following steps:
[0139] Step 1: Dissolve the metal oxide and divalent copper source in water to obtain solution A;
[0140] Step 2: Dissolve ammonia in water to obtain solution B;
[0141] Step 3: Add solution B dropwise to solution A to obtain a metal precipitate, and adjust the solution to maintain a certain pH value;
[0142] Step 4: Filter the precipitate obtained in Step 3, wash it with water, and dry it.
[0143] Finally, the precursor was calcined in air, washed repeatedly with anhydrous ethanol and ultrapure water, and then dried in an oven to obtain Cu-ZrO2.
[0144] In step one, the metal oxide is ZrO2 with a content of 5 g / L; the divalent copper source is copper chloride with a content of 300 mg / L; the concentration of ammonia water is 4 mol / L; in step three, the pH is adjusted and maintained at 9.5; the reaction time in step three is 5 h; in step four, the precipitate is washed until neutral; the drying temperature in step four is 100℃ and the drying time is 24 h.
[0145] The samples prepared according to Example 3 were used to test the HEDP degradation performance of activated PMS. The HEDP concentration was 0.1 mmol / L, the catalyst dosage was 0.2 g / L, and the PMS dosage was 2 mmol / L. At wastewater pH = 9, the prepared Cu-ZrO2 activated PMS system showed good performance in the presence of Cl- and SO42-. 2 -, NO3-, CO3 2 Under conditions where competing anions such as humic acid coexist, the degradation efficiency of organophosphonic acid HEDP still reaches 95%.
[0146] Application Example 4
[0147] A supported copper single-atom catalyst: the support is ZrO2, and the copper loading is 6 wt%;
[0148] The method for preparing this supported copper single-atom catalyst includes the following steps:
[0149] Step 1: Dissolve the metal oxide and divalent copper source in water to obtain solution A;
[0150] Step 2: Dissolve ammonia in water to obtain solution B;
[0151] Step 3: Add solution B dropwise to solution A to obtain a metal precipitate, and adjust the solution to maintain a certain pH value;
[0152] Step 4: Filter the precipitate obtained in Step 3, wash it with water, and dry it.
[0153] Finally, the precursor was calcined in air, washed repeatedly with anhydrous ethanol and ultrapure water, and then dried in an oven to obtain Cu-ZrO2.
[0154] In step one, the metal oxide is ZrO2 with a content of 5 g / L; the divalent copper source is copper nitrate with a content of 300 mg / L; the concentration of ammonia water is 4 mol / L; in step three, the pH is adjusted and maintained at 9.5; the reaction time in step three is 4 h; in step four, the precipitate is washed until neutral; the drying temperature in step four is 80℃ and the drying time is 24 h.
[0155] Comparative Example 2
[0156] The samples prepared in Example 4 were tested for their HEDP degradation performance under different oxidants (persulfate monophosphate (PMS), persulfate monophosphate (PDS), and hydrogen peroxide (H2O2)). The HEDP concentration was 0.1 mmol / L, the catalyst dosage was 0.2 g / L, and the PMS dosage was 2 mmol / L. At wastewater pH 9, the prepared Cu-ZrO2-activated PMS exhibited the best performance in degrading organophosphonic acid HEDP. This is because PDS and H2O2 have symmetrical structures, while the asymmetrical structure of PMS is more easily activated by copper single atoms to produce active substances.
[0157] Application Example 5
[0158] A supported copper single-atom catalyst: the support is ZrO2, and the copper loading is 6 wt%;
[0159] The method for preparing this supported copper single-atom catalyst includes the following steps:
[0160] Step 1: Dissolve the metal oxide and divalent copper source in water to obtain solution A;
[0161] Step 2: Dissolve ammonia in water to obtain solution B;
[0162] Step 3: Add solution B dropwise to solution A to obtain a metal precipitate, and adjust the solution to maintain a certain pH value;
[0163] Step 4: Filter the precipitate obtained in Step 3, wash it with water, and dry it.
[0164] Finally, the precursor was calcined in air, washed repeatedly with anhydrous ethanol and ultrapure water, and then dried in an oven to obtain a supported copper single-atom catalyst.
[0165] In step one, the metal oxide is ZrO2 with a content of 5 g / L; the divalent copper source is copper nitrate with a content of 300 mg / L; the concentration of ammonia water is 4 mol / L; in step three, the pH is adjusted and maintained at 9.5; the reaction time in step three is 5 h; in step four, the precipitate is washed until neutral; the drying temperature in step four is 100℃ and the drying time is 24 h.
