Heavy metal wastewater treatment agent and application thereof
By combining a strong oxidant, modified nano-zero-valent iron, and a flocculant, the problem of single-component and single-effect heavy metal wastewater treatment agents was solved, achieving a highly efficient removal of heavy metals.
Patent Information
- Application Number
- CN202511064331.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-31
- Publication Date
- 2026-05-15
- Estimated Expiration
- 2045-07-31
AI Technical Summary
Existing heavy metal wastewater treatment agents have limited components and limited effects, making them difficult to effectively remove heavy metals, especially with low removal efficiency under the interference of organic matter.
A combination of three reagents is used: liquid reagent A (strong oxidant, chelating agent and catalyst), solid reagent B (modified nano-zero valent iron), and liquid reagent C (flocculator and coagulant aid). Through oxidation, chelation, adsorption and reduction processes, combined with thiol and porphyrin compounds to modify nano-zero valent iron, a highly efficient heavy metal removal system is formed.
It significantly improves the efficiency of heavy metal removal, especially under the interference of organic matter, and can still effectively remove heavy metals, reducing the amount of reagents used and improving the treatment effect.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of wastewater treatment technology, specifically relating to a heavy metal wastewater treatment agent and its application. Background Technology
[0002] Heavy metals are non-biodegradable, can remain in water bodies for extended periods, and can be amplified through the biological processes of the food chain, accumulating in hundreds or thousands of quantities and causing toxic effects on organisms in the food chain. In recent years, with the continuous development of industrialization, a large amount of wastewater containing heavy metals has been generated. If not properly treated, it will seriously endanger the environment and human health.
[0003] Extensive research has been conducted on the treatment of industrial heavy metal wastewater. Commonly used methods include neutralization precipitation, sulfide precipitation, ferric salt precipitation, ion exchange, adsorption, and electrolysis. These methods all utilize large quantities of reagents. However, current heavy metal reagents are characterized by their limited composition, singular effectiveness, and inability to significantly reduce the impact of interfering substances on heavy metal removal, resulting in low removal efficiency. Therefore, developing a highly efficient reagent resistant to organic interference is of great significance for heavy metal removal.
[0004] In view of this, the present invention is proposed. Summary of the Invention
[0005] Based on the above problems, the first technical solution of the present invention is a heavy metal wastewater treatment agent, comprising three components: reagent A, reagent B, and reagent C.
[0006] Among them, reagent A is a liquid reagent, which includes a strong oxidant, a chelating agent and a catalyst;
[0007] Reagent B is a solid reagent, mainly a heavy metal adsorbent;
[0008] Agent C is a liquid agent, including flocculants and coagulants.
[0009] Furthermore, in the reagent A, the strong oxidant is potassium ferrate or potassium permanganate; the catalyst is sodium humate; the chelating agent is inorganic sodium pyrophosphate, and the mass ratio of the strong oxidant, the catalyst and the chelating agent is (40-45):(2-5):(2-5).
[0010] Furthermore, the heavy metal adsorbent in reagent B is modified nano-zero-valent iron, and its preparation method is as follows:
[0011] A first solution containing nano-zero-valent iron powder and a second solution containing mercapto-modified material are mixed and reacted to obtain a primary modified material;
[0012] The first modified compound and a third solution containing allyl porphyrin compounds are mixed and reacted to obtain the second modified compound;
[0013] The modified material was freeze-dried to obtain a black powder, namely modified nano-zero valent iron.
[0014] Furthermore, the mass ratio of the mercapto-modified compound to nano-zero-valent iron is (0.2-0.5):1; the mass ratio of the porphyrin compound to nano-zero-valent iron is (0.05-0.2):1.
[0015] Furthermore, the flocculant in reagent C is polyferric sulfate or polyaluminum ferric silicate; the coagulant aid is anionic polyacrylamide.
[0016] The second technical solution of this application discloses the application of the above-mentioned wastewater treatment agent in the treatment of wastewater containing heavy metals. The heavy metal wastewater is acidic wastewater containing one or more of the following heavy metals: lead, zinc, arsenic, cadmium, copper, nickel, and magnesium, or organic compounds such as phenols, lipids, and sulfates, and has a pH < 5.
[0017] Furthermore, the specific method for applying the wastewater treatment agent is as follows:
[0018] Add reagent A to the wastewater, stir and react until the solution ORP ≥ 300mV, then allow for one precipitation.
[0019] Adjust the pH of the supernatant after the first precipitation to 10-11, add reagent B, stir and react, and then precipitate a second time.
[0020] Add reagent C to the supernatant after secondary sedimentation. After reaction and sedimentation, the supernatant meets the wastewater discharge standards.
