Preparation method and application of nano-metal adsorbent for industrial arsenic and chlorine removal
By preparing composite metal oxide nano-adsorbents, combined with polyacrylic acid and nano-carriers, the problems of narrow pH range and small adsorption capacity of activated alumina adsorbents were solved, achieving efficient removal of arsenic and chlorine while reducing regeneration frequency and health risks.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- PETROCHINA CO LTD
- Filing Date
- 2024-10-15
- Publication Date
- 2026-04-17
Smart Images
Figure BDA0005086062800000071 
Figure BDA0005086062800000072
Abstract
Description
Technical Field
[0001] This invention belongs to the field of adsorption materials technology, specifically relating to a method for preparing and applying a nano-metal adsorbent for industrial arsenic and chlorine removal. Background Technology
[0002] In the ethylene industry, waste gases and wastewater often contain high concentrations of heavy metals such as chlorine and arsenic during hydrocarbon cracking, catalytic reforming, hydrogenation processes, and wastewater treatment, posing significant challenges to treatment. The presence of arsenic compounds and chlorides can not only cause catalyst poisoning but also lead to severe environmental pollution. Therefore, to avoid these problems, industrial processes often require the adsorption and removal of arsenic and chlorine, aiming to remove arsenic compounds and chlorides as much as possible; otherwise, it will negatively impact product quality and the environment.
[0003] Developing practical technologies for removing arsenic and chlorine pollution from wastewater and exhaust gases is a hot topic both domestically and internationally. Currently, various technologies are being explored to remove arsenic and chlorine from wastewater and exhaust gases. Highly efficient arsenic and chlorine removal technologies include membrane separation, coagulation and sedimentation, ion exchange, biological treatment, and adsorption. Among these, adsorption technology offers advantages such as high efficiency, low cost of adsorbents, a wide variety of adsorbents to choose from, and the ability to regenerate adsorbents. The core of current adsorption technology is the development of highly efficient adsorption materials. Among numerous adsorbents, nano-metal adsorbents, with their high surface atomic unsaturation, abundant surface functional groups, diverse chemical composition, and varied structures and morphologies, are widely used in wastewater and exhaust gas environments.
[0004] Adsorption refers to the surface phenomenon where surrounding substances spontaneously concentrate or accumulate at a phase interface. Adsorption can occur between different phase interfaces. In wastewater and waste gas treatment, solid adsorbents are generally used to adsorb and remove pollutants from wastewater and waste gas. The core of adsorption lies in the selection of the adsorbent. Currently, the main adsorbent used in China for arsenic and chlorine removal is activated alumina. This material is inexpensive and readily available, but it has drawbacks such as a narrow operating pH range, low adsorption capacity leading to frequent regeneration, and high aluminum leaching from water, which can be harmful to human health.
[0005] Metal oxides are among the most common adsorbent materials. However, with the continuous reduction of the concentration threshold for pollutants, the adsorption effect of single metal oxides is no longer sufficient. While some metal oxides have good adsorption capacity, their respective defects are also significant. Therefore, composite metal oxides have emerged. The synergistic effect of composite metal oxides significantly improves the adsorption performance of adsorbents, and the shortcomings of each metal can be complemented, resulting in superior material performance. Composite materials refer to new materials with novel properties formed by combining two or more materials with different properties through physicochemical methods. In recent years, research on using composite metal oxides (bimetallic or trimetallic oxides) as adsorbents to remove specific pollutants has increased significantly, and numerous scholars have conducted extensive research on their adsorption behavior and mechanisms. Summary of the Invention
[0006] The purpose of this invention is to provide a method for preparing a nano-metal adsorbent for industrial removal of arsenic and chlorine.
[0007] To achieve the above objectives, the present invention provides a method for preparing a nano-metal adsorbent for industrial arsenic and chlorine removal, comprising the following steps:
[0008] S1, the first metal compound is ultrasonically mixed with a polyethylene glycol solution, then the second metal compound is added, the mixture is heated and stirred, the solution is then adjusted to alkaline, cooled and aged, washed, filtered and dried to obtain a composite metal oxide;
[0009] S2, add polyacrylic acid to deionized water, dissolve it, then add the composite metal oxide, stir, then add the nanocarrier, stir, filter, and wash to obtain the nano metal adsorbent.
