Method for strengthening autocatalysis complex breaking of heavy metal complex in heavy-related wastewater

Abstract

The invention discloses a method for strengthening autocatalytic complex breaking of a heavy metal complex in heavy-related wastewater, relates to the technical field of wastewater treatment, and is technically characterized by providing the method for strengthening autocatalytic complex breaking of the heavy metal complex in the heavy-related wastewater. By directionally activating a complex metal center and strengthening electron transfer in a heavy metal complex molecule, efficient targeted decomplexing of complex heavy metals in wastewater is realized under the condition of not additionally introducing any auxiliary technology, the treatment process is simple, the cost is reduced, and a new solution is provided for deep purification of heavy metal pollution in industrial wastewater.

Description

Technical Field

[0001] The present invention relates to the technical field of wastewater treatment, and particularly to a method for enhancing the self-catalytic complex-breaking of heavy metal complexes in heavy metal-containing wastewater. Background Art

[0002] Since organic chelating agents such as ethylenediaminetetraacetic acid (EDTA), nitrilotriacetic acid (NTA), and citric acid (CA) are widely used in industrial processes, heavy metal ions in wastewater usually exist in the form of stable complexes. Different from ionic metals, complex-bound heavy metals are difficult to be effectively removed by traditional chemical precipitation or adsorption methods due to their stable structures, which is the root cause of the difficulty in meeting the discharge standards of wastewater in the "heavy metal-containing" industry. Currently, the treatment of complex-bound heavy metals in industrial wastewater usually adopts the process flow of "oxidative complex-breaking - ion release - chemical precipitation", and its core lies in destroying the outer organic ligands of complex-bound heavy metals through advanced oxidation processes and releasing heavy metal ions through oxidative complex-breaking.

[0003] However, the oxidative complex-breaking process of traditional advanced oxidation technologies for complex-bound heavy metals is extremely susceptible to the influence of coexisting impurities in wastewater, resulting in poor complex-breaking selectivity and low removal efficiency. Some studies have found that by irradiating with ultraviolet light to excite the intramolecular electron transfer (LMCT) between the complex organic ligand and the metal, the coordination structure of complex-bound heavy metals can be accurately destroyed, realizing selective complex-breaking for complex-bound heavy metals under complex water quality conditions. However, the high turbidity conditions of actual wastewater severely inhibit the photocatalytic complex-breaking efficiency, and the treatment process is complex, and the process cost remains high.

[0004] Therefore, the present invention aims to provide a method for enhancing the self-catalytic complex-breaking of heavy metal complexes in heavy metal-containing wastewater to solve the above problems. Summary of the Invention

[0005] The purpose of the present invention is to solve the above problems and provide a method for enhancing the self-catalytic complex-breaking of heavy metal complexes in heavy metal-containing wastewater. By utilizing the self-catalytic activity of complex-bound heavy metals, the complex-bound metal center is directionally activated, the intramolecular electron transfer of heavy metal complexes is enhanced, and under the condition of not introducing any additional auxiliary technologies, efficient targeted complex-breaking of complex-bound heavy metals in wastewater is achieved. The treatment process is simple, the cost is reduced, and a new solution is provided for the deep purification of heavy metal pollution in industrial wastewater.

[0006] In order to achieve the above purpose, the technical solution of the present invention is as follows:

[0007] The present invention provides a method for enhancing the self-catalytic breaking of heavy metal complexes in heavy-metal-containing wastewater. By using the complex heavy metals in the wastewater as catalysts, an electron transfer pathway of oxidant-metal-organic ligand is directly formed between the oxidant and the complex heavy metals, and the intramolecular electron transfer of the complex heavy metals is enhanced according to the actual water quality characteristics, thereby mediating the transformation of high-valent metal centers and the selective generation of specific active species, precisely destroying the coordination structure of the heavy metal complexes, and thus achieving efficient targeted breaking of the complex heavy metals.