[0021] Beneficial effects: (1) Through the pretreatment of organic matter and the chelation, adsorption and reduction of heavy metals, the removal efficiency of complex heavy metal ions is effectively improved.
[0022] (2) The adsorption performance of zero-valent iron nanoparticles for heavy metals was enhanced by modifying them with mercapto compounds. Compared with traditional sulfide modification, mercapto compounds have antioxidant properties. The electron transfer efficiency was improved by secondary modification with porphyrin compounds, which enhanced the reduction performance of zero-valent iron nanoparticles and significantly improved the overall removal performance of zero-valent iron nanoparticles for heavy metals.
[0023] (3) The system is always in a high oxidation environment during the use of the agent, which effectively reduces the occurrence of heavy metal complexation reaction, resulting in better removal effect and less agent usage. Detailed Implementation
[0024] The technical solutions will now be clearly and completely described in conjunction with embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.
[0025] Unless otherwise specified, the technical terms in this specification have the same meaning as those generally understood by those skilled in the art; however, in case of any conflict, the definitions in this specification shall prevail.
[0026] The first embodiment of this application discloses a heavy metal wastewater treatment agent, comprising three components: agent A, agent B, and agent C.
[0027] Among them, reagent A is a liquid reagent, including strong oxidant potassium ferrate or potassium permanganate, catalyst sodium humate, and chelating agent pyrophosphate: the mass ratio of strong oxidant, catalyst and chelating agent is (40-45):(2-5):(2-5).
[0028] In the above-mentioned reagent A, the strong oxidant is used to remove organic matter from wastewater and increase the wastewater ORP, so that heavy metals are dispersed in the water in ionic form. At the same time, in order to improve the removal rate of organic matter by the oxidant, a certain amount of sodium humate is added as a catalyst. The chelating agent is pyrophosphate, which is an inorganic chelating agent. In addition to effectively adsorbing heavy metal ions, it can also effectively reduce the consumption of permanganate and the generation of MnO2 by the chelating agent.
[0029] Reagent B is a solid reagent, mainly a heavy metal adsorbent, and its preparation method is as follows:
[0030] A first solution containing nano-zero-valent iron powder and a second solution containing mercapto-modified material are mixed and reacted to obtain a primary modified material;
[0031] The first modified compound and a third solution containing porphyrin compounds are mixed and reacted to obtain the second modified compound;
[0032] The modified material was freeze-dried to obtain a black powder, namely modified nano-zero valent iron.
[0033] In this embodiment, the solvent for the first solution is deionized water, the solvent for the second solution is an alcohol, and the pH of the second solution is 3-3.5. After the first and second solutions are mixed, the pH of the mixed solution also needs to be adjusted to 3-3.5. The solvent for the third solution is an organic solvent, and the pH is 4-5. The mass ratio of the mercapto-modified compound to nano-zero-valent iron is (0.2-0.5):1; the mass ratio of the porphyrin compound to nano-zero-valent iron is (0.05-0.2):1.
[0034] This embodiment first modifies nano-zero-valent iron with thiol compounds, enhancing its adsorption performance for heavy metals. Compared to traditional sulfide modification, thiol compounds exhibit antioxidant properties. Subsequent secondary modification with porphyrin compounds improves electron transfer efficiency and enhances the reduction performance of the nano-zero-valent iron, resulting in a significant improvement in the overall removal performance of the modified nano-zero-valent iron heavy metal adsorbent.
[0035] Agent C is a liquid agent comprising a flocculant, polyferric sulfate or polyaluminum ferric silicate, and a coagulant aid, anionic polyacrylamide; the mass ratio of flocculant to coagulant aid is (10-50):(1-2), with the remainder being water; the anionic polyacrylamide has an analytical volume of 8-10 million and a particle size of 20-100 mesh. The second technical solution of this application discloses the application of the above-mentioned wastewater treatment agent in the treatment of wastewater containing heavy metals, wherein the heavy metal wastewater is acidic wastewater containing one or more of the following heavy metals: lead, zinc, arsenic, cadmium, copper, nickel, and magnesium, or organic matter such as phenols, lipids, and sulfates, and has a pH < 5.
[0036] Furthermore, the specific method for applying the wastewater treatment agent is as follows:
[0037] Add reagent A to the wastewater and stir until the solution ORP ≥ 300mV. Then, perform a single precipitation. This is mainly used to remove organic matter from wastewater by oxidizing and decomposing it or forming insoluble precipitates. At the same time, it maintains a high ORP in the entire treatment system so that heavy metals exist in the water in ionic form and prevent the formation of heavy metal complexes.