[0010] The method for preparing the industrial arsenic and chlorine removal nano-metal adsorbent of the present invention is characterized in that, in step S1, the pH of the solution is adjusted to 8-12.
[0011] The method for preparing the industrial arsenic and chlorine removal nano-metal adsorbent of the present invention is characterized in that, in step S1, the aging temperature is 5-20℃ and the aging time is 2-6 hours.
[0012] The method for preparing the industrial arsenic and chlorine removal nano-metal adsorbent of the present invention is characterized in that the first metal and the second metal are one or more of copper, magnesium, iron, cerium and manganese, the first metal and the second metal are different, and the molar ratio of the first metal atom to the second metal atom is 1 to 2:1.
[0013] The method for preparing the industrial arsenic and chlorine removal nano-metal adsorbent of the present invention is characterized in that, in step S1, the heating temperature is 30-80℃ and the stirring time is 1-15 hours; in step S2, the stirring conditions after adding the nano-carrier are stirring at 0-50℃ for 1-10 hours.
[0014] The method for preparing the industrial arsenic and chlorine removal nano-metal adsorbent of the present invention is characterized in that, in step S2, the average molecular weight of polyacrylic acid is 2000-4000000, and the mass ratio of polyacrylic acid to deionized water is 1:1-50.
[0015] The method for preparing the industrial arsenic and chlorine removal nano-metal adsorbent of the present invention is characterized in that, in step S2, the mass ratio of composite metal oxide, nano-carrier and polyacrylic acid is 1:(0.1-1):(5-50).
[0016] The method for preparing the industrial arsenic and chlorine removal nano-metal adsorbent of the present invention is characterized in that the nano-carrier is one or more of graphene oxide, activated carbon, carbon nanotubes, alumina, and molecular sieves.
[0017] The method for preparing the industrial arsenic and chlorine removal nano-metal adsorbent of the present invention is characterized in that the molecular sieve is one or more of 13X, ZSM-5, ZSM-22, ZSM-23, NaY, and HY.
[0018] The method for preparing the industrial arsenic and chlorine removal nano-metal adsorbent of the present invention is characterized in that the average particle size of the nanocarrier is 2-2000 nm.
[0019] To achieve the above objectives, the present invention also provides an application of the nano-metal adsorbent prepared by the above method in the treatment of waste gas and liquid containing arsenic and chlorine compounds.
[0020] Beneficial effects:
[0021] (1) The nano metal adsorbent for industrial arsenic and chlorine removal described in this invention has good particle morphology and adjustable particle size.
[0022] (2) The dual adsorption of metal compounds and nano-adsorbents in the industrial arsenic removal nano metal adsorbent described in the invention can double the adsorption amount of arsenic compounds and chlorides.
[0023] (3) The industrial nano metal adsorbent for removing arsenic and chlorine used in this invention impregnates the active nano adsorbent carrier with a solution containing metal ions, and grafts the metal ions onto the nano adsorbent carrier through PPA self-polymerization. Detailed Implementation
[0024] The present invention will now be described in detail through embodiments. It should be noted that the following embodiments are only for further illustration of the present invention and should not be construed as limiting the scope of protection of the present invention. Those skilled in the art can make some non-essential improvements and adjustments to the present invention based on the above description.
[0025] Example 1
[0026] Iron-copper composite oxide was prepared by co-precipitation: 3.8 g of prepared Fe3O4 was mixed with 30 ml of polyethylene glycol solution (5 wt%) and sonicated for 30 min. Then, it was mixed with 4.3 g of CuCl2, stirred rapidly, and heated to 50 °C. After the temperature stabilized, 1 mol / L NaOH solution was slowly added dropwise until the pH stabilized at around 11.5. After the pH stabilized, stirring was stopped, and the solution was aged at 8 °C for 4 h. After aging, the supernatant was poured off, an equal amount of deionized water was added, and the mixture was allowed to stand to precipitate. The supernatant was then poured off again, and the material was washed repeatedly. Finally, the solution was filtered, and the material was dried at 80 °C. After grinding, it was sealed and stored to obtain the iron-copper composite oxide.