[0166] Comparative Example 3
[0167] The samples prepared corresponding to Example 5 were used to test the performance of activated PMS in degrading different organophosphonic acids. The concentration of HEDP was 0.1 mmol / L, the catalyst dosage was 0.2 g / L, and the PMS dosage was 2 mmol / L. Figure 4 As shown, at pH=9, the prepared Cu-ZrO2 activated PMS system can achieve 100% degradation of different organophosphonic acids within 120 minutes.
[0168] Application Example 6
[0169] A supported copper single-atom catalyst: the support is ZrO2, and the copper loading is 6 wt%;
[0170] The method for preparing this supported copper single-atom catalyst includes the following steps:
[0171] Step 1: Dissolve the metal oxide and divalent copper source in water to obtain solution A;
[0172] Step 2: Dissolve ammonia in water to obtain solution B;
[0173] Step 3: Add solution B dropwise to solution A to obtain a metal precipitate, and adjust the solution to maintain a certain pH value;
[0174] Step 4: Filter the precipitate obtained in Step 3, wash it with water, and dry it.
[0175] Finally, the precursor was calcined in air, washed repeatedly with anhydrous ethanol and ultrapure water, and then dried in an oven to obtain a supported copper single-atom catalyst.
[0176] In step one, the metal oxide is ZrO2 with a content of 5 g / L; the divalent copper source is copper nitrate with a content of 300 mg / L; the concentration of ammonia water is 4 mol / L; in step three, the pH is adjusted and maintained at 9; the reaction time in step three is 4 h; in step four, the precipitate is washed until neutral; the drying temperature in step four is 80℃ and the drying time is 36 h.
[0177] The Cu-ZrO2 prepared in Example 6 was used to activate PMS, and the degradation effect of organophosphonic acid (HEDP) was tested under different pH conditions. The HEDP concentration was 0.1 mmol / L, the catalyst dosage was 0.2 g / L, and the PMS dosage was 2 mmol / L. Cu-ZrO2 was also added separately to the wastewater as a control. Figure 5 As shown, the prepared Cu-ZrO2 activated PMS system exhibits excellent degradation performance of HEDP over a wide pH range, achieving 100% degradation under both neutral and weakly alkaline conditions. Furthermore, under different pH conditions, the Cu-ZrO2 / PMS system significantly enhances the HEDP degradation performance compared to the homogeneous Cu(II) / PMS system.
[0178] Comparative Example 4-1
[0179] The sample prepared in accordance with Example 6 was tested for performance at a HEDP concentration of 0.05 mmol / L, a catalyst dosage of 0.1 g / L, and a PMS dosage of 1 mmol / L. At wastewater pH = 9, the prepared Cu-ZrO2-activated PMS system achieved 100% degradation of HEDP within 60 minutes.
[0180] Comparative Example 4-2
[0181] The sample prepared in accordance with Example 6 was tested for performance at a HEDP concentration of 0.4 mmol / L, a catalyst dosage of 0.5 g / L, and a PMS dosage of 4 mmol / L. At wastewater pH = 9, the prepared Cu-ZrO2-activated PMS system achieved 100% degradation of HEDP within 90 minutes.
[0182] In summary, the technical solution of this application is based on the intersection of environmental functional materials and deep treatment of industrial wastewater. Through atomically precise catalyst design, it successfully overcomes the core bottlenecks of traditional processes, such as low efficiency, high metal leaching, and narrow applicability, and provides an efficient and stable systematic solution for the treatment of organophosphonic acid polluted wastewater.
[0183] To address the issues of secondary metal ion pollution and slow degradation efficiency in homogeneous copper-activated persulfate (PMS) degradation systems for organophosphonic acids (HEDPs), a support-single-atom synergistic mechanism is employed. Metal oxides such as ZrO2, TiO2, and ZnO are selected as supports to construct Cu-OM (M = Zr / Ti / Zn) bonding structures to stably anchor copper single atoms. The three catalysts used to activate PMS for persulfate degradation all achieved 100% degradation efficiency for HEDPs. This degradation technology utilizes the preferential coordination of the -PO(OH)2 group of organophosphonic acids (such as HEDPs) with metal sites on the support surface to form a "Cu(II)-phosphonic acid-support" ternary complex. Under the action of PMS, this complex is rapidly oxidized to generate highly active Cu(III) species, directly driving intramolecular charge transfer (LMCT) and efficiently breaking CP bonds (phosphate conversion rate >98%), thus avoiding side reactions caused by free radical pathways. The PMS system activated by synthesized Cu-ZrO2 achieved 100% degradation of various organophosphonic acids; the catalyst was effective in environments containing Cl- and SO42-. 2- Even in complex water matrices such as humic acid, it can still maintain a HEDP degradation rate of over 95%; it can be recycled 5 times and still maintain an efficiency of over 90%; its effective pH range is broadened to 6-10 (the traditional Fenton system needs to be strictly controlled at pH≈3), which greatly reduces the difficulty and cost of wastewater pretreatment; after the reaction, the copper leaching rate is about 0.0015 mg / L (far lower than the industrial discharge standard of 1 mg / L).
