Method for removing acetaminophen with molybdenum powder fortified ferric iron / tripolyphosphate activated molecular oxygen

Abstract

The application provides a method for removing acetaminophen by using molybdenum powder to strengthen trivalent iron / tripolyphosphate activated molecular oxygen, in particular, molybdenum powder is used to reduce trivalent iron into divalent iron, and the divalent iron and the tripolyphosphate are used to activate molecular oxygen to remove acetaminophen. The addition of molybdenum powder has obvious advantages for trivalent iron / tripolyphosphate activated molecular oxygen, and the removal rate is greatly improved compared with the case without molybdenum powder, and the treatment efficiency of pollutants is improved. The presence of tripolyphosphate can avoid the precipitation of trivalent iron and divalent iron, and can also strengthen the activation of molecular oxygen. Under the condition of medium alkalinity, the system has strong removal capacity for acetaminophen. The morphology of molybdenum powder before and after the reaction and the cycle experiment show that the molybdenum powder has strong stability in the trivalent iron / tripolyphosphate system and can be reused.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of environmental engineering, and particularly relates to a method for removing acetaminophen by using molybdenum powder reinforced trivalent iron / tripolyphosphate activated molecular oxygen. BACKGROUND

[0002] At present, drug abuse exists in China, and with drugs being continuously discharged into the environment, the ecological environment and human body will be harmed to a certain extent. How to effectively treat the drugs discharged into the environment has become a research hotspot. The conventional treatment process is difficult to completely degrade the drugs, and the mineralization degree is low. The advanced oxidation method has the advantage of high mineralization degree, and is therefore widely applied to remove drugs.

[0003] Molecular oxygen as a green and environmentally friendly oxidant has attracted widespread attention. The active substances formed by the activation of molecular oxygen can oxidize and degrade pollutants. Metal-activated molecular oxygen advanced oxidation technology has been studied by many scholars. Ferrous iron is an ideal metal for activating molecular oxygen. However, the activation efficiency of ferrous iron for molecular oxygen is low, and the yield of active substances is low. The addition of a complex can enhance the activation of molecular oxygen by ferrous iron, and generate more active substances. Common ligands include oxalate, nitrilotriacetic acid (NTA), EDTA, vitamins, tripolyphosphate, etc. Too much organic ligand will consume hydroxyl radicals, which is not conducive to the degradation of pollutants. Organic ligands have certain limitations in enhancing the activation of molecular oxygen by ferrous iron. Among them, tripolyphosphate is an inorganic ligand, which has obvious advantages compared with organic ligands. Tripolyphosphate can enhance the activation of molecular oxygen by ferrous iron to produce active substances to degrade pollutants. However, ferrous iron is not suitable for treating pollutants in a medium alkaline environment, so the combination of trivalent iron, molybdenum powder and tripolyphosphate can achieve the removal of pollutants in a medium alkaline environment. SUMMARY

[0004] In order to overcome the shortcomings of conventional advanced oxidation technology, such as the need for external oxidation agent, the easy generation of secondary pollution, and the poor reactivity in a medium alkaline environment, the purpose of the present application is to provide a method for removing acetaminophen by using molybdenum powder reinforced trivalent iron / tripolyphosphate activated molecular oxygen.

[0005] The purpose of the present application is achieved by the following scheme: a method for removing acetaminophen by using molybdenum powder reinforced trivalent iron / tripolyphosphate activated molecular oxygen. First, a tripolyphosphate mother liquor is prepared, then raw water containing pollutants is prepared, a certain amount of tripolyphosphate is added to the raw water, and the pH of the raw water is adjusted. Then, molybdenum powder is weighed. A certain amount of Fe 3+ The mother liquor and molybdenum powder are added to the raw water containing pollutants, and a magnetic stirrer is started to remove the pollutants.