[0027] Add 50g PAA to 100ml of deionized water, pour in 1g of the above composite metal oxide, and after mechanically stirring the mixture in a three-necked flask, add 1g GO and continue stirring for 3h. After filtering and washing the solution, the PAA-grafted nano metal adsorbent, namely iron-copper composite oxide / graphene oxide carrier, is obtained.
[0028] Example 2
[0029] Take 250 mL of 0.2 mol·L⁻¹ -1 Fe(NO3)3 solution was mixed with 30 ml of polyethylene glycol solution (5 wt%) and sonicated for 30 min. Then, it was mixed with 3.5 g of CuCl2, stirred rapidly, and heated to 50 °C. After the temperature stabilized, 1 mol / L NaOH solution was slowly added dropwise until the pH stabilized at around 10.5. After the pH stabilized, stirring was stopped, and the solution was aged at 5 °C for 6 h. After aging, the supernatant was poured off, an equal amount of deionized water was added, and the mixture was allowed to stand to precipitate. The supernatant was then poured off again, and the material was rinsed repeatedly. Finally, the solution was filtered, and the material was dried at 80 °C. After grinding, it was sealed and stored to obtain the iron-copper composite oxide.
[0030] Add 50g PAA to 100ml of deionized water, pour in 1g of the above composite metal oxide, and after mechanically stirring the mixture in a three-necked flask, add 0.3g GO and continue stirring for 3h. After filtering and washing the solution, the PAA-grafted nano metal adsorbent, namely iron-copper composite oxide / graphene oxide carrier, is obtained.
[0031] Example 3
[0032] Take 3.8 g of the prepared Fe3O4 and mix it with 30 ml of polyethylene glycol solution (5 wt%), then sonicate for 30 min. Add 20 ml of 1 mol·L⁻¹ solution. -1 KOH solution was added to 0.05 mol·L⁻¹ -1 The solution is then mixed with the above solution in a KMnO4 solution, stirred rapidly, and heated to 50°C. After the temperature stabilizes, 1 mol / L NaOH solution is slowly added dropwise until the pH stabilizes at around 9. Once the pH stabilizes, stirring is stopped, and the solution is aged at 20°C for 6 hours. After aging, the supernatant is poured off, an equal amount of deionized water is added, and the mixture is allowed to stand and precipitate. The supernatant is then poured off again, and the material is washed repeatedly. Finally, the solution is filtered, and the material is dried at 80°C. After grinding, it is sealed and stored to obtain the iron-manganese composite oxide, i.e., the iron-manganese composite oxide / graphene oxide carrier.
[0033] Add 6g PAA to 100ml of deionized water, pour in 1g of the above composite metal oxide, and after mechanically stirring the mixture in a three-necked flask, add 1g GO and continue stirring for 3h. After filtering and washing the solution, obtain the PAA-grafted nano metal adsorbent, namely the iron-copper composite oxide / graphene oxide carrier.
[0034] Example 4
[0035] Take 3.8g of the prepared Fe3O4 and mix it with 30ml of polyethylene glycol solution (5wt%) and sonicate for 30min. Then mix it with 4.85g of Cu(NO3)2, stir rapidly and heat to 50℃. After the temperature stabilizes, slowly add 1mol / L NaOH solution to the solution until the pH stabilizes at around 8. After the pH stabilizes, stop stirring and age the solution at 8℃ for 4h. After aging, pour off the supernatant, add an equal amount of deionized water, let it stand to precipitate, and then pour off the supernatant again. Repeat this process of rinsing the material several times. Finally, filter the solution, dry the material at 80℃, grind it and seal it for storage to obtain the iron-copper composite oxide, i.e., iron-copper composite oxide / graphene oxide carrier.
[0036] Add 50g PAA to 100ml of deionized water, pour in 1g of the above composite metal oxide, and after mechanically stirring the mixture in a three-necked flask, add 1g GO and continue stirring for 3h. After filtering and washing the solution, the PAA-grafted nano metal adsorbent, namely iron-copper composite oxide / graphene oxide carrier, is obtained.