[0038] Adjust the pH of the supernatant after the first precipitation to 10-11, add reagent B, stir and react for a second precipitation, the reaction time is 1-1.5h, and the precipitation time is 3-5h. Through the adsorption, reduction and other effects of modified nano iron, heavy metal ions are adsorbed or insoluble precipitates are generated.
[0039] Add reagent C to the supernatant after secondary sedimentation. After reaction and sedimentation, the supernatant meets the wastewater discharge standards.
[0040] Furthermore, the concentration of agent A is 3-5%, and the dosage is 0.1-0.2 L / m³. 3 The dosage of water and reagent B is 0.1-0.3 kg / m³. 3 The concentration of reagent C is prepared at 5-10%, and the dosage is 0.05-0.1 L / m³. 3 water.
[0041] The technical solution of this application will be further described below through specific embodiments.
[0042] Example 1
[0043] Preparation of reagent A: Dissolve 4g of potassium permanganate in 100mL of boiling water, add 0.2g of metal chelating agent pyrophosphate, dissolve completely, and add 0.2g of catalyst to the solution before use to obtain reagent A;
[0044] Preparation of drug B:
[0045] a. Dissolve 5.6g of nano-zero ferric iron in 100mL of water to obtain the first solution. Then add 10mL of 10% mercaptoethanol solution to the first solution (the second solution, where the mass ratio of nano-zero ferric iron to mercaptoethanol is 1:0.2). Adjust the pH of the solution to 3, shake thoroughly and sonicate for 15min to obtain the first modified product.
[0046] b. Dissolve 0.28 g of iron porphyrin in 100 mL of N,N'-dimethylformamide and react at 30 °C for 2 h to obtain a third solution. Add 5.6 g of the primary modifier (the mass ratio of the primary modifier to iron porphyrin is 0.05:1) to the third solution. Under the protection of pyridine, adjust the pH to 4-5 and react at 80 °C for 2 h to obtain the secondary modifier.
[0047] c. Take out the secondary modified material, rinse it several times with deionized water and ethanol, and freeze-dry it to obtain reagent B;
[0048] Preparation of reagent C: Dissolve 5g of polyferric sulfate and 0.25g of anionic polyacrylamide in 100mL of water to prepare reagent C.
[0049] Example 2
[0050] Preparation of reagent A: Dissolve 4.5g of potassium permanganate in 100mL of boiling water, add 0.5g of metal chelating agent pyrophosphate, dissolve completely, and add 0.5g of catalyst to the solution before use to obtain reagent A;
[0051] Preparation of drug B:
[0052] a. Dissolve 5.6g of nano-zero ferric iron in 100mL of water to obtain the first solution. Then add 25mL of 10% mercaptoethanol solution to the first solution (the second solution, where the mass ratio of nano-zero ferric iron to mercaptoethanol is 1:0.5). Adjust the pH of the solution to 4-5, shake thoroughly and sonicate for 15min to obtain the first modified product.
[0053] b. Dissolve 0.56g of iron porphyrin in 100mL of N,N-dimethylformamide and react at 30℃ for 2h to obtain a third solution. Add 5.6g of the primary modifier (the mass ratio of the primary modifier to iron porphyrin is 0.2:1) to the third solution. Under the protection of pyridine, adjust the pH to 4-5 and react at 80℃ for 2h to obtain the secondary modifier.
[0054] c. Take out the secondary modified material, rinse it several times with deionized water and ethanol, and freeze-dry it to obtain reagent B;
[0055] Preparation of reagent C: Dissolve 10g of polyferric sulfate and 1g of anionic polyacrylamide in 100mL of water to prepare reagent C.
[0056] Example 3
[0057] Preparation of reagent A: Dissolve 4g of potassium ferrate in 100mL of boiling water, add 0.2g of metal chelating agent pyrophosphate, dissolve completely, and add 0.2g of catalyst to the solution before use to obtain reagent A;
[0058] Preparation of drug B:
[0059] a. Dissolve 5.6g of nano-zero ferric iron in 100mL of water to obtain the first solution. Then add 10mL of 10% mercaptoethanol solution to the first solution (the second solution, where the mass ratio of nano-zero ferric iron to mercaptoethanol is 1:0.2). Adjust the pH of the solution to 3, shake thoroughly and sonicate for 15min to obtain the first modified product.
[0060] b. Dissolve 0.28 g of iron porphyrin in 100 mL of N,N'-dimethylformamide and react at 30 °C for 2 h to obtain a third solution. Add 5.6 g of the primary modifier (the mass ratio of the primary modifier to iron porphyrin is 0.05:1) to the third solution. Under the protection of pyridine, adjust the pH to 4-5 and react at 80 °C for 2 h to obtain the secondary modifier.