[0006] A method for removing acetaminophen by using molybdenum powder to strengthen trivalent iron / tripolyphosphate activated molecular oxygen, which is to reduce trivalent iron to divalent iron by molybdenum powder, and to activate molecular oxygen to remove acetaminophen by divalent iron and tripolyphosphate, comprising the following steps:

[0007] Preparation of tripolyphosphate mother liquor with a concentration of 100 mmol / L;

[0008] Preparation of Fe 3+ Mother liquor with a concentration of 100 mmol / L;

[0009] Preparation of raw water containing pollutants;

[0010] Add tripolyphosphate mother liquor to raw water to make the final concentration of tripolyphosphate 0.1-0.6 mmol / L, adjust the pH value of raw water to 3-9; then weigh molybdenum powder, and the concentration of molybdenum powder is 0.1-0.4 g / L; add Fe 3+ Mother liquor with a concentration of 100 mmol / L and molybdenum powder to raw water containing pollutants, so that the molar ratio of Fe 3+ To tripolyphosphate is 2:1 to 1:3; magnetic stirring, and removal of pollutants.

[0011] According to the above scheme, the concentration of the tripolyphosphate mother liquor is 100 mmol / L, and the final concentration of the added tripolyphosphate is 0.1-0.6 mmol / L.

[0012] According to the above scheme, the molybdenum powder is commercial molybdenum powder, and the concentration of the added molybdenum powder is 0.1-0.4 g / L.

[0013] According to the above scheme, the concentration of the Fe 3+ Mother liquor is 100 mmol / L, prepared by using FeCl3, and the final concentration of the added Fe 3+ Is 0.1-0.2 mmol / L.

[0014] According to the above scheme, the pollutants in the raw water are acetaminophen, and the concentration is 1-50 µM.

[0015] According to the above scheme, the pH value of the raw water is adjusted to 3-9.

[0016] According to the above scheme, the stirring speed of the stirrer is 100-400 r / min.

[0017] According to the above scheme, the stirring reaction time is 10-60 min.

[0018] The technical principle of the present application is:

[0019] The tripolyphosphate can form Fe(III)-tripolyphosphate complex with trivalent iron, which can prevent the precipitation of trivalent iron in the reaction solution.

[0020] The addition of molybdenum powder accelerates the cycling of ferric and ferrous iron, forming a Fe(II)-tripolyphosphate complex. This Fe(II)-tripolyphosphate complex activates molecular oxygen, generating more H₂O₂ and ∙OH, which rapidly degrades acetaminophen.

[0021] This invention accelerates the cycling of ferric and ferrous iron (Fe2+) by adding molybdenum powder, promoting the activation of molecular oxygen by ferrous iron and tripolyphosphate (TP), and generating more active substances H2O2 and ∙OH. This invention solves the problems of low activation efficiency and poor removal effect of ferrous iron for molecular oxygen, achieving rapid removal of acetaminophen, and can be applied in moderately alkaline water treatment environments. The addition of molybdenum powder significantly enhances the activation of molecular oxygen by ferric iron / TP, greatly improving the removal rate compared to the absence of molybdenum powder and increasing the treatment efficiency of pollutants. Furthermore, the presence of TP prevents precipitation of ferric and ferrous iron and also strengthens the activation of molecular oxygen. Under moderately alkaline conditions, this system exhibits strong removal capacity for acetaminophen. The morphology of molybdenum powder before and after the reaction and cycling experiments show that molybdenum powder has strong stability in the ferric iron / TP system and can be reused.

[0022] The advantages of this invention are:

[0023] (1) This invention uses molybdenum powder to enhance the activation of molecular oxygen by ferric iron / tripolyphosphate to remove acetaminophen. The addition of ferric iron and molybdenum powder enables the ferrous iron / tripolyphosphate in the reaction system to react with molecular oxygen, producing more active substances, thus solving the problem of low activation efficiency of ferrous iron for molecular oxygen and poor treatment effect. (2) This invention is the first to propose the use of inorganic co-catalyst molybdenum powder to enhance the activation of molecular oxygen by ferric iron / tripolyphosphate to remove acetaminophen.

[0024] (3) The present invention uses inorganic complexing agents, which will not consume the free radicals of the reaction system and have more advantages than organic complexes.