[0037] Example 5
[0038] Take 3.8g of the prepared Fe3O4 and mix it with 30ml of polyethylene glycol solution (5wt%) and sonicate for 30min. Then mix it with 4.3g of CuSO4, stir rapidly and heat to 50℃. After the temperature stabilizes, slowly add 1mol / L NaOH solution to the solution until the pH stabilizes at around 12. After the pH stabilizes, stop stirring and age the solution at 8℃ for 4h. After aging, pour off the supernatant, add an equal amount of deionized water, let it stand to precipitate, and then pour off the supernatant again. Repeat this process of rinsing the material several times. Finally, filter the solution, dry the material at 80℃, grind it and seal it for storage to obtain the iron-copper composite oxide, i.e., iron-copper composite oxide / graphene oxide carrier.
[0039] Add 50g PAA to 100ml of deionized water, pour in 1g of the above composite metal oxide, and after mechanically stirring the mixture in a three-necked flask, add 1g GO and continue stirring for 3h. After filtering and washing the solution, the PAA-grafted nano metal adsorbent, namely iron-copper composite oxide / graphene oxide carrier, is obtained.
[0040] Example 6
[0041] Take 3.8g of the prepared Fe3O4 and mix it with 30ml of polyethylene glycol solution (5wt%) and sonicate for 30min. Then mix it with 4.3g of CuCl2, stir rapidly and heat to 50℃. After the temperature stabilizes, slowly add 1mol / L NaOH solution to the solution until the pH stabilizes at about 11.5. After the pH stabilizes, stop stirring and age the solution at 8℃ for 4h. After aging, pour off the supernatant, add an equal amount of deionized water, let it stand to precipitate, and then pour off the supernatant again. Repeat this process of rinsing the material several times. Finally, filter the solution, dry the material at 80℃, grind it and seal it for storage to obtain the iron-copper composite oxide, i.e., iron-copper composite oxide / carbon nanotube carrier.
[0042] Add 50g of PAA to 100ml of deionized water, pour in 1g of the above composite metal oxide, and after mechanically stirring the mixture in a three-necked flask, add 1g of carbon nanotubes and continue stirring for 3h. After filtering and washing the solution, obtain the PAA-grafted nano metal adsorbent, namely the iron-copper composite oxide / graphene oxide carrier.
[0043] Example 7
[0044] Take 3.8g of the prepared Fe3O4 and mix it with 30ml of polyethylene glycol solution (5wt%) and sonicate for 30min. Then mix it with 4.3g of CuCl2, stir rapidly and heat to 50℃. After the temperature stabilizes, slowly add 1mol / L NaOH solution to the solution until the pH stabilizes at about 11.5. After the pH stabilizes, stop stirring and age the solution at 8℃ for 4h. After aging, pour off the supernatant, add an equal amount of deionized water, let it stand to precipitate, and then pour off the supernatant again. Repeat this process of rinsing the material several times. Finally, filter the solution, dry the material at 80℃, grind it and seal it for storage to obtain the iron-copper composite oxide, i.e., iron-copper composite oxide / alumina carrier.
[0045] Add 50g PAA to 100ml of deionized water, pour in 1g of the above composite metal oxide, and after mechanically stirring the mixture in a three-necked flask, add 1g of aluminum oxide and continue stirring for 3h. After filtering and washing the solution, the PAA-grafted nano metal adsorbent, namely iron-copper composite oxide / graphene oxide carrier, is obtained.
[0046] Comparative Example 1
[0047] Add 50g PAA to 100ml deionized water, add 4.42g CuCl2 and 3.6g FeCl3, and after mechanically stirring the mixture in a three-necked flask, add 1g GO and stir for 3h. After filtering and washing the solution, obtain the PAA-grafted nano-metal adsorbent, namely PAA / graphene oxide carrier.
[0048] Comparative Example 2
[0049] Take 3.8g of the prepared Fe3O4 and mix it with 30ml of polyethylene glycol solution (5wt%) and sonicate for 30min. Then mix it with 4.3g of CuCl2, stir rapidly and heat to 50℃. After the temperature stabilizes, slowly add 1mol / L NaOH solution to the solution until the pH stabilizes at about 11.5. After the pH stabilizes, stop stirring and age the solution at 8℃ for 4h. After aging, pour off the supernatant, add an equal amount of deionized water, let it stand to precipitate, add 1g of GO, and continue stirring for 3h. Then pour off the supernatant again. Repeat this process to wash the material several times. Finally, filter the solution, dry the material at 80℃, grind it and seal it for storage to obtain the iron-copper composite oxide.