[0008] In this solution, it mainly focuses on various heavy metal complexes in the wastewater, such as one or more of complex copper, nickel, lead, chromium, zinc, etc., where the heavy metal concentration ranges from 0.1 to 1.0 mM. The heavy metal chelating agent reacts with the heavy metal to form heavy metal complexes, and the heavy metal complexes include EDTA-Ni, EDTA-Cu, HEDP-Cu, NTA-Ni, CA-Zn, EDTA-Ni / Co, EDTA-Ni / Cu, EDTA-Ni / Mn, EDTA-Cu, HEDP-Cu, and EDTA-Pb. A self-catalytic breaking system for enhancing the intramolecular electron transfer is specifically constructed. According to different electron transfer enhancement mechanisms, it is mainly divided into three mechanisms: alkali enhancement, multi-metal center synergistic enhancement, and special active species-mediated enhancement. The present invention can specifically construct a self-catalytic breaking system based on the LMCT process of complex heavy metals according to the water quality characteristics of the wastewater, without significantly adjusting the water quality conditions, and achieve efficient selective breaking of high-steady heavy metals therein.

[0009] The oxidants include peroxymonosulfate (PMS), percarbonate (SPC), periodate (PI), persulfate (PDS), and calcium peroxide (CaO2). The dosage of PMS is 1 - 5 mM, the dosage of SPC is 2 - 10 mM, the dosage of PI is 0.3 - 0.5 mM, the dosage of PDS is 0.3 - 10.0 mM, and the dosage of CaO2 is 3 - 15 mM.

[0010] Compared with the prior art, the beneficial effects of this solution are as follows:

[0011] The present invention utilizes the self-catalytic activity of complex heavy metals to construct a self-catalytic breaking system with a suitable oxidant and heavy metal complexes. By directionally activating the complex metal centers and enhancing the intramolecular electron transfer of heavy metal complexes, efficient targeted breaking of complex heavy metals in wastewater is achieved without introducing any additional auxiliary technologies. The treatment process is simple, the cost is reduced, and a new solution is provided for the deep purification of heavy metal pollution in industrial wastewater. Brief Description of the Drawings

[0012] Figure 1 is the self-catalytic targeted breaking mechanism diagram of complex heavy metals in the embodiment of the present invention;

[0013] Figure 2 It is a schematic diagram comparing the complex-breaking efficiency of EDTA-Ni in the Fenton system and the self-catalytic complex-breaking system in the embodiments of the present invention;

[0014] Figure 3 It is a schematic diagram comparing the complex-breaking efficiency of EDTA-Cu in the Fenton system and the self-catalytic complex-breaking system in the embodiments of the present invention;

[0015] Figure 4 It is a schematic diagram comparing the complex-breaking efficiency of HEDP-Ni in the Fenton system and the self-catalytic complex-breaking system in the embodiments of the present invention;

[0016] Figure 5 It is a schematic diagram comparing the complex-breaking efficiency of HEDP-Cu in the Fenton system and the self-catalytic complex-breaking system in the embodiments of the present invention;

[0017] Figure 6 It is a schematic diagram comparing the complex-breaking efficiency of NTA-Ni in the Fenton system and the self-catalytic complex-breaking system in the embodiments of the present invention;

[0018] Figure 7 It is a schematic diagram comparing the complex-breaking efficiency of CA-Zn in the Fenton system and the self-catalytic complex-breaking system in the embodiments of the present invention;

[0019] Figure 8 It is a schematic diagram comparing the complex-breaking efficiency of EDTA-Ni / Co in the Fenton system and the self-catalytic complex-breaking system in the embodiments of the present invention;

[0020] Figure 9 It is a schematic diagram comparing the complex-breaking efficiency of EDTA-Ni / Cu in the Fenton system and the self-catalytic complex-breaking system in the embodiments of the present invention;

[0021] Figure 10 It is a schematic diagram comparing the complex-breaking efficiency of EDTA-Ni / Mn in the Fenton system and the self-catalytic complex-breaking system in the embodiments of the present invention;

[0022] Figure 11 It is a schematic diagram comparing the complex-breaking efficiency of EDTA-Cu in the Fenton system and the Cl--enhanced self-catalytic complex-breaking system in the embodiments of the present invention;

[0023] Figure 12 It is a schematic diagram comparing the complex-breaking efficiency of HEDP-Cu in the Fenton system and the Cl--enhanced self-catalytic complex-breaking system in the embodiments of the present invention;

[0024] Figure 13 It is a schematic diagram comparing the complex-breaking efficiency of HEDP-Ni in the Fenton system and the Cl--enhanced self-catalytic complex-breaking system in the embodiments of the present invention;

[0025] Figure 14It is a schematic diagram comparing the complex-breaking efficiency of EDTA-Pb in the Fenton system and the Cl⁻-enhanced autocatalytic complex-breaking system in the embodiments of the present invention. Detailed implementation manners

[0026] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions of the present invention will be further described in detail below in conjunction with the embodiments and drawings of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0027] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below in conjunction with the embodiments.