[0025] (4) This invention is applicable to the treatment of acetaminophen in a moderately alkaline environment. Attached Figure Description

[0026] Figure 1 The graph shows the effect of different systems on the removal of acetaminophen in Example 1.

[0027] like Figure 1 As shown, the system with Fe3+, tripolyphosphate and molybdenum powder achieved a pollutant removal rate of 87.5%, while the removal rate without molybdenum powder was 0.98% and the removal rate without Fe3+ was only 0.23%.

[0028] Figure 2 Example 2: Effect of different ratios of ferric iron and tripolyphosphate on the removal of acetaminophen.

[0029] As shown in Figure 2 The removal rates of pollutants were 66.8%, 81.9%, 87.5% and 82.0% respectively when the molar ratio of Fe3+ and tripolyphosphate was 2:1, 1:1, 1:2 and 1:3.

[0030] Figure 3 The effect diagram of different concentrations of molybdenum powder on the removal of acetaminophen in Example 3

[0031] As shown in Figure 3 The removal rates of pollutants were 58.0%, 75.6%, 87.5% and 90.8% respectively when 0.01g, 0.02g, 0.03g and 0.04g of molybdenum powder was added.

[0032] Figure 4 The effect diagram of different pH on the removal of acetaminophen in Example 4

[0033] As shown in Figure 4 The removal rates of pollutants were 5.0%, 87.5% and 73.2% respectively when the initial pH was 3, 7 and 9.

[0034] Figure 5 The cycle degradation diagram of molybdenum powder in Example 5

[0035] As shown in Figure 5 The removal rates of pollutants were 87.5%, 86.3%, 85.5%, 89.4% and 85.5% respectively when the molybdenum powder was used for 5 times.

[0036] Figure 6 The morphology diagram of molybdenum powder before and after cycle in Example 5

[0037] As shown in Figure 6 The morphology of molybdenum powder before and after reaction did not have obvious difference after being used for many times, which indicated that the molybdenum powder could be used for many times in the reaction system and had good stability. DETAILED DESCRIPTION

[0038] The content of the present application will be described in detail by specific examples, and the specific examples described are only used to explain the present application and do not limit the present application.

[0039] Example 1

[0040] A method for removing acetaminophen by molybdenum powder strengthened ferric iron / tripolyphosphate activated molecular oxygen, which reduces ferric iron to ferrous iron by molybdenum powder, and removes acetaminophen by complexing ferrous iron and tripolyphosphate to activate molecular oxygen, according to the following steps:

[0041] Prepare a tripolyphosphate mother liquor with a concentration of 100mmol / L;

[0042] Prepare a 100 mmol / L solution of triFe 3+ Mother liquor;

[0043] Prepare 100 mL of 50 µM acetaminophen as the raw water containing the target pollutant;

[0044] When the tripolyphosphate mother liquor was added to the original water, the final concentration of tripolyphosphate (the concentration of tripolyphosphate in the water after adding the tripolyphosphate mother liquor) was 0.4 mmol / L;

[0045] Weigh 0.03g of molybdenum powder and add Fe 3+ Add Fe to 100 mL of pollutants at a molar ratio of 1:2 with tripolyphosphate. 3 + The final concentration (Fe added) 3+ Fe in the mother liquor and raw water 3+ The concentration of tripolyphosphate was 0.2 mmol / L, and the final concentration of tripolyphosphate (the concentration of tripolyphosphate in the water after adding the mother liquor of tripolyphosphate) was 0.4 mmol / L.

[0046] Operating procedures: After adding tripolyphosphate, maintain the pH of the raw water at 7, and finally press Fe... 3+ Mix 0.2 mmol / L FFe with tripolyphosphate at a molar ratio of 1:2. 3+ Add 0.03g of molybdenum powder to 100mL of raw water containing the target pollutant, turn on the stirrer and stir at 350r / min for 60min to degrade and remove acetaminophen in the water.

[0047] like Figure 1 As shown, Fe was added 3+ The system containing tripolyphosphate and molybdenum powder achieved a pollutant removal rate of 87.5%, while the removal rate without molybdenum powder was 0.98%, and without Fe... 3+ The removal rate was only 0.23%.