[0184] This solution demonstrates adaptability to multiple scenarios. For organic phosphonic acid scale inhibitors (such as HEDP and ATMP) enriched in circulating cooling water treatment (power and petrochemical industries), the Cu single-atom / PMS system can achieve near-complete degradation within 30 minutes at room temperature. Compared to biological methods (degradation cycle > 48 hours) and homogeneous oxidation technologies with metal risks, its operating costs can be reduced by more than 40%, and the catalyst retains over 95% activity after six cycles. Furthermore, this technology is easily integrated with existing persulfate oxidation equipment, requiring only the addition of a fixed-bed catalyst reactor. This can significantly promote the transformation of the water treatment industry from the energy-intensive "chemical precipitation" model to the efficient, low-consumption "atom-economical catalytic oxidation" model.
[0185] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.
Claims
1. A method for treating organophosphonic acid wastewater using a supported copper single-atom catalyst, characterized in that, The organophosphonic acid wastewater is degraded by adding persulfate and the supported copper single-atom catalyst described above; the persulfate is a permonosulfate with an asymmetric structure. The supported copper single-atom catalyst is a metal oxide supported on copper single atoms, wherein the loading of copper single atoms is 1-10 wt% of the total catalyst weight; the supported copper single-atom catalyst is prepared by the following method: Step 1, the metal oxide is ultrasonically dispersed in ultrapure water, and a copper source is added dropwise to the suspension to form solution A; Step 2, an ammonia solution is added dropwise to solution A to carry out the reaction and the pH of the solution is adjusted, the precipitate is separated, washed and dried to obtain the precursor; Step 3, the precipitate is calcined in an air atmosphere, washed and dried to obtain the supported copper single-atom catalyst; the metal oxide is one or more of zirconium dioxide, titanium dioxide and zinc oxide.
2. The method for treating organophosphonic acid wastewater using a supported copper single-atom catalyst according to claim 1, characterized in that, The organophosphonic acid is one or more of hydroxyethylidene diphosphonic acid, aminotrimethylenephosphonic acid, ethylenediaminetetramethylenephosphonic acid, and diethylenetriaminepentamethylidenephosphonic acid.
3. The method for treating organophosphonic acid wastewater using a supported copper single-atom catalyst according to claim 1, characterized in that, In step one, the copper source is one or both of copper chloride and copper nitrate.
4. The method for treating organophosphonic acid wastewater using a supported copper single-atom catalyst according to claim 1, characterized in that, In step one, the concentration of the metal oxide in solution A is 5 g / L, and the concentration of the copper source is 50-300 mg / L.
5. The method for treating organophosphonic acid wastewater using a supported copper single-atom catalyst according to claim 1, characterized in that, Step two includes one or more of the following: i) The concentration of the ammonia solution is 1-4 mol / L; ii) The reaction time is 2-5 h; iii) The pH of the solution is adjusted to 9-9.
5.
6. The method for treating organophosphonic acid wastewater using a supported copper single-atom catalyst according to claim 1, characterized in that, Step three includes one or both of the following: i) The calcination temperature is 400-600℃; ii) The drying temperature is 80-100℃ and the time is 24-48 h.
7. The method for treating organophosphonic acid wastewater using a supported copper single-atom catalyst according to claim 1, characterized in that, The supported copper single-atom catalyst activated persulfate in organophosphonic acid wastewater at pH=9 and completed the degradation of organophosphonic acid within 30 min; in, The supported copper single-atom catalyst is zirconium dioxide supported with copper single atoms, and the loading amount of copper single atoms is 6 wt% of the total weight of the catalyst; the dosage of the supported copper single-atom catalyst is 0.01-1 g / L; The persulfate is permonosulfate, and the dosage of the persulfate is 0.1-5 mmol / L.