[0028] Embodiment 1:

[0029] The water quality of the heavy industrial wastewater is shown in Table 1. The pH value of the wastewater is as high as 11. Since Ni in the wastewater forms a highly stable complexed nickel with EDTA, the content of Ni in the water is as high as 1 mM (58 mg / L) under strong alkaline conditions. By comparing the complex-breaking efficiency of EDTA-Ni in this wastewater with the traditional Fenton method, as Figure 2 shown, the traditional Fenton method not only needs to adjust the acidity and alkalinity of the wastewater to maintain it at about 3, but also its complex-breaking efficiency is only 40.0%; while using the autocatalytic activity of EDTA-Ni and combining with the original alkaline conditions of the wastewater, directly adding 5.0 mM PMS to the system, under the same reaction conditions (reacting for 2 h at 25 °C), the complex-breaking efficiency of EDTA-Ni is as high as 98.7%. After alkali treatment, the content of Ni in the wastewater 2+ is lower than 1.0 mg / L.

[0030] Table 1 High-alkaline industrial wastewater mainly polluted by EDTA-Ni

[0031]

[0032] Embodiment 2:

[0033] The water quality of the heavy industrial wastewater is shown in Table 2. The pH value of the wastewater is as high as 9. The main heavy metal complex in the water is EDTA-Cu. Under alkaline conditions, the content of Cu in the water is as high as 0.7 mM (45 mg / L). By comparing the complex-breaking efficiency of EDTA-Cu in this wastewater with the traditional Fenton method, as Figure 3As shown, the traditional Fenton method requires adjusting the pH of the wastewater to maintain it at around 3, and its complex-breaking efficiency is only 72.9%; while using the autocatalytic activity of EDTA-Cu and combining with the original alkaline conditions of the wastewater, directly adding 1.5 mM PMS to the system, under the same reaction conditions (reacting at 25 °C for 2 h), the complex-breaking efficiency of EDTA-Cu is as high as 99.1%. After alkali treatment, the Cu content in the wastewater 2+ is less than 0.5 mg / L.

[0034] Table 2 Highly alkaline industrial wastewater with EDTA-Cu as the main heavy metal pollution

[0035]

[0036] Example 3:

[0037] The water quality of the heavy industry wastewater is shown in Table 3. The pH value of this wastewater is 10, and the main heavy metal complex in the water is hydroxyethane diphosphonic acid copper (HEDP-Cu). Under alkaline conditions, the Cu content in the water is as high as 0.1 mM (6.4 mg / L). By comparing the complex-breaking efficiency of HEDP-Cu in this wastewater with the traditional Fenton method, as Figure 4 shown, the traditional Fenton method requires adjusting the pH of the wastewater to maintain it at around 3.0, and its complex-breaking efficiency is only 19.1%; while using the autocatalytic activity of HEDP-Cu and combining with the original alkaline conditions of the wastewater, directly adding 2.0 mM percarbonate (SPC) to the system, under the same reaction conditions (reacting at 25 °C for 2 h), the complex-breaking efficiency of HEDP-Cu is as high as 97.9%. After alkali treatment, the Cu content in the wastewater 2+ is less than 0.2 mg / L.

[0038] Table 3 Highly alkaline industrial wastewater with HEDP-Cu as the main heavy metal pollution

[0039]

[0040] Example 4:

[0041] The water quality of the heavy industry wastewater is shown in Table 3. The pH value of this wastewater is 10, and the main heavy metal complex in the water is hydroxyethane diphosphonic acid nickel (HEDP-Ni). Under alkaline conditions, the Cu content in the water is as high as 0.5 mM (29.4 mg / L). By comparing the complex-breaking efficiency of HEDP-Cu in this wastewater with the traditional Fenton method, as Figure 5As shown, the traditional Fenton method requires adjusting the pH of the wastewater to maintain it at around 3.0, and its complex-breaking efficiency is only 42.1%; while utilizing the autocatalytic activity of HEDP-Cu and combining with the original alkaline conditions of the wastewater, directly adding 10.0 mM SPC to the system, under the same reaction conditions (reacting at 25 °C for 2 h), the complex-breaking efficiency of HEDP-Ni is as high as 98.6%. After alkali treatment, the Ni content in the wastewater 2+ is lower than 0.5 mg / L.