[0050] Add 50g of PAA to 100ml of deionized water, pour in 1g of the above composite metal oxide, and after mechanically stirring the mixture in a three-necked flask, filter and wash the solution to obtain the PAA-grafted nano metal adsorbent, namely the iron-copper composite oxide / graphene oxide carrier.
[0051] Comparative Example 3
[0052] Add 50g PAA to 100ml deionized water, pour in 3.8g of prepared Fe3O4, and after mechanically stirring the mixture in a three-necked flask, add 1g GO and continue stirring for 3h. After filtering and washing the solution, obtain the PAA-grafted nano metal adsorbent, namely iron oxide / graphene oxide carrier.
[0053] Test methods
[0054] Take 20 ml of the test sample containing arsenic and chlorine, add it to the adsorbent of the example and comparative examples respectively, stir and filter to obtain the adsorbed sample.
[0055] Take 5g of the adsorbed sample, dissolve it in 5% hydrochloric acid, and after adjusting the volume, determine the arsenic content in the acid solution by atomic fluorescence hydride generation.
[0056] The chlorine content in acidic solutions was determined using the microcoulometric method.
[0057] The specific results are shown in Tables 1 and 2 below.
[0058] Table 1 Arsenic concentrations before and after adsorption
[0059]
[0060] Table 2 Chlorine concentration before and after adsorption
[0061]
[0062] Of course, the present invention may have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the claims of the present invention.
Claims
1. A method for preparing an industrial nano-metal adsorbent for removing arsenic and chlorine, characterized in that, Includes the following steps: S1, the first metal compound is ultrasonically mixed with a polyethylene glycol solution, then the second metal compound is added, the mixture is heated and stirred, the solution is then adjusted to alkaline, cooled and aged, washed, filtered and dried to obtain a composite metal oxide; S2, add polyacrylic acid to deionized water, dissolve it, then add the composite metal oxide, stir, then add the nanocarrier, stir, filter, and wash to obtain the nano metal adsorbent.
2. The preparation method of the industrial arsenic and chlorine removal nano-metal adsorbent according to claim 1, characterized in that, In step S1, the pH of the solution is adjusted to 8-12.
3. The method for preparing the industrial arsenic and chlorine removal nano-metal adsorbent according to claim 1, characterized in that, In step S1, the aging temperature is 5-20℃ and the aging time is 2-6 hours.
4. The preparation method of the industrial arsenic and chlorine removal nano-metal adsorbent according to claim 1, characterized in that, The first metal and the second metal are one or more of copper, magnesium, iron, cerium and manganese. The first metal and the second metal are different. The molar ratio of the first metal atom to the second metal atom is 1 to 2:
1.
5. The method for preparing the industrial arsenic and chlorine removal nano-metal adsorbent according to claim 1, characterized in that, In step S1, the heating temperature is 30-80℃ and the stirring time is 1-15 hours; in step S2, the stirring conditions after adding the nanocarrier are 0-50℃ for 1-10 hours.
6. The preparation method of the industrial arsenic and chlorine removal nano-metal adsorbent according to claim 1, characterized in that, In step S2, the average molecular weight of polyacrylic acid is 2,000-4,000,000, and the mass ratio of polyacrylic acid to deionized water is 1:1-50.
7. The method for preparing the industrial arsenic and chlorine removal nano-metal adsorbent according to claim 1, characterized in that, In step S2, the mass ratio of the composite metal oxide, nanocarrier, and polyacrylic acid is 1:(0.1-1):(5-50).
8. The method for preparing the industrial arsenic and chlorine removal nano-metal adsorbent according to claim 1, characterized in that, The nanocarrier is one or more of graphene oxide, activated carbon, carbon nanotubes, alumina, and molecular sieves.
9. The method for preparing the industrial arsenic and chlorine removal nano-metal adsorbent according to claim 1, characterized in that, The molecular sieve is one or more of 13X, ZSM-5, ZSM-22, ZSM-23, NaY, and HY.
10. The method for preparing the industrial arsenic and chlorine removal nano-metal adsorbent according to claim 1, characterized in that, The average particle size of the nanocarrier is 2-2000 nm.
11. The application of the nano-metal adsorbent prepared by the method of any one of claims 1-10 in the treatment of waste gas and liquid containing arsenic and chlorine compounds.