[0061] c. Take out the secondary modified material, rinse it several times with deionized water and ethanol, and freeze-dry it to obtain reagent B;
[0062] Preparation of reagent C: Dissolve 5g of polyferric sulfate and 0.25g of anionic polyacrylamide in 100mL of water to prepare reagent C.
[0063] Comparative Example 1
[0064] Unlike the previous example, agent A is not used to oxidize the organic matter in the wastewater; instead, agents B and C are used to remove pollutants from the wastewater.
[0065] Comparative Example 2
[0066] The difference from Example 1 is that Agent B uses unmodified nano-zero valent iron.
[0067] Comparative Example 3
[0068] The difference from Example 1 is that, for the preparation of reagent B, only mercaptoethanol is used to modify it according to step b to obtain the primary modified product, and no secondary modification is performed.
[0069] Example 1 of effect verification
[0070] The wastewater to be treated is mining wastewater, and the main pollutants include COD (phenols, sulfides), lead, arsenic, cadmium and other heavy metal compounds, with average concentrations of COD 230 mg / L, lead 5.5 mg / L, arsenic 15.6 mg / L and cadmium 0.4 mg / L, respectively. The pH value of the wastewater is <5.
[0071] According to the aforementioned application method and dosage of the reagents, the reagents prepared in Examples 1, 2, 3 and Comparative Examples 1, 2, 3 were added to the wastewater and reacted at room temperature. The concentration of heavy metals in the effluent was measured according to the national standard method, and the removal rate of heavy metal pollutants was calculated. The results are shown in Table 1.
[0072] Table 1 Heavy metal removal rate (%)
[0073]
[0074] As shown in Table 1, Examples 1-3 all achieved a removal rate of over 90% for heavy metal compounds in mining wastewater, which is a significant improvement compared to Comparative Documents 1-3.
[0075] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.
Claims
1. A heavy metal wastewater treatment agent, characterized in that, It includes three components: drug A, drug B, and drug C; Among them, reagent A is a liquid reagent, which includes a strong oxidant, a chelating agent and a catalyst; Reagent B is a solid reagent, mainly a heavy metal adsorbent; Agent C is a liquid agent, including flocculants and coagulants; The heavy metal adsorbent in reagent B is modified nano-zero-valent iron, and its preparation method is as follows: A first solution containing nano-zero-valent iron powder and a second solution containing mercapto-modified material are mixed and reacted to obtain a primary modified material; The first modified compound and a third solution containing porphyrin compounds are mixed and reacted to obtain the second modified compound; The modified material was freeze-dried to obtain a black powder, namely modified nano-zero valent iron. The mass ratio of the mercapto-modified compound to nano-zero-valent iron is (0.2-0.5):1; the porphyrin compound is an allylporphyrin compound; the mass ratio of the allylporphyrin compound to nano-zero-valent iron is (0.05-0.2):
1.
2. The wastewater treatment agent according to claim 1, characterized in that, In the reagent A, the strong oxidant is potassium ferrate or potassium permanganate; the catalyst is sodium humate; and the chelating agent is inorganic sodium pyrophosphate. The mass ratio of the strong oxidant, the catalyst and the chelating agent is (40-45):(2-5):(2-5).
3. The wastewater treatment agent according to claim 1, characterized in that, The flocculant in reagent C is polyferric sulfate or polyaluminum ferric silicate; the coagulant aid is anionic polyacrylamide.
4. The application of the wastewater treatment agent according to any one of claims 1-3 in the treatment of wastewater containing heavy metals, characterized in that, The heavy metal wastewater is an acidic wastewater containing one or more of the following heavy metals: lead, zinc, arsenic, cadmium, copper, nickel, and magnesium, or organic compounds such as phenols, lipids, and sulfates, with a pH < 5.
5. The application according to claim 4, characterized in that, The specific application method of the wastewater treatment agent is as follows: Add reagent A to the wastewater, stir and react until the solution ORP ≥ 300mV, then allow for one precipitation. Adjust the pH of the supernatant after the first precipitation to 10-11, add reagent B, stir and react, and then precipitate a second time. Add reagent C to the supernatant after secondary sedimentation. After reaction and sedimentation, the supernatant meets the wastewater discharge standards.
6. The application according to claim 5, characterized in that, The concentration of reagent A is 3-5%, and the dosage is 0.1-0.2 L / m³ of water; the dosage of reagent B is 0.1-0.3 kg / m³; and the concentration of reagent C is 5-10%, and the dosage is 0.05-0.1 L / m³ of water.