[0042] Table 4 Highly alkaline industrial wastewater mainly polluted by HEDP-Ni

[0043]

[0044] Example 5:

[0045] The water quality of the heavy industry wastewater involved is shown in Table 5. The pH value of this wastewater is 8, the main heavy metal complex in the water is nitrilotriacetic acid nickel (NTA-Ni), and the Ni content in the water is as high as 0.5 mM (29 mg / L). By comparing with the traditional Fenton method for the complex-breaking efficiency of NTA-Ni in this wastewater, as Figure 6 shown, the traditional Fenton method requires adjusting the pH of the wastewater to maintain it at around 3, and its complex-breaking efficiency is only 56.7%; while utilizing the autocatalytic activity of NTA-Ni, directly adding 0.5 mM periodate (PI) to the system, under the same reaction conditions (reacting at 25 °C for 0.5 h), the complex-breaking efficiency of NTA-Ni is as high as 99.7%. After alkali treatment, the Ni content in the wastewater 2+ is lower than 0.1 mg / L.

[0046] Table 5 Alkaline industrial wastewater mainly polluted by NTA-Ni

[0047]

[0048] Example 6:

[0049] The water quality of the heavy industry wastewater involved is shown in Table 6. The pH value of this wastewater is 9, the main heavy metal complex in the water is zinc oxalate (CA-Zn), and the Zn content in the water is as high as 0.6 mM (39 mg / L). By comparing with the traditional Fenton method for the complex-breaking efficiency of CA-Zn in this wastewater, as Figure 7 shown, the complex-breaking efficiency of the traditional Fenton method is only 80.7%; while utilizing the autocatalytic activity of CA-Zn, directly adding 0.3 mM periodate (PI) to the system, under the same reaction conditions (reacting at 25 °C for 0.5 h), the complex-breaking efficiency of CA-Zn is as high as 100%. After alkali treatment, the Ni content in the wastewater 2+ is much lower than 0.1 mg / L.

[0050] Table 6 Highly alkaline industrial wastewater mainly polluted by CA-Zn

[0051]

[0052] Example 7:

[0053] The water quality of the heavy industry wastewater involved is shown in Table 7. The pH value of this wastewater is 6. There are mainly two heavy metal complexes in the water, namely NTA-Ni / Co. The content of Ni in the water is as high as 0.3 mM (17 mg / L), and the Ni / Co molar ratio is 30:1. By comparing with the traditional Fenton method for the complex-breaking efficiency of NTA-Ni / Co in this wastewater, as Figure 8 shown, the traditional Fenton method needs to adjust the acidity and alkalinity of the wastewater to maintain it at about 3, and its complex-breaking efficiencies are 76.9% and 30.0% respectively; while through the synergistic catalysis of the dual-metal centers of NTA-Ni / Co, directly adding 1.0 mM PMS to the system, under the same reaction conditions (reacting at 25 °C for 0.5 h), the complex-breaking efficiencies of NTA-Ni / Co are as high as 97.7% and 100% respectively. After alkali treatment, the concentration of Ni in the wastewater 2+ is lower than 0.5 mg / L, and the concentration of Co 2+ is far lower than 0.1 mg / L.

[0054] Table 7 Industrial wastewater mainly polluted by EDTA-Ni / Co

[0055]

[0056] Example 8:

[0057] The water quality of the heavy industry wastewater involved is shown in Table 8. The pH value of this wastewater is 7. There are mainly two heavy metal complexes in the water, namely EDTA-Ni / Cu. The content of Ni in the water is as high as 0.1 mM (5.8 mg / L), and the Ni / Cu molar ratio is 1:10. By comparing with the traditional Fenton method for the complex-breaking efficiency of EDTA-Ni / Co in this wastewater, as Figure 9 shown, the complex-breaking efficiencies of the traditional Fenton method for the two metals are 57.6% and 68.0% respectively; while through the synergistic catalysis of the dual-metal centers of EDTA-Ni / Cu, directly adding 3.0 mM PMS to the system, under the same reaction conditions (reacting at 25 °C for 0.5 h), the complex-breaking efficiencies of EDTA-Ni / Cu are as high as 91.6% and 99.5% respectively. After alkali treatment, the concentrations of Ni 2+ and Cu 2+ in the wastewater are both lower than 0.5 mg / L.