[0048] Example 2

[0049] A method for removing acetaminophen using molybdenum powder-enhanced trivalent iron / tripolyphosphate activated molecular oxygen is similar to the steps in Example 1, except that the Fe is changed. 3+ The effects of tripolyphosphate and sodium phosphate on pollutant removal rates were analyzed at molar ratios, following the steps outlined below:

[0050] Prepare a 100 mmol / L tripolyphosphate stock solution;

[0051] Prepare a 100 mmol / L solution of triFe 3+ Mother liquor;

[0052] Prepare 100 mL of 50 µM acetaminophen as the raw water for the target pollutant;

[0053] Add the tripolyphosphate mother liquor to the raw water to adjust the pH of the raw water to 7, then weigh out 0.03g of molybdenum powder and add Fe... 3+ Fe and tripolyphosphate were added to 100 mL of pollutants at molar ratios of 2:1, 1:1, 1:2, and 1:3, respectively. 3+ The final concentration is the Fe added. 3+ Fe in the mother liquor and raw water 3+ The concentration of the polyphosphate was 0.2 mmol / L, and the final concentrations of the tripolyphosphate (the concentrations of polyphosphate in the water after adding the polyphosphate mother liquor) were 0.1 mmol / L, 0.2 mmol / L, 0.4 mmol / L, and 0.6 mmol / L, respectively.

[0054] The operating procedure is as follows: After adding tripolyphosphate, maintain the pH of the raw water at 7, and finally add 0.2 mmol / L FE. 3+ Add 0.03g of molybdenum powder, turn on the stirrer and stir at 350r / min for 60min to degrade and remove acetaminophen in water.

[0055] like Figure 2 As shown, Fe 3+ The removal rates of pollutants by the molar ratios of Fe to tripolyphosphate were 66.8%, 81.9%, 87.5%, and 82.0%, respectively. 3+ The molar ratio of 1:(1-3) to tripolyphosphate is more effective in removing pollutants.

[0056] Example 3

[0057] A method for removing acetaminophen using molybdenum powder-enhanced trivalent iron / tripolyphosphate activated molecular oxygen is similar to the steps in Example 1, except that the effect of changing the amount of molybdenum powder added on the pollutant removal rate is analyzed. The method is as follows:

[0058] Prepare a 100 mmol / L tripolyphosphate stock solution;

[0059] Prepare a 100 mmol / L solution of triFe 3+ Mother liquor;

[0060] Prepare 100 mL of 50 µM acetaminophen as the target pollutant in the raw water containing the pollutant;

[0061] Weigh out 0.01g, 0.02g, 0.03g, and 0.04g of molybdenum powder respectively, and add Fe... 3+ Add Fe to 100 mL of raw water containing contaminants at a molar ratio of 1:2 with tripolyphosphate.3+ The final concentration of Fe 3+ The final concentration of Fe 3+ The final concentration of Fe 3+ The final concentration of Fe 3+ The final concentration of Fe 3+ The final concentration of Fe 3 The final concentration of Fe + The final concentration of Fe 3+ The final concentration of Fe 3+ The final concentration of Fe 3+ The final concentration of Fe The final concentration of Fe

[0062] The final concentration of Fe The final concentration of Fe

[0063] The final concentration of Fe Figure 3 The final concentration of Fe The final concentration of Fe

[0064] The final concentration of Fe The final concentration of Fe

[0065] The final concentration of Fe The final concentration of Fe

[0066] The final concentration of Fe The final concentration of Fe

[0067] The final concentration of Fe The final concentration of Fe

[0068] The final concentration of Fe The final concentration of Fe

[0069] The final concentration of Fe The final concentration of Fe

[0070] The final concentration of Fe0.03g of molybdenum powder, and the stirrer was started at a speed of 350 r / min to stir the reaction for 60 min to degrade and remove the acetaminophen in the water.