[0058] Table 8 Industrial wastewater mainly polluted by EDTA-Ni / Cu

[0059]

[0060]

[0061] Example 9:

[0062] The water quality of the heavy industrial wastewater is shown in Table 9. The pH value of the wastewater is 7. There are mainly two heavy metal complexes in the water, namely EDTA-Ni / Mn. The content of Ni in the water is as high as 0.5 mM (30 mg / L), and the Ni / Mn molar ratio is 1:1. By comparing with the traditional Fenton method for the complex-breaking efficiency of EDTA-Ni / Mn in this wastewater, as Figure 10 shown, the complex-breaking efficiencies of the traditional Fenton method for the two metals are 62.6% and 68.0% respectively; while through the synergistic catalysis of the bimetallic centers of EDTA-Ni / Mn, directly adding 2.0 mM PMS to the system, under the same reaction conditions (reacting at 25 °C for 0.5 h), the complex-breaking efficiencies of EDTA-Ni / Cu are as high as 97.7% and 98.3% respectively. After alkali treatment, the average concentrations of Ni 2+ and Cu 2+ in the wastewater are both lower than 1.0 mg / L.

[0063] Table 9 Industrial wastewater mainly polluted by EDTA-Ni / Mn

[0064]

[0065] Example 10:

[0066] The water quality of the heavy industrial wastewater is shown in Table 10. The pH value of the wastewater is as high as 5, and the water contains a high concentration of Cl-. The main heavy metal complex in the water is EDTA-Cu, and the content of Cu in the water is as high as 1.0 mM (64 mg / L). By comparing with the traditional Fenton method for the complex-breaking efficiency of EDTA-Cu in this wastewater, as Figure 11 shown, the complex-breaking efficiency of the traditional Fenton method for EDTA-Cu is only 52.1%; while using the autocatalytic activity of EDTA-Cu and combining with the high-salt characteristics of the wastewater, directly adding 0.3 mM persulfate (PDS) to the system, under the same reaction conditions (reacting at 25 °C for 2 h), the complex-breaking efficiency of EDTA-Cu is as high as 99.9%. After alkali treatment, the content of Cu 2+ in the wastewater is lower than 0.1 mg / L.

[0067] Table 10 Acidic high-salt industrial wastewater mainly polluted by EDTA-Cu

[0068]

[0069] Example 11:

[0070] The water quality of the heavy industry-related wastewater is shown in Table 11. The pH value of this wastewater is 3, and it contains a high concentration of Cl-. The main heavy metal complex in the water is HEDP-Cu, and the content of Cu in the water is as high as 0.2 mM (13 mg / L). By comparing with the traditional Fenton method for the complex-breaking efficiency of HEDP-Cu in this wastewater, as Figure 13 shown, the complex-breaking efficiency of the traditional Fenton method for HEDP-Cu is only 38.6%; while using HEDP-Cu directly to construct a self-catalytic complex-breaking system with calcium peroxide (CaO2), where the addition amount of CaO2 is 3.0 mM, combined with the high-salt characteristics of the wastewater, strengthening electron transfer, and at the same time significantly promoting the generation of chlorine radicals (Cl■) and singlet oxygen ( 1 O2), strengthening the targeted complex-breaking of HEDP-Cu. Under the same reaction conditions (reacting for 2 h at 25 °C), the complex-breaking efficiency of HEDP-Cu is as high as 99.7%. After alkali treatment, the content of Cu in the wastewater 2+ is far lower than 0.1 mg / L.

[0071] Table 11 Acidic high-salt industrial wastewater mainly polluted by HEDP-Cu

[0072]

[0073] Example 12:

[0074] The water quality of the heavy industry-related wastewater is shown in Table 12. The pH value of this wastewater is 4, and it contains a high concentration of Cl-. The main heavy metal complex in the water is HEDP-Ni, and the content of Cu in the water is as high as 0.7 mM (41 mg / L). By comparing with the traditional Fenton method for the complex-breaking efficiency of HEDP-Ni in this wastewater, as Figure 13 shown, the complex-breaking efficiency of the traditional Fenton method for HEDP-Ni is only 32.7%; while using HEDP-Cu directly to construct a self-catalytic complex-breaking system with calcium peroxide (CaO2), where the addition amount of CaO2 is 15.0 mM, combined with the high-salt characteristics of the wastewater, strengthening electron transfer, and at the same time significantly promoting the generation of chlorine radicals (Cl■) and singlet oxygen ( 1 O2), strengthening the targeted complex-breaking of HEDP-Ni. Under the same reaction conditions (reacting for 2 h at 25 °C), the complex-breaking efficiency of HEDP-Ni is as high as 99.3%. After alkali treatment, the content of Ni in the wastewater 2+ is far lower than 0.5 mg / L.