[0071] As shown in Figure 4 , the removal rates of the pollutants were 5.0%, 87.5%, and 73.2% when the initial pH was 3, 7, and 9, respectively. The effect was best when the pH was 7.

[0072] Example 5

[0073] A method for removing acetaminophen by using molybdenum powder to strengthen ferric iron / tripolyphosphate activated molecular oxygen, which is similar to the steps in Example 1, but analyzes whether the molybdenum powder is stable after repeated use, according to the following steps:

[0074] Prepare a 100 mmol / L tripolyphosphate stock solution;

[0075] Prepare a 100 mmol / L Fe 3+ stock solution;

[0076] Prepare 100 mL of 50 µM acetaminophen as the target pollutant in the raw water containing pollutants;

[0077] Weigh 0.03 g of molybdenum powder, and add Fe 3+ and tripolyphosphate to 100 mL of pollutants at a molar ratio of 1:2, and the final concentration of Fe 3 + The final concentration of Fe 3+ (the concentration of Fe 3+ in the raw water after adding the Fe 3+ stock solution) is 0.2 mmol / L, and the final concentration of tripolyphosphate (the concentration of tripolyphosphate in the water after adding the tripolyphosphate stock solution) is 0.4 mmol / L;

[0078] The operation steps are as follows: after adding tripolyphosphate, the pH of the raw water is still maintained at 7, and finally 0.2 mmol / L of Fe 3+ and 0.03 g of molybdenum powder are added, the stirrer is started at a speed of 350 r / min to stir the reaction for 60 min to degrade and remove the acetaminophen in the water. After the reaction is completed, the molybdenum powder after the reaction is recovered and applied in the next test, and the molybdenum powder is repeatedly used for multiple times.

[0079] As shown in Figure 5 , the removal rates of the pollutants were 87.5%, 86.3%, 85.5%, 89.4%, and 85.5% when the molybdenum powder was used for 5 times.

[0080] As shown in Figure 6As shown in Fig. 4, there is no obvious difference in the morphology of the molybdenum powder before and after the reaction, indicating that the molybdenum powder can be used repeatedly in the reaction system and has good stability.

Claims

1. A method of molybdenum powder fortified ferric iron / tripolyphosphate activated molecular oxygen removal of acetaminophen characterized in that, To reduce ferric iron to ferrous iron for molybdenum powder, the ferrous iron and tripolyphosphate complexed activated molecular oxygen to remove acetaminophen, comprising the following steps: Prepare a tripolyphosphate stock solution with a concentration of 100 mmol / L; Fe was prepared at a concentration of 100 mmol / L 3+ Mother liquor; Prepare raw water containing contaminants; The phosphate trimer mother liquor is added into raw water to make the final concentration of phosphate trimer 0.1-0.6 mmol / L, and the pH value of the raw water is adjusted to 3-9; then molybdenum powder is weighed, and the concentration of the molybdenum powder is 0.1-0.4 g / L; the Fe 3+ mother liquor with a concentration of 100 mmol / L is added into raw water containing pollutants, and the molar ratio of Fe 3+ to phosphate trimer is 2:1 to 1:3; magnetic stirring is carried out, and the pollutants are removed.

2. The method of removing acetaminophen with molybdenum powder fortified ferric iron / tripolyphosphate activated molecular oxygen according to claim 1, characterized in that, The molybdenum powder is a commercial molybdenum powder.

3. The method of removing acetaminophen with molybdenum powder fortified ferric iron / tripolyphosphate activated molecular oxygen according to claim 1, characterized in that The Fe 3+ The mother liquor was prepared using FeCl3, and was added to the raw water containing pollutants to a final concentration of 0.1-0.2 mmol / L.

4. The method of removing acetaminophen with molybdenum powder fortified ferric iron / tripolyphosphate activated molecular oxygen according to claim 1, wherein, The contaminants in the raw water containing contaminants are acetaminophen with a concentration of 1-50 µM.

5. The method of removing acetaminophen with molybdenum powder fortified ferric iron / tripolyphosphate activated molecular oxygen of claim 1, wherein, The rotation speed of magnetic stirring is 100-400 r / min, and the stirring time is 10-60 min.