[0075] Table 12 Acidic high-salt industrial wastewater mainly polluted by HEDP-Ni

[0076]

[0077] Embodiment 13:

[0078] The water quality of heavy industrial wastewater is shown in Table 13. The pH value of the wastewater is 4, and the water contains high concentrations of Cl-. The main heavy metal complex in the water is EDTA-Pb, and the content of Pb in the water is as high as 0.3mM (62mg / L). The decomposition efficiency of EDTA-Pb in the wastewater is compared with that of the traditional Fenton method. Figure 14 As shown in the figure, the efficiency of traditional Fenton method for EDTA-Pb decomposition is only 88.0%. However, the self-catalytic decomposition system is constructed by directly combining EDTA-Pb with 10.0 mM PDS, which strengthens the electron transfer based on the high salt characteristics of water and significantly promotes the reaction of chlorine free radicals (Cl■) and singlet oxygen ( 1 O2) was generated, and the targeted decomposition of EDTA-Pb was strengthened. Under the same reaction conditions (reaction temperature 25℃ for 2h), the final decomposition efficiency of EDTA-Pb was as high as 100%. After alkali treatment, Pb 2+ The content is far less than 0.1mg / L.

[0079] Table 13 Acidic high-salt industrial wastewater with EDTA-Pb as the main heavy metal pollution

[0080]

[0081] In general, the solution provided by the embodiments of the present invention is as described in the above invention content. According to different wastewater quality characteristics, a self-catalytic decomposition system based on complexed heavy metals is specifically constructed, and efficient targeted decomposition of heavy metal complexes in water is achieved by effectively strengthening the electron transfer within the complexed molecules, as shown in Table 14.

[0082] Table 14 Construction of complexed heavy metal autocatalytic decomposition system for different industrial wastewater quality characteristics

[0083]

[0084]

[0085] The above specific embodiments are merely explanations of the present invention and are not limitations of the present invention. After reading this specification, those skilled in the art may make modifications to the embodiments without any creative contribution as needed. However, such modifications are protected by the patent law as long as they are within the scope of the claims of the present invention.

Claims

1. A method for enhancing the autocatalytic breaking of heavy metal complexes in heavy metal-containing wastewater, characterized in that: The method is as follows: Using the complex-bound heavy metals in the wastewater as catalysts, directly form an oxidant-metal-organic ligand electron transfer pathway with the oxidant and the complex-bound heavy metals, and strengthen the intramolecular electron transfer of the complex-bound heavy metals according to the actual water quality characteristics, thereby mediating the transformation of high-valent metal centers and the selective generation of specific active species, precisely destroying the coordination structure of the heavy metal complexes, and thus achieving efficient targeted complex-breaking of the complex-bound heavy metals.

2. The method for autocatalytic breaking of heavy metal complexes in heavy-metal-containing wastewater as claimed in claim 1, wherein: The heavy metals in the complex-bound heavy metals specifically include one or more of copper, nickel, lead, chromium, and zinc.

3. The method for autocatalytic breaking of heavy metal complexes in heavy-metal-containing wastewater as claimed in claim 2, wherein: The heavy metal chelating agent reacts with the heavy metal to form a heavy metal complex, and the heavy metal complex includes EDTA-Ni, EDTA-Cu, HEDP-Cu, NTA-Ni, CA-Zn, EDTA-Ni / Co, EDTA-Ni / Cu, EDTA-Ni / Mn, EDTA-Cu, HEDP-Cu, and EDTA-Pb.

4. A method for enhancing the autocatalytic breaking of heavy metal complexes in heavy metal-containing wastewater as claimed in claim 1, characterized in that: The oxidant includes peroxymonosulfate, percarbonate, periodate, persulfate, and calcium peroxide.

5. A method for enhancing the autocatalytic breaking of heavy metal complexes in heavy-metal-containing wastewater as claimed in claim 1, characterized in that: The electron transfer strengthening mechanism includes an alkali strengthening mechanism, a multi-metal center synergistic strengthening mechanism, and a special active species-mediated strengthening mechanism.

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