6. The process for the removal of paracetamol by molybdenum powder fortified ferric trichloride / tri-polyphosphate activated molecular oxygen according to any one of claims 1 to 5, characterized in that According to the following steps: Prepare a tripolyphosphate stock solution with a concentration of 100 mmol / L; Fe was prepared at a concentration of 100 mmol / L 3+ Mother liquor; Prepare 100 mL of 50 µM acetaminophen as raw water containing target contaminants; Add the tripolyphosphate stock solution to the raw water, and the final concentration of tripolyphosphate is 0.4 mmol / L; Take 0.03g of molybdenum powder, add 0.03g of Fe 3+ and tripolyphosphate in a molar ratio of 1:2 to 100mL of raw water containing target pollutants, Fe 3+ The final concentration of Fe 3+ in the mother liquor added to raw water is 0.2mmol / L; The operation steps are: after adding the tripolyphosphate, the pH of the raw water is still maintained at 7, finally, 0.2g of Fe 3+ and 0.03g of molybdenum powder are added into 100mL of raw water containing target pollutants, a stirrer is started to stir at a speed of 350r / min for 60min to degrade and remove the acetaminophen in the water. 3+ and 0.03g of molybdenum powder are added into 100mL of raw water containing target pollutants, a stirrer is started to stir at a speed of 350r / min for 60min to degrade and remove the acetaminophen in the water.

7. The method of removing paracetamol with molybdenum powder fortified ferric iron / tripolyphosphate activated molecular oxygen according to any one of claims 1 to 5, characterized in that According to the following steps: Prepare a tripolyphosphate stock solution with a concentration of 100 mmol / L; Fe was prepared at a concentration of 100 mmol / L 3+ Mother liquor; Prepare 100 mL of 50 µM acetaminophen as raw water containing target contaminants; Again take 0.03g molybdenum powder, add Fe 3+ And tripolyphosphate respectively in the proportion of 2:1, 1:1, 1:2, 1:3 to 100mL raw water containing target pollutants, add Fe 3+ The final concentration of Fe 3+ The final concentration of polyphosphate in raw water is 0.1mmol / L, 0.2mmol / L, 0.4mmol / L, 0.6mmol / L respectively. The operation steps are: after adding the tripolyphosphate, the pH of the raw water is still 7, and finally 0.2 mmol / L Fe 3+ and 0.03 g of molybdenum powder, and the stirrer is started to stir at a rotating speed of 350 r / min for 60 min to degrade and remove the acetaminophen in the water.

8. The method of removing acetaminophen with molybdenum powder fortified ferric iron / tripolyphosphate activated molecular oxygen according to any one of claims 1 to 5, characterized in that According to the following steps: Prepare a tripolyphosphate stock solution with a concentration of 100 mmol / L; Fe was prepared at a concentration of 100 mmol / L 3+ Mother liquor; Prepare 100 mL of 50 µM acetaminophen as raw water containing target contaminants; Take 0.01g, 0.02g, 0.03g, 0.04g molybdenum powder respectively, add Fe 3+ and tripolyphosphate to 100mL raw water containing pollutants in a molar ratio of 1:2, Fe 3+ The final concentration of Fe 3+ in the raw water is 0.2mmol / L, and the final concentration of tripolyphosphate in the raw water is 0.4mmol / L. The operation steps are: after adding the tripolyphosphate, the pH of the raw water is still maintained at 7, finally, 0.2mmol / L of Fe 3+ and the weighed molybdenum powder, the stirrer is started to stir at a speed of 350 r / min for 60 min of reaction, and the acetaminophen in water is degraded and removed.

9. The method of removing acetaminophen with molybdenum powder fortified ferric iron / tripolyphosphate activated molecular oxygen according to any one of claims 1 to 5, characterized in that According to the following steps: Prepare a tripolyphosphate stock solution with a concentration of 100 mmol / L; Prepare 100 mL of 50 µM acetaminophen as raw water containing target contaminants; The pH value is 